2013-09-04, 16:38
(2013-09-04, 14:42)RichG Wrote: Applying ReplayGain to a file is most definitely not lossless (by definition).
Well, it's tricky because it depends on how you interpret “lossless”. With a good tool like foobar2000 or MP3Gain, the volume is adjusted (which is usually not revertible, except for MP3Gain) , so it is lossy. However, the file is not reencoded, so it is lossless.
On wikipedia, i found the following statement: “Some lossy audio formats, such as MP3, are structured in a way that they encode the volume of each compressed frame in a stream, and tools such as MP3Gain take advantage of this for directly applying the gain adjustment to MP3 files, adding undo information so that the process is reversible.” Hydrogenaudio, however, states: “Limitations: Although the metadata, if written, contains precise adjustment & peak values, the audio data modifications are limited to 1.5dB steps and may become irreversible (however, that's a very rare condition; see the ‘mp3gain is NOT lossless’ forum thread)”
So it is tricky. As it is not really 100 % for shure revertible even with MP3Gain, I would recommend to make a backup of purchased and important mp3 files. But as the audio quality doesn’t suffer, it may be a suitable solution for doveman2.
