MP3's and Bitrates

[snoogans]

CD quality is what, 44 hertz? What bitrate do they use? Just wondering if encoding over 128 or 192 is worth it. You can't go higher than the source...sounds logical.

 

[Robb33]

Whenever I DL mp3's I always look for ones that are over the bitrate of 128. You can really hear the difference.

 

[sciencewhiz]

Ok so this a half-assed way to get CD bitrates but here it goes:

A CD hold 650 MB which is 5200Mb which is 5324800 Kb. A CD is 74 minute long or 4440 seconds. Divide the 2 and you get 1200 Kb/sec.

 

[Workin']

CD bitrate:

44,100 samples/sec X 16 bits/sample x 2 channels = 1,411,200 bits/sec

Means the CD audio bitrate is about 1.4 MEGAbits/sec - quite a bit higher than 128 kilobits/sec. Like about 11 times higher. So you don't have to worry that your mp3 bitrate will be higher than a CD's!

And yes, there can be a substantial difference in sound quality going from 128 kbits to 192 - that's a 50% increase in data rate. But you can see that mp3 quality can't even approach CD quality - obviously when you throw out 90% of the data (1.4 Mb/s to .128 Mb/s) something gets lost....

 

[snoogans]

Ah ha...didn't know the bitrate was that high for CD's. Thanks for clearing that up, guys

Guess i should start using 192 more often

 

[sciencewhiz]

Only encode as high as you can hear the difference. If you can't tell the difference between 128 and 192, why waste the diskspace.

 

[Becks2k]

okay 128 is crap 192 should be the min, i do 256 to be save and its a nicer number than 192. I tried up to 320 and mp3s always sound a little different than the wave, i'm probably biased in my comparision but the mp3 always seems to be missing something.

anyways 128=crap 192 is the min i'll dl 256 is waht i encode at

 

[glen]

Blind testing has shown that properly encoded mp3s, especially vbr, are indistiguishible from CD about half the time.

 

[Becks2k]

properly encoded at what bit rate?

 

[glen]

Let me see if I can find one of the blind tests done on the net. Mp3s are surprisingly good.

 

[glen]

Link to article on mp3 vs CD quality with results of blind testing

 

[glen]

MP3 vs AAC vs WMA

 

[glen]

Good article on 128 vs VBR vs 256 vs cd quality

 

[Workin']

Glen, those are some good links. I've seen the S&V ones before, actually I think I posted them a few weeks ago during a heated Fraunhofer vs. Xing vs. Blade vs. LAME debate on these boards.

That last link sums it all up pretty well, and I would have to agree that after trying all the mp3 encoders out there, LAME VBR is by far the best sounding, I usually use V4, JS, min. bitrate 92k (typical average bitrate ~130) instead of V1, JS, min. bitrate 128k (typical average bitrate ~180) because I can't usually hear the difference and the smaller file size meets my needs better. But with few exceptions I can't tell the mp3 from the source when encoded that way. Plus, LAME is free, which is incredible. The only drawback is that encoding on my system (C300A@464) is slightly slower than real-time.

 

[glen]

Which software do you use the LAME codecs with? Can I make my Adaptec software use the LAME codec?

 

[sciencewhiz]

I thought that Blade used the Fraunhofer algorithm.

I'm not really into MP3s but I read on the BladeEnc website that Blade sounds better when encoding at above 160 and LAME wins when recording below 160. I have to say that when I encode with blade at 128 or below, it sounds awful. I do most of my encoding with Blade at 192 or 320 depending on what I am going to use it for.

 

[Strafe]

I'm in the process of archiving all of my cd's I'm using LAME and EAC to get my files as close to original as possible with compression. I use LAME VBR with -V1 -mj -h -b128 options which gives me variable bitrate files no lower than 128Kbps. I've done about 30 discs so far and the average bitrate has been ~180-200. That way I dont have to encode at 320Kbps to make sure I'm not losing anything. The file minimum is 128 and it varies up to 320 depending on what the track requires.

see r3mix.net for some excellent info.

 

[Workin']

sciencewhiz - I think Blade uses ISO code, not Fraunhofer.

glen - I use cdex with LAME, but there are several other front-ends for it. I don't think there's a way to get Adaptec to use the LAME encoder.

 

[sciencewhiz]

workin', you are right. I remembered wrong. I guess I'll have to check my facts before I post next time.

 

[minus1969]

is there a program that converts high bitrates to low bitrates? I use a diamond Rio w/ 32 megs of memory, so I can tollerate lower bitrates if it means more music. Anyone know of a program that does this?

 

[glen]

I think any ripper will do it.