[FFmpeg-devel] [PATCH 48/48] fftools/ffmpeg: use av_packet_alloc() to allocate packets

[Andreas Rheinhardt]

Jack Waller:
> On Sat, Mar 6, 2021 at 12:44 AM James Almer <jamrial at gmail.com> wrote:
> 
>> Signed-off-by: James Almer <jamrial at gmail.com>
>> ---
>>  fftools/ffmpeg.c     | 318 +++++++++++++++++++++++--------------------
>>  fftools/ffmpeg.h     |   4 +
>>  fftools/ffmpeg_opt.c |   5 +-
>>  3 files changed, 177 insertions(+), 150 deletions(-)
>>
>> diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
>> index 2abbc0ff29..46bb014de8 100644
>> --- a/fftools/ffmpeg.c
>> +++ b/fftools/ffmpeg.c
>>
>> @@ -610,9 +611,9 @@ static void ffmpeg_cleanup(int ret)
>>
>>          if (ost->muxing_queue) {
>>              while (av_fifo_size(ost->muxing_queue)) {
>> -                AVPacket pkt;
>> +                AVPacket *pkt;
>>                  av_fifo_generic_read(ost->muxing_queue, &pkt,
>> sizeof(pkt), NULL);
>>
> 
> Should you modify av_fifo_generic_read() for its second arguments( &pkt) as
> well?

No, he is switching said FIFO to using pointers to AVPackets instead of
AVPackets. The code above makes pkt (which is now a pointer) point to a
separately allocated AVPacket. Said pointer is now the owner of this
AVPacket struct; the packet is freed immediately after its usage (which
I consider wasteful).
(Is this actually a real FIFO? It seems that something is put in there
and then the FIFO is completely drained and never used afterwards. The
cyclic nature of a FIFO is never used and using av_dynarray would be
easier.)

- Andreas