[MEncoder-users] Does MEncoder has issues with AAC audio encoding?

Werner Van Belle werner at yellowcouch.org
Mon Jul 16 01:05:09 CEST 2007


Hello,

I have been following this treath from afar, but it seems to me that the 
oringal poster his soundcard might be the problem. Many soundcards (including 
soundblaster stuff) also amplify the signal digitally. So, if you have a sine 
wave in, and the sound cards mixer device is set to 100% then it will amplify 
the sine wave above the 32767 value, and thus end up with a clipped wave. 

This will of course only happen when the bytes going into the soundcard have 
an amplitude that is sufficiently high. Distortion will not occur if only an 
amplitude of 16384 is sent in the soundcard. Therefor, I suspect that the 
difference between the two decoders/encoders lies not in their quality but 
rather in the output amplitude they achieve.

Practically: if the origanl poster could turn down his PCM and master volume 
to 75% then I suspect no distrotion will occur in any case.

With kind regards,

Werner,-

-- 
Dr. Werner Van Belle
http://werner.yellowcouch.org/
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