Replaygain values for flac and mp3 files
Reply #3 – 2005-08-27 19:27:08
Awhile back I noticed that Lame cbr and abr (--preset) encodes lost some volume compared to vbr encodes, and tested to find out the differences. The procedure is detailed in this post . Here's the stuff from that post that applies to the present discussion: General findings: * The amount of volume lost wasn't exact at a given encoder setting - it varied within a range of +/-5 dB, usually. The range (and thus the standard deviation) was tigher at higher bitrates. * Higher bitrates had less volume loss. * Variation in dB loss from song to song (in the second group, where the song volumes varied) did not appear to be correlated with volume. So, a wav file with a volume of 98 dB should lose the same amount of volume upon encoding with --preset 128 as a wav file with a volume of 92 dB. * Using --scale 1 did not guarantee exactly equivalent volume; the songs still varied within a range, but given a sufficiently large sample the mean deviation was 0 dB. Specific findings - volume loss at given settings: --preset (abr) 128 - lost 0.58 dB avg, range 0.54 to 0.65 dB --preset cbr 128 - lost 0.60 dB avg --preset 128 --scale 1 - lost 0.00 dB avg, range -0.08 to +0.03 --preset 136 -b 128 - lost 0.61 dB avg, range 0.54 to 0.69 dB --preset 145 - lost 0.43 dB, range 0.41 to 0.47 dB --preset 160 - lost 0.44 dB, range 0.42 to 0.47 dB --preset cbr 160 - lost 0.44 dB, range 0.41 to 0.46 dB --preset 176 - lost 0.26 dB, range 0.21 to 0.34 dB --preset 192 - lost 0.25 dB, range 0.23 to 0.30 dB --preset cbr 192 - lost 0.26 dB, range 0.22 to 0.31 Note that this was done over a year ago, and I think I was using Lame 3.92 or 3.95. However, I have no reason to believe things would be different with 3.90.3 or 3.96.1 or 3.97alphas. edit: table formatting