MP3 VBR settings

[MajorMetal87]

Hello, I have a question regarding the MP3 settings in Codec Tinker.
I would like to use VBR 190k (170k–210k), equivalent to -q:a 2 or LAME -V2, and also set a lowpass filter as it is done in the original LAME/FFmpeg encoder.

Unfortunately, I haven’t been able to find a clear guide for this. For example, when I set the configuration to mp3:190k, the resulting files end up with a higher bitrate than expected.

Thank you very much.

[TypNull]

Hey,
lowpass filter support isn't currently implemented in Codec Tinker, if this is something you'd like to see added, feel free to open a GitHub issue describing what cutoff frequency you'd like to set and for which format/quality level, so it can be tracked and considered.

Regarding your current question: to get -q:a 2 (LAME V2, ~170–210 kbps), you need to set the bitrate to 170, not 190. Setting 190 will actually give you V1 instead, which is why your files come out larger than expected. You can see exactly how I set the bitrate-to-quality mapping in the source here:

Tubifarry/Tubifarry/Core/Model/AudioMetadataHandler.cs

Lines 59 to 72 in 4c277a4

	AudioFormat.MP3,
	bitrate => {
	int qualityLevel = bitrate switch {
	>= 220 => 0, // V0 (~220-260kbps avg)
	>= 190 => 1, // V1 (~190-250kbps)
	>= 170 => 2, // V2 (~170-210kbps)
	>= 150 => 3, // V3 (~150-195kbps)
	>= 130 => 4, // V4 (~130-175kbps)
	>= 115 => 5, // V5 (~115-155kbps)
	>= 100 => 6, // V6 (~100-140kbps)
	>= 85 => 7, // V7 (~85-125kbps)
	>= 65 => 8, // V8 (~65-105kbps)
	_ => 9 // V9 (~45-85kbps)
	};

I'm not really someone to write much documentation but the Wiki sub-page is free for anyone to edit, as well as the Servarr Wiki. The readme just contains the bare minimum necessary to start .