[Ffmpeg-devel] [PATCH] flacenc - rice param search

Michael Niedermayer michaelni
Tue Jun 27 22:58:21 CEST 2006


On Tue, Jun 27, 2006 at 02:27:06AM -0400, Justin Ruggles wrote:
> Hello,
> Here is another update for the FLAC encoder.  I only added a few things,
> but it's still a pretty large patch.
> 1) search for optimal rice parameters and partition order. i also
> modified the stereo method estimation to use this to calculate estimated
> bit count instead of using just the pure sums.
> 2) search for the best fixed prediction order
> 3) constant subframe mode (good for encoding silence)
> Note that the regression test for the decoded wav file also changed.
> This is due to FFmpeg's FLAC decoder truncating the file, which it did
> before anyway...just at a different cutoff point.  The generated FLAC
> files are still 100% lossless.
> With this update, FFmpeg's FLAC encoder has speed and compression
> somewhere between "flac -1" and "flac -2".  On my machine, it's about
> 15% faster than "flac -2", and about 10% slower than "flac -1".  The
> encoding parameters are identical to "flac -2" (fixed predictors, 1152
> blocksize, partition order 0 to 3).



Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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