[Flac] flac 1.40 verses ffmpeg

[Michael D. Lawler]

These are all 44.1kHz and adding -b 4608 helped, 
but ffmpeg still does better than flac for this handful of files.

At 09:07 AM 9/27/2022, Martijn van Beurden wrote:
>Op di 27 sep. 2022 om 14:22 schreef Michael D. 
>Lawler <<mailto:mdlawler at lawlers.us>mdlawler at lawlers.us>:
>My conclusion is that ffmpeg's library is doing something that -e
>does, but not using a lot of CPU so perhaps this could be studied and
>flac could be updated to improve compression further with reasonable
>CPU usage.  I have all of the files and could provide the ones where
>-e is necessary and the few where ffmpeg still does better with -8pe
>--lax -l 32.
>
>
>
>One important difference between libflac and 
>ffmpeg is that they use different blocksizes. 
>FLAC as you've used it will default to blocksize 
>4096 no matter what sample rate the input is. 
>ffmpeg will adapt its blocksize to the 
>samplerate. For 44.1kHz and 48kHz, it uses 
>blocksize 4608. In the past it has been shown 
>this benefits certain kinds of music, but the 
>4096 used by libflac does better for others. 
>ffmpeg uses a larger blocksize for higher 
>samplerates and a smaller blocksize for lower 
>samplerates. This might be the reason you're seeing this difference.
>
>Perhaps you can find out what the sample rates 
>are of the files that ffmpeg compresses better 
>than libflac. If those are mainly 44.1kHz or 
>48kHz, you can try to improve on it with libFALC by adding -b 4608
>
>Kind regards, Martijn van Beurden

-- 
Michael D. Lawler
email mailto:mdlawler at lawlers.us
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