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MAX not following my settings for 192kbps CBR .m4a?

Posted: Mon May 15, 2006 1:35 pm
by mullet
I set my encodes to be .m4a set to 192 kbps CBR... and the outputs range from 189kbps to 192kbps. What gives? Are these VBR files? or is this this how MAX handles encoding? The files sound and work fine on my iPod, but I'm not so sure this is how MAX should be behaving. Any insight would be appreciated...


Posted: Thu May 18, 2006 11:59 pm
by folded_bread
I also have experienced this bit rate variation. Specifically trying to do .m4a 192/CBR and then looking at the bit rate it varies from 187-190 usually. Anyone know what's going on?

Posted: Fri May 19, 2006 12:35 am
by sbooth
I am by no means an expert but what I gather by reading is that "true" CBR only applies to codecs with with a fixed frame size (e.g. old-style MP3). For encoders that have a minimum frame size or use a "bit pool" for CBR encoding (like AAC) you will never get an exact bitrate.