JohnB wrote: > I've found the answer to my own question: > > _flac_(not_compressed)_ > There is no compression level specified in the resulting command: this > means that sox will apply the default compression level. In the official > XIPH FLAC encoder the default compression level is 5 (it is likely, but > not guaranteed, to be the same with sox). To implement this option > properly the compression level should be set as -C 0, which is lower > compression, not no compression. > > _flac_(medium_compression)_ = 5 > > _flac_(max_compression)_ = 8 > > A couple of points about this: > > Assuming that sox flac encoding operates the same way as the official > XIPH FLAC encoder: > > Compression level 0 does not mean that there is no compression. The > difference in the actual compression from level "0" to level "8" is not > that great - only achieving an additional 2 to 5% reduction for > 44.1kHz/96kHz files though that can increase to something of the order > of 13% for 192 kHz files. (All very dependent on file content.) > > The difference in actual compression going from level "5" to level "8" > is only an additional 1% or 2% - but at a significant cost in terms of > processing. > > The amount of processing required for various compression levels differs > greatly: compression level "5" can take around 2.5 x the time as level > "0". > > Compression level "8" can take around 8 x the processing time as level > "0". > > So I think it might be a good idea to limit the flac options to "low > compression" (-C 0) and "medium compression" (-C 5). > > And, of course to implement C -0 for "low compression" > > [Later Edit] > I've just done some tests on file size reductions for three FLAC > compression levels. The files I used might not be representative but, > for what it's worth: > > > Code: -------------------- > > S/rate 192 96 44.1 > -0 82% 56% 46% > -5 71% 52% 44% > -8 70% 51% 43% -------------------- > >
Good catch! It's a bug, when using no compression C-3PO is intended to use -C 0. I'll fix it. ________________________________________________________________________ Author of C-3PO plugin, Squeezelite-R2, Falcon Web interface - See www.marcoc1712.it ------------------------------------------------------------------------ marcoc1712's Profile: http://forums.slimdevices.com/member.php?userid=34842 View this thread: http://forums.slimdevices.com/showthread.php?t=105309 _______________________________________________ Squeezecenter mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/squeezecenter
