[FFmpeg-devel] [PATCH v1 2/4] lavc/hevcdec: do not let missing ref frames invovled in dpb process

[Wang, Fei W]

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> Michael Niedermayer
> Sent: Tuesday, June 7, 2022 8:07 PM
> To: FFmpeg development discussions and patches <ffmpeg-devel at ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH v1 2/4] lavc/hevcdec: do not let missing ref
> frames invovled in dpb process
> 
> On Tue, Jun 07, 2022 at 03:08:28PM +0800, Fei Wang wrote:
> > From: Xu Guangxin <guangxin.xu at intel.com>
> >
> > We will generate a new frame for a missed reference. The frame can
> > only be used for reference. We assign an invalid decode sequence to
> > it, so it will not be involved in any dpb process.
> >
> > Tested-by: Fei Wang <fei.w.wang at intel.com>
> > Signed-off-by: Xu Guangxin <guangxin.xu at intel.com>
> > ---
> >  libavcodec/hevc_refs.c | 13 ++++++++++++-
> >  libavcodec/hevcdec.c   |  4 ++--
> >  libavcodec/hevcdec.h   |  3 +++
> >  3 files changed, 17 insertions(+), 3 deletions(-)
> 
> This causes segfaults

Thanks Michael, could you share your clip to me? I can't reproduce this with all my clips.

Thanks
Fei

> 
> Thread 9 "ffmpeg_g" received signal SIGSEGV, Segmentation fault.
> [Switching to Thread 0x7fffcc5ad700 (LWP 14108)]
> 0x00005555564b88c0 in ff_emu_edge_vfix19_sse ()
> (gdb) bt
> #0  0x00005555564b88c0 in ff_emu_edge_vfix19_sse ()
> #1  0x00005555561c515c in emulated_edge_mc_avx2 ()
> #2  0x0000555555d21bc8 in hls_prediction_unit.isra ()
> #3  0x0000555555d2420b in hls_coding_quadtree ()
> #4  0x0000555555d2338d in hls_coding_quadtree ()
> #5  0x0000555555d25371 in hls_decode_entry ()
> #6  0x0000555555bd77e5 in avcodec_default_execute ()
> #7  0x0000555555d2a00f in hevc_decode_frame ()
> #8  0x0000555555edc5a3 in frame_worker_thread ()
> #9  0x00007ffff75fc6db in start_thread (arg=0x7fffcc5ad700) at
> pthread_create.c:463
> #10 0x00007fffed17061f in clone ()
> at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
> 
> [...]
> --
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
> 
> I do not agree with what you have to say, but I'll defend to the death your right
> to say it. -- Voltaire