ayka-667--SysDVRClient-PS4/README.md

SysDVR for PS4

Play your Nintendo Switch on your TV through a jailbroken PS4, no dock needed.

SysDVR-PS4 is a PS4 homebrew port of the SysDVR client. The Switch runs the SysDVR sysmodule and streams its screen and sound over Wi-Fi. The PS4 receives the stream, decodes it and shows it on the TV it's plugged into.

 ┌──────────────┐   Wi-Fi / LAN    ┌──────────────┐   HDMI   ┌──────┐
 │ Nintendo     │  TCP 9911 video  │ PS4          │ ───────► │  TV  │
 │ Switch       │ ───────────────► │ SysDVR-PS4   │          └──────┘
 │ (SysDVR)     │  TCP 9922 audio  │ (.pkg)       │
 └──────────────┘  UDP 19999 disc. └──────────────┘

⚠️ Status: experimental. The protocol, H.264 decoding, scaling and audio code was tested on a PC against a simulated Switch (see Testing). The app has not yet been tested on real PS4 hardware. Please open an issue with your log.txt if something goes wrong.

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Features

• 📡 Automatic discovery: finds the Switch on your network (SysDVR's UDP broadcast), no IP needed
• 🎮 Manual IP entry with the controller if your network blocks broadcasts
• 🎞️ 720p ~30 fps H.264, software decoding (FFmpeg, multithreaded, SSE/AVX optimised for the PS4's Jaguar CPU)
• ⚡ Low latency: the socket is always drained on its own thread, and if decoding falls behind the app skips to the next keyframe instead of piling up delay
• 🖥️ Fullscreen 1080p (scaled) or 1:1 720p
• 🔊 Audio, 48 kHz stereo PCM with a low-latency jitter buffer
• 🔁 Auto-reconnects if the Wi-Fi drops or the Switch goes to sleep
• 💡 Option to turn off the Switch's screen while streaming (SysDVR 6.1+)
• 📊 On-screen stats (fps, bitrate, decoder load, delay, skipped frames, audio buffer)
• ⚙️ Settings saved to /data/sysdvr-ps4/config.ini

Requirements

Switch

• A Switch with custom firmware (Atmosphère) and the SysDVR sysmodule installed (5.x / 6.x, protocol 02 or 03).
• SysDVR set to TCP Bridge mode (network). USB mode and "Simple network / RTSP" mode won't work.

PS4

• A jailbroken PS4 (GoldHEN or similar) that can install fake PKGs (debug settings → Package Installer).
• Connected to the same local network as the Switch. Wired Ethernet on the PS4 is recommended.

Installation

1. Download IV0000-SDVR00001_00-SYSDVRPS4CLIENT0.pkg from the Releases page.
2. Copy it to a FAT32/exFAT USB drive (or send it with a remote package installer).
3. On the PS4: Settings → Debug Settings → Game → Package Installer, pick the pkg.
4. The SysDVR PS4 app shows up on the home screen.

Usage

1. On the Switch: open the SysDVR Settings homebrew and choose TCP Bridge. Reboot if it asks you to.
2. Make sure the Switch and the PS4 are on the same Wi-Fi network / router.
3. On the PS4: start SysDVR PS4. It searches for the Switch and connects on its own.
4. Launch a game on the Switch. The picture appears on the TV.

SysDVR only captures games. The Switch home menu and some applets are not streamed, so a black or "waiting" screen is normal until a game is running. A few games block capture entirely.

Controls

Button	Action
OPTIONS	Open / close the settings menu
△ Triangle	Show / hide stats (see Stats overlay)
□ Square	Toggle fullscreen (1080p) / 1:1 (720p)
✕ Cross	Reconnect (when not connected)
PS button	Return to the PS4 home screen

Settings menu: D-pad Up/Down to select, Left/Right or ✕ to change, ○ to close.

IP editor: Left/Right picks the octet, Up/Down changes it by 1, L1/R1 by 10, ✕ saves, □ switches back to automatic discovery, ○ cancels.

Settings (/data/sysdvr-ps4/config.ini)

The file is created on first launch. Edit it over FTP or change the values from the in-app menu.

Key	Default	Description
ip	auto	Switch IP address, or auto for discovery
threads	2	H.264 decoder threads (1–6). Each extra thread decodes faster but adds about 33 ms (one frame) of latency. 1 gives the lowest latency if your PS4 keeps up.
fast	0	1 skips the deblocking filter. Much faster decoding, slightly blockier picture. It is also switched on automatically while the decoder is catching up.
smooth	1	Bilinear scaling. 0 uses the cheaper fast-bilinear scaler.
max_delay_ms	150	When decoded video falls this far behind, queued frames are dropped and decoding restarts at the next keyframe.
audio	1	Enable sound
fullscreen	1	Scale to 1080p (0 = native 720p, centred)
screen_off	0	Turn off the Switch screen while streaming (SysDVR 6.1+)
audio_batch	0	SysDVR audio batching (0–3). Each step adds ~21 ms of audio per packet, so 0 is the lowest latency.
audio_buffer_ms	60	Target audio buffer. Raise it if the sound crackles, lower it for less delay.

Config files from 1.0 are upgraded automatically: threads, audio_batch and audio_buffer_ms are reset to the new low-latency defaults once.

Stats overlay

Press △ while streaming:

Field	Meaning
fps / Mbit/s	Frames decoded per second and stream bitrate
decode	Average time the decoder thread spends per frame. Close to 33 ms means the PS4 is at its limit: try fast or more threads.
delay	Extra delay of the shown frame compared to the fastest frame of this session (network + queue + decoding)
queue / skipped	Frames waiting to be decoded / frames dropped to catch up. skipped going up all the time means the decoder is too slow.
audio / underruns	Audio buffered right now / times the buffer ran dry (crackles). Raise audio_buffer_ms if underruns keeps going up.

A log is written to /data/sysdvr-ps4/log.txt.

Troubleshooting

Problem	Fix
Stuck on "Searching for the Switch on the network..."	Broadcasts may be blocked (guest Wi-Fi, AP isolation, mesh). Enter the Switch IP by hand (System Settings → Internet on the Switch).
"Unexpected reply: is SysDVR in TCP Bridge mode?"	SysDVR is in USB or RTSP mode. Switch it to TCP Bridge.
"Unsupported SysDVR protocol version"	Update SysDVR on the Switch to 5.5 or later.
Connected but black screen	Launch a game. The home menu isn't captured.
Video freezes for a moment now and then	The decoder fell behind and skipped to the next keyframe (skipped goes up in the stats). Turn on Fast decoding, set threads to 3, or turn off Smooth scaling.
Choppy video, skipped stays at 0	Network problem: use Ethernet on the PS4 and keep the Switch close to the router (5 GHz).
Too much latency	threads = 1 (if decode stays well under 33 ms), lower max_delay_ms and audio_buffer_ms.
Crackling sound	Raise audio_buffer_ms to 100–200.

How it works

SysDVR's TCP Bridge protocol (spec):

1. Discovery: every 2 s the Switch broadcasts SysDVR|<version>|<proto>|<serial> on UDP port 19999.
2. Connection: the client opens two sockets, 9911 (video) and 9922 (audio). The Switch sends the 10-byte hello SysDVR|03\0. The client replies with a 16-byte ProtoHandshakeRequest (magic 0xAAAAAAAA, version, stream flags, InjectPPSSPS). The Switch answers with a result code (4 bytes for proto 02, 72 bytes for proto 03).
3. Streaming: each packet has an 18-byte header (0xCCCCCCCC magic, size, timestamp, flags) followed by an H.264 access unit (Annex B) or 16-bit 48 kHz stereo PCM.

On the PS4 side:

Module	Role
src/sysdvr_proto.c	Discovery, connect with timeout, handshake (proto 02/03), packet reading and resync
src/video.c	Network thread (always drains the socket) → packet queue with catch-up (drops to the next keyframe when it gets older than max_delay_ms) → decoder thread, FFmpeg libavcodec H.264 (frame threads, deblocking skipped while behind) → libswscale YUV→BGRA scaling (sliced, multithreaded) written directly into the framebuffer
src/audio.c	Network thread → ring buffer with latency control → sceAudioOut (256-sample grains)
src/gfx.c	sceVideoOut triple-buffered 1920×1080 framebuffer (a new frame never waits for the previous vsync), text rendering with stb_easy_font
src/main.c	UI, DualShock 4 input, settings menu, IP editor, auto-discovery thread
src/util.c	Logging, config file

The Switch encodes H.264 High profile, CABAC, 1280×720. The PS4's hardware decoder (sceVideodec2) is barely documented for homebrew, so this port uses a trimmed-down FFmpeg (H.264 decoder only, ~2.6 MB) cross-compiled for the PS4 with its x86 SIMD (SSSE3/AVX) enabled.

Building from source

The build has been tested on Windows 11 + WSL (Debian 13). Plain Linux works too.

1. Prerequisites

• OpenOrbis PS4 Toolchain (copied to ~/ps4build/oo in WSL, or point OO_PS4_TOOLCHAIN at it)
• In Linux/WSL: clang lld llvm make nasm curl

  sudo apt install clang lld llvm make nasm curl
  

• On Windows, to package: the OpenOrbis Windows tools plus any .NET runtime ≥ 6

2. Build FFmpeg for the PS4 (once)

./toolchain/build_ffmpeg.sh        # -> ~/ps4build/ffmpeg-ps4

The script downloads FFmpeg 7.1.1, configures it for x86_64-pc-freebsd12 with the OpenOrbis sysroot (wrapper toolchain/ps4-cc), keeps only the H.264 decoder and swscale, and works around two PS4-specific issues (no sysctl/sched_getaffinity, and the FFmpeg 7.1 aom_film_grain link bug).

3. Build the app

Windows (WSL + Windows PkgTool):

powershell -ExecutionPolicy Bypass -File build.ps1

Linux:

make            # needs libssl1.1 for OpenOrbis' Linux PkgTool
# or just the gp4 + eboot, then package with another PkgTool:
make pkg.gp4

Output: IV0000-SDVR00001_00-SYSDVRPS4CLIENT0.pkg

Testing

make test builds the real video.c, audio.c and sysdvr_proto.c natively (PS4 APIs replaced by stubs in tests/stubs). It runs them against tests/fake_switch.py, a fake Switch that implements the SysDVR sysmodule side (UDP discovery, handshake 02/03, H.264 + PCM streaming). It runs two scenarios:

1. a normal decoder: nothing may be skipped, and the delay must stay low;
2. a decoder made artificially too slow for the stream (SYSDVR_TEST_DECODE_DELAY_MS=45): frames must be skipped, and the delay must stay bounded instead of growing.

sudo apt install ffmpeg libavcodec-dev libswscale-dev python3
make test
# ==> Real-time decoder
# ... frames decoded=255 rendered=239 skipped=0 ... delay avg=34 max=44 ms
# RESULT: OK
# ==> Decoder too slow for the stream (must skip frames, not build up latency)
# ... skipped=124 ... delay avg=123 max=200 ms
# RESULT: OK

You can also run python3 tests/fake_switch.py video.h264 on a PC and point the PS4 app at that PC's IP to test on a real PS4 without a Switch.

Project layout

├── src/                 PS4 app source (C)
├── tests/               fake Switch + native test harness + stubs
├── toolchain/           FFmpeg cross-build script and clang wrapper
├── tools/make_icon.py   generates sce_sys/icon0.png and pic1.png
├── sce_sys/             package metadata (icon, background, about)
├── sce_module/          libc.prx / libSceFios2.prx from OpenOrbis
├── Makefile             Linux/WSL build
└── build.ps1            one-click Windows build

Credits

• exelix11/SysDVR, the Switch sysmodule and the protocol this client implements (GPLv2)
• OpenOrbis PS4 Toolchain
• FFmpeg (LGPL 2.1+), statically linked
• stb_easy_font (public domain)

License

GPL-2.0, like SysDVR. See LICENSE.

This project is not affiliated with Nintendo or Sony. Only use it with hardware and games you own.