[vlc-devel] [PATCH 1/2] avcodec: do not cancel the pending picture requests on Flush

[Steve Lhomme]

On 2020-07-09 12:33, Francois Cartegnie wrote:
> Le 09/07/2020 à 11:56, Steve Lhomme a écrit :
>>   
>> -    /* Abort pictures in order to unblock all avcodec workers threads waiting
>> -     * for a picture. This will avoid a deadlock between avcodec_flush_buffers
>> -     * and workers threads */
>> -    decoder_AbortPictures( p_dec, true );
>> -
>>       /* do not flush buffers if codec hasn't been opened (theora/vorbis/VC1) */
>>       if( avcodec_is_open( p_context ) )
>>           avcodec_flush_buffers( p_context );
>>   
>>       date_Set(&p_sys->pts, VLC_TICK_INVALID); /* To make sure we recover properly */
>> -
>> -    /* Reset cancel state to false */
>> -    decoder_AbortPictures( p_dec, false );
>>   }
> 
> Having output of pictures after a change in timeline/continuity
> will create inconsistency with the timestamps and maybe sidedata.

That's the job of libavcodec not to push frames from before the flush 
occured. What decoder_AbortPictures() does is just giving it NULL frames 
while we are doing the flush.