[FFmpeg-devel] allocate enough memory for full audio frame in ffmpeg.c

[Michael Niedermayer]

On Thu, Jun 10, 2010 at 01:22:23PM -0400, Justin Ruggles wrote:
> Michael Niedermayer wrote:
> 
> > On Sun, Jun 06, 2010 at 11:41:14AM -0400, Justin Ruggles wrote:
> >> Hi,
> >>
> >> This patch fixes part of Issue 1921.
> >>
> >> do_audio_out() in ffmpeg.c reads samples from the input to a FIFO until
> >> it has enough for a full output frame, then reads from that FIFO to
> >> audio_buf for encoding.  do_audio_out() is called for each input packet,
> >> and the allocated size of audio_buf is based on each single packet.
> >> However, it often takes multiple calls of do_audio_out() to fill the
> >> FIFO enough to encode a single output frame, so sometimes audio_buf is
> >> not large enough.  This patch ensures that audio_buf is large enough
> >> before reading from the FIFO.
> >>
> >> This still doesn't fix the FLAC encoder part of Issue 1921, but that is
> >> a separate issue really.  The FLAC encoder is lazy and requires a large
> >> output buffer instead of checking the remaining buffer size before every
> >> write.
> >>
> >> -Justin
> >>
> > 
> >>  ffmpeg.c |    9 +++++++++
> >>  1 file changed, 9 insertions(+)
> >> 34c8e17759394eaba1c8c60f85b226de8f9e5d4c  audio_buf_size.patch
> >> Index: ffmpeg.c
> >> ===================================================================
> >> --- ffmpeg.c	(revision 23504)
> >> +++ ffmpeg.c	(working copy)
> >> @@ -962,6 +962,15 @@
> >>              AVPacket pkt;
> >>              av_init_packet(&pkt);
> >>  
> >> +            /* make sure audio_buf is large enough to hold the frame */
> >> +            if (allocated_audio_buf_size < frame_bytes) {
> >> +                av_fast_malloc(&audio_buf, &allocated_audio_buf_size, frame_bytes);
> > 
> > cant this size be considered where we allocate the buffer?
> 
> Yeah, that sounds better.  New patch attached.  This patch also changes
> the last small frame encoding to also read the remaining FIFO data to
> audio_buf, for the same reason.
> 
> Thanks,
> Justin
> 

>  ffmpeg.c |    9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 931f26b48a130b93813b79f4e228ff2e608fe141  audio_buf_size_2.patch

ok if tested

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In fact, the RIAA has been known to suggest that students drop out
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