[FFmpeg-devel] [PATCH 3/4] avcodec/avcodec: Don't reset decoder-fields for encoders when flushing

[Andreas Rheinhardt]

Anton Khirnov:
> Quoting Andreas Rheinhardt (2022-04-13 16:49:51)
>> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
>> ---
>> Needs to be applied before
>> https://ffmpeg.org/pipermail/ffmpeg-devel/2022-March/294507.html
>> or flushing an encoder will segfault.
>> Btw: All this stuff is unused by subtitle decoders,
>> so one could condition the else on that and avoid the allocations.
>>
>>  libavcodec/avcodec.c | 23 +++++++++++------------
>>  1 file changed, 11 insertions(+), 12 deletions(-)
>>
>> diff --git a/libavcodec/avcodec.c b/libavcodec/avcodec.c
>> index ded6b5b307..0d971a61d4 100644
>> --- a/libavcodec/avcodec.c
>> +++ b/libavcodec/avcodec.c
>> @@ -422,6 +422,17 @@ void avcodec_flush_buffers(AVCodecContext *avctx)
>>          }
>>          if (avci->in_frame)
>>              av_frame_unref(avci->in_frame);
>> +    } else {
>> +        av_packet_unref(avci->last_pkt_props);
>> +        while (av_fifo_read(avci->pkt_props, avci->last_pkt_props, 1) >= 0)
>> +            av_packet_unref(avci->last_pkt_props);
>> +
>> +        av_packet_unref(avci->in_pkt);
>> +
>> +        avctx->pts_correction_last_pts =
>> +        avctx->pts_correction_last_dts = INT64_MIN;
>> +
>> +        av_bsf_flush(avci->bsf);
>>      }
>>  
>>      avci->draining      = 0;
>> @@ -430,22 +441,10 @@ void avcodec_flush_buffers(AVCodecContext *avctx)
>>      av_frame_unref(avci->buffer_frame);
>>      av_packet_unref(avci->buffer_pkt);
>>  
>> -    av_packet_unref(avci->last_pkt_props);
>> -    while (av_fifo_read(avci->pkt_props, avci->last_pkt_props, 1) >= 0)
>> -        av_packet_unref(avci->last_pkt_props);
>> -
>> -    av_packet_unref(avci->in_pkt);
>> -
>>      if (HAVE_THREADS && avctx->active_thread_type & FF_THREAD_FRAME)
>>          ff_thread_flush(avctx);
>>      else if (ffcodec(avctx->codec)->flush)
>>          ffcodec(avctx->codec)->flush(avctx);
>> -
>> -    avctx->pts_correction_last_pts =
>> -    avctx->pts_correction_last_dts = INT64_MIN;
>> -
>> -    if (avci->bsf)
> 
> did you drop this check on purpose?
> 

Yes. We currently open bsfs for all decoders (even if it is a null-bsf).

- Andreas