How to exlpain that VBR > 192 CBR
Reply #5 – 2008-04-02 09:32:24
Short version: - There are two kinds of "quality" - technical/theoretical, and perceived/practical. The first describes how accurate a signal is stored on a media, before it even reaches your ears. The second describes how indistinguishable to the original it sounds to you, in your mind. - The term "CD Quality" describes a certain "technical qualitylevel" - it is not about "perceived quality". Thus, even if you perceive something as "indistinguishable", it may still on the media (i.e. harddrive) be stored at below CD-Quality. Why is that possible? Well, because: your hearing-abilities < CD-Quality - Why does technical quality matter anyways? Well, it matters whenever what you do with audio is NOT listening, but something else. MP3 is good enough for listening, but it does not have reserves if you do significant additional processing on the audio - this applies to reencoding as well as intensive DSPs. - Not all music is the same. A track has more difficult to compress parts, and less difficult to compress parts. CBR cannot distinguish between the two - it always puts in the same effort, no matter if its difficult to encode parts, or easy to encode parts. VBR on the other hand can put in more effort for difficult parts, and save effort during easy parts. Thus, the soundquality of CBR goes "up and down", while with VBR, it is more constant. (CBR = constant bitrate, variable quality | VBR = variable bitrate, constant quality). - Lyx