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feat: decode H.265 and AV1 with NVDEC on Linux - #353
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The NVDEC decoders decoded H.264 and VP9. They now decode H.265 (Main profile) and AV1 (profile 0) as well, where the GPU does (AV1 since Ampere), asking the driver which codecs it decodes. NVDEC's parser takes the bitstream, so a codec is mostly a matter of telling it which. NVDEC's AV1 parser takes temporal units, which begin with a temporal delimiter, and WebRTC's AV1 frames come without one, so one is put in front. Frames of AV1 spatial layers above the first go to dav1d, as those of VP9 go to libvpx. H.265 has no software decoder to fall back to: what NVDEC cannot decode is an error, and WebRTC asks for a key frame. With NVENC's H.265, NVIDIA GPUs on Linux now carry H.265 calls both ways.
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Brings in the work upstream added from October 11 to 15: hardware video codecs on every platform, through Media Foundation, VideoToolbox, VA-API and NVDEC, with WebRTC built with H.265 (devopvoid#346 to devopvoid#348, devopvoid#352, devopvoid#353, devopvoid#356, devopvoid#359, devopvoid#371 to devopvoid#377); HEVC and AV1 decoding in the media player, with dav1d and Vulkan Video (devopvoid#331, devopvoid#345); encoded frame injectors (devopvoid#365); receiver source changes and audio packet infos (devopvoid#366); audio codec factories (devopvoid#340); network thread observers called on a callback thread (devopvoid#364); screen capture with ScreenCaptureKit (devopvoid#354); Windows audio devices that mix more than two channels (devopvoid#358); autoninja (devopvoid#357); and the release channels of the docs site (devopvoid#361). Fork-side adaptations: - The factory keeps the CreatePeerConnectionFactory overload without a worker thread, and still switches device capture on the network thread. devopvoid#355 copies WebRTC's factory setup and has the audio module learn a worker thread, which only matters for a worker thread distinct from the network thread, and WebRTC is removing those. The audio codec factories and hardware codec switches of devopvoid#340 and devopvoid#359 go to that overload. - WebRTC stays on a commit on main, so the move to branch 8059 (devopvoid#360) and its fixed clang package are left out. - The data channels variant builds WebRTC without H.265 and without the extra targets, leaves out the audio codec factory bindings and addTransceiverOfType, and skips the new tests that need audio or video. - dav1d is built against the sysroot on native Linux builds as well, as FFmpeg is. CI installs Meson for the full variant only, checks out the dav1d submodule, and adds its commit to the FFmpeg cache key. The fork's Windows SDK step stays, without upstream's second one. - The release workflow records the docs' version in the tagged commit, as upstream's now does. The docs site still builds from main, since this fork publishes none. - The Maven files stay deleted: Jetty is bumped in the version catalog, and the docs lockfile takes upstream's bumps on top of the fork's newer VitePress. - The media module's README builds with Gradle.
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Summary
Brings #350 to
main. #350 was merged intofeat/windows-hevc-codecsafter that branch had already gone tomainwith #347, so its change never reachedmain. This is its squash commit (931b5e8) applied tomain; the only codec code that differs betweenmainand #350's base is #348's VP9 encoder, which touches no NVDEC or Linux file.The NVDEC decoders on Linux decoded H.264 and VP9. They now decode H.265 (Main profile) and AV1 (profile 0) too, where the GPU does (AV1 since Ampere):
NvdecLibraryasks the driver (cuvidGetDecoderCaps) for H.265 and AV1 as it does for the others, and the factory offers what the GPU decodes: H.265 in theH265Formatof feat: encode and decode H.265 in hardware on Windows #347, AV1 in profile 0.With NVENC's H.265 from #347, an NVIDIA GPU on Linux now carries H.265 calls both ways.
Rebased onto
mainafter #352: where both describe Linux decoding (the hardware decoding table in the codec guide, the Javadoc ofHardwareVideoDecoderFactoryand the comment inLinuxHardwareVideoCodecFactories.cpp), the text now names NVDEC's four codecs and VA-API's VP9 decoder, when turned on. The code is #350's as it was.Testing
hardwareDecodesH265andhardwareCropsPaddedH265with NVENC and NVDEC, and the AV1 decoder tests.Not verified
Nothing here has run on an NVIDIA GPU under Linux: there is none here, and CI has no GPU, where the hardware tests skip. In particular whether NVDEC's AV1 parser needs the temporal delimiter, which is harmless if it does not.