I'm trying to convert a WAV file (decoded from FLAC) to MP3 CBR @ 320 (yes, I know that that there are more reasons in favor of VBR than not, it's more of a whim of mine than anything else) and so far, ffmpeg has been doing all I need. However, I can see a very consistent difference between LAME CLI, ffmpeg and Audacity with LAME when comparing with a few tools:
| | LAME 3.100 CLI | ffmpeg 4.2 (Lavf 58.29.100/LAME 3.100) CLI | Audacity 2.3.2 (LAME 3.100) |
|---|
| MediaInfo | Constant/320/Encoder Settings: -m s -V 4 -q 3 -lowpass 20.5 | Variable/320/ | Constant/320/Encoder Settings: -m s -V 4 -q 3 -lowpass 20.5 |
| Spectral Analysis | Almost nothing between shelf and cutoff | Almost nothing between shelf and cutoff | Considerably more happening between shelf and cutoff |
| Fakin' the Funk* | 256kbps | 192kbps | 320kbps |
*I know that this tool is not a really good indicative and is probably misreading info, but it seems to a least notice the visible difference the Audacity file has in it's spectrogram
Commands/settings used for the encodes:
LAME: lame -b 320 -q 3 -m s [File].wav [File].mp3
ffmpeg: ffmpeg -i "[File].wav" -c:a libmp3lame -b:a 320k -compression_level 2 -cutoff 20500 -joint_stereo 0 "[File].mp3" -y
Audacity: Import .wav file > Export as MP3 > Insane preset, Stereo, Default Variable Speed
What I'd like to understand is why all of this results are coming different, if they are all, in theory, LAME
Thanks