[Ffmpeg-devel] [PATCH] Shift autodetection for tiny_psnr.c

[Michael Niedermayer]

Hi

On Sat, Oct 07, 2006 at 05:07:12PM +0300, Siarhei Siamashka wrote:
> On Saturday 07 October 2006 16:51, Michael Niedermayer wrote:
> 
> > > > > And I have difficulties with figuring this shift out. I'll try to
> > > > > make an automatic shift detection patch for tiny_psnr.c to solve this
> > > > > problem.
> > > >
> > > > You can use Octave and it's xcorr function to figure out the shift.
> > >
> > > Well, don't know what this Octave thing is (links are always welcome),
> > > but a simple patch for automatic shift autodetection is attached. It
> > > works only for shifts +-16384 and is quite slow, but probably could be
> > > useful nevertheless. At least I use it in my mp3 decoding quality
> > > experiments now :)
> >
> > does the shift detection have an anything in common with tiny_psnr.c?
> > if no it should either br changes to reuse the comparission code or
> > be a seperate tool (detect_shift.c or so maybe)
> 
> It is a patch for tiny_psnr.c, if you specify '?' instead of a number for
> shift value in a command line, it tries to autodetect shift.
> 
> I'm trying to setup a large test using it (a directory with lots of wav files,
> each one gets compressed with different bitrates and gets decoded with
> different decoders, with results compared against each other using 
> tiny_psnr). In such automated test, shift autodetection is very desirable.

but each decoder should always have the same shift/delay so its redundant

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

In the past you could go to a library and read, borrow or copy any book
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