68 mins of CD audio = ... 690 MB?!?!?! UPDATED

[RaynorWolfcastle]

ok, i'm completely stumped and don't know what to say.
I've tried using 2 different programs to converts mp3s to wavs for burning but no matter what I do, I always end up with a larger size then i should. NERO (and win explorer for that matter) tell me that 68 MB of CD audio = 690 MB

The wavs are encoded correctly: PCM,2 channels,16 bit, 44.1 KHz.

Can someone illuminate me as to what is wrong? I think one of the songs might have a problem (time not correct) but they all sound right. Is there any shorter way to discover whether this is really the problem, short of timing each song?

-Ice

 

[nortexoid]

i don't get what u're trying to do...

why dont' u simply encode the tracks to mp3 and let nero auto convert them for u...if u dont' want quality loss encode them to an extremely high mp3 (variable) bit rate.

 

[Sugadaddy]

CD audio are measured in minutes, not MB. If you have 80min CDR, just put 80 minutes of music on them. It'll be more than 700MB, but it doesn't matter. The 700MB is for data.

 

[Finality]

Encoding audio to a CD and to a .wav file are different. An audio CD has different standards.

Why not simply let Nero do the deocing for you? I just use the Wizard to create an audio CD. Drag and drop the mp3s into the CD and Nero decodes it into CD format.

 

[Sugadaddy]

Also make sure you're selecting CD-Audio, and not burning a data CD...

 

[zippy]

Yeah, it doesn't matter how many MB it is- so long as it's equal to or less than the number of minutes that the CD-R is rated for.

Also, I agree, just do the create audio CD wizard in nero, drag the MP3s to the window of the stuff to be burned, click burn and it converts them on the fly. Makes life...well, burning audio CDs...very easy.

 

[Hawk]

So what does it mean when Nero says "lost sync with MP3" or if the MP3 is bad or something? It still burns okay (at least I can't tell that it messed up...).

 

[Noriaki]

You can't compare Wav MB size to CDR MB size.

If you are burning Audio you use the Minute rating.
If you are burning Data you use the MB rating.

The size of the audio file in MB is irrelevant. Because if you use MP3s you can get it down to like 1MB/minute, but if you put 72minutes worth of MP3s into CD-Audio format it will still take up nearly all of the CD.

 

[Workin']

<< You can't compare Wav MB size to CDR MB size. >>

Don't be silly. Of course you can! Bits are bits, doesn't matter if it's music or porn or term papers. Actually, the CD audio data is slightly smaller than the .wav file size. The data structure of a .wav file and CD audio are the same - they are both linear PCM (pulse code modulated) data. The .wav file just has a header appended that tells the computer what it is and adds some error correction code to account for the different block sizes used to write a data file vs. CD audio. When you write a .wav file to a music CD the header is stripped, the block sizes are adjusted, and voila', it's a music CD!

The simple math: 44,100 samples/second X 60 seconds/minute X 16 bits/sample X 2 channels = 84,672,000 bits per minute of audio = 10,584,000 bytes/minute = 10.094 megabytes per minute of CD audio

icecool83 - you don't seem to have a problem, your .wav files are going to be about 10 or 12 times larger than the mp3 it came from.

edited for spelling

 

[Noriaki]

I fit 720MB worth of Wavs onto a 74minute CD last week...

That's a 70MB difference....

 

[Workin']

<< I fit 720MB worth of Wavs onto a 74minute CD last week...

That's a 70MB difference.... >>

It's a miracle! 720MB = less than 72 minutes! (720/10.094 = 71.3). The rated data capcity excludes space taken up by formatting and error correction data. Kind of like how a 1.44MB floppy is really 2MB, a 650MB CD-R is &quot;really&quot; lots larger.

For me it is easier to look at the raw data size than to try and figure out the time. For others it may be easier to use the time. But to say you can't figure out or use the data file size is plain wrong.

 

[NelsonMuntz]

<< Kind of like how a 1.44MB floppy is really 2MB, a 650MB CD-R is &quot;really&quot; lots larger. >>


??? I am stoopid. I don't get it? Is a 1.44 Mb floppy really 2 Mb?

 

[Workin']

<< I am stoopid. I don't get it? Is a 1.44 Mb floppy really 2 Mb >>

No, man, you're not stupid. A 1.44 floppy really has space for 2 MB. But when you format it, the format information takes up .56 MB of space, leaving 1.44 for data.

 

[wyvrn]

Yeah, same thing as when you use Direct CD to format a cdrom, you lost about 100 MB to the formatting. Floppies are larger than 1.44MB, but the writeable area is not.

 

[RaynorWolfcastle]

ok, here's the problem, i tried burning a cd twice and the burner choked, even though it said 78:06.09secs on an 80 min cd, this was with the NTI burning ROM. So i figure the burning program or my burner must have a problem, so i decided to check the burning prog and downloaded a demo of Nero. Just before trying another burn, I look in the info tab and it tells me 78 mins of audio = 793 MB. WTF?!?! a 74 minute CD is 650 MB, an 80 min CD is 700 MB but 78 mins of audio is 793 MB?!?!

So i reconverted the song with a different program, same result. I decided to trim it down, to something that would fit onto a CD, and i got 68 mins=690 MB.

Now I'm no audio expert but i have burned 75 mins of audio on a 700 MB CD, and all of a sudden, 68 min = 690 MB? Something is definetly wrong here.

I believe one of the songs might have a problem, and show that it is less time than it actually is, I'll have to check again.

Again, any ideas would be appreciated

-Ice

edit: this wasn't a buffer underrun problem btw, it gave me some weird illegal request error

 

[Workin']

<< a 74 minute CD is 650 MB >>

No dude, it's not. It's only &quot;650MB&quot; for data. It's significantly more for music. Go back and read my earlier posts in this thread!

Your file sizes sound about right - maybe one or more of the files are corrupt. Try converting them again and see what happens. Maybe you already did that... The problem is somewhere else, not in the disc capacity.

 

[Budman]

It all depends on what you're burning,when i make a VCD i can put 780megs into a 80min cd (700 megs).

As long as you dont go over the 74 or 80 min of the cd capacity you'll be fine.