[RedSmurf]

Originally Posted by Starcat

As far as bitrates are concerned, am I correct in thinking that CD bitrate is 1411 kbps?
If so, if 320 or 384 is supposedly "CD quality", that still leaves a huge difference between them and true CD bitrates (more than 1000 kbps).
Why the big discrepancy?

Because 384kbps is not "CD quality". The only thing that's CD quality is uncompressed or losslessly compressed audio. They just use that term because practically nobody can discern between actual CD audio and MP3 at such bitrates.

[Nightfly]

Originally Posted by RedSmurf

Because 384kbps is not "CD quality". The only thing that's CD quality is uncompressed or losslessly compressed audio. They just use that term because practically nobody can discern between actual CD audio and MP3 at such bitrates.

Redsmurf,

What is ABR ...I see this when I download VBR files sometimes.

I know it's the same as VBR but what does the "A" stand for?

Thanks

[vikulenka]

Originally Posted by Nightfly

Redsmurf,

What is ABR ...I see this when I download VBR files sometimes.

I know it's the same as VBR but what does the "A" stand for?

Thanks

Sorry, I am not RedSmurf, but I found that it means Average Bit Rate :-

An Introduction to Compressed Audio with Ogg Vorbis

Not sure I fully understand the difference between constant and average bitrate though.

Sorry, not an audiophile.

[Nightfly]

Originally Posted by vikulenka

Sorry, I am not RedSmurf, but I found that it means Average Bit Rate :-

An Introduction to Compressed Audio with Ogg Vorbis

Not sure I fully understand the difference between constant and average bitrate though.

Sorry, not an audiophile.

Thank you Average Bit Rate is the same as Variable Bit Rate which
is my preference...

Thanks for telling me what the A stands for...

[vikulenka]

Originally Posted by Nightfly

Thank you Average Bit Rate is the same as Variable Bit Rate which
is my preference...

Thanks for telling me what the A stands for...

Hmmm, not according to that article's description. ABR is constant, rather than variable. Unless I am missing something.

[Nightfly]

Originally Posted by vikulenka

Hmmm, not according to that article's description. ABR is constant, rather than variable. Unless I am missing something.

When I download a file from Sparks using VBR 256 it comes down
as abr.256 but I am certain that it is VBR because I can see the changes
in my winamp player.When I use constant the player will stay at 256 and not move.When I have a vbr file it changes br according to the music dynamics.

Maybe it is just a mp3 labeling problem.But I think we will soon find out....

[phobozad]

Originally Posted by Nightfly

When I download a file from Sparks using VBR 256 it comes down
as abr.256 but I am certain that it is VBR because I can see the changes
in my winamp player.When I use constant the player will stay at 256 and not move.When I have a vbr file it changes br according to the music dynamics.

Maybe it is just a mp3 labeling problem.But I think we will soon find out....

You could say that average bitrate is a type of variable bit rate. The encoder aims to end up averaging the bitrate specified - going a little above and below it throughout the encoding. VBR is quality based. You can specify either a quality "rating" or just the max and min bitrates. The encoder will attempt to maximize quality by analyzing how much of a quality difference there will be between the original and encoded sound. When increasing the bitrate will not result in a certain amount of quality increase that is the bitrate it will encode that chunk with. VBR gives the best sound quality, however it also tends to be a larger file (especially if the maximum bitrate is set high). With CBR (constant bit rate), the entire song is encoded at the same bitrate, which ends up wasting bits on simple parts and loosing quality on complex sounds.

Unless you are super anal about sound quality like me (I can't even listen to 128kbps or even 160kbps mp3s) you won't be able to tell the difference between ABR and VBR (unless it is a very low bitrate).

[Nightfly]

Originally Posted by phobozad

You could say that average bitrate is a type of variable bit rate. The encoder aims to end up averaging the bitrate specified - going a little above and below it throughout the encoding. VBR is quality based. You can specify either a quality "rating" or just the max and min bitrates. The encoder will attempt to maximize quality by analyzing how much of a quality difference there will be between the original and encoded sound. When increasing the bitrate will not result in a certain amount of quality increase that is the bitrate it will encode that chunk with. VBR gives the best sound quality, however it also tends to be a larger file (especially if the maximum bitrate is set high). With CBR (constant bit rate), the entire song is encoded at the same bitrate, which ends up wasting bits on simple parts and loosing quality on complex sounds.

Unless you are super anal about sound quality like me (I can't even listen to 128kbps or even 160kbps mp3s) you won't be able to tell the difference between ABR and VBR (unless it is a very low bitrate).

Hey Phob,

I appreciate your detailed answer, that I always wondered about.

Even though the Sparks abr.256 sounds great to me.It's not vbr as I thought.
I feel that it is a slight misrepresentation of the actual quality
that you "think" you are getting.... You can only see it only when you manually download from Sparks instead of using Alltunes..Manually is much faster.

[jazzy639]

Theres a 224kbps VBR option which I tend to use. Are we saying that VBR > ABR? If so, could 224kbps VBR > 256kbps ABR?

[RedSmurf]

Originally Posted by jazzy639

Theres a 224kbps VBR option which I tend to use. Are we saying that VBR > ABR? If so, could 224kbps VBR > 256kbps ABR?

Yes, that's possible for certain songs. "224kbps VBR" just means that when encoding a large amount of different songs, the bitrate will average to 224kbps. But a song that contains weird sounds that are hard to encode, can require more than 256kbps, and songs with only smooth sounds will require less. For instance, I mostly encode in Ogg Vorbis at quality setting 6, which should average to 192kbps. But "Alpha Beta Gaga" by Air requires 248kbps when encoded in this format. "777" by Autechre scores even higher with 263kbps.