So VBR with highest quality setting it is then. Thank you for this full and very helpful explanation. Cheers Amie
-----Original Message----- From: pc-audio-boun...@pc-audio.org [mailto:pc-audio-boun...@pc-audio.org] On Behalf Of Kevin Lloyd Sent: 30 December 2009 13:40 To: PC Audio Discussion List Subject: Re: Pros and cons of varible bit rate Yep, there would be a difference but the higher the ABR then the smaller the difference between the resulting file and that encoded using high quality VBR. For example, if you set your ABR to 300kbps then ABR would steal a little from less complex parts of the music and use those to supplement parts of the music that are more complex and need more than 300kbps. The result is that ABR will try to maintain a jagged line around the 300kbps mark so imagine it just dropping slightly above and below the line through the music track. With VBR with a maximum of 320kbps then you are guaranteed that if a long part of the track needs 320kbps then it will get that. You don't have that guarantee with ABR because it may not have enough bits in hand from the less complex parts of the track to maintain 320kbps for the same amount of time and may instead cap it at 310kbps. ABR is a poor man's VBR where it is important that you can predict the file size. Much better than constant bit rates of less than 320kbps though. For example, a file at ABR of 256kbps will sound better than a file encoded with a constant bit rate of 256kbps. The reason being that the ABR file will be fluctuating just above and below the 256kbps mark as required whereas the constant bit rate will have been crudely chopped as soon as it needed to go above 256kbps. Regards. Kevin E-mail: kevin.llo...@sky.com ----- Original Message ----- From: "Amie Slavin" <amie.sla...@ntlworld.com> To: "'PC Audio Discussion List'" <pc-audio@pc-audio.org> Sent: Wednesday, December 30, 2009 12:28 PM Subject: RE: Pros and cons of varible bit rate > So is there any difference between ABR set to a higher bit rate and VBR > with > the quality set to the highest? > Amie > > > -----Original Message----- > From: pc-audio-boun...@pc-audio.org [mailto:pc-audio-boun...@pc-audio.org] > On Behalf Of Kevin Lloyd > Sent: 27 December 2009 14:00 > To: Kevin Lloyd; PC Audio Discussion List > Subject: Re: Pros and cons of varible bit rate > > and here's a reference to the choices around minimum bit rates when using > VBR: > CDex Manual > File Edit Bookmark Options Help > Contents Index Back Print Up << >> > Bitrate Options: > There are three types of bitrate options that you can specify for each the > encoder (although some encoders may not allow any options). > 1) Constant Bitrate (CBR) > This is the default encoding mode, and also the most basic. In this mode, > the bitrate will be the same throughout the whole file. So, a second of > audio > from one > part of the file takes just as much disk space as a second from any other > part of that file -- regardless of whether either part is silence, > acoustically > simple, or > quite complex. This means that you are likely to hear distortion more in > the complex parts than in the simple parts. The advantage of CBR formats > is > > that > even > older players understand them, and that you can reliably predict the file > size from the duration of the sound (or vice versa). > 2) Average Bitrate (ABR) > In this mode, you tell the encoder to aim for an average bitrate that you > specify, skimping on the simpler parts of the music, and using higher > bitrates > for the parts > of your music that are more complex. The result will be of higher quality > than you'd get in a CBR encoded file of the same size. This mode is highly > recommended > > over CBR. This encoding mode is similar to VBR. > 3) Variable bitrate (VBR) > In this mode, you say what level of quality you want in the output file, > and > > the encoder compresses each second as best it can to get just that level > of > quality -- > using less information to represent simpler parts of the song, and more > information to represent the more complex parts. However, this mode relies > heavily > on the > encoder's model of how you perceive quality, and could lead to a few "bad > choices" in the encoding process. If possible, you may want to specify a > minimum > > bitrate (e.g., 64 Kbps) to avoid those potential errors. > > > To unsubscribe from this list, send a blank email to: > pc-audio-unsubscr...@pc-audio.org > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.430 / Virus Database: 270.14.118/2584 - Release Date: > 12/23/09 > 19:02:00 > > > To unsubscribe from this list, send a blank email to: > pc-audio-unsubscr...@pc-audio.org To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.431 / Virus Database: 270.14.121/2589 - Release Date: 12/30/09 07:27:00 To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org
