[FFmpeg-devel] [PATCH] S/PDIF demuxer ( was:[PATCH]?Detect?DTS?in wav (issue70) + about ac3-in-wav)
Fri Aug 6 15:17:29 CEST 2010
On Wed, Aug 04, 2010 at 06:15:12PM +0300, Anssi Hannula wrote:
> Michael Niedermayer kirjoitti keskiviikko, 4. elokuuta 2010 15:53:04:
> > On Wed, Jul 28, 2010 at 05:12:21AM +0300, Anssi Hannula wrote:
> > > Michael Niedermayer kirjoitti tiistai, 27. hein?kuuta 2010 16:59:27:
> > > > On Tue, Jul 27, 2010 at 07:59:13AM +0300, Anssi Hannula wrote:
> > > > > + if (sync_codes == consecutive_codes + 1 &&
> > > > > + !memcmp(p->buf + 8, "WAVE", 4) && !memcmp(p->buf, "RIFF",
> > > > > 4)) + /* all sync codes (except first one as it was only
> > > > > after WAV headers)
> > > > > + were consecutive, but the buffer was too small;
> > > > > + also, this looks like a WAV file, so we need to delay wav
> > > > > demuxer
> > > > > + from grabbing this file until we get a big enough
> > > > > buffer to see if
> > > > > + there are more consecutive codes (we want
> > > > > to be selected for
> > > > > + (ac3-in-)spdif-in-wav as chained demuxers
> > > > > are not yet supported),
> > > > > + therefore return the same score as
> > > > > wav demuxer to make it a tie */
> > > > > + return AVPROBE_SCORE_MAX - 1;
> > > >
> > > > or make the wav demuxer only return a low score for small probe sizes
> > > > above would for example behave oddly if the wav demuxer is disabled
> > >
> > > How low?
> > < AVPROBE_SCORE_MAX/4 so the code in utils.c doesnt stop early
> > > I mean, if we change it to AVPROBE_SCORE_MAX / 8 or so, every wav file
> > > would needlessy be probed 1MB, even while 2k would have been enough (if
> > > no spdif sync codes were in first 2k).
> > we can return a larger score once the amount of data available becomes
> > large enough like 100k ?
> It would still mean that all normal wavs are probed 50-100k even if 2k would
> be enough (as spdif-in-wav would've started in the beginning).
thats only s16le wavs iirc and 50-100k of raw 16bit audio doesnt seem much to
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
Awnsering whenever a program halts or runs forever is
On a turing machine, in general impossible (turings halting problem).
On any real computer, always possible as a real computer has a finite number
of states N, and will either halt in less than N cycles or never halt.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Size: 190 bytes
Desc: Digital signature
More information about the ffmpeg-devel