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View Full Version : quicktime export to AIFF and Cd burning..




trevu
Sep 20, 2008, 09:23 AM
Could someone who actually knows the definitive answer please lend me a hand with the following questions....

1) If I have a mp3 file encoded at 192kbps with LAME 3.97 from an unknown source (hopefully the original CD, but this could be an issue) and then I export it to AIFF in quicktime Pro, do I now have essentially a CD quality version of the same track? I have some orchestral classical music at mp3 192kbps and some excellent headphones which will really bring out the rich sound IF this is an accurate assumption. I have tried it and listened to it and I think I hear this increased depth to the sound, but its not as obvious as I expected.....I figured my logic may be flawed. I guess the source quality of the file that was compressed to mp3 holds the key.

2) If I have an album bought from the itunes store at 128kbps aac and I burn it to a CD as an audio CD, do I now have in my hand essentially a CD with the songs at the same quality as the original CD source, i.e. itunes expands the compressed files back, OR do i have tracks in AIFF format but limited to the quality of the compressed file. Obviously you can change the format of any music file, but not necessarily de-compressing it out to its original quality.

Ta



WinterMute
Sep 20, 2008, 03:40 PM
No, what you have is a bigger version of the quality that was originally in the MP3.

All lossy codecs use what is called perceptual encoding, which means the codec decides what parts of the frequency range and dynamics you couldn't hear and removes them. This is how it reduces the data rate, the lower the rate, the more the waveform has been bastardised.

You will be able to burn a correctly encoded audio CD from the resulting conversion, as the files will be.aiff, however they can never recover the lost information, and are simply larger versions.

If the MP3 sound OK to you it will still sound OK off the CD, but it won't sound better.

trevu
Sep 20, 2008, 06:26 PM
I really appreciate that answer and should have asked it quite a long time ago...........

Thanks for clearing that up - my ears don't deceive me! :)