I hear a lot about CBR and VBR; what’s wrong with ABR?, Was “MP3 ABR WHY NOT.” (shouting won’t make anyone likelier to reply) Options

[soylentgreen]

I have read numerous forums and articles about mp3 cbr and vbr, some swear by cbr others vbr, the debate just goes on and on. I,ve tried cbr 256, vbr 256, cbr 320, cbr 192 cbr etc and I cant hear any difference. My question is why bother with cbr or vbr, why dont people just go with MP3 ABR, would this not be the ideal compromise, or I am missing something, as there does seem to be lack of mp3 abr on offer as downloads from the likes of Napster etc.

[Northpack]

I have read numerous forums and articles about mp3 cbr and vbr, some swear by cbr others vbr, the debate just goes on and on.

I'd be very, very sceptical when people "swear" by something. Either you have reasons for using certain encoder settings under certain conditions - then you should be able to explain those reasons in accordance with the technical specifications of the encoder - or you just have an unfounded and irrational belief that some settings subjectively sound better to you - then all you can do is to "swear" by them.

Just think about what the concept of variable/constant bitrate means in terms of quality:

VBR - variable bitrate, constant quality
CBR - constant bitrate, variable quality

If you have a file encoded at an average of 160kbps, it is very likely that the VBR file will sound better than the CBR file. So unless you want to use MP3 at its limit where both modes converge (320kbps), VBR is always preferable for quality. CBR mode only makes sense for those scenarios where you absolutely need a constant bitrate. Even for streaming applications, there's often a small deviation in bitrate allowed over a period of time, so the ABR mode was developed as a compromise between the two (average variating bitrate, more constant quality than CBR).

This post has been edited by Northpack: Oct 7 2011, 08:38