dasVideo

Video playback for daslang — decode a video file to frames

• audio and hand them to your renderer, with A/V sync. A native C++ backend with a thin daslang surface, modeled on dasVulkan / dasImgui.

Status: playable. MPEG-1 video + MP2 audio decode, OpenGL output (RGBA and YUV-shader routes), and A/V-synced playback with sound all work on Windows / Linux / macOS. Next: a dasImgui embed, then the dav1d (AV1) backend. See ROADMAP.md.

Design

• Decode: pl_mpeg (MPEG-1) → dav1d (AV1). Royalty-free, permissively-licensed codecs only.
• Output: the player owns, the consumer borrows — per-frame pixels via RAII block accessors: get_data() $(rgb : array<uint8>#) { ... } (RGBA8) or get_data() $(y, u, v : array<uint8>#) { ... } (native YUV planes).
• Audio + sync via dasAudio — push PCM, drive video off the audio clock.

Full rationale: ORIGINAL_PLAN.md. Phased checklist: ROADMAP.md.

Licensing — two gates, both kept green

dasVideo ships only codecs that are both royalty-free (no codec patent dues) and permissively licensed:

Codec	Patents	Code
MPEG-1 + MP2	expired (~2012)	pl_mpeg — MIT
AV1 + Opus / Vorbis	royalty-free by design	dav1d BSD-2, libopus/libvorbis BSD (P5)

Out of scope by design: FFmpeg (bind it yourself if you need it), H.264 / H.265 / AAC (patent pools), Ogg / Theora (a separate repo on demand).

Vendored dependencies

What	Version	License
pl_mpeg	master	MIT

Build

The native module links a daslang SDK; point DASLANG_DIR at its root (include/ + lib/):

cmake -S . -B _build -DCMAKE_BUILD_TYPE=Release -DDASLANG_DIR=<daslang-root>
cmake --build _build --config Release

Output: <repo>/dasModuleVideo.shared_module. Run a script against it:

daslang -load_module <repo> tests/test_video.das

The daslang binary must be a DLL build (das_is_dll_build() true) — the .das_module only loads the native module under that flag. As a daspkg package, consumers just daspkg install github.com/borisbat/dasVideo (registered once it decodes — ROADMAP P6).

Examples

Windowed players (need a display; the audio one also needs an audio device — so they run by hand, not in CI). They loop by default and take a clargs CLI (--video, --scale, --max-frames, --shot out.png, --noloop, --help):

daslang -load_module <repo> examples/play_rgba_gl.das    # RGBA → one texture
daslang -load_module <repo> examples/play_yuv_gl.das     # native YUV planes → GPU YUV→RGB
daslang -load_module <repo> examples/play_audio_gl.das   # video + sound, A/V synced (--mute to pace by wall-clock)

License

MIT — see LICENSE.