Posted by Justin on December 17 2018, 8:56pm:
Hmm, lame command line always uses j-stereo too (even on Extreme, or 320kbps CBR). Doing some testing to see if there's some other difference.
Posted by Justin on December 17 2018, 9:41pm:
OK I've done extensive testing, and there was a bug in REAPER's mp3 encoding which would cause it to make output which was attenuated by 0.0002dB. I don't think that could be noticed. Anyway, fixing that, now it produces the exact same results as the command line LAME (except for a missing ReplayGain tag, which could also make a difference on playback if the playing device uses ReplayGain).
Posted by Justin on December 17 2018, 9:57pm:
The other factor to note is that we don't clip the input to LAME -- so you should put a brickwall limiter in front of it if you want it to be bit-for-bit identical to what rendering to 16-bit then encoding would be.
Posted by Justin on December 17 2018, 10:12pm:
Of all of the above factors, or joint stereo, my money is on ReplayGain tagging being the difference.
Posted by John (93.138.119.x) on December 18 2018, 12:03pm:
Yeah, that 0.0002 db (how did you find such a small number xd) definitely isn't at fault ahahaha. Specification says that in MJ mode LAME can decide to used L/R or M/S and that too much switching could cause artifacts. ReplayGain is something I even haven't considered. Thanks for considering this and fixing it
