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ogg auto-encoding lo-volume passages at lo bitrates?, ...tried this question with mp3s with no luck.
selection7
post May 20 2011, 07:31
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First, my audio to be encoded never has any true, dead silence.
But for example, I have a track that's nothing but a count in and and then only noise floor afterwards...and I want this 4min file to encode at no more than maybe 600kb since 97% of the file should be encoded at ~32kpbs while the part with actual audible sound gets encoded at more like ~200kbps. I know it's common for variable bitrate encoders to vary bitrates depending on frequency, but I want it to vary depending on volume too! Yes, encoders do reduce bitrate drastically when the file is flatlining dead silence, but I don't want to have to noisegate to achieve this and I don't have dead silence, just noise floor. I'm not the only one who'll be encoding with this purpose in mind and that's an extra step I'd like to avoid for multiple reasons.

I can't find an ogg encoder that will do this? Has anyone achieved this or have any useful info/suggestions?

EXTRA INFO:
What I'm doing is encoding separate tracks that make up one song, but I'm finding that my LAME encoder (and others I've tried) encode near silence (noise floor) at roughly the same bitrate as very loud audio even. I want it to encode at something like 32kpbs when the audio level is that low.
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Sunhillow
post May 20 2011, 17:47
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What settings did you use when the noise floor was encoded at high bitrates? You must not use the -b parameter with vbr ;-)

Bitrate in VBR encoding does not depend on frequency, but of the signal's spectral composition. If there is a lot of content that is not masked my other parts of the content you will need a higher bitrate. Examples for this are white (or pink) noise, cympals, trumpets, harpsichords, death metal etc

I would not send musig through a noisegate, this sounds ugly. Better try a dynamic expansion below an appropriate threshold ...

This post has been edited by Sunhillow: May 20 2011, 17:47
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