[FFmpeg-devel] [PATCH 2/2] avcodec/decode: don't discard the buffered packet if the underlying bsf can't take it

[James Almer]

On 7/12/2023 6:08 AM, Anton Khirnov wrote:
> Quoting James Almer (2023-07-12 04:06:44)
>> Signed-off-by: James Almer <jamrial at gmail.com>
>> ---
>>   libavcodec/decode.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/libavcodec/decode.c b/libavcodec/decode.c
>> index 239ad70b41..cd49cca7c2 100644
>> --- a/libavcodec/decode.c
>> +++ b/libavcodec/decode.c
>> @@ -242,7 +242,8 @@ int ff_decode_get_packet(AVCodecContext *avctx, AVPacket *pkt)
>>               (!AVPACKET_IS_EMPTY(avci->buffer_pkt) || dc->draining_started)) {
>>               ret = av_bsf_send_packet(avci->bsf, avci->buffer_pkt);
>>               if (ret < 0) {
>> -                av_packet_unref(avci->buffer_pkt);
>> +                if (ret != AVERROR(EAGAIN))
>> +                    av_packet_unref(avci->buffer_pkt);
> 
> It seems very wrong for ff_decode_get_packet() to return EAGAIN when
> we have a buffered packet.

The idea is preventing dropping a packet in the hypothetical case the 
bsf can't take it. Is this scenario possible, or is the call to 
av_bsf_receive_packet() within the loop ensuring it wont?