Center the Art view, theme the scrollbars, single-zip downloads

The editing area now centers in wide windows instead of hugging the app list, scrollbars match the app instead of Chrome's grey ones, and the build artifact holds the PSGFX folder directly (GitHub already zips it). Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_019sEKffq7xSxkEwHu87bM8X
Play the music: point app.db's snd0Info at it; add icon presets
2026-10-17 21:00:33 +02:00 · 2026-10-11 18:10:36 +00:00 · 2026-10-11 17:52:08 +00:00 · 2026-10-11 17:35:13 +00:00
53 changed files with 62593 additions and 60 deletions
@@ -29,10 +29,11 @@ jobs:
          cp release/HOW-TO.txt dist/PSGFX/
          cd dist && zip -r PSGFX-windows.zip PSGFX

+      # GitHub zips artifacts itself, so upload the folder: one zip to open, not a zip in a zip.
      - uses: actions/upload-artifact@v4
        with:
          name: PSGFX-windows
-          path: dist/PSGFX-windows.zip
+          path: dist/PSGFX

      - name: Attach to release
        if: startsWith(github.ref, 'refs/tags/v')
@@ -1,21 +1,675 @@
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+address new problems or concerns.
+
+  Each version is given a distinguishing version number.  If the
+Program specifies that a certain numbered version of the GNU General
+Public License "or any later version" applies to it, you have the
+option of following the terms and conditions either of that numbered
+version or of any later version published by the Free Software
+Foundation.  If the Program does not specify a version number of the
+GNU General Public License, you may choose any version ever published
+by the Free Software Foundation.
+
+  If the Program specifies that a proxy can decide which future
+versions of the GNU General Public License can be used, that proxy's
+public statement of acceptance of a version permanently authorizes you
+to choose that version for the Program.
+
+  Later license versions may give you additional or different
+permissions.  However, no additional obligations are imposed on any
+author or copyright holder as a result of your choosing to follow a
+later version.
+
+  15. Disclaimer of Warranty.
+
+  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
+OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
+IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<https://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<https://www.gnu.org/licenses/why-not-lgpl.html>.

-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
@@ -18,8 +18,9 @@ It works through [PS5 Upload](https://github.com/phantomptr/ps5upload): keep the
 - **Custom backgrounds.** Any 16:9 image becomes the backdrop behind the app on the home screen. Homebrew gets full 4K backgrounds.
 - **Homebrew and installed games.** Homebrew apps registered with PS5 Upload show up with their icons, and so do your installed PS4 and PS5 games, with their real names.
 - **Live preview.** A replica of the PS5 home screen shows your art before anything touches the console. Drop an image on the tile to set the icon, or anywhere else to set the background.
+- **Home-screen music (new in 1.3).** Drop an MP3, WAV or FLAC on an app or game, pick where the clip starts and how long it runs, and listen to it before applying. PSGFX converts it to the PS5's own format (`snd0.at9`, ATRAC9), levels it like official games, and loops it while the tile is selected. Clips can run up to about 85 seconds, the most the PS5's 2 MB limit allows.
 - **Rename from the Art view.** Change a homebrew app's or game's home-screen name right next to its art. For homebrew, PSGFX also updates the name in the app's `param.json` so changing its art later keeps the new name.
- **One-click restore.** The first time you change something, PSGFX saves the original next to it. **Restore original art** puts it back exactly.
+- **One-click restore.** The first time you change something, PSGFX saves the original next to it. **Restore original** puts it back exactly.
 - **Clean list.** System apps and leftovers are tucked away under *Show other items*.
 - **Home layout (new in 1.1).** Hide any tile (PlayStation Store, Game Library, PS Plus, media apps), rename games and apps, move apps between the Games and Media tabs, and reorder your games by dragging or with A–Z / Z–A.
 - **Lock order.** Keeps your arrangement in place even after you play other games.
@@ -43,7 +44,7 @@ It works through [PS5 Upload](https://github.com/phantomptr/ps5upload): keep the
 6. Close that app or game on the PS5, then click **Apply to PS5**.
 7. Restart the PS5 to see the new art on the home screen.

-To undo, select the app and click **Restore original art**.
+To undo, select the app and click **Restore original**.

 ### Home layout

@@ -82,7 +83,7 @@ On Windows, run `./build.sh` from an [MSYS2](https://www.msys2.org/) MinGW shell

 ### How it works

-PSGFX runs a small local web server (127.0.0.1 only) and opens your browser to it. PS5 Upload 6.0 replaced its old protocol (FTX2, ports 9113 and 9114) with AVA1, an encrypted connection on port 9120 that the console only opens to an app it has paired with. So PSGFX doesn't talk to the console itself: it sends each command to the PS5 Upload app's local engine (`POST http://127.0.0.1:19113/api/mgmt/call`), which runs it over its paired connection. It uses the payload's existing commands to list apps, read and write files, and back up. Homebrew art is written to the app's `sce_sys` folder and to the home-screen metadata folder. Game art is written to `/user/appmeta/<title id>` in the same size and format as the original files. When the home-screen database (`app.db`) shows the game's tile art coming from somewhere PSGFX can't write, such as inside the game's own package, PSGFX writes the image to `/user/appmeta/<title id>/psgfx_*` and points the database at it. It keeps the original paths in `psgfx_original.json` for **Restore original art** and backs up the database first, as Home layout does. Backgrounds are encoded as BC7 DDS where the console uses DDS.
+PSGFX runs a small local web server (127.0.0.1 only) and opens your browser to it. PS5 Upload 6.0 replaced its old protocol (FTX2, ports 9113 and 9114) with AVA1, an encrypted connection on port 9120 that the console only opens to an app it has paired with. So PSGFX doesn't talk to the console itself: it sends each command to the PS5 Upload app's local engine (`POST http://127.0.0.1:19113/api/mgmt/call`), which runs it over its paired connection. It uses the payload's existing commands to list apps, read and write files, and back up. Homebrew art is written to the app's `sce_sys` folder and to the home-screen metadata folder. Game art is written to `/user/appmeta/<title id>` in the same size and format as the original files. When the home-screen database (`app.db`) shows the game's tile art coming from somewhere PSGFX can't write, such as inside the game's own package, PSGFX writes the image to `/user/appmeta/<title id>/psgfx_*` and points the database at it. It keeps the original paths in `psgfx_original.json` for **Restore original** and backs up the database first, as Home layout does. Backgrounds are encoded as BC7 DDS where the console uses DDS. Music becomes `snd0.at9` (ATRAC9, 48 kHz stereo, 192 kb/s, looped), written to the app's `sce_sys` folder for homebrew and to `/user/appmeta/<title id>` for games, with its loudness in `param.json` (`pubtools.loudnessSnd0`).

 `tools/mock_engine.py` is a stand-in for the PS5 Upload engine and console that serves a folder on your computer as if it were a PS5. Use it to develop without a console:

@@ -96,10 +97,11 @@ If PS5 Upload's engine runs somewhere else (a NAS or Docker), add `"engine": "ho
 ## Credits

 - [PS5 Upload](https://github.com/phantomptr/ps5upload) by phantomptr, whose app and payload PSGFX works through
+- [PS5 AT9 Converter](https://github.com/blackbearreloaded/ps5-at9-converter) by BlackBearReloaded, whose ATRAC9 encoder PSGFX's music feature is ported from, and [LibAtrac9](https://github.com/Thealexbarney/LibAtrac9) by Alex Barney
 - [bc7enc](https://github.com/richgel999/bc7enc) by Rich Geldreich, [stb](https://github.com/nothings/stb) by Sean Barrett, [BLAKE3](https://github.com/BLAKE3-team/BLAKE3), [JSON for Modern C++](https://github.com/nlohmann/json) by Niels Lohmann, and the [Sora](https://github.com/sora-xor/sora-font) typeface. See [THIRD_PARTY_NOTICES.md](THIRD_PARTY_NOTICES.md).

 ## License

-[MIT](LICENSE).
+PSGFX is free software under the [GNU General Public License v3.0 or later](LICENSE). Versions up to 1.2 were released under the MIT License; 1.3 moved to the GPL because it includes the ATRAC9 encoder from [PS5 AT9 Converter](https://github.com/blackbearreloaded/ps5-at9-converter), which is GPL-3.0-or-later.

 PSGFX is an independent fan project. It is not affiliated with, endorsed by, or sponsored by Sony Interactive Entertainment. "PlayStation" and "PS5" are trademarks of Sony Interactive Entertainment Inc. Only use PSGFX with games you own.
@@ -8,6 +8,9 @@ PSGFX includes the following components. Their full license texts are in the hea
 | stb_image, stb_image_write, stb_image_resize2 by Sean Barrett | `src/lib/stb_*.h` | MIT or public domain |
 | BLAKE3 reference implementation | `src/lib/blake3*` | CC0 1.0 or Apache 2.0 |
 | JSON for Modern C++ by Niels Lohmann | `src/lib/json.hpp` | MIT |
+| PS5 AT9 Converter by BlackBearReloaded (ATRAC9 encoder and audio processing, ported to C++) | `src/lib/at9/` | GPL-3.0-or-later |
+| LibAtrac9 by Alex Barney (ATRAC9 tables) | `src/lib/at9/` | MIT |
+| minimp3, dr_wav, dr_flac (audio decoding) | `src/lib/at9/`, see `src/lib/at9/NOTICES.md` | CC0 / public domain or MIT-0 |
 | Sora typeface, The Sora Project Authors | `assets/fonts/*.woff2` (embedded in `src/assets_embed.cpp`) | SIL Open Font License 1.1, see `assets/fonts/OFL.txt` |

 PSGFX talks to the payload of [PS5 Upload](https://github.com/phantomptr/ps5upload) over the network. It does not include any PS5 Upload code.
@@ -9,7 +9,7 @@ mkdir -p build

 BLAKE3_FLAGS="-O2 -DBLAKE3_NO_SSE2 -DBLAKE3_NO_SSE41 -DBLAKE3_NO_AVX2 -DBLAKE3_NO_AVX512"
 SQLITE_FLAGS="-O2 -DSQLITE_THREADSAFE=1 -DSQLITE_OMIT_LOAD_EXTENSION -DSQLITE_DEFAULT_MEMSTATUS=0"
-SOURCES="src/main.cpp src/ui.cpp src/assets_embed.cpp src/lib/bc7enc.cpp src/lib/bc7decomp.cpp"
+SOURCES="src/main.cpp src/ui.cpp src/assets_embed.cpp src/lib/bc7enc.cpp src/lib/bc7decomp.cpp src/presets_embed.cpp src/lib/at9/at9_encoder.cpp src/lib/at9/at9_snd0.cpp src/lib/at9/at9_decode.cpp src/lib/at9/at9_tables.cpp"

 if [[ "${1:-}" == "linux" ]]; then
  for f in src/lib/blake3.c src/lib/blake3_dispatch.c src/lib/blake3_portable.c; do
@@ -1,4 +1,4 @@
-PSGFX 1.2
+PSGFX 1.3
 Custom icons and backgrounds for your PS5 homebrew and games, and your home-screen layout.

 BEFORE YOU START
@@ -18,8 +18,13 @@ STEPS
 5. Close that app or game on the PS5, then click "Apply to PS5".
 6. Restart the PS5 to see the new art.

+MUSIC (new in 1.3)
+ - Drop an MP3, WAV or FLAC on the preview, or use "Choose song".
+ - Set where it starts and how long it runs, listen to it, then Apply.
+ - It plays when the app's or game's tile is selected. Restart the PS5 to hear it.
+
 UNDO
- - Select the app and click "Restore original art".
+ - Select the app and click "Restore original".

 HOME LAYOUT (new in 1.1)
 1. Connect, then click "Home layout" at the top.
@@ -0,0 +1,14 @@
+# src/lib/at9 notices
+
+- `at9.h`, `at9_encoder.cpp`, `at9_snd0.cpp`, `at9_decode.cpp`, `at9_internal.h`:
+  C++ port of [PS5 AT9 Converter](https://github.com/blackbearreloaded/ps5-at9-converter)
+  v0.1.0 (commit 65be0a1), Copyright (C) 2026 BlackBearReloaded, GPL-3.0-or-later.
+- `at9_tables.h`, `at9_tables.cpp`: ATRAC9 constant tables (Huffman codebooks, scale factor
+  weights, gradient curve, band extension tables) from
+  [LibAtrac9](https://github.com/Thealexbarney/LibAtrac9), MIT License, Copyright (c) 2018
+  Alex Barney (full text in the file header). Generated by `tools/at9check/gen_tables.py`
+  from `ps5at9/atrac9_tables.py`.
+- `minimp3.h`, `minimp3_ex.h`: [minimp3](https://github.com/lieff/minimp3) by lieff
+  (commit ea99364), dedicated to the public domain under CC0 1.0.
+- `dr_wav.h` (v0.14.6), `dr_flac.h` (v0.13.4): [dr_libs](https://github.com/mackron/dr_libs)
+  by David Reid (commit dfe8377), public domain (Unlicense) or MIT No Attribution, at your choice.
@@ -0,0 +1,76 @@
+// PS5 snd0.at9 maker: audio decoding, excerpt preparation and ATRAC9 encoding.
+//
+// C++ port of PS5 AT9 Converter v0.1.0 (ps5at9/{cli,dsp,at9file,atrac9,
+// atrac9_encoder}.py, https://github.com/blackbearreloaded/ps5-at9-converter).
+// Copyright (C) 2026 BlackBearReloaded (original Python implementation)
+// C++ port: part of PSGFX.
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+// Input decoding uses minimp3 (CC0) and dr_wav / dr_flac (public domain or
+// MIT-0); the ATRAC9 tables come from LibAtrac9 (MIT). See NOTICES.md.
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace at9 {
+
+// Decoded audio: interleaved float samples in [-1, 1].
+struct Audio {
+    int rate = 0;
+    int channels = 0;
+    std::vector<float> pcm;
+};
+
+// Decode MP3, WAV (PCM 8/16/24/32-bit, float; RIFF/RF64), AIFF/AIFC or FLAC.
+// The format is detected from the content, like the Python tool does.
+bool decode_file(const std::vector<uint8_t> &bytes, Audio &out, std::string &err);
+
+// Defaults mirror the Python CLI (ps5_at9.py) defaults.
+struct Options {
+    int bitrate_kbps = 192;      // 72, 96, 120, 144, 168 or 192
+    bool loop = true;            // whole-track loop (smpl chunk); CLI --no-loop sets false
+    double start_sec = 0;        // excerpt start
+    double duration_sec = 15;    // excerpt length; <= 0 means "max" (longest that fits 2 MiB)
+    double fade_in = 0.01;       // seconds
+    double fade_out = 0.01;      // seconds
+    double lufs = -28;           // integrated loudness target (param.json loudnessSnd0)
+    double true_peak_db = -2;    // true-peak ceiling, dBTP
+    bool normalize = true;       // false = keep source level, only limit peaks
+};
+
+struct Result {
+    std::vector<uint8_t> at9;        // complete snd0.at9 file
+    double loudness_lufs = 0;        // integrated loudness of the processed excerpt (-inf if silent)
+    double seconds = 0;              // excerpt length
+    std::string loudness_param;      // "%.2f" of loudness_lufs: value for pubtools.loudnessSnd0
+    std::vector<float> processed;    // what was encoded: 48 kHz interleaved stereo, after
+                                     // resample, cut, loudness, limiting and fades
+};
+
+// Whole CLI pipeline: to stereo, resample to 48 kHz, cut the excerpt, loudness
+// normalise, true-peak limit, fades, ATRAC9 encode, RIFF build. Throws
+// std::runtime_error (readable message) on bad options, an empty excerpt or a
+// file above the 2 MiB PS5 limit.
+Result make_snd0(const Audio &in, const Options &o);
+
+// 16-bit PCM WAV of interleaved 48 kHz stereo float samples (for previews).
+std::vector<uint8_t> wav_bytes(const std::vector<float> &stereo48k);
+
+// Lower-level pieces, used by the test harness.
+namespace detail {
+// Same as make_snd0; optionally returns the processed excerpt in double
+// precision (planar, 2 channels) and lets the caller choose the thread count
+// (0 = hardware concurrency). Output bytes do not depend on the thread count.
+Result make_snd0_ex(const Audio &in, const Options &o, std::vector<double> *left,
+                    std::vector<double> *right, unsigned threads);
+// ATRAC9-encode 48 kHz stereo (full scale = 1.0); returns the data chunk.
+std::vector<uint8_t> encode_atrac9(const std::vector<double> &left, const std::vector<double> &right,
+                                   int bitrate_kbps, unsigned threads);
+// Complete .at9 file around a data chunk.
+std::vector<uint8_t> build_at9(int bitrate_kbps, uint32_t sample_count, const std::vector<uint8_t> &data,
+                               bool loop);
+} // namespace detail
+
+} // namespace at9
@@ -0,0 +1,141 @@
+// Input decoding for the snd0.at9 maker: MP3 (minimp3), WAV/RF64/AIFF
+// (dr_wav) and FLAC (dr_flac). Format detection mirrors ps5at9/audio_io.py.
+// Copyright (C) 2026 BlackBearReloaded (original Python implementation)
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "at9.h"
+
+#include <cstdlib>
+#include <cstring>
+
+#define MINIMP3_IMPLEMENTATION
+#define MINIMP3_FLOAT_OUTPUT
+#define MINIMP3_NO_STDIO
+#include "minimp3_ex.h"
+
+#define DR_WAV_IMPLEMENTATION
+#define DR_WAV_NO_STDIO
+#define DR_WAV_NO_WCHAR
+#include "dr_wav.h"
+
+#define DR_FLAC_IMPLEMENTATION
+#define DR_FLAC_NO_STDIO
+#define DR_FLAC_NO_WCHAR
+#define DR_FLAC_NO_OGG
+#include "dr_flac.h"
+
+namespace at9 {
+namespace {
+
+bool starts(const std::vector<uint8_t> &b, size_t off, const char *s) {
+    size_t n = std::strlen(s);
+    return b.size() >= off + n && std::memcmp(b.data() + off, s, n) == 0;
+}
+
+// Integer samples are scaled by 1 / 2^31 after left-justification, exactly as
+// the Python reader does (16- and 24-bit input is represented exactly).
+constexpr double INT_SCALE = 1.0 / 2147483648.0;
+
+bool decode_wav(const std::vector<uint8_t> &bytes, Audio &out, std::string &err) {
+    drwav wav;
+    if (!drwav_init_memory(&wav, bytes.data(), bytes.size(), nullptr)) {
+        err = "could not read WAV/AIFF file";
+        return false;
+    }
+    bool ok = true;
+    if (wav.channels < 1 || wav.sampleRate < 1) {
+        err = "unsupported WAVE format";
+        ok = false;
+    } else {
+        const size_t ch = wav.channels;
+        const drwav_uint64 frames = wav.totalPCMFrameCount;
+        out.rate = (int)wav.sampleRate;
+        out.channels = (int)ch;
+        out.pcm.clear();
+        if (wav.translatedFormatTag == DR_WAVE_FORMAT_IEEE_FLOAT) {
+            out.pcm.resize((size_t)frames * ch);
+            drwav_uint64 got = drwav_read_pcm_frames_f32(&wav, frames, out.pcm.data());
+            out.pcm.resize((size_t)got * ch);
+        } else {
+            std::vector<drwav_int32> tmp((size_t)frames * ch);
+            drwav_uint64 got = drwav_read_pcm_frames_s32(&wav, frames, tmp.data());
+            out.pcm.resize((size_t)got * ch);
+            for (size_t i = 0; i < out.pcm.size(); i++) out.pcm[i] = (float)(tmp[i] * INT_SCALE);
+        }
+        if (out.pcm.empty()) {
+            err = "the WAV/AIFF file contains no audio";
+            ok = false;
+        }
+    }
+    drwav_uninit(&wav);
+    return ok;
+}
+
+bool decode_flac(const std::vector<uint8_t> &bytes, Audio &out, std::string &err) {
+    drflac *f = drflac_open_memory(bytes.data(), bytes.size(), nullptr);
+    if (!f) {
+        err = "could not decode FLAC";
+        return false;
+    }
+    const size_t ch = f->channels;
+    out.rate = (int)f->sampleRate;
+    out.channels = (int)ch;
+    out.pcm.clear();
+    std::vector<drflac_int32> buf(4096 * ch);
+    for (;;) {
+        drflac_uint64 got = drflac_read_pcm_frames_s32(f, 4096, buf.data());
+        if (!got) break;
+        for (size_t i = 0; i < (size_t)got * ch; i++) out.pcm.push_back((float)(buf[i] * INT_SCALE));
+    }
+    drflac_close(f);
+    if (out.pcm.empty() || out.rate <= 0) {
+        err = "could not decode FLAC (no audio)";
+        return false;
+    }
+    return true;
+}
+
+bool decode_mp3(const std::vector<uint8_t> &bytes, Audio &out, std::string &err) {
+    mp3dec_t dec;
+    mp3dec_file_info_t info;
+    std::memset(&info, 0, sizeof info);
+    if (mp3dec_load_buf(&dec, bytes.data(), bytes.size(), &info, nullptr, nullptr) || !info.buffer ||
+        !info.samples || info.channels <= 0 || info.hz <= 0) {
+        std::free(info.buffer);
+        err = "could not decode MP3: no MPEG audio frames found";
+        return false;
+    }
+    out.rate = info.hz;
+    out.channels = info.channels;
+    out.pcm.assign(info.buffer, info.buffer + info.samples - info.samples % info.channels);
+    std::free(info.buffer);
+    return true;
+}
+
+} // namespace
+
+bool decode_file(const std::vector<uint8_t> &bytes, Audio &out, std::string &err) {
+    out = Audio();
+    err.clear();
+    if (bytes.size() < 12) {
+        err = "the file is too small to be audio";
+        return false;
+    }
+    if ((starts(bytes, 0, "RIFF") || starts(bytes, 0, "RF64")) && starts(bytes, 8, "WAVE"))
+        return decode_wav(bytes, out, err);
+    if (starts(bytes, 0, "FORM") && (starts(bytes, 8, "AIFF") || starts(bytes, 8, "AIFC")))
+        return decode_wav(bytes, out, err);
+    if (starts(bytes, 0, "fLaC")) return decode_flac(bytes, out, err);
+    if (starts(bytes, 0, "OggS")) {
+        err = "unsupported input format (OGG); use MP3, WAV, AIFF or FLAC";
+        return false;
+    }
+    if (starts(bytes, 4, "ftyp")) {
+        err = "unsupported input format (MP4); use MP3, WAV, AIFF or FLAC";
+        return false;
+    }
+    // ID3, an MPEG frame sync, or junk before the first frame: try MP3.
+    return decode_mp3(bytes, out, err);
+}
+
+} // namespace at9
@@ -0,0 +1,53 @@
+// Internal helpers shared by the at9 sources.
+// Copyright (C) 2026 BlackBearReloaded (original Python implementation)
+// SPDX-License-Identifier: GPL-3.0-or-later
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <vector>
+
+namespace at9 {
+namespace internal {
+
+constexpr double PI = 3.141592653589793238462643383279502884;
+constexpr int RATE = 48000;
+constexpr int SUPERFRAME_SAMPLES = 1024;
+constexpr int ENCODER_DELAY = 256;
+constexpr uint32_t PS5_SIZE_LIMIT = 2u * 1024u * 1024u;
+
+// numpy's pairwise summation (used by np.sum / np.mean along a contiguous
+// axis). Reproducing its order keeps results bit-identical to the reference
+// where the inputs are identical.
+double pairwise_sum_large(const double *a, std::ptrdiff_t n, std::ptrdiff_t stride);  // n > 128
+
+inline double pairwise_sum(const double *a, std::ptrdiff_t n, std::ptrdiff_t stride = 1) {
+    if (n < 8) {
+        double res = 0.;
+        for (std::ptrdiff_t i = 0; i < n; i++) res += a[i * stride];
+        return res;
+    }
+    if (n <= 128) {
+        double r[8];
+        for (int j = 0; j < 8; j++) r[j] = a[j * stride];
+        std::ptrdiff_t i;
+        for (i = 8; i < n - (n % 8); i += 8)
+            for (int j = 0; j < 8; j++) r[j] += a[(i + j) * stride];
+        double res = ((r[0] + r[1]) + (r[2] + r[3])) + ((r[4] + r[5]) + (r[6] + r[7]));
+        for (; i < n; i++) res += a[i * stride];
+        return res;
+    }
+    return pairwise_sum_large(a, n, stride);
+}
+
+// np.add.reduceat segment: first element, then the pairwise sum of the rest.
+inline double reduceat_sum(const double *a, std::ptrdiff_t n) {
+    return n <= 0 ? 0.0 : a[0] + pairwise_sum(a + 1, n - 1);
+}
+
+int frame_bytes_for(int bitrate_kbps);  // throws on unsupported rates
+uint32_t header_size(bool loop);
+uint64_t file_size(uint64_t sample_count, uint32_t superframe_bytes, bool loop);
+
+} // namespace internal
+} // namespace at9
@@ -0,0 +1,531 @@
+// snd0.at9 pipeline: channel mapping, resampling, loudness (BS.1770-4),
+// true-peak limiting, fades, and the make_snd0 driver; preview WAV writer.
+//
+// C++ port of ps5at9/dsp.py, ps5at9/cli.py and parts of ps5at9/audio_io.py and
+// ps5at9/wav.py from PS5 AT9 Converter v0.1.0
+// (https://github.com/blackbearreloaded/ps5-at9-converter).
+// Copyright (C) 2026 BlackBearReloaded (original Python implementation)
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "at9.h"
+#include "at9_internal.h"
+
+#include <algorithm>
+#include <cmath>
+#include <cstdio>
+#include <deque>
+#include <limits>
+#include <numeric>
+#include <stdexcept>
+#include <string>
+#include <thread>
+
+namespace at9 {
+namespace {
+
+using namespace internal;
+using Planar = std::vector<std::vector<double>>;
+
+// Run fn(begin, end) over [0, n) split across threads. Every output element
+// is computed independently, so results do not depend on the thread count.
+template <class F> void parallel_chunks(size_t n, unsigned threads, F fn) {
+    const size_t min_chunk = 16384;
+    unsigned t = std::max(1u, std::min<unsigned>(threads, (unsigned)((n + min_chunk - 1) / min_chunk)));
+    if (t <= 1) {
+        fn((size_t)0, n);
+        return;
+    }
+    std::vector<std::thread> pool;
+    size_t step = (n + t - 1) / t;
+    for (unsigned i = 0; i < t; i++) {
+        size_t b = i * step, e = std::min(n, b + step);
+        if (b < e) pool.emplace_back([=] { fn(b, e); });
+    }
+    for (auto &th : pool) th.join();
+}
+
+// ---------------------------------------------------------------- numpy.i0 (Cephes)
+
+const double I0A[30] = {
+    -4.4153416464793395e-18, 3.3307945188222384e-17, -2.431279846547955e-16, 1.715391285555133e-15,
+    -1.1685332877993451e-14, 7.676185498604936e-14, -4.856446783111929e-13, 2.95505266312964e-12,
+    -1.726826291441556e-11, 9.675809035373237e-11, -5.189795601635263e-10, 2.6598237246823866e-09,
+    -1.300025009986248e-08, 6.046995022541919e-08, -2.670793853940612e-07, 1.1173875391201037e-06,
+    -4.4167383584587505e-06, 1.6448448070728896e-05, -5.754195010082104e-05, 0.00018850288509584165,
+    -0.0005763755745385824, 0.0016394756169413357, -0.004324309995050576, 0.010546460394594998,
+    -0.02373741480589947, 0.04930528423967071, -0.09490109704804764, 0.17162090152220877,
+    -0.3046826723431984, 0.6767952744094761};
+
+const double I0B[25] = {
+    -7.233180487874754e-18, -4.830504485944182e-18, 4.46562142029676e-17, 3.461222867697461e-17,
+    -2.8276239805165836e-16, -3.425485619677219e-16, 1.7725601330565263e-15, 3.8116806693526224e-15,
+    -9.554846698828307e-15, -4.150569347287222e-14, 1.54008621752141e-14, 3.8527783827421426e-13,
+    7.180124451383666e-13, -1.7941785315068062e-12, -1.3215811840447713e-11, -3.1499165279632416e-11,
+    1.1889147107846439e-11, 4.94060238822497e-10, 3.3962320257083865e-09, 2.266668990498178e-08,
+    2.0489185894690638e-07, 2.8913705208347567e-06, 6.889758346916825e-05, 0.0033691164782556943,
+    0.8044904110141088};
+
+double chbevl(double x, const double *vals, int n) {
+    double b0 = vals[0], b1 = 0.0, b2 = 0.0;
+    for (int i = 1; i < n; i++) {
+        b2 = b1;
+        b1 = b0;
+        b0 = x * b1 - b2 + vals[i];
+    }
+    return 0.5 * (b0 - b2);
+}
+
+double i0(double x) {
+    x = std::fabs(x);
+    if (x <= 8.0) return std::exp(x) * chbevl(x / 2.0 - 2, I0A, 30);
+    return std::exp(x) * chbevl(32.0 / x - 2.0, I0B, 25) / std::sqrt(x);
+}
+
+double sinc(double x) {
+    double y = PI * x;
+    if (y == 0) y = std::numeric_limits<double>::epsilon();
+    return std::sin(y) / y;
+}
+
+// ---------------------------------------------------------------- resampling
+
+// Polyphase Kaiser-windowed low-pass h[phase][tap] (taps = 2 * half).
+std::vector<double> kaiser_phases(int up, double rate_in, double pass_hz, double stop_hz, double atten_db,
+                                  int &half) {
+    double beta = 0.1102 * (atten_db - 8.7);
+    double width = (stop_hz - pass_hz) / rate_in;
+    int taps = (int)std::ceil((atten_db - 8.0) / (2.285 * 2.0 * PI * width));
+    half = std::max(8, taps / 2 + 1);
+    double cutoff = (pass_hz + stop_hz) / 2.0 / rate_in;
+    const int L = 2 * half;
+    std::vector<double> h((size_t)up * L);
+    double ib = i0(beta);
+    for (int p = 0; p < up; p++) {
+        double phase = (double)p / up;
+        double *row = &h[(size_t)p * L];
+        for (int j = 0; j < L; j++) {
+            double t = (double)(-half + 1 + j) - phase;
+            double v = 2.0 * cutoff * sinc(2.0 * cutoff * t);
+            double r = t / half;
+            double c = std::min(std::max(1.0 - r * r, 0.0), 1.0);
+            double win = i0(beta * std::sqrt(c)) / ib;
+            row[j] = v * win;
+        }
+        double sum = pairwise_sum(row, L);
+        for (int j = 0; j < L; j++) row[j] /= sum;
+    }
+    return h;
+}
+
+long long gcd_ll(long long a, long long b) {
+    while (b) {
+        long long t = a % b;
+        a = b;
+        b = t;
+    }
+    return a;
+}
+
+std::vector<double> resample_channel(const std::vector<double> &x, const std::vector<double> &h, int half, int up,
+                                     int down, size_t n_out, unsigned threads) {
+    const size_t n_in = x.size();
+    const int L = 2 * half;
+    std::vector<double> pad(n_in + 2 * half + 2, 0.0);
+    std::copy(x.begin(), x.end(), pad.begin() + half);
+    std::vector<double> out(n_out);
+    parallel_chunks(n_out, threads, [&](size_t begin, size_t end) {
+        for (size_t n = begin; n < end; n++) {
+            long long pos = (long long)n * down;
+            long long base = pos / up;
+            int phase = (int)(pos % up);
+            const double *c = &h[(size_t)phase * L];
+            const double *s = &pad[base + 1];
+            double acc = 0.0;
+            for (int j = 0; j < L; j++) acc += s[j] * c[j];
+            out[n] = acc;
+        }
+    });
+    return out;
+}
+
+Planar resample(const Planar &pcm, int rate_in, int rate_out, unsigned threads) {
+    if (rate_in == rate_out) return pcm;
+    long long g = gcd_ll(rate_in, rate_out);
+    int up = (int)(rate_out / g), down = (int)(rate_in / g);
+    double nyquist = std::min(rate_in, rate_out) / 2.0;
+    double pass_hz = std::min(20000.0, 0.9 * nyquist);
+    int half = 0;
+    std::vector<double> h = kaiser_phases(up, rate_in, pass_hz, nyquist, 100.0, half);
+    size_t n_in = pcm[0].size();
+    size_t n_out = (size_t)std::ceil((double)((long long)n_in * up) / (double)down);
+    Planar out;
+    for (const auto &ch : pcm) out.push_back(resample_channel(ch, h, half, up, down, n_out, threads));
+    return out;
+}
+
+// ---------------------------------------------------------------- loudness
+
+std::vector<double> k_weight(const std::vector<double> &x) {
+    // ITU-R BS.1770-4 K-weighting at 48 kHz: high shelf, then high-pass.
+    static const double sb[3] = {1.53512485958697, -2.69169618940638, 1.19839281085285};
+    static const double sa[3] = {1.0, -1.69065929318241, 0.73248077421585};
+    static const double hb[3] = {1.0, -2.0, 1.0};
+    static const double ha[3] = {1.0, -1.99004745483398, 0.99007225036621};
+    std::vector<double> y(x.size());
+    double x1 = 0, x2 = 0, y1 = 0, y2 = 0;
+    for (size_t n = 0; n < x.size(); n++) {
+        double x0 = x[n];
+        double y0 = sb[0] * x0 + sb[1] * x1 + sb[2] * x2 - sa[1] * y1 - sa[2] * y2;
+        x2 = x1;
+        x1 = x0;
+        y2 = y1;
+        y1 = y0;
+        y[n] = y0;
+    }
+    x1 = x2 = y1 = y2 = 0;
+    for (size_t n = 0; n < y.size(); n++) {
+        double x0 = y[n];
+        double y0 = hb[0] * x0 + hb[1] * x1 + hb[2] * x2 - ha[1] * y1 - ha[2] * y2;
+        x2 = x1;
+        x1 = x0;
+        y2 = y1;
+        y1 = y0;
+        y[n] = y0;
+    }
+    return y;
+}
+
+double integrated_loudness(const Planar &pcm) {
+    const size_t block = (size_t)(0.4 * 48000), step = (size_t)(0.1 * 48000);
+    const size_t n = pcm[0].size();
+    Planar w;
+    for (const auto &ch : pcm) {
+        std::vector<double> k = k_weight(ch);
+        for (double &v : k) v = v * v;
+        w.push_back(std::move(k));
+    }
+    if (n < block) {
+        double power = 0.0;
+        for (const auto &ch : w) power += pairwise_sum(ch.data(), (std::ptrdiff_t)n) / (double)n;
+        return power > 0 ? -0.691 + 10.0 * std::log10(power) : -std::numeric_limits<double>::infinity();
+    }
+    Planar csum;
+    for (const auto &ch : w) {
+        std::vector<double> c(n + 1);
+        c[0] = 0.0;
+        double acc = 0.0;
+        for (size_t i = 0; i < n; i++) {
+            acc += ch[i];
+            c[i + 1] = acc;
+        }
+        csum.push_back(std::move(c));
+    }
+    std::vector<double> z, lk;
+    for (size_t s = 0; s + block <= n; s += step) {
+        double v = 0.0;
+        for (size_t c = 0; c < csum.size(); c++) {
+            double e = (csum[c][s + block] - csum[c][s]) / (double)block;
+            v = c ? v + e : e;
+        }
+        z.push_back(v);
+        lk.push_back(-0.691 + 10.0 * std::log10(v));
+    }
+    std::vector<double> gated;
+    for (size_t i = 0; i < z.size(); i++)
+        if (lk[i] > -70.0) gated.push_back(z[i]);
+    if (gated.empty()) return -std::numeric_limits<double>::infinity();
+    double relative =
+        -0.691 + 10.0 * std::log10(pairwise_sum(gated.data(), (std::ptrdiff_t)gated.size()) / gated.size()) - 10.0;
+    std::vector<double> fin;
+    for (size_t i = 0; i < z.size(); i++)
+        if (lk[i] > -70.0 && lk[i] > relative) fin.push_back(z[i]);
+    return -0.691 + 10.0 * std::log10(pairwise_sum(fin.data(), (std::ptrdiff_t)fin.size()) / fin.size());
+}
+
+// ---------------------------------------------------------------- true peak
+
+struct Oversampler {
+    std::vector<double> h;
+    int half = 0;
+    Oversampler() { h = kaiser_phases(4, 48000, 18000.0, 24000.0, 60.0, half); }
+};
+
+const Oversampler &oversampler() {
+    static const Oversampler o;
+    return o;
+}
+
+// Per-sample true peak (max |x| over 4x oversampled points), max over channels.
+std::vector<double> true_peak_envelope(const Planar &pcm, unsigned threads) {
+    const Oversampler &O = oversampler();
+    const int half = O.half, L = 2 * half;
+    const size_t n = pcm[0].size();
+    std::vector<double> env(n, 0.0);
+    std::vector<double> pad(n + 2 * half + 2);
+    for (size_t c = 0; c < pcm.size(); c++) {
+        std::fill(pad.begin(), pad.end(), 0.0);
+        std::copy(pcm[c].begin(), pcm[c].end(), pad.begin() + half);
+        parallel_chunks(n, threads, [&](size_t begin, size_t end) {
+            for (size_t i = begin; i < end; i++) {
+                const double *s = &pad[i + 1];
+                double m = 0.0;
+                for (int p = 0; p < 4; p++) {
+                    const double *k = &O.h[(size_t)p * L];
+                    double acc = 0.0;
+                    for (int j = 0; j < L; j++) acc += s[j] * k[j];
+                    m = std::max(m, std::fabs(acc));
+                }
+                env[i] = c ? std::max(env[i], m) : m;
+            }
+        });
+    }
+    return env;
+}
+
+double max_of(const std::vector<double> &v) {
+    double m = -std::numeric_limits<double>::infinity();
+    for (double x : v) m = std::max(m, x);
+    return m;
+}
+
+// Minimum over the centred window [n - width, n + width] (edges extended).
+std::vector<double> sliding_min(const std::vector<double> &x, int width) {
+    if (width <= 0) return x;
+    const long long n = (long long)x.size();
+    std::vector<double> out(n);
+    std::deque<long long> dq;  // indices into x with increasing values
+    long long next = 0;
+    for (long long i = 0; i < n; i++) {
+        long long hi = std::min(n - 1, i + width);
+        while (next <= hi) {
+            while (!dq.empty() && x[dq.back()] >= x[next]) dq.pop_back();
+            dq.push_back(next++);
+        }
+        long long lo = i - width;
+        while (dq.front() < lo) dq.pop_front();
+        out[i] = x[dq.front()];
+    }
+    return out;
+}
+
+// Mean over the centred window [n - width, n + width] (edges extended).
+std::vector<double> moving_average(const std::vector<double> &x, int width) {
+    if (width <= 0) return x;
+    const size_t n = x.size();
+    const size_t w = 2 * (size_t)width + 1;
+    std::vector<double> c(n + 2 * width + 1);
+    c[0] = 0.0;
+    double acc = 0.0;
+    for (size_t i = 0; i < n + 2 * (size_t)width; i++) {
+        double v = i < (size_t)width ? x[0] : (i - width < n ? x[i - width] : x[n - 1]);
+        acc += v;
+        c[i + 1] = acc;
+    }
+    std::vector<double> out(n);
+    for (size_t i = 0; i < n; i++) out[i] = (c[i + w] - c[i]) / (double)w;
+    return out;
+}
+
+bool limit_true_peak(Planar &pcm, double ceiling_db, unsigned threads, int rate = 48000, double attack = 0.002,
+                     double release = 0.05) {
+    std::vector<double> env = true_peak_envelope(pcm, threads);
+    const double ceiling = std::pow(10.0, ceiling_db / 20.0);
+    if (max_of(env) <= ceiling) return false;
+    double target = ceiling_db;
+    int a = std::max(1, (int)(attack * rate));
+    int r = std::max(1, (int)(release * rate));
+    for (int it = 0; it < 8; it++) {
+        double t = std::pow(10.0, target / 20.0);
+        std::vector<double> need(env.size());
+        for (size_t i = 0; i < env.size(); i++) need[i] = std::min(1.0, t / std::max(env[i], 1e-12));
+        std::vector<double> gain = moving_average(sliding_min(need, a), a / 2);
+        gain = moving_average(sliding_min(gain, r), r / 2);
+        for (auto &ch : pcm)
+            for (size_t i = 0; i < ch.size(); i++) ch[i] = ch[i] * gain[i];
+        env = true_peak_envelope(pcm, threads);
+        if (max_of(env) <= ceiling) break;
+        target -= 0.05;
+    }
+    return true;
+}
+
+// ---------------------------------------------------------------- fades
+
+void apply_fades(Planar &pcm, int rate, double fade_in, double fade_out) {
+    const long long n = (long long)pcm[0].size();
+    long long fi = std::min(n, (long long)std::nearbyint(fade_in * rate));
+    long long fo = std::min(n, (long long)std::nearbyint(fade_out * rate));
+    for (auto &ch : pcm) {
+        for (long long i = 0; i < fi; i++) ch[i] *= 0.5 - 0.5 * std::cos(PI * (i + 0.5) / fi);
+        for (long long i = 0; i < fo; i++) ch[n - fo + i] *= 0.5 + 0.5 * std::cos(PI * (i + 0.5) / fo);
+    }
+}
+
+// ---------------------------------------------------------------- helpers
+
+Planar to_stereo(const Audio &in, size_t a, size_t b) {
+    const int ch = in.channels;
+    const size_t frames = b - a;
+    Planar out(2, std::vector<double>(frames));
+    auto at = [&](size_t i, int c) { return (double)in.pcm[(a + i) * ch + c]; };
+    if (ch == 1) {
+        for (size_t i = 0; i < frames; i++) out[0][i] = out[1][i] = at(i, 0);
+    } else if (ch == 6) {  // FL FR FC LFE BL BR, ITU-R BS.775 downmix
+        const double k = 1.0 / std::sqrt(2.0);
+        const double norm = 1.0 + 2.0 * k;
+        for (size_t i = 0; i < frames; i++) {
+            out[0][i] = (at(i, 0) + k * at(i, 2) + k * at(i, 4)) / norm;
+            out[1][i] = (at(i, 1) + k * at(i, 2) + k * at(i, 5)) / norm;
+        }
+    } else {
+        for (size_t i = 0; i < frames; i++) {
+            out[0][i] = at(i, 0);
+            out[1][i] = at(i, 1);
+        }
+    }
+    return out;
+}
+
+std::string fmt_time(double seconds) {
+    double minutes = std::floor(seconds / 60.0);
+    double sec = seconds - minutes * 60.0;
+    char buf[64];
+    std::snprintf(buf, sizeof buf, "%d:%06.3f", (int)minutes, sec);
+    return buf;
+}
+
+uint64_t max_samples_for(int bitrate, bool loop) {
+    uint64_t sfb = (uint64_t)frame_bytes_for(bitrate) * 4;
+    uint64_t superframes = (PS5_SIZE_LIMIT - header_size(loop)) / sfb;
+    return superframes * SUPERFRAME_SAMPLES - ENCODER_DELAY;
+}
+
+} // namespace
+
+namespace detail {
+
+Result make_snd0_ex(const Audio &in, const Options &o, std::vector<double> *left, std::vector<double> *right,
+                    unsigned threads) {
+    static const int rates[] = {72, 96, 120, 144, 168, 192};
+    if (std::find(std::begin(rates), std::end(rates), o.bitrate_kbps) == std::end(rates))
+        throw std::runtime_error("bit rate must be 72, 96, 120, 144, 168 or 192 kb/s");
+    if (in.rate <= 0 || in.channels <= 0 || in.pcm.size() < (size_t)in.channels)
+        throw std::runtime_error("the input has no audio");
+    if (!(o.start_sec >= 0) || !std::isfinite(o.start_sec)) throw std::runtime_error("start must be positive");
+    const bool max_dur = !(o.duration_sec > 0);
+    const size_t total = in.pcm.size() / in.channels;
+
+    // audio_io.load: decode from up to 0.25 s before the start so resampling
+    // can be trimmed cleanly afterwards.
+    const double margin = 0.25;
+    const double begin = std::max(0.0, o.start_sec - margin);
+    const double offset = o.start_sec - begin;
+    size_t a = (size_t)std::floor(begin * in.rate);
+    size_t b = total;
+    if (!max_dur) {
+        double length = o.duration_sec + offset + margin;
+        b = (size_t)std::min<double>((double)total, (double)a + std::ceil(length * in.rate));
+    }
+    if (a >= total || b <= a) throw std::runtime_error("the start time is beyond the end of the input");
+
+    if (threads == 0) threads = std::max(1u, std::thread::hardware_concurrency());
+    Planar pcm = resample(to_stereo(in, a, b), in.rate, RATE, threads);
+    const size_t skip = (size_t)std::nearbyint(offset * RATE);
+    const size_t available = pcm[0].size() > skip ? pcm[0].size() - skip : 0;
+    const bool loop = o.loop;
+    const uint64_t max_samples = max_samples_for(o.bitrate_kbps, loop);
+    size_t count;
+    if (max_dur)
+        count = (size_t)std::min<uint64_t>(available, max_samples);
+    else
+        count = std::min(available, (size_t)std::nearbyint(o.duration_sec * RATE));
+    if (count == 0) throw std::runtime_error("the selected excerpt is empty");
+    for (auto &ch : pcm) ch = std::vector<double>(ch.begin() + skip, ch.begin() + skip + count);
+
+    const uint32_t sfb = (uint32_t)frame_bytes_for(o.bitrate_kbps) * 4;
+    const uint64_t size = file_size(count, sfb, loop);
+    if (size > PS5_SIZE_LIMIT) {
+        char msg[256];
+        std::snprintf(msg, sizeof msg,
+                      "%.3f s at %d kb/s makes a %llu-byte file, above the 2 MiB PS5 limit; use at most %.3f s "
+                      "(or a lower bit rate)",
+                      count / (double)RATE, o.bitrate_kbps, (unsigned long long)size, max_samples / (double)RATE);
+        throw std::runtime_error(msg);
+    }
+
+    const double source_lufs = integrated_loudness(pcm);
+    if (o.normalize && std::isfinite(source_lufs)) {
+        double gain_db = o.lufs - source_lufs;
+        double g = std::pow(10.0, gain_db / 20.0);
+        for (auto &ch : pcm)
+            for (double &v : ch) v = v * g;
+    }
+    limit_true_peak(pcm, o.true_peak_db, threads, RATE);
+    apply_fades(pcm, RATE, o.fade_in, o.fade_out);
+    const double final_lufs = integrated_loudness(pcm);
+
+    Result r;
+    std::vector<uint8_t> data = encode_atrac9(pcm[0], pcm[1], o.bitrate_kbps, threads);
+    r.at9 = build_at9(o.bitrate_kbps, (uint32_t)count, data, loop);
+    if (r.at9.size() != size) throw std::runtime_error("internal error: unexpected file size");
+    r.loudness_lufs = final_lufs;
+    r.seconds = count / (double)RATE;
+    char buf[64];
+    if (std::isfinite(final_lufs))
+        std::snprintf(buf, sizeof buf, "%.2f", final_lufs);
+    else
+        std::snprintf(buf, sizeof buf, "%s", final_lufs < 0 ? "-inf" : "inf");  // Python's "%.2f" % -inf
+    r.loudness_param = buf;
+    r.processed.resize(count * 2);
+    for (size_t i = 0; i < count; i++) {
+        r.processed[2 * i] = (float)pcm[0][i];
+        r.processed[2 * i + 1] = (float)pcm[1][i];
+    }
+    if (left) *left = pcm[0];
+    if (right) *right = pcm[1];
+    return r;
+}
+
+} // namespace detail
+
+Result make_snd0(const Audio &in, const Options &o) { return detail::make_snd0_ex(in, o, nullptr, nullptr, 0); }
+
+std::vector<uint8_t> wav_bytes(const std::vector<float> &stereo48k) {
+    const uint32_t channels = 2, rate = 48000, bits = 16;
+    const size_t frames = stereo48k.size() / 2;
+    const uint32_t payload = (uint32_t)(frames * channels * 2);
+    std::vector<uint8_t> out;
+    out.reserve(44 + payload + 1);
+    auto u16 = [&](uint32_t x) {
+        out.push_back((uint8_t)x);
+        out.push_back((uint8_t)(x >> 8));
+    };
+    auto u32 = [&](uint32_t x) {
+        u16(x & 0xFFFF);
+        u16(x >> 16);
+    };
+    auto tag = [&](const char *t) { out.insert(out.end(), t, t + 4); };
+    tag("RIFF");
+    u32(4 + 8 + 16 + 8 + payload + (payload & 1));
+    tag("WAVE");
+    tag("fmt ");
+    u32(16);
+    u16(1);
+    u16(channels);
+    u32(rate);
+    u32(rate * channels * bits / 8);
+    u16(channels * bits / 8);
+    u16(bits);
+    tag("data");
+    u32(payload);
+    for (size_t i = 0; i < frames * 2; i++) {
+        double v = std::nearbyint((double)stereo48k[i] * 32768.0);
+        v = std::min(std::max(v, -32768.0), 32767.0);
+        int s = (int)v;
+        u16((uint32_t)(uint16_t)(int16_t)s);
+    }
+    if (payload & 1) out.push_back(0);
+    return out;
+}
+
+} // namespace at9
@@ -0,0 +1,57 @@
+// ATRAC9 constant tables, converted from LibAtrac9
+// (https://github.com/Thealexbarney/LibAtrac9) via ps5at9/atrac9_tables.py of
+// PS5 AT9 Converter. Generated by tools/at9check/gen_tables.py; do not edit.
+//
+// SPDX-License-Identifier: MIT
+//
+// MIT License
+//
+// Copyright (c) 2018 Alex Barney
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+#pragma once
+#include <cstdint>
+
+namespace at9 {
+namespace tables {
+
+struct Huff { int size; int value_count_power; const uint8_t *bits; const uint16_t *codes; };
+
+// Scale factor codebooks indexed by word length (unsigned 1..6, signed 2..5); size 0 = absent.
+extern const Huff SF_UNSIGNED[7];
+extern const Huff SF_SIGNED[6];
+// Spectrum codebooks [codebook set][word length 0..7][codebook index]; size 0 = absent.
+extern const Huff SPECTRUM[2][8][4];
+extern const int SF_WEIGHTS[8][32];
+extern const int GRADIENT_MAIN[48];
+// Band extension tables (decoder only).
+extern const int BEX_GROUP_INFO[8][3];
+extern const int BEX_VALUE_COUNTS[5][6];
+extern const int BEX_DATA_LENGTHS[5][6][4];
+extern const double BEX_MODE0_BANDS3[5][32];
+extern const double BEX_MODE0_BANDS4[5][16];
+extern const double BEX_MODE0_BANDS5[3][32];
+extern const double BEX_MODE2_SCALE[64];
+extern const double BEX_MODE3_INITIAL[16];
+extern const double BEX_MODE3_RATE[16];
+extern const double BEX_MODE4_MULTIPLIER[8];
+
+} // namespace tables
+} // namespace at9
@@ -10,6 +10,8 @@
 #include "imaging.h"
 #include "ps5client.h"
 #include "layout.h"
+#include "lib/at9/at9.h"
+#include "presets.h"
 #include "lib/json.hpp"

 #include <atomic>
@@ -27,7 +29,7 @@
 #include <shellapi.h>
 #include <tlhelp32.h>
 #endif
-#define STUDIO_VERSION "1.2"
+#define STUDIO_VERSION "1.3"

 using json = nlohmann::json;

@@ -40,6 +42,11 @@ struct Staged {                 // the user's image, decoded; converted per targ
    img::Image src;
    std::vector<uint8_t> preview_png;
    std::string note;
+    // Music: the decoded file, the clip settings, and the snd0.at9 made from them.
+    at9::Audio audio;
+    at9::Options opt;
+    at9::Result enc;
+    std::vector<uint8_t> preview_wav;
 };
 static std::mutex g_mu;
 static std::string g_ip;
@@ -385,7 +392,52 @@ static std::vector<uint8_t> fetch_background(const std::string &id, const std::s
    return {};
 }

+static std::string secs(double v) { char b[32]; snprintf(b, sizeof b, "%d:%02d", (int)v / 60, (int)v % 60); return b; }
+
+// Cuts, levels and encodes the clip; the result is what Apply uploads, so size problems show up now.
+static void encode_music(Staged &s) {
+    s.enc = at9::make_snd0(s.audio, s.opt);
+    s.preview_wav = at9::wav_bytes(s.enc.processed);
+    double total = (double)s.audio.pcm.size() / std::max(1, s.audio.channels) / std::max(1, s.audio.rate);
+    s.note = "";
+    if (s.opt.start_sec + 0.5 >= total) s.note = "The start is past the end of the song.";
+}
+static json music_json(const Staged &s) {
+    double total = (double)s.audio.pcm.size() / std::max(1, s.audio.channels) / std::max(1, s.audio.rate);
+    return {{"ok", true}, {"note", s.note}, {"seconds", s.enc.seconds}, {"total", total}, {"kb", (int)(s.enc.at9.size() / 1024)},
+            {"start", s.opt.start_sec}, {"duration", s.opt.duration_sec},
+            {"summary", secs(s.opt.start_sec) + " to " + secs(s.opt.start_sec + s.enc.seconds) + ", " + std::to_string(s.enc.at9.size() / 1024) + " KB"}};
+}
+static json stage_music(const std::vector<uint8_t> &bytes) {
+    Staged s;
+    std::string err;
+    if (!at9::decode_file(bytes, s.audio, err)) throw ps5::Error("That file isn't an MP3, WAV or FLAC PSGFX can read" + (err.empty() ? std::string(".") : " (" + err + ")."));
+    encode_music(s);
+    json j = music_json(s);
+    std::lock_guard<std::mutex> l(g_mu);
+    g_staged["music"] = std::move(s);
+    return j;
+}
+// Start (seconds) and length (seconds; 0 = the longest that fits in the PS5's 2 MB limit).
+static json music_clip(const json &req) {
+    Staged s;
+    {
+        std::lock_guard<std::mutex> l(g_mu);
+        auto it = g_staged.find("music");
+        if (it == g_staged.end()) throw ps5::Error("Add a song first.");
+        s = it->second;
+    }
+    s.opt.start_sec = std::max(0.0, req.value("start", s.opt.start_sec));
+    s.opt.duration_sec = std::max(0.0, req.value("duration", s.opt.duration_sec));
+    encode_music(s);
+    json j = music_json(s);
+    std::lock_guard<std::mutex> l(g_mu);
+    g_staged["music"] = std::move(s);
+    return j;
+}
+
 static json stage(const std::string &kind, const std::vector<uint8_t> &bytes) {
+    if (kind == "music") return stage_music(bytes);
    Staged s;
    if (!img::decode(bytes, s.src)) throw ps5::Error("That file isn't a PNG or JPEG image.");
    const img::Image &src = s.src;
@@ -408,8 +460,9 @@ static json stage(const std::string &kind, const std::vector<uint8_t> &bytes) {
 // A file on the PS5 we're going to replace, and the format it has to stay in.
 struct Target { std::string name; bool dds = false; int w = 0, h = 0; };

-static std::vector<uint8_t> encode_for(const std::string &kind, const img::Image &src, const Target &t) {
-    img::Image im = img::cover(src, t.w, t.h);
+static std::vector<uint8_t> encode_for(const std::string &kind, const Staged &s, const Target &t) {
+    if (kind == "music") return s.enc.at9;
+    img::Image im = img::cover(s.src, t.w, t.h);
    img::opaque(im);
    return t.dds ? img::to_bc7_dds(im) : img::to_png(im);
 }
@@ -418,6 +471,7 @@ static std::vector<uint8_t> encode_for(const std::string &kind, const img::Image
 static std::vector<Target> homebrew_targets(const std::string &kind) {
    if (kind == "icon") return {{"icon0.png", false, 512, 512}};
    if (kind == "background") return {{"pic0.dds", true, 3840, 2160}, {"pic1.dds", true, 3840, 2160}};
+    if (kind == "music") return {{"snd0.at9"}};
    return {};
 }

@@ -426,6 +480,7 @@ static std::vector<Target> homebrew_targets(const std::string &kind) {
 static std::vector<Target> game_targets(ps5::Client &c, const std::string &id, const std::string &kind,
                                        json &log, std::vector<std::string> &seen) {
    std::vector<Target> out;
+    if (kind == "music") return {{"snd0.at9"}};   // added when the game has none; backed up when it has one
    for (auto &e : list_dir(c, appmeta(id))) {
        std::string name = e.value("name", ""), ln = lower(name);
        std::string ek = e.value("kind", "");
@@ -505,6 +560,13 @@ static void sync_home(ps5::Client &c, const std::string &id, const std::string &
 // Restore, and the database is backed up first, as Home layout does.
 static const char *const ORIGINALS = "psgfx_original.json";
 static std::string art_column(const std::string &kind) { return kind == "icon" ? "icon0Info" : "pic0Info"; }
+// The column holding a title's selection-music path, if this database has one (snd0Info or similar).
+static std::string music_column(const layout::Info &info) {
+    auto it = info.cols.find(info.concept_t);
+    if (it == info.cols.end()) return "";
+    for (auto &c : it->second) if (lower(c).find("snd0") != std::string::npos) return c;
+    return "";
+}

 // Size and format from an image's first bytes; false if it isn't a PNG or DDS we can match.
 static bool probe_art(const std::vector<uint8_t> &h, Target &t) {
@@ -525,15 +587,16 @@ static std::vector<uint8_t> read_head(ps5::Client &c, const std::string &path) {
    catch (...) { return {}; }
 }

-// Sets an art column for this title in every table that has it (all user profiles).
+// Sets an art column for this title in every table that has it (all user profiles). Empty = NULL.
 static void set_art_column(layout::DB &db, const layout::Info &info, const std::string &id, const std::string &concept,
                           const std::string &col, const std::string &value) {
+    layout::Val v = value.empty() ? layout::Val(nullptr) : layout::Val(value);
    for (auto &[table, cols] : info.cols) {
        if (!cols.count(col)) continue;
        if (cols.count("localConceptId") && !concept.empty())
-            db.exec("UPDATE " + layout::q(table) + " SET " + layout::q(col) + "=? WHERE localConceptId=?", {value, concept});
+            db.exec("UPDATE " + layout::q(table) + " SET " + layout::q(col) + "=? WHERE localConceptId=?", {v, concept});
        else if (cols.count("titleId"))
-            db.exec("UPDATE " + layout::q(table) + " SET " + layout::q(col) + "=? WHERE titleId=?", {value, id});
+            db.exec("UPDATE " + layout::q(table) + " SET " + layout::q(col) + "=? WHERE titleId=?", {v, id});
    }
 }

@@ -556,6 +619,27 @@ static json read_originals(ps5::Client &c, const std::string &id) {
    catch (...) { return json::object(); }
 }

+static std::string ts_query() { return "?ts=" + std::to_string((long long)time(nullptr)); }
+
+// The home screen only plays a title's music when its app.db row names the file (snd0Info);
+// the PS5 fills that in at install time, so an app installed without music has it empty.
+// Points it at `path` (homebrew: /user/app/<id>/sce_sys/snd0.at9, like the PS5 does), or
+// clears it when `path` is empty.
+static void point_music(const std::string &id, const std::string &path, json &log) {
+    std::lock_guard<std::mutex> l(g_layout_mu);
+    try {
+        auto orig = pull_db();
+        layout::DB db(orig);
+        auto info = layout::analyze(db, g_layout_user);
+        std::string col = music_column(info);
+        if (col.empty()) { log.push_back("This firmware's home-screen database has no music entry, so the music may not play."); return; }
+        set_art_column(db, info, id, concept_of(db, info, id), col, path.empty() ? "" : path + ts_query());
+        upload_db(orig, db, (path.empty() ? "Before removing music for " : "Before music for ") + id, log);
+    } catch (const std::exception &e) {
+        log.push_back(std::string("Couldn't point the home screen at the music (") + e.what() + "), so it may not play.");
+    }
+}
+
 // Returns the staged slots it handled; the rest fall back to replacing the art-folder files.
 static std::set<std::string> game_apply_db(ps5::Client &c, const std::string &id, const std::map<std::string, Staged> &staged, json &log) {
    std::set<std::string> done;
@@ -576,10 +660,12 @@ static std::set<std::string> game_apply_db(ps5::Client &c, const std::string &id
    json originals = read_originals(c, id);
    std::vector<std::string> replaced;   // our older files, deleted once the database points away from them
    for (auto &[kind, s] : staged) {
-        const std::string col = art_column(kind);
+        const std::string col = kind == "music" ? music_column(info) : art_column(kind);
+        if (col.empty()) continue;
        std::string value = db.scalar_str("SELECT " + layout::q(col) + " FROM " + layout::q(info.concept_t) + " WHERE localConceptId=?", {concept});
        std::string path = layout::strip_query(value);
-        if (path.empty() || path[0] != '/') continue;
+        // A title without music has no snd0Info at all; the home screen plays nothing until it's set.
+        if (!(kind == "music" && path.empty()) && (path.empty() || path[0] != '/')) continue;
        std::string base = path.substr(path.find_last_of('/') + 1);
        bool in_dir = path == dir + "/" + base, ours = in_dir && base.rfind("psgfx_", 0) == 0;
        if (in_dir && !ours) {   // a real file in the art folder: replacing it in place works
@@ -588,19 +674,25 @@ static std::set<std::string> game_apply_db(ps5::Client &c, const std::string &id
            if (regular) continue;
        }
        Target t;
-        if (!probe_art(read_head(c, path), t)) {
-            t.dds = ends_with(lower(base), ".dds");
-            t.w = kind == "icon" ? 512 : t.dds ? 3840 : 1920;
-            t.h = kind == "icon" ? 512 : t.dds ? 2160 : 1080;
+        if (kind == "music") {
+            t.name = "psgfx_snd0_" + now_stamp("%Y%m%d%H%M%S") + ".at9";
+            c.upload(dir + "/" + t.name, encode_for(kind, s, t));
+            log.push_back("Uploaded " + t.name + " (" + std::to_string(s.enc.at9.size() / 1024) + " KB)");
+        } else {
+            if (!probe_art(read_head(c, path), t)) {
+                t.dds = ends_with(lower(base), ".dds");
+                t.w = kind == "icon" ? 512 : t.dds ? 3840 : 1920;
+                t.h = kind == "icon" ? 512 : t.dds ? 2160 : 1080;
+            }
+            std::string stem = kind == "icon" ? "icon0" : "pic0";
+            t.name = "psgfx_" + stem + "_" + now_stamp("%Y%m%d%H%M%S") + (t.dds ? ".dds" : ".png");
+            c.upload(dir + "/" + t.name, encode_for(kind, s, t));
+            log.push_back("Uploaded " + t.name + " (" + std::to_string(t.w) + "x" + std::to_string(t.h) + ")");
        }
-        std::string stem = kind == "icon" ? "icon0" : "pic0";
-        t.name = "psgfx_" + stem + "_" + now_stamp("%Y%m%d%H%M%S") + (t.dds ? ".dds" : ".png");
-        c.upload(dir + "/" + t.name, encode_for(kind, s.src, t));
-        log.push_back("Uploaded " + t.name + " (" + std::to_string(t.w) + "x" + std::to_string(t.h) + ")");
        if (!originals.contains(col)) originals[col] = value;
        if (ours) replaced.push_back(dir + "/" + base);
        size_t qp = value.find('?');
-        set_art_column(db, info, id, concept, col, dir + "/" + t.name + (qp == std::string::npos ? "" : value.substr(qp)));
+        set_art_column(db, info, id, concept, col, dir + "/" + t.name + (qp == std::string::npos ? ts_query() : value.substr(qp)));
        done.insert(kind);
    }
    if (done.empty()) return done;
@@ -633,27 +725,54 @@ static bool game_restore_db(ps5::Client &c, const std::string &id, json &log) {
    return true;
 }

+// The home screen plays snd0.at9 at the level param.json gives in pubtools.loudnessSnd0.
+static void set_music_loudness(ps5::Client &c, const std::string &param_path, const std::string &value, json &log) {
+    if (value.empty() || value.find("inf") != std::string::npos) return;   // a silent clip has no level
+    try {
+        auto b = c.read_file(param_path, 1u << 20);
+        auto j = nlohmann::ordered_json::parse(b.begin(), b.end());
+        if (!j.contains("pubtools") || !j["pubtools"].is_object()) j["pubtools"] = nlohmann::ordered_json::object();
+        if (j["pubtools"].value("loudnessSnd0", std::string()) == value) return;
+        j["pubtools"]["loudnessSnd0"] = value;
+        std::string out = j.dump(2);
+        c.upload(param_path, std::vector<uint8_t>(out.begin(), out.end()));
+        log.push_back("Set the music level in " + param_path.substr(param_path.find_last_of('/') + 1) + " (" + value + " LUFS)");
+    } catch (const std::exception &e) {
+        log.push_back(std::string("Couldn't set the music level in param.json (") + e.what() + "); the music may play louder or quieter than intended.");
+    }
+}
+
 static json do_apply(const std::string &id, const std::string &src, std::string kind_of_app) {
    if (mounted_image(src)) kind_of_app = "game";
    json log = json::array();
    std::map<std::string, Staged> staged;
    { std::lock_guard<std::mutex> l(g_mu); staged = g_staged; }
-    if (staged.empty()) throw ps5::Error("Add at least one image first.");
+    if (staged.empty()) throw ps5::Error("Add an image or a song first.");
+    const bool music = staged.count("music") > 0;
    auto c = client();

    if (kind_of_app == "game") {
        auto via_db = game_apply_db(c, id, staged, log);
+        if (via_db.count("music") && exists(c, appmeta(id), "param.json")) {
+            backup_once(c, appmeta(id), "param.json", log);
+            set_music_loudness(c, appmeta(id) + "/param.json", staged["music"].enc.loudness_param, log);
+        }
        int written = (int)via_db.size();
        std::vector<std::string> seen;
        for (auto &[kind, s] : staged) {
            if (via_db.count(kind)) continue;
            auto targets = game_targets(c, id, kind, log, seen);
            if (targets.empty()) log.push_back(std::string("This game has no ") + (kind == "icon" ? "icon" : "background") + " file this tool can replace.");
+            if (kind == "music" && exists(c, appmeta(id), "param.json")) {
+                backup_once(c, appmeta(id), "param.json", log);
+                set_music_loudness(c, appmeta(id) + "/param.json", s.enc.loudness_param, log);
+            }
            for (auto &t : targets) {
                backup_once(c, appmeta(id), t.name, log);
-                auto bytes = encode_for(kind, s.src, t);
+                auto bytes = encode_for(kind, s, t);
                c.upload(appmeta(id) + "/" + t.name, bytes);
-                log.push_back("Replaced " + t.name + " (" + std::to_string(t.w) + "x" + std::to_string(t.h) + ")");
+                log.push_back(kind == "music" ? "Uploaded " + t.name + " (" + std::to_string(bytes.size() / 1024) + " KB)"
+                                              : "Replaced " + t.name + " (" + std::to_string(t.w) + "x" + std::to_string(t.h) + ")");
                written++;
            }
        }
@@ -664,7 +783,7 @@ static json do_apply(const std::string &id, const std::string &src, std::string
            for (auto &n : log) notes += " " + n.get<std::string>();
            throw ps5::Error("Nothing was changed. Files in this game's art folder: " + (list.empty() ? std::string("(none)") : list) + "." + notes);
        }
-        log.push_back("Done. Restart the PS5 to see the new art.");
+        log.push_back(music ? "Done. Restart the PS5 to see and hear the change." : "Done. Restart the PS5 to see the new art.");
    } else {
        if (src.empty()) throw ps5::Error("This app's folder is unknown.");
        const std::string dir = src + "/sce_sys";
@@ -673,12 +792,20 @@ static json do_apply(const std::string &id, const std::string &src, std::string
            for (auto &t : homebrew_targets(kind)) {
                changed.push_back(t.name);
                backup_once(c, dir, t.name, log);
-                auto bytes = encode_for(kind, s.src, t);
+                auto bytes = encode_for(kind, s, t);
                c.upload(dir + "/" + t.name, bytes);
                log.push_back("Uploaded " + t.name + " (" + std::to_string(bytes.size() / 1024) + " KB)");
            }
        }
+        if (music) {   // not backed up: it also holds a rename, and the level is harmless without the music
+            set_music_loudness(c, dir + "/param.json", staged["music"].enc.loudness_param, log);
+            changed.push_back("param.json");
+        }
        sync_home(c, id, src, changed, log);
+        if (music) {
+            point_music(id, "/user/app/" + id + "/sce_sys/snd0.at9", log);
+            log.push_back("Restart the PS5, then hover the app to hear its music.");
+        }
    }
    { std::lock_guard<std::mutex> l(g_mu); g_icon_cache.erase(id); g_staged.clear(); }
    return {{"ok", true}, {"log", log}};
@@ -714,7 +841,11 @@ static json do_restore(const std::string &id, const std::string &src, std::strin
        }
    }
    if (kind_of_app == "game") log.push_back("Done. Restart the PS5 to see the original art.");
-    else sync_home(c, id, src, names, log);
+    else {
+        sync_home(c, id, src, names, log);
+        if (std::find(names.begin(), names.end(), "snd0.at9") != names.end())
+            point_music(id, exists(c, dir, "snd0.at9") ? "/user/app/" + id + "/sce_sys/snd0.at9" : "", log);
+    }
    { std::lock_guard<std::mutex> l(g_mu); g_icon_cache.erase(id); }
    return {{"ok", true}, {"log", log}};
 }
@@ -869,6 +1000,25 @@ static void handle(sock_t s, Req &r) {
        }
        if (r.path.rfind("/api/stage/", 0) == 0 && r.method == "POST") { respond_json(s, stage(r.path.substr(11), r.body)); return; }
        if (r.path.rfind("/api/unstage/", 0) == 0) { std::lock_guard<std::mutex> l(g_mu); g_staged.erase(r.path.substr(13)); respond_json(s, {{"ok", true}}); return; }
+        if (r.path.rfind("/api/presets/", 0) == 0) {   // /api/presets/<title id> -> the built-in icons for it
+            std::string id = r.path.substr(13);
+            json list = json::array();
+            for (size_t i = 0; i < PRESETS_COUNT; i++) if (id == PRESETS[i].title_id) list.push_back({{"i", i}, {"app", PRESETS[i].app}});
+            respond_json(s, {{"ok", true}, {"presets", list}}); return;
+        }
+        if (r.path.rfind("/api/preset/", 0) == 0) {    // /api/preset/<index>: the image; POST stages it as the icon
+            size_t i = (size_t)strtoull(r.path.c_str() + 12, nullptr, 10);
+            if (i >= PRESETS_COUNT) { respond(s, 404, "text/plain", "none", 4); return; }
+            if (r.method == "POST") { respond_json(s, stage("icon", std::vector<uint8_t>(PRESETS[i].data, PRESETS[i].data + PRESETS[i].len))); return; }
+            respond(s, 200, "image/png", PRESETS[i].data, PRESETS[i].len); return;
+        }
+        if (r.path == "/api/music/clip" && r.method == "POST") { respond_json(s, music_clip(json::parse(std::string(r.body.begin(), r.body.end())))); return; }
+        if (r.path == "/api/staged/music") {
+            std::vector<uint8_t> b;
+            { std::lock_guard<std::mutex> l(g_mu); auto it = g_staged.find("music"); if (it != g_staged.end()) b = it->second.preview_wav; }
+            if (b.empty()) { respond(s, 404, "text/plain", "none", 4); return; }
+            respond(s, 200, "audio/wav", b.data(), b.size()); return;
+        }
        if (r.path.rfind("/api/staged/", 0) == 0) {
            std::vector<uint8_t> b;
            { std::lock_guard<std::mutex> l(g_mu); auto it = g_staged.find(r.path.substr(12)); if (it != g_staged.end()) b = it->second.preview_png; }
@@ -0,0 +1,7 @@
+// Preset icons built into PSGFX, by title ID (assets/presets, embedded by tools/embed_presets.py).
+#pragma once
+#include <cstddef>
+
+struct Preset { const char *app; const char *title_id; const unsigned char *data; size_t len; };
+extern const Preset PRESETS[];
+extern const size_t PRESETS_COUNT;
@@ -22,6 +22,13 @@ html,body{margin:0;min-height:100%}
 body{background:radial-gradient(1200px 700px at 70% -10%,#13244a 0%,transparent 60%),var(--bg);background-attachment:fixed;color:var(--text);font-size:14px;line-height:1.5}
 button,input{font:inherit;color:inherit}
 :focus-visible{outline:2px solid var(--blue-hi);outline-offset:2px}
+/* Scrollbars in the app's own style, not the browser's grey ones. */
+::-webkit-scrollbar{width:12px;height:12px}
+::-webkit-scrollbar-track,::-webkit-scrollbar-corner{background:transparent}
+::-webkit-scrollbar-thumb{background:rgba(160,190,255,.2);border-radius:12px;border:3px solid transparent;background-clip:padding-box}
+::-webkit-scrollbar-thumb:hover{background-color:rgba(160,190,255,.3)}
+::-webkit-scrollbar-thumb:active{background-color:var(--blue)}
+@supports not selector(::-webkit-scrollbar){*{scrollbar-width:thin;scrollbar-color:rgba(160,190,255,.22) transparent}}

 .top{display:flex;align-items:center;gap:20px;padding:16px 24px;border-bottom:1px solid var(--line)}
 .brand{display:flex;align-items:flex-end;gap:10px}
@@ -54,7 +61,7 @@ button,input{font:inherit;color:inherit}
 .app.locked{opacity:.5}
 .empty{color:var(--muted);padding:8px;font-size:13px}

-main{border-left:1px solid var(--line);padding:24px;display:flex;flex-direction:column;gap:20px;max-width:1180px}
+main{border-left:1px solid var(--line);padding:24px max(24px,calc((100% - 1132px)/2));display:flex;flex-direction:column;gap:20px;min-width:0}

 /* The PS5 home-screen replica: the one bold element. */
 .stage{position:relative;aspect-ratio:16/9;width:min(100%,calc((100vh - 330px)*16/9));min-width:min(100%,520px);margin:0 auto;border-radius:var(--r-lg);overflow:hidden;background:linear-gradient(135deg,#101b33,#060913);border:1px solid var(--line);box-shadow:0 30px 80px rgba(0,0,0,.5)}
@@ -82,6 +89,20 @@ main{border-left:1px solid var(--line);padding:24px;display:flex;flex-direction:
 .slot{background:var(--glass);border:1px solid var(--line);border-radius:var(--r-md);padding:14px;display:flex;gap:12px;align-items:center;min-height:92px}
 .slot .thumb{width:64px;height:64px;border-radius:10px;background:var(--bg2) center/cover no-repeat;flex:none;border:1px solid var(--line)}
 .slot.bgslot .thumb{width:96px;height:54px}
+.slot.musicslot{grid-column:1/-1;flex-wrap:wrap}
+.presets{grid-column:1/-1;background:var(--glass);border:1px solid var(--line);border-radius:var(--r-md);padding:14px}
+.presets .t{font-weight:600}.presets .s{color:var(--muted);font-size:12px}
+.presets .row{display:flex;gap:10px;flex-wrap:wrap;margin-top:10px}
+.presets button{width:72px;height:72px;padding:0;border-radius:12px;border:2px solid transparent;background:var(--bg2) center/cover no-repeat;cursor:pointer}
+.presets button:hover{border-color:var(--line)}
+.presets button[aria-pressed="true"]{border-color:var(--blue-hi)}
+.slot.musicslot .thumb{display:grid;place-items:center;font-size:26px;color:var(--muted)}
+.mclip{display:none;gap:10px;align-items:center;flex-wrap:wrap;width:100%;margin-top:4px}
+.mclip.on{display:flex}
+.mclip label{color:var(--muted);font-size:12px;display:flex;gap:6px;align-items:center}
+.mclip input,.mclip select{padding:5px 8px;border-radius:var(--r-sm);border:1px solid var(--line);background:var(--glass);color:var(--text);font-size:12px}
+.mclip input{width:70px}
+.mclip audio{height:32px;flex:1;min-width:220px}
 .slot .meta{min-width:0;flex:1}
 .slot .t{font-weight:600}
 .slot .s{color:var(--muted);font-size:12px}
@@ -176,7 +197,7 @@ main{border-left:1px solid var(--line);padding:24px;display:flex;flex-direction:
 </head>
 <body>
 <header class="top">
-  <div class="brand"><img src="/wordmark.png" alt="PSGFX"><span>1.2</span></div>
+  <div class="brand"><img src="/wordmark.png" alt="PSGFX"><span>1.3</span></div>
  <nav class="views" aria-label="View"><button data-v="art" aria-pressed="true">Art</button><button data-v="layout" aria-pressed="false">Home layout</button></nav>
  <form class="connect" id="cf">
    <span class="dot" id="dot" aria-hidden="true"></span>
@@ -208,7 +229,7 @@ main{border-left:1px solid var(--line);padding:24px;display:flex;flex-direction:
        <div class="titlezone"><div class="tname" id="tname"></div></div>
        <div class="play" aria-hidden="true">Play</div>
        <div class="staged-badge" id="badge">Preview - not applied yet</div>
-        <div class="stage-hint">Drop an image on the tile or the background</div>
+        <div class="stage-hint">Drop an image on the tile or the background, or a song anywhere</div>
        <div class="drop d-bg" data-kind="background">Background</div>
        <div class="drop d-icon" data-kind="icon">Icon</div>
      </div>
@@ -218,11 +239,19 @@ main{border-left:1px solid var(--line);padding:24px;display:flex;flex-direction:
      <div class="slots" style="margin-top:20px">
        <div class="slot" data-kind="icon"><div class="thumb"></div><div class="meta"><div class="t">Icon</div><div class="s">Square, 512 × 512 or larger</div><div class="row"><button class="btn pick">Choose image</button><button class="btn clear hidden">Remove</button></div></div></div>
        <div class="slot bgslot" data-kind="background"><div class="thumb"></div><div class="meta"><div class="t">Background</div><div class="s">16:9, ideally 3840 × 2160</div><div class="row"><button class="btn pick">Choose image</button><button class="btn clear hidden">Remove</button></div></div></div>
+        <div class="presets hidden" id="presets"><div class="t">Preset icons</div><div class="s" id="presetsS"></div><div class="row" id="presetsRow"></div></div>
+        <div class="slot musicslot" data-kind="music"><div class="thumb" aria-hidden="true">&#9835;</div><div class="meta"><div class="t">Music</div><div class="s">MP3, WAV or FLAC. Plays when the tile is selected.</div><div class="row"><button class="btn pick">Choose song</button><button class="btn clear hidden">Remove</button></div></div>
+          <div class="mclip" id="mclip">
+            <label>Start <input id="mstart" value="0:00" inputmode="numeric" title="Where the clip starts in the song (m:ss)"></label>
+            <label>Length <select id="mlen"><option value="15">15 s</option><option value="30">30 s</option><option value="60">60 s</option><option value="0">Longest that fits</option></select></label>
+            <audio id="maudio" controls preload="none"></audio>
+          </div>
+        </div>
      </div>

      <div class="actions" style="margin-top:20px">
        <button class="btn primary" id="apply" disabled>Apply to PS5</button>
-        <button class="btn" id="restore">Restore original art</button>
+        <button class="btn" id="restore">Restore original</button>
        <span class="note" id="anote">Close the app on your PS5 before applying.</span>
      </div>
      <ul class="log" id="log"></ul>
@@ -273,11 +302,13 @@ main{border-left:1px solid var(--line);padding:24px;display:flex;flex-direction:
 <div class="scrim" id="dlg"><div class="dlg" id="dlgBody"></div></div>
 <div class="busyv" id="busyv"><span id="busyT">Working…</span></div>
 <input type="file" id="file" accept="image/png,image/jpeg" hidden>
+<input type="file" id="afile" accept=".mp3,.wav,.flac,.aif,.aiff,audio/*" hidden>

 <script>
 const $ = s => document.querySelector(s);
 const st = { apps: [], sel: null, staged: {} };
-const KINDS = ['icon','background'];
+const KINDS = ['icon','background','music'];
+const HINT = {icon:'Square, 512 × 512 or larger', background:'16:9, ideally 3840 × 2160', music:'MP3, WAV or FLAC. Plays when the tile is selected.'};

 async function api(path, opts={}) {
  const r = await fetch(path, opts);
@@ -351,6 +382,27 @@ async function select(a, btn){
  const game = a.kind === 'game';
  $('#anote').textContent = game ? 'Close the game first. The PS5 may put back its original art when the game updates.' : 'Close the app on your PS5 before applying.';
  refreshPreview(true);
+  loadPresets(a);
+}
+
+async function loadPresets(a){
+  const box = $('#presets'), row = $('#presetsRow');
+  box.classList.add('hidden'); row.innerHTML = '';
+  let j; try { j = await api('/api/presets/' + encodeURIComponent(a.title_id)); } catch { return; }
+  if (st.sel !== a || !j.presets.length) return;
+  $('#presetsS').textContent = 'Made for ' + j.presets[0].app + '. Pick one to use it as the icon.';
+  for (const p of j.presets) {
+    const b = document.createElement('button');
+    b.style.backgroundImage = `url(/api/preset/${p.i})`; b.title = p.app + ' preset ' + (row.children.length + 1);
+    b.setAttribute('aria-label', b.title); b.setAttribute('aria-pressed', 'false');
+    b.onclick = async () => {
+      row.querySelectorAll('button').forEach(x => x.setAttribute('aria-pressed', 'false'));
+      try { const r = await api('/api/preset/' + p.i, {method:'POST'}); st.staged.icon = {note: r.note || ''}; b.setAttribute('aria-pressed', 'true'); refreshPreview(false); }
+      catch (err) { $('#presetsS').textContent = err.message; }
+    };
+    row.appendChild(b);
+  }
+  box.classList.remove('hidden');
 }

 function refreshPreview(loadCurrent){
@@ -362,13 +414,17 @@ function refreshPreview(loadCurrent){
    bg.src = '/api/current/'+encodeURIComponent(a.title_id)+'?src='+encodeURIComponent(a.src)+'&t='+t; }
  document.querySelectorAll('.slot').forEach(sl => {
    const k = sl.dataset.kind, s = st.staged[k];
-    sl.querySelector('.thumb').style.backgroundImage = s ? `url(/api/staged/${k}?t=${t})` : '';
+    if (k !== 'music') sl.querySelector('.thumb').style.backgroundImage = s ? `url(/api/staged/${k}?t=${t})` : '';
    sl.querySelector('.clear').classList.toggle('hidden', !s);
    const sEl = sl.querySelector('.s');
    if (s && s.note) { sEl.textContent = s.note; sEl.classList.add('warn'); }
-    else if (s) { sEl.textContent = 'Ready to apply'; sEl.classList.remove('warn'); }
-    else { sEl.textContent = {icon:'Square, 512 × 512 or larger',background:'16:9, ideally 3840 × 2160'}[k]; sEl.classList.remove('warn'); }
+    else if (s) { sEl.textContent = s.summary ? 'Ready to apply: ' + s.summary : 'Ready to apply'; sEl.classList.remove('warn'); }
+    else { sEl.textContent = HINT[k]; sEl.classList.remove('warn'); }
  });
+  const m = st.staged.music;
+  $('#mclip').classList.toggle('on', !!m);
+  if (m && m.fresh) { $('#maudio').src = '/api/staged/music?t='+t; m.fresh = false; }
+  if (!m) $('#maudio').removeAttribute('src');
  updateApply();
 }
 const newName = () => { const v = $('#aname').value.trim(); return v && v !== (st.sel.title_name || st.sel.title_id) ? v : null; };
@@ -383,15 +439,35 @@ async function stage(kind, file){
  const sl = document.querySelector(`.slot[data-kind="${kind}"] .s`);
  sl.textContent = 'Loading…'; sl.classList.remove('warn');
  try {
+    if (kind === 'music') sl.textContent = 'Converting… this takes a few seconds.';
    const j = await api('/api/stage/'+kind, {method:'POST', body: await file.arrayBuffer()});
-    st.staged[kind] = {note: j.note || ''};
+    st.staged[kind] = {note: j.note || '', summary: j.summary || '', fresh: true};
+    if (kind === 'music') { $('#mstart').value = fmtTime(j.start); $('#mlen').value = String(j.duration); }
  } catch (err) { sl.textContent = err.message; sl.classList.add('warn'); return; }
  refreshPreview(false);
 }

+const fmtTime = v => Math.floor(v/60) + ':' + String(Math.floor(v%60)).padStart(2,'0');
+const parseTime = v => { const p = String(v).trim().split(':').map(Number); if (p.some(isNaN)) return 0; return p.length > 1 ? p[0]*60 + p[1] : p[0]; };
+async function reclip(){
+  const sl = document.querySelector('.slot[data-kind="music"] .s');
+  sl.textContent = 'Converting…'; sl.classList.remove('warn');
+  try {
+    const j = await api('/api/music/clip', {method:'POST', body: JSON.stringify({start: parseTime($('#mstart').value), duration: Number($('#mlen').value)})});
+    st.staged.music = {note: j.note || '', summary: j.summary || '', fresh: true};
+    $('#mstart').value = fmtTime(j.start);
+  } catch (err) { sl.textContent = err.message; sl.classList.add('warn'); return; }
+  refreshPreview(false);
+}
+$('#mstart').addEventListener('change', reclip); $('#mlen').addEventListener('change', reclip);
+$('#afile').onchange = e => { const f = e.target.files[0]; if (f) stage('music', f); };
+const isAudio = f => /^audio\//.test(f.type) || /\.(mp3|wav|flac|aiff?)$/i.test(f.name);
+
 let pickKind = null;
 document.querySelectorAll('.slot').forEach(sl => {
-  sl.querySelector('.pick').onclick = () => { pickKind = sl.dataset.kind; $('#file').value=''; $('#file').click(); };
+  sl.querySelector('.pick').onclick = () => {
+    if (sl.dataset.kind === 'music') { $('#afile').value=''; $('#afile').click(); return; }
+    pickKind = sl.dataset.kind; $('#file').value=''; $('#file').click(); };
  sl.querySelector('.clear').onclick = async () => { await api('/api/unstage/'+sl.dataset.kind); delete st.staged[sl.dataset.kind]; refreshPreview(true); };
 });
 $('#file').onchange = e => { const f = e.target.files[0]; if (f && pickKind) stage(pickKind, f); };
@@ -411,7 +487,7 @@ stageEl.addEventListener('dragover', e => {
 });
 stageEl.addEventListener('drop', e => {
  e.preventDefault(); dragDepth=0; stageEl.classList.remove('dragging');
-  const f = e.dataTransfer.files[0]; if (f) stage(zoneAt(e.clientX, e.clientY), f);
+  const f = e.dataTransfer.files[0]; if (f) stage(isAudio(f) ? 'music' : zoneAt(e.clientX, e.clientY), f);
 });
 window.addEventListener('dragover', e => e.preventDefault()); window.addEventListener('drop', e => e.preventDefault());

@@ -436,7 +512,7 @@ $('#apply').onclick = async () => {
  if (artDone) refreshPreview(true); else updateApply();
 };
 $('#restore').onclick = async () => {
-  const a = st.sel; showLog(['Restoring original art…'], '');
+  const a = st.sel; showLog(['Restoring the original art and music…'], '');
  try {
    const j = await api('/api/restore', {method:'POST', body: JSON.stringify({title_id:a.title_id, src:a.src, kind:a.kind})});
    showLog(j.log, 'ok'); refreshPreview(true);
@@ -0,0 +1,3 @@
+at9check
+at9check.exe
+__pycache__/
@@ -0,0 +1,115 @@
+// at9check: command-line harness for src/lib/at9 (the C++ snd0.at9 maker).
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+//   at9check IN OUT.at9 [SECONDS] [options]
+//     SECONDS          excerpt length (default 15; "max" or 0 = longest that fits)
+//     --start S        excerpt start (seconds)
+//     --bitrate K      72..192 kb/s
+//     --fade-in S / --fade-out S / --loudness L / --true-peak D
+//     --no-normalize / --no-loop
+//     --threads N      encoder threads (0 = all cores)
+//     --dump-pcm F     write the processed excerpt as raw float64 (left block, then right block)
+//     --preview F      write the processed excerpt as 16-bit WAV (wav_bytes)
+//   at9check --encode-raw PCM.f64 OUT.at9 [--bitrate K] [--no-loop] [--threads N]
+//     encode raw planar float64 stereo 48 kHz PCM (left block, then right block) directly.
+#include "../../src/lib/at9/at9.h"
+
+#include <chrono>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <fstream>
+#include <iterator>
+#include <stdexcept>
+#include <string>
+#include <vector>
+
+static std::vector<uint8_t> read_file(const std::string &p) {
+    std::ifstream f(p, std::ios::binary);
+    if (!f) throw std::runtime_error("cannot read " + p);
+    return std::vector<uint8_t>((std::istreambuf_iterator<char>(f)), std::istreambuf_iterator<char>());
+}
+
+static void write_file(const std::string &p, const void *d, size_t n) {
+    std::ofstream f(p, std::ios::binary);
+    f.write((const char *)d, (std::streamsize)n);
+    if (!f) throw std::runtime_error("cannot write " + p);
+}
+
+int main(int argc, char **argv) {
+    try {
+        std::vector<std::string> pos;
+        at9::Options o;
+        unsigned threads = 0;
+        std::string dump, preview, raw;
+        for (int i = 1; i < argc; i++) {
+            std::string a = argv[i];
+            auto next = [&]() -> std::string {
+                if (i + 1 >= argc) throw std::runtime_error("missing value for " + a);
+                return argv[++i];
+            };
+            if (a == "--start") o.start_sec = std::atof(next().c_str());
+            else if (a == "--bitrate") o.bitrate_kbps = std::atoi(next().c_str());
+            else if (a == "--fade-in") o.fade_in = std::atof(next().c_str());
+            else if (a == "--fade-out") o.fade_out = std::atof(next().c_str());
+            else if (a == "--loudness") o.lufs = std::atof(next().c_str());
+            else if (a == "--true-peak") o.true_peak_db = std::atof(next().c_str());
+            else if (a == "--no-normalize") o.normalize = false;
+            else if (a == "--no-loop") o.loop = false;
+            else if (a == "--threads") threads = (unsigned)std::atoi(next().c_str());
+            else if (a == "--dump-pcm") dump = next();
+            else if (a == "--preview") preview = next();
+            else if (a == "--encode-raw") raw = next();
+            else pos.push_back(a);
+        }
+        if (!raw.empty()) {
+            if (pos.size() != 1) throw std::runtime_error("usage: at9check --encode-raw PCM.f64 OUT.at9");
+            std::vector<uint8_t> b = read_file(raw);
+            size_t n = b.size() / 16;
+            std::vector<double> l(n), r(n);
+            std::memcpy(l.data(), b.data(), n * 8);
+            std::memcpy(r.data(), b.data() + n * 8, n * 8);
+            auto t0 = std::chrono::steady_clock::now();
+            std::vector<uint8_t> data = at9::detail::encode_atrac9(l, r, o.bitrate_kbps, threads);
+            std::vector<uint8_t> file = at9::detail::build_at9(o.bitrate_kbps, (uint32_t)n, data, o.loop);
+            double dt = std::chrono::duration<double>(std::chrono::steady_clock::now() - t0).count();
+            write_file(pos[0], file.data(), file.size());
+            std::printf("{\"bytes\": %zu, \"samples\": %zu, \"encode_seconds\": %.3f}\n", file.size(), n, dt);
+            return 0;
+        }
+        if (pos.size() < 2 || pos.size() > 3) {
+            std::fprintf(stderr, "usage: at9check IN OUT.at9 [SECONDS|max] [options]\n");
+            return 2;
+        }
+        if (pos.size() == 3) o.duration_sec = pos[2] == "max" ? 0 : std::atof(pos[2].c_str());
+        auto t0 = std::chrono::steady_clock::now();
+        std::vector<uint8_t> bytes = read_file(pos[0]);
+        at9::Audio audio;
+        std::string err;
+        if (!at9::decode_file(bytes, audio, err)) throw std::runtime_error(err);
+        auto t1 = std::chrono::steady_clock::now();
+        std::vector<double> l, r;
+        at9::Result res = at9::detail::make_snd0_ex(audio, o, &l, &r, threads);
+        auto t2 = std::chrono::steady_clock::now();
+        write_file(pos[1], res.at9.data(), res.at9.size());
+        if (!dump.empty()) {
+            std::vector<double> both(l);
+            both.insert(both.end(), r.begin(), r.end());
+            write_file(dump, both.data(), both.size() * 8);
+        }
+        if (!preview.empty()) {
+            std::vector<uint8_t> w = at9::wav_bytes(res.processed);
+            write_file(preview, w.data(), w.size());
+        }
+        std::printf("{\"input_rate\": %d, \"input_channels\": %d, \"input_frames\": %zu, \"bytes\": %zu, "
+                    "\"seconds\": %.6f, \"loudness_param\": \"%s\", \"decode_seconds\": %.3f, "
+                    "\"make_snd0_seconds\": %.3f}\n",
+                    audio.rate, audio.channels, audio.pcm.size() / (audio.channels ? audio.channels : 1),
+                    res.at9.size(), res.seconds, res.loudness_param.c_str(),
+                    std::chrono::duration<double>(t1 - t0).count(), std::chrono::duration<double>(t2 - t1).count());
+        return 0;
+    } catch (const std::exception &e) {
+        std::fprintf(stderr, "error: %s\n", e.what());
+        return 1;
+    }
+}
@@ -0,0 +1,16 @@
+#!/bin/sh
+# Build the at9check harness. Usage: tools/at9check/build.sh [g++|x86_64-w64-mingw32-g++]
+set -e
+here=$(cd "$(dirname "$0")" && pwd)
+root=$(cd "$here/../.." && pwd)
+cxx=${1:-${CXX:-g++}}
+out="$here/at9check"
+extra="-pthread"
+case "$cxx" in
+  *mingw*) out="$here/at9check.exe"; extra="-static -pthread" ;;
+esac
+"$cxx" -std=c++17 -O2 -Wall -Wextra -Wno-unused-function \
+  "$here/at9check.cpp" "$root"/src/lib/at9/at9_encoder.cpp "$root"/src/lib/at9/at9_snd0.cpp \
+  "$root"/src/lib/at9/at9_decode.cpp "$root"/src/lib/at9/at9_tables.cpp \
+  -o "$out" $extra
+echo "built $out"
@@ -0,0 +1,233 @@
+#!/usr/bin/env python3
+# Compare the C++ snd0.at9 maker (tools/at9check) against the Python reference
+# (PS5 AT9 Converter, https://github.com/blackbearreloaded/ps5-at9-converter).
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+# Usage: tools/at9check/compare.py /path/to/ps5-at9-converter [WORKDIR]
+#
+# For each generated input it runs the Python CLI and the C++ harness with the
+# same options, then reports:
+#   - whether the .at9 files are byte-identical, and the first differing offset;
+#   - header (first 168 bytes / chunk layout) equality;
+#   - processed-PCM difference (C++ vs Python pipeline before encoding);
+#   - encoder-only identity: both encoders fed the very same PCM;
+#   - SNR of each decoded file (Python reference decoder) vs the processed input,
+#     and of the two decoded files vs each other;
+#   - file size vs the 2 MiB limit, and timings.
+import json
+import math
+import os
+import shutil
+import subprocess
+import sys
+import time
+
+import numpy as np
+
+REF = os.path.abspath(sys.argv[1] if len(sys.argv) > 1 else "/tmp/claude-0/at9")
+WORK = os.path.abspath(sys.argv[2] if len(sys.argv) > 2 else "at9check-work")
+HERE = os.path.dirname(os.path.abspath(__file__))
+EXE = os.path.join(HERE, "at9check")
+sys.path.insert(0, REF)
+
+from ps5at9 import at9file, atrac9, audio_io, dsp, wav  # noqa: E402
+from ps5at9.atrac9_encoder import Encoder  # noqa: E402
+
+RATE = 48000
+
+
+def write_wav_any(path, x, rate, kind):
+    """x: (channels, frames) float in [-1, 1]. kind: pcm16 | pcm24 | float32."""
+    x = np.atleast_2d(x)
+    ch, n = x.shape
+    inter = x.T
+    if kind == "float32":
+        payload, tag, bits = inter.astype("<f4").tobytes(), 3, 32
+    else:
+        bits = 16 if kind == "pcm16" else 24
+        scale = float(1 << (bits - 1))
+        ints = np.clip(np.round(inter * scale), -scale, scale - 1).astype("<i4")
+        payload = ints.astype("<i2").tobytes() if bits == 16 else \
+            np.ascontiguousarray(ints).view(np.uint8).reshape(n, ch, 4)[:, :, :3].tobytes()
+        tag = 1
+    import struct
+    w = bits // 8
+    fmt = struct.pack("<HHIIHH", tag, ch, rate, rate * ch * w, ch * w, bits)
+    body = b"WAVE" + b"fmt " + struct.pack("<I", len(fmt)) + fmt + b"data" + struct.pack("<I", len(payload)) + payload
+    if len(payload) & 1:
+        body += b"\0"
+    with open(path, "wb") as f:
+        f.write(b"RIFF" + struct.pack("<I", len(body)) + body)
+
+
+def make_inputs():
+    os.makedirs(WORK, exist_ok=True)
+    rng = np.random.default_rng(12345)
+    items = []
+
+    def add(name, x, rate, kind, args=(), seconds=None):
+        p = os.path.join(WORK, name)
+        write_wav_any(p, x, rate, kind)
+        items.append((name, p, list(args), seconds))
+
+    t = np.arange(20 * RATE) / RATE
+    f0, f1 = 30.0, 18000.0
+    sweep = 0.5 * np.sin(2 * np.pi * f0 * 20 / math.log(f1 / f0) * (np.exp(t / 20 * math.log(f1 / f0)) - 1))
+    add("sweep-48k-16.wav", np.vstack([sweep, sweep]), RATE, "pcm16")
+    add("noise-48k-f32.wav", np.clip(rng.standard_normal((2, 16 * RATE)) * 0.25, -1, 1), RATE, "float32")
+    t44 = np.arange(20 * 44100) / 44100
+    tones = sum(a * np.sin(2 * np.pi * f * t44 + p) for a, f, p in
+                ((0.2, 110, 0), (0.15, 220.5, 1), (0.1, 440, 2), (0.08, 1318.5, 0.3), (0.05, 3520, 0.7)))
+    env = 0.6 + 0.4 * np.sin(2 * np.pi * 0.5 * t44) ** 2
+    noise = rng.standard_normal((2, len(t44))) * 0.03
+    music = np.vstack([tones * env, np.roll(tones, 300) * env]) + noise
+    add("music-44k-24.wav", music, 44100, "pcm24")
+    add("silence-48k-16.wav", np.zeros((2, 10 * RATE)), RATE, "pcm16")
+    t2 = np.arange(2 * RATE) / RATE
+    add("short-2s-48k-16.wav", np.vstack([0.4 * np.sin(2 * np.pi * 660 * t2), 0.4 * np.sin(2 * np.pi * 990 * t2)]),
+        RATE, "pcm16")
+    t12 = np.arange(12 * RATE) / RATE
+    add("stereo-diff-48k-16.wav", np.vstack([0.5 * np.sin(2 * np.pi * 523.25 * t12),
+                                             np.clip(rng.standard_normal(len(t12)) * 0.2, -1, 1)]), RATE, "pcm16")
+    add("mono-22k-16.wav", 0.3 * np.sin(2 * np.pi * 300 * np.arange(8 * 22050) / 22050)[None, :], 22050, "pcm16")
+    # Loud music: exercises the true-peak limiter and an excerpt start.
+    add("loud-start-48k-16.wav", np.clip(np.vstack([music[0], music[1]])[:, :18 * 44100] * 3.0, -1, 1),
+        44100, "pcm16", args=["--start", "2.5"])
+    # Long input for the timing of an 85 s excerpt.
+    tl = np.arange(90 * RATE) / RATE
+    long = 0.3 * np.sin(2 * np.pi * 220 * tl) * (0.5 + 0.5 * np.sin(2 * np.pi * 0.1 * tl)) + \
+        rng.standard_normal((2, len(tl))) * 0.02
+    add("long-90s-48k-16.wav", long, RATE, "pcm16", seconds="85")
+    ff = shutil.which("ffmpeg")
+    if ff:
+        src = os.path.join(WORK, "music-44k-24.wav")
+        mp3 = os.path.join(WORK, "music.mp3")
+        subprocess.run([ff, "-loglevel", "error", "-y", "-i", src, "-c:a", "libmp3lame", "-b:a", "192k", mp3],
+                       check=True)
+        items.append(("music.mp3", mp3, [], None))
+        flac = os.path.join(WORK, "music.flac")
+        subprocess.run([ff, "-loglevel", "error", "-y", "-i", src, "-c:a", "flac", flac], check=True)
+        items.append(("music.flac", flac, [], None))
+        aiff = os.path.join(WORK, "music.aiff")
+        subprocess.run([ff, "-loglevel", "error", "-y", "-i", src, "-c:a", "pcm_s16be", aiff], check=True)
+        items.append(("music.aiff", aiff, [], None))
+    for name in ("tone-44k-stereo.mp3", "tone-44k.flac"):
+        p = os.path.join(REF, "tests", "data", name)
+        if os.path.exists(p):
+            items.append((name, p, [], None))
+    return items
+
+
+def py_processed(path, start=0.0, duration=15.0, bitrate=192, loop=True):
+    """The Python CLI pipeline up to the encoder (mirrors ps5at9/cli.py run())."""
+    max_samples = (2 * 1024 * 1024 - at9file.header_size(loop)) // (bitrate * 1000 * 256 // (8 * RATE) * 4) \
+        * 1024 - 256
+    pcm, rate, offset = audio_io.load(path, start, duration)
+    pcm = dsp.resample(dsp.to_stereo(pcm), rate, RATE)
+    skip = int(round(offset * RATE))
+    available = max(0, pcm.shape[1] - skip)
+    count = min(available, max_samples) if duration is None else min(available, int(round(duration * RATE)))
+    pcm = np.ascontiguousarray(pcm[:, skip:skip + count])
+    lufs = dsp.integrated_loudness(pcm)
+    if math.isfinite(lufs):
+        pcm = pcm * 10.0 ** ((-28.0 - lufs) / 20.0)
+    pcm, _ = dsp.limit_true_peak(pcm, -2.0, RATE)
+    return dsp.apply_fades(pcm, RATE, 0.01, 0.01)
+
+
+def decode(blob):
+    info = at9file.read_at9(blob)
+    out = atrac9.Decoder(info.config).decode(info.data)
+    return info, out[:, 256:256 + info.sample_count] / 32768.0
+
+
+def snr(ref, test):
+    num = float(np.sum(ref ** 2))
+    den = float(np.sum((ref - test) ** 2))
+    if den == 0:
+        return math.inf
+    if num == 0:
+        return -math.inf
+    return 10 * math.log10(num / den)
+
+
+def chunks(blob):
+    out, pos = [], 12
+    import struct
+    while pos + 8 <= len(blob):
+        cid, size = blob[pos:pos + 4], struct.unpack_from("<I", blob, pos + 4)[0]
+        out.append((cid.decode("latin-1"), size))
+        pos += 8 + size + (size & 1)
+    return out
+
+
+def main():
+    if not os.path.exists(EXE):
+        sys.exit("build the harness first: tools/at9check/build.sh")
+    results = []
+    all_ok = True
+    for name, path, args, seconds in make_inputs():
+        stem = os.path.join(WORK, name.replace(".", "_"))
+        py_out, cpp_out = stem + ".py.at9", stem + ".cpp.at9"
+        dur = seconds or "15"
+        py_args = ["-q", "--duration", dur] + args
+        t0 = time.time()
+        subprocess.run([sys.executable, os.path.join(REF, "ps5_at9.py"), "-i", path, "-o", py_out] + py_args,
+                       check=True)
+        py_time = time.time() - t0
+        cpp = subprocess.run([EXE, path, cpp_out, dur, "--dump-pcm", stem + ".cpp.f64"] + args,
+                             check=True, capture_output=True, text=True)
+        meta = json.loads(cpp.stdout)
+        a, b = open(py_out, "rb").read(), open(cpp_out, "rb").read()
+        r = {"input": name, "bytes": len(b), "py_bytes": len(a), "identical": a == b,
+             "cpp_seconds": meta["make_snd0_seconds"], "py_seconds": round(py_time, 2),
+             "excerpt_s": meta["seconds"], "loudness_param": meta["loudness_param"]}
+        if a != b:
+            diff = next((i for i in range(min(len(a), len(b))) if a[i] != b[i]), min(len(a), len(b)))
+            r["first_diff"] = diff
+            r["differing_superframes"] = int(sum(a[168 + i * 512:168 + (i + 1) * 512] != b[168 + i * 512:168 + (i + 1) * 512]
+                                                 for i in range((len(b) - 168) // 512)))
+        r["header_identical"] = a[:168 - 4] == b[:168 - 4] and chunks(a) == chunks(b)
+        r["size_ok"] = len(b) <= 2 * 1024 * 1024
+        # processed PCM: C++ vs Python pipeline
+        start = float(args[args.index("--start") + 1]) if "--start" in args else 0.0
+        ref = py_processed(path, start, float(dur))
+        raw = np.fromfile(stem + ".cpp.f64", dtype="<f8")
+        cpp_pcm = raw.reshape(2, -1)
+        r["pcm_max_abs_diff"] = float(np.max(np.abs(cpp_pcm - ref))) if cpp_pcm.shape == ref.shape else "shape"
+        # Encoder only: both encoders on the C++-processed PCM.
+        enc = Encoder(2, 192)
+        py_data = enc.encode(cpp_pcm * 32768.0)
+        py_blob = at9file.build_at9(enc.config, 2, cpp_pcm.shape[1], py_data)
+        raw_out = stem + ".raw.at9"
+        subprocess.run([EXE, "--encode-raw", stem + ".cpp.f64", raw_out], check=True, capture_output=True)
+        raw_blob = open(raw_out, "rb").read()
+        r["encoder_only_identical"] = raw_blob == py_blob
+        if raw_blob != py_blob:
+            # Same input PCM: the streams must at least decode to the same audio
+            # (different but equivalent parameter choices; see README notes).
+            _i, d1 = decode(raw_blob)
+            _i, d2 = decode(py_blob)
+            r["encoder_only_decoded_max_diff"] = float(np.max(np.abs(d1 - d2)))
+        # Decode both with the Python reference decoder.
+        info_c, dec_c = decode(b)
+        _info_p, dec_p = decode(a)
+        r["snr_cpp_vs_input_db"] = round(snr(cpp_pcm, dec_c), 2)
+        r["snr_py_vs_input_db"] = round(snr(ref, dec_p), 2) if ref.shape == dec_p.shape else None
+        r["snr_cpp_vs_py_decoded_db"] = round(snr(dec_p, dec_c), 2) if dec_p.shape == dec_c.shape else None
+        ok = r["header_identical"] and r["size_ok"] and (
+            r["encoder_only_identical"] or r["encoder_only_decoded_max_diff"] < 1e-6)
+        if not r["identical"] and r["snr_cpp_vs_py_decoded_db"] != math.inf:
+            # Must stay well below the coding noise.
+            ok = ok and r["snr_cpp_vs_py_decoded_db"] is not None and \
+                r["snr_cpp_vs_py_decoded_db"] > r["snr_cpp_vs_input_db"] + 10
+        r["ok"] = ok
+        all_ok &= ok
+        results.append(r)
+        print(json.dumps(r), flush=True)
+    print("ALL OK" if all_ok else "SOME CHECKS FAILED")
+    return 0 if all_ok else 1
+
+
+if __name__ == "__main__":
+    sys.exit(main())
@@ -0,0 +1,102 @@
+#!/usr/bin/env python3
+# Generate src/lib/at9/at9_tables.{h,cpp} from ps5at9/atrac9_tables.py
+# (PS5 AT9 Converter, which converted them from LibAtrac9, MIT License,
+# Copyright (c) 2018 Alex Barney).
+#
+# Usage: tools/at9check/gen_tables.py /path/to/ps5-at9-converter src/lib/at9
+import os
+import sys
+
+src, dst = sys.argv[1], sys.argv[2]
+sys.path.insert(0, src)
+from ps5at9 import atrac9_tables as T  # noqa: E402
+
+LICENSE = open(os.path.join(src, "third_party", "LibAtrac9.LICENSE.txt")).read().strip()
+HEAD = """// ATRAC9 constant tables, converted from LibAtrac9
+// (https://github.com/Thealexbarney/LibAtrac9) via ps5at9/atrac9_tables.py of
+// PS5 AT9 Converter. Generated by tools/at9check/gen_tables.py; do not edit.
+//
+// SPDX-License-Identifier: MIT
+//
+""" + "\n".join(("// " + l).rstrip() for l in LICENSE.splitlines()) + "\n"
+
+
+def ints(v, per=20):
+    v = list(v)
+    rows = [", ".join(str(x) for x in v[i:i + per]) for i in range(0, len(v), per)]
+    return "{\n    " + ",\n    ".join(rows) + "\n}" if v else "{0}"
+
+
+def dbls(v):
+    return "{" + ", ".join(repr(float(x)) for x in v) + "}"
+
+
+maxcode = max(max(c) for b, c in list(T.SF_UNSIGNED.values()) + list(T.SF_SIGNED.values()))
+maxcode = max(maxcode, max(max(c) for _p, _b, c in T.SPECTRUM.values()))
+assert maxcode < 65536
+
+h = [HEAD, "#pragma once", "#include <cstdint>", "", "namespace at9 {", "namespace tables {", "",
+     "struct Huff { int size; int value_count_power; const uint8_t *bits; const uint16_t *codes; };", "",
+     "// Scale factor codebooks indexed by word length (unsigned 1..6, signed 2..5); size 0 = absent.",
+     "extern const Huff SF_UNSIGNED[7];", "extern const Huff SF_SIGNED[6];",
+     "// Spectrum codebooks [codebook set][word length 0..7][codebook index]; size 0 = absent.",
+     "extern const Huff SPECTRUM[2][8][4];",
+     "extern const int SF_WEIGHTS[8][32];",
+     "extern const int GRADIENT_MAIN[%d];" % len(T.GRADIENT_MAIN),
+     "// Band extension tables (decoder only).",
+     "extern const int BEX_GROUP_INFO[8][3];", "extern const int BEX_VALUE_COUNTS[5][6];",
+     "extern const int BEX_DATA_LENGTHS[5][6][4];",
+     "extern const double BEX_MODE0_BANDS3[5][32];", "extern const double BEX_MODE0_BANDS4[5][16];",
+     "extern const double BEX_MODE0_BANDS5[3][32];",
+     "extern const double BEX_MODE2_SCALE[%d];" % len(T.BEX_MODE2_SCALE),
+     "extern const double BEX_MODE3_INITIAL[%d];" % len(T.BEX_MODE3_INITIAL),
+     "extern const double BEX_MODE3_RATE[%d];" % len(T.BEX_MODE3_RATE),
+     "extern const double BEX_MODE4_MULTIPLIER[%d];" % len(T.BEX_MODE4_MULTIPLIER),
+     "", "} // namespace tables", "} // namespace at9", ""]
+
+c = [HEAD, '#include "at9_tables.h"', "", "namespace at9 {", "namespace tables {", ""]
+
+
+def book(name, bits, codes, vcp):
+    c.append("static const uint8_t %s_bits[] = %s;" % (name, ints(bits)))
+    c.append("static const uint16_t %s_codes[] = %s;" % (name, ints(codes)))
+    return "{%d, %d, %s_bits, %s_codes}" % (len(bits), vcp, name, name)
+
+
+refs = {}
+for n, (b, cc) in sorted(T.SF_UNSIGNED.items()):
+    refs[n] = book("sfu%d" % n, b, cc, 0)
+c.append("const Huff SF_UNSIGNED[7] = {{0, 0, nullptr, nullptr}, %s};" %
+         ", ".join(refs.get(n, "{0, 0, nullptr, nullptr}") for n in range(1, 7)))
+refs = {}
+for n, (b, cc) in sorted(T.SF_SIGNED.items()):
+    refs[n] = book("sfs%d" % n, b, cc, 0)
+c.append("const Huff SF_SIGNED[6] = {%s};" % ", ".join(refs.get(n, "{0, 0, nullptr, nullptr}") for n in range(6)))
+refs = {}
+for (s, w, ci), (p, b, cc) in sorted(T.SPECTRUM.items()):
+    refs[(s, w, ci)] = book("sp%d_%d_%d" % (s, w, ci), b, cc, p)
+rows = []
+for s in range(2):
+    ws = []
+    for w in range(8):
+        ws.append("{" + ", ".join(refs.get((s, w, ci), "{0, 0, nullptr, nullptr}") for ci in range(4)) + "}")
+    rows.append("{" + ",\n  ".join(ws) + "}")
+c.append("const Huff SPECTRUM[2][8][4] = {\n " + ",\n ".join(rows) + "};")
+c.append("const int SF_WEIGHTS[8][32] = {%s};" % ",\n    ".join(ints(r, 32) for r in T.SF_WEIGHTS))
+c.append("const int GRADIENT_MAIN[%d] = %s;" % (len(T.GRADIENT_MAIN), ints(T.GRADIENT_MAIN, 48)))
+c.append("const int BEX_GROUP_INFO[8][3] = {%s};" % ", ".join(ints(r) for r in T.BEX_GROUP_INFO))
+c.append("const int BEX_VALUE_COUNTS[5][6] = {%s};" % ", ".join(ints(r) for r in T.BEX_VALUE_COUNTS))
+c.append("const int BEX_DATA_LENGTHS[5][6][4] = {%s};" %
+         ", ".join("{" + ", ".join(ints(x) for x in r) + "}" for r in T.BEX_DATA_LENGTHS))
+for name, rows_, w in (("BEX_MODE0_BANDS3", T.BEX_MODE0_BANDS3, 32), ("BEX_MODE0_BANDS4", T.BEX_MODE0_BANDS4, 16),
+                       ("BEX_MODE0_BANDS5", T.BEX_MODE0_BANDS5, 32)):
+    c.append("const double %s[%d][%d] = {%s};" % (name, len(rows_), w, ",\n    ".join(dbls(r) for r in rows_)))
+for name in ("BEX_MODE2_SCALE", "BEX_MODE3_INITIAL", "BEX_MODE3_RATE", "BEX_MODE4_MULTIPLIER"):
+    v = getattr(T, name)
+    c.append("const double %s[%d] = %s;" % (name, len(v), dbls(v)))
+c += ["", "} // namespace tables", "} // namespace at9", ""]
+
+with open(os.path.join(dst, "at9_tables.h"), "w") as f:
+    f.write("\n".join(h))
+with open(os.path.join(dst, "at9_tables.cpp"), "w") as f:
+    f.write("\n".join(c))
@@ -0,0 +1,30 @@
+#!/usr/bin/env python3
+"""Regenerate src/presets_embed.cpp from assets/presets/<App name>/<TITLE ID>/<n>.png (preset icons).
+Run from the repository root:  python3 tools/embed_presets.py"""
+import os, re
+
+root = "assets/presets"
+items = []
+for app in sorted(os.listdir(root)):
+    for tid in sorted(os.listdir(os.path.join(root, app))):
+        d = os.path.join(root, app, tid)
+        if not os.path.isdir(d) or not re.fullmatch(r"[A-Z]{4}\d{5}", tid): continue
+        names = sorted((n for n in os.listdir(d) if n.lower().endswith(".png")),
+                       key=lambda n: (int(m.group()) if (m := re.match(r"\d+", n)) else 1 << 30, n))
+        for n in names: items.append((app, tid, os.path.join(d, n)))
+
+out = ["// Generated by tools/embed_presets.py - do not edit.",
+       "#include <cstddef>", '#include "presets.h"']
+for i, (_, _, path) in enumerate(items):
+    data = open(path, "rb").read()
+    out.append(f"static const unsigned char p{i}[] = {{")
+    for j in range(0, len(data), 24):
+        out.append("  " + ",".join(str(b) for b in data[j:j + 24]) + ",")
+    out.append("};")
+out.append("extern const Preset PRESETS[] = {")
+for i, (app, tid, _) in enumerate(items):
+    out.append(f'  {{"{app}", "{tid}", p{i}, sizeof p{i}}},')
+out.append("};")
+out.append(f"extern const size_t PRESETS_COUNT = {len(items)};")
+open("src/presets_embed.cpp", "w").write("\n".join(out) + "\n")
+print(f"wrote src/presets_embed.cpp ({len(items)} icons)")