> On Jan 6, 2023, at 23:52, Zhao Zhili <quinkbl...@foxmail.com> wrote: > > From: Zhao Zhili <zhiliz...@tencent.com> > > v2: > 1. Check vps_max_layers and vps_max_layer_id inside hevc decoder > 2. Add hevc_extract_layer bsf to do the job rather than modifing > hevc_metadata, > 3. Check vps_max_layers_minus1 and vps_max_layer_id inside bsf > 4. Update vps_max_layers_minus1 and vps_max_layer_id when rewrite as base > layer > 5. vps_extension should be updated rather than drop entirely, add a TODO
Will push soon if there's no objections. > > --------------------------------------------- > 1. Don't drop nal->nuh_layer_id > 0 until decoder. > 2. Make hevcdec able to decode a selected layer. > 3. Add hevc_extract_layer bsf to extract a selected layer. > > Partially fix #7965. There is a sample in ticket #7965 which can be used to > test > the patchset. Or use videotoolbox encoder to create a sample (FFmpeg needs to > be > patched first, "avutil/hwcontext_videotoolbox: BGRA should be full range" > http://ffmpeg.org/pipermail/ffmpeg-devel/2023-January/305252.html), e.g., > > ./ffmpeg -i cctv.mp4 \ > -i pig.mp4 \ > -c:v hevc_videotoolbox \ > -alpha_quality 0.75 \ > -filter_complex '[1:v]scale=640x480[v1];[0:v][v1]alphamerge[v2]' \ > -map [v2] -an -t 60 \ > -pix_fmt bgra \ > -b:v 4M \ > -tag:v hvc1 \ > alpha.mp4 -y > > > Now it's able to use two decoders to decode the base layer and alpha > layer, and then combine the results, e.g., > > ./ffmpeg -i alpha.mp4 \ > -strict -2 -nuh_layer_id 1 -i alpha.mp4 \ > -frames 60 \ > -filter_complex '[0:v][1:v]alphamerge[vout]' \ > -map '[vout]' -an test-%d.png > > It only works with software decoder. > > hevc_extract_layer can be used together with hardware decoder. The following > example is how to extract the alpha layer and rewrite as base layer: > > ./ffmpeg -i alpha.mp4 \ > -an -c:v copy \ > -bsf:v hevc_extract_layer=nuh_layer_id=1 \ > test.mp4 > > Zhao Zhili (4): > avcodec/hevc_parse: keep nal->nuh_layer_id > 0 > avcodec/cbs_h2645: keep nal->nuh_layer_id > 0 > avcodec/hevcdec: add nuh_layer_id option > avcodec: add hevc_extract_layer bsf > > configure | 1 + > doc/bitstream_filters.texi | 12 +++ > libavcodec/Makefile | 1 + > libavcodec/bitstream_filters.c | 1 + > libavcodec/cbs_h2645.c | 3 - > libavcodec/hevc_extract_layer_bsf.c | 126 ++++++++++++++++++++++++++++ > libavcodec/hevc_parse.c | 2 - > libavcodec/hevcdec.c | 56 ++++++++++++- > libavcodec/version.h | 2 +- > 9 files changed, 197 insertions(+), 7 deletions(-) > create mode 100644 libavcodec/hevc_extract_layer_bsf.c > > -- > 2.25.1 > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
