[FFmpeg-devel] [PATCH 2/2] ffmpeg: use AV_BUFFERSRC_FLAG_PUSH.

[Michael Niedermayer]

On Sun, Aug 19, 2012 at 06:35:59PM +0200, Nicolas George wrote:
> It reduces the lifespan of buffers in filter graphs,
> and therefore the memory consumption.
> 
> Signed-off-by: Nicolas George <nicolas.george at normalesup.org>
> ---
>  ffmpeg.c |   11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> 
> It fixes the accumulation problem right now. The frames are still being
> processed for nothing, but it will require a little more work, and that is
> part of it.
> 
> Also, I wanted to propose it for some time, before noticing the accumulation
> problem.
> 
> 
> diff --git a/ffmpeg.c b/ffmpeg.c
> index bace20c..ec40237 100644
> --- a/ffmpeg.c
> +++ b/ffmpeg.c
> @@ -193,7 +193,8 @@ static void sub2video_push_ref(InputStream *ist, int64_t pts)
>          av_buffersrc_add_ref(ist->filters[i]->filter,
>                               avfilter_ref_buffer(ref, ~0),
>                               AV_BUFFERSRC_FLAG_NO_CHECK_FORMAT |
> -                             AV_BUFFERSRC_FLAG_NO_COPY);
> +                             AV_BUFFERSRC_FLAG_NO_COPY |
> +                             AV_BUFFERSRC_FLAG_PUSH);
>  }
>  
>  static void sub2video_update(InputStream *ist, AVSubtitle *sub, int64_t pts)
> @@ -1509,7 +1510,8 @@ static int decode_audio(InputStream *ist, AVPacket *pkt, int *got_output)
>                                            decoded_frame_tb,
>                                            (AVRational){1, ist->st->codec->sample_rate});
>      for (i = 0; i < ist->nb_filters; i++)
> -        av_buffersrc_add_frame(ist->filters[i]->filter, decoded_frame, 0);
> +        av_buffersrc_add_frame(ist->filters[i]->filter, decoded_frame,
> +                               AV_BUFFERSRC_FLAG_PUSH);
>  
>      decoded_frame->pts = AV_NOPTS_VALUE;
>  
> @@ -1620,9 +1622,10 @@ static int decode_video(InputStream *ist, AVPacket *pkt, int *got_output)
>              buf->refcount++;
>              av_buffersrc_add_ref(ist->filters[i]->filter, fb,
>                                   AV_BUFFERSRC_FLAG_NO_CHECK_FORMAT |
> -                                 AV_BUFFERSRC_FLAG_NO_COPY);
> +                                 AV_BUFFERSRC_FLAG_NO_COPY |
> +                                 AV_BUFFERSRC_FLAG_PUSH);
>          } else
> -        if(av_buffersrc_add_frame(ist->filters[i]->filter, decoded_frame, 0)<0) {
> +        if(av_buffersrc_add_frame(ist->filters[i]->filter, decoded_frame, AV_BUFFERSRC_FLAG_PUSH)<0) {
>              av_log(NULL, AV_LOG_FATAL, "Failed to inject frame into filter network\n");
>              exit_program(1);
>          }

Maybe i misunderstand the code but cant this break filters like
overlay ?
i mean if there would be 2 video streams in a file and a overlay
filter combining them. Then demuxing from this file would push frames
up to the overlay filter and if the 2 streams are not interleaved
correctly then the overlay filter would get input with mismatching
timestamps. Before this patch there would be buffering in the source


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Opposition brings concord. Out of discord comes the fairest harmony.
-- Heraclitus
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20120821/082ba913/attachment.asc>