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Re: cdda2wav giving more than 700 MB of wav files



H. S. wrote (Friday 24 June 2005 8:23 am):
> While making a backup a music CD, I noticed that I am getting around
> 728MB of wav files from the original.

If I understand the process correctly, this is entirely normal. You see, a 
given CD can either have up to 700MB of data or up to 80mins of audio. But 
80mins of audio equates to 807.5MB of data!

The reason for this is that in data mode a whole bunch of error-checking data 
is interspersed with the real data on the CD, and naturally the 
error-checking data takes up space. In audio mode this error-checking data is 
considered unnecessary and is not used, freeing space for more audio. If you 
were to add in the same error-checking to an audio CD you'd lose more than 10 
minutes of available audio time.

The quality flag of cdda2wav probably has no relation to the file size. WAV is 
a raw, uncompressed file type, so the size of a wav file for a given duration 
of audio is exactly predictable, (44100 samples/sec, 2 channels, 2 
bytes/channel/sample. The size in bytes is then 44100 * 2 * 2 * duration in 
seconds.) If you want something smaller you'll have to look into some sort of 
compressed format. If for your purposes a lossy format is adequate, I'd 
suggest Ogg Vorbis. Otherwise, FLAC might be good (though it is larger than 
Vorbis, they're both smaller than WAV).

Hope that helps,
Brendon

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