On 12/03/2024 03:33, Wang, Fei W wrote: > On Mon, 2024-03-11 at 21:57 -0300, James Almer wrote: >> On 3/11/2024 9:49 PM, Michael Niedermayer wrote: >>> On Mon, Mar 11, 2024 at 06:53:31PM +0000, Frank Plowman wrote: >>>> VVC's subpictures feature is not yet implemented in the native >>>> decoder. >>>> Throw an AVERROR_PATCHWELCOME when trying to decode a bitstream >>>> using >>>> the feature. Fixes crashes when trying to decode bitstreams >>>> which >>>> use the feature. >>>> >>>> Signed-off-by: Frank Plowman <p...@frankplowman.com> >>>> --- >>>> libavcodec/vvc/vvc_ps.c | 15 +++++++++++++++ >>>> 1 file changed, 15 insertions(+) >>> >>> This breaks fate-vvc-conformance-SUBPIC_A_3 >>> >>> make fate-vvc-conformance-SUBPIC_A_3 >>> TEST vvc-conformance-SUBPIC_A_3 >>> --- ./tests/ref/fate/vvc-conformance-SUBPIC_A_3 2024-03-05 >>> 02:37:36.235300141 +0100 >>> +++ tests/data/fate/vvc-conformance-SUBPIC_A_3 2024-03-12 >>> 01:47:27.301593567 +0100 >>> @@ -1,9 +0,0 @@ >>> -#tb 0: 1/25 >>> -#media_type 0: video >>> -#codec_id 0: rawvideo >>> -#dimensions 0: 1920x1080 >>> -#sar 0: 0/1 >>> -0, 0, 0, 1, 6220800, 0xa419cfb6 >>> -0, 1, 1, 1, 6220800, 0xa419cfb6 >>> -0, 2, 2, 1, 6220800, 0xa419cfb6 >>> -0, 3, 3, 1, 6220800, 0xa419cfb6 >>> Test vvc-conformance-SUBPIC_A_3 failed. Look at >>> tests/data/fate/vvc-conformance-SUBPIC_A_3.err for details. >>> tests/Makefile:318: recipe for target 'fate-vvc-conformance- >>> SUBPIC_A_3' failed >>> make: *** [fate-vvc-conformance-SUBPIC_A_3] Error 69 >>> >>> thx >> >> The sample appears to decode fine and doesn't crash, although all >> four >> frames are exactly the same (I don't know is that's intended). > > The result is correct. Assume native decode can handle subpic, at least > a part of the feature. > >> Maybe the crashes can be fixed in some other form? And abort only if >> FF_COMPLIANCE_STRICT is requested. > > Previous I made a patch to fix the crash in setup ps, but still get > error in decoding slice, it's better to return AVERROR_PATCHWELCOME > only in case of pps_single_slice_per_subpic_flag. > > https://github.com/intel-media-ci/ffmpeg/pull/723 > > Thanks > Fei
Hi, Thanks all for your reviews. Yes, the feature is most problematic if pps_single_slice_per_subpic_flag is 1. This is because there is some unimplemented logic in the parameter set parser in this case which leads to some out-of-bounds accesses. Subpictures will also fail to decode bitexact if sps_independent_subpics is 1, although in practice the distortion this introduces is fairly subtle. I think we are able to decode other subpicture bitstreams bitexact. SUBPIC_A_HUAWEI_3 falls into this last category. I posted a patch, like yours Fei, which errors only the most problematic pps_single_slice_per_subpic_flag bitstreams some time ago: https://patchwork.ffmpeg.org/project/ffmpeg/patch/20240201140055.63805-1-p...@frankplowman.com/ and the feedback I received there was to make this patch. I have also implemented the logic needed for pps_single_slice_per_subpic_flag here: https://github.com/ffvvc/FFmpeg/pull/191. I would be happy to make a v2 of the pps_single_slice_per_subpic_flag patch which moves where the error is being returned, or to put the GitHub PR on the ML if people would rather one of those two alternatives. Thanks again, -- Frank _______________________________________________ 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".
