[FFmpeg-devel] [FFmpeg-cvslog] libavcodec/libx264: add user data unregistered SEI encoding

[Brad Hards]

On Tuesday, 19 October 2021 9:53:50 AM AEDT James Almer wrote:
> On 10/18/2021 7:38 PM, James Almer wrote:
> > On 10/18/2021 7:34 PM, Derek Buitenhuis wrote:
> >> On 10/18/2021 11:05 PM, Michael Niedermayer wrote:
> >>> This code breaks bitexact mode for some files, i have not looked into
> >>> this
> >>> any deeper yet.
> >> 
> >> [23:18] <@jamrial_> Daemon404: that libx264 patch conflicts with the
> >> closed caption code. it overwrites the extra_sei struct and leaks it
> >> 
> >> ^ presumably this is why
> > 
> > Actually no. It calls av_fast_realloc() on a (potentially) av_malloc'd
> > buffer, which i think is a valid scenario. Also, these samples have no
> > closed captions, so the relevant code is never run.
> > 
> > The problem i guess is in the following line:
> > 
> > sei_payload->payload = side_data->data;
> > 
> > Which should be an av_memdup() or similar, because side_data->data is
> > the frame's side data, and by the time the encoder tries to do something
> > with it, it may have been freed.
> > Also, this code should set x4->pic.extra_sei.sei_free to av_free().
> 
> The following should fix it
My mail client mangled the patch, but manually applying it worked with my test case. I 
don't know what the issue is with the bitexact issue identifier by Michael, but will keep 
looking.

Brad