[FFmpeg-devel] [PATCH] Detect DTS in wav (issue70) ????+?about?ac3-in-wav

[Michael Niedermayer]

On Wed, Aug 18, 2010 at 04:19:40PM +0300, Anssi Hannula wrote:
> On Wednesday 18 August 2010 13:33:11 Michael Niedermayer wrote:
> > On Wed, Aug 18, 2010 at 08:24:58AM +0300, Anssi Hannula wrote:
> > > On Wednesday 18 August 2010 07:29:15 Anssi Hannula wrote:
> > > > On Tuesday 17 August 2010 15:26:52 Michael Niedermayer wrote:
> > > > > i meant that the code is a mess and id like it to be simpler.
> > > > 
> > > > Attached is a completely different simpler approach, then.
> > > > Since we are about to do the
> > > > lower-wav-score-for-s16le-files-if-small-buffer trick anyway for the
> > > > spdif-in-wav files, attached patch does the same for dts- in-wav,
> > > > marking such files as raw dts.
> > > > 
> > > > Better?
> > 
> > no, its still a mess
> 
> So it is worse than the fallback_id one?

i dont know, ive not seen a clean implementation of either solution yet


> 
> > everything looks much more complex than it should be and its not clear
> > at all why the changes are done.
> 
> Ok.
> 
> > a patch touching probe functions from 2 seperate formats is already quite
> > suspect.
> > if dts detection is not good enough it can be improved in a seperate
> > patch
> > and each improvement should be seperate and be justified
> > for example why do you add such huge amounts of code, is the dts detection
> > failing for you?
> 
> The current dts detection returns AVPROBE_SCORE_MAX/2+1 on match, which won't 
> be enough to top wav's AVPROBE_SCORE_MAX-1.

but your patch reduced wavs score IIRC


> 
> The added code allows dts probe to return AVPROBE_SCORE_MAX when dts markers 
> are found with intervals which makes the stream bitrate match PCM bitrate (and 
> thus transmittable in standard pcm wav / audiocd).

what does a pcm wav bitrate have to do with dts detection?
dts_probe() should return a score that represents how likely it is dts
if it shows false positives or false negatives it should be improved
same for wav.

this may very well not be enough and some less clean code might be needed
i know but it feels as if you are picking the first thing that works and
make no attempt at picking the simplest and cleanest solution
maybe iam wrong but iam missing some kind of argumentation why it cant be
done cleaner

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Let us carefully observe those good qualities wherein our enemies excel us
and endeavor to excel them, by avoiding what is faulty, and imitating what
is excellent in them. -- Plutarch
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