Iirc encoding is not exactly specified by design. Leaving implementers (some) degree of freedom on what acoustic models to use, what audio data to throw away, e

Iirc encoding is not exactly specified by design. Leaving implementers (some) degree of freedom on what acoustic models to use, what audio data to throw away, etc. This is one area where LAME lagged in its early days (not today). How a decoder should work is exactly defined (a quick look on Wikipedia mentions ISO/IEC 11172-3, not sure if that's a free/open standard or not). So one should expect 1:1 correspondence between encoded stream and decoded sound (minus rounding errors?), regardless of decoder used. For already-encoded MP3s in people's archives this doesn't matter anyway, as the loss in "lossy compression" was already eaten, and no amount of re-coding or bitrates can recover that. Transcoding = more loss. Not to mention the hassles involved in transcoding, likely for little gain if any.