forked from unom/punktfunk
enricobuehler
28c50d1c5b
Three encode paths shipped a bitstream with no colour description at all, leaving primaries/transfer/matrix/range "unspecified": - Vulkan Video HEVC (`vk_build.rs`) built an SPS with no VUI whatsoever. This is the DEFAULT backend for AMD/Intel Linux hosts on HEVC/AV1. - Vulkan Video AV1 packed `color_description_present_flag = 0`. - The openh264 software path wrote nothing (it converts BT.709 limited and relied on decoders defaulting to that). - The libav-NVENC Linux path excluded packed-RGB 4:2:0, on the belief that "NVENC's internal CSC writes its own VUI". It doesn't: libavcodec derives `colourDescriptionPresentFlag` from the AVCodecContext colour fields, so leaving them unspecified emits none. Reachable on a CPU/dmabuf capture, a build without `--features nvenc`, or PUNKTFUNK_NVENC_DIRECT=0. Unsignalled looks fine on every punktfunk client — `csc_rows` falls back to BT.709 on "unspecified" — which is why this survived. Vendor TV decoders do not: they guess colorimetry from RESOLUTION, and an LG webOS panel reads a 4K SDR stream as BT.2020 and renders it visibly washed out. All four now signal BT.709 limited, which is what every host CSC actually produces (`rgb2yuv.comp`, `convert_bt709`, the swscale paths) and what the Welcome's `ColorInfo::SDR_BT709` already advertises out-of-band. NVENC, VAAPI, QSV, AMF and the Windows libav path were already correct. Two tests, both parsing the REAL emitted bitstream rather than re-asserting the constants: an independent bit-walk of the AV1 sequence header (the packed OBU must stay identical to the `StdVideoAV1ColorConfig` handed to the driver), and an H.264 SPS/VUI parse proving openh264 honours the request instead of dropping it. Not yet verified on hardware: the HEVC VUI depends on the driver's SPS writer emitting `vui_parameters()`. PUNKTFUNK_VULKAN_ENCODE=0 falls back to VAAPI if a driver mishandles it. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> (cherry picked from commit 3c56ff5717b2c9a0871953127da3dadd6a84220d)