ok, I'm wondering if --preset insane still makes use of the bit reservoir. If it does and therefor improves sound quality wouldn't it be smart to have a 2-pass --preset standard mode? Let's say, frame1 needs only 128kbps, but frame2 needs 400kbps, LAME could decide to use a lot more kbps in frame1 and store the extra bytes in the bit reservoir so that frame2 can use it. I learned that it is possible to store up to 320kbps in the bit reservoir...

what do you guys think?

Hi there

I think the biggest fame can only be 320 not above and the bit reservoir and it could
not be used much in preset insane. The lower presets mode use differanct frame
sizes instead of relying on the bit reservoir.


edit: tried to write in english even though its my first and at the monent the only
language i know

well, there is --freeformat you know. However, the idea was to get higher bitrates (when needed) in a regular mp3 file. So let's say LAME was able to use 320kbps + the bit reservoir you could use up to 640kbps for one frame (assuming that the previous frame doesn't need anything)

That is a cool idea. What about VBR from 8kbps to 640kbps. That seems like a good
match. In steps of 8kbps so it just uses as much bits as it needs. There for it would be
moving away from CBR space wasting.

I'm talking about VBR...I'm not sure if you got my point. You won't safe any space, but rather achieve higher quality when needed without breaking mp3 standards...

Let's wait for Gabriels answer

I think the biggest size can only be 320, this includes the bit reservoir when keeping
to the standards.
(Warning: I'm igorant but willing to learn )

The bit reservoir max size is the size of the biggest allowed full frame.
In "usual" encodings, it means the size of a 320kbps frame, so a 320kbps cbr encode can not benefit from bit reservoir.

When using freeformat to encode at higher bitrate, the bit reservoir definition is still the same: it can only hold as much data as the max allowed frame size. As in freeformat all frames must have the same size, the max size is equal to your (only allowed) frame size, thus it is useless.

note: to be exact it is not the bit reservoir size, but the size of data belonging to a frame/granule. The bit reservoir pointer itself is limited to 511 slots.

ok, thanks for clarifying this