Can anyone give an idea how an external application (frontend) can get vbr histogram values while lame encoding stdin?

Well. LAME developers, don't you want to tell me? Sorry if my question is not clear... So, I'll try to ask more specifically. Is there in lame.exe code something like file mapping object or something else to access encoding statistics frome another process during _encoding_of_the_<STDIN>?

if you don't get an answer here or from lame developers in general you could try asking the developer of razorlame. That program accesses the vbr histogram.

...and since the source-code to razorlame is available, you can see the code he uses.

You have to grab stdout.
That is how RazorLame is doing it (this has already been discussed here)

I know about razorlame, and I saw its source. And I know that they use pipe to read STDOUT of lame console during encoding (and then they seek for histogram bars in the buffer to "decode" it to the values). Very good! But when you'll try to encode STDIN (say some stream) with VBR option there will be NO VBR HISTOGRAM in the lame console - you may see yourself. Hence razorlame's method seems to be useless here. That is the question...

Is this at all related to the problem I'm having with mp3s not getting lame tags when encoding an stdin source? I'm using LAME 3.90.2 (dibrom) and Speek's Multi-frontend with Oggdec and Mppdec as sources. Oh, and guys - transcoding ist death, but that isn't the issue here

edit: actually, i'd like to withdraw a lot of this - it seems to be something to do with mppdec.