Thorsten Wilms wrote: > Hi! > > I'm interested in losless compression of typical Jack audifiles > for exchange. That means float32 sample format. Hmm, interesting. > Flac doesn't handle float, only pcm. > wavpack handles both. > > So I was told that converting from (wav) float32 to pcm24 and back > should be losless, if the float file is normalized. I would be **very** surprised if it was. For a normalised WAV file the maximum value would be 1.0 which will correspond to a pcm24 value of 0x7ffffff. The float32 file could also contain a sample with a value of 1/(2^25) which is smaller than the pcm24 value of 0x1. Hence, float32 -> pcm24 -> float32 is not lossless. > This would cut > down on file-size by itself and allow to use Flac. > I tested this using sndfile-convert and diff tells me there are > differences. The file sizes are identical. > diff did not report differences for a wav-unpacked file (staying > in float32). The wavpack algorithm must do soemthing special with float32 data. Maybe what you want to do is add wavpack to libsndfile :-). Erik -- +-----------------------------------------------------------+ Erik de Castro Lopo +-----------------------------------------------------------+ "If POSIX threads are a good thing, perhaps I don't want to know what they're better than." -- Rob Pike
