[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 10:32 AM, Anton Khirnov wrote:
> Quoting James Almer (2023-07-12 13:40:25)
>> 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?
> 
> This block can only be entered if decode_get_packet() returned EAGAIN,
> which should always mean that the bsf is empty.

Right, patch dropped then.