[FFmpeg-devel] [PATCH] flac encoding, issue 526

[Michael Niedermayer]

On Sat, Jul 19, 2008 at 02:07:37PM -0400, Justin Ruggles wrote:
> Justin Ruggles wrote:
> > Justin Ruggles wrote:
> >> Mathieu Velten wrote:
> >>> new patch attached
> >>>
> >>> if ((data == NULL) || (avctx->frame_size != s->frame.blocksize)) {
> >>>      write_streaminfo(s, avctx->extradata);
> >>> }
> >>>
> >>> this is also execute during the first frame, so the header stored in
> >>> extradata will have the length of the first frame instead of 0 during
> >>> the encoding.
> >>> is it a problem ?
> >> Yes, it's a problem.  Check for the last frame at the beginning of
> >> flac_encode_frame().
> >>
> >> int last_frame = (data == NULL) || (avctx->frame_size != s->frame.blocksize)
> >>
> >> ...
> >>
> >> if(last_frame)
> >>     write_streaminfo(...)
> > 
> > Oh, I see what you mean.  You also need to set s->frame.blocksize in
> > flac_encode_init().
> 
> A simple solution might be something like:
> 
> 1. add full_blocksize to the FlacEncodeContext
> 2. set avctx->frame_size and s->full_blocksize at flac_encode_init()
> 3. use s->full_blocksize to write the block size to the header in
> write_streaminfo()
> 4. check the current avctx->frame_size against s->full_blocksize to
> check for last frame.

hm
what if there is just one frame in the whole file?
add CODEC_CAP_DELAY and you should always get a NULL frame, thats easier
to test for

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

Republics decline into democracies and democracies degenerate into
despotisms. -- Aristotle
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