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Old Apr 30, 2009 | 04:30 PM
  #51  
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I burned a CD off of itunes, and most of the songs on the CD were purchased, and like half of the tracks were not able to be read, any idea what the problem is?? The songs are in mp3 and mp4 (or whatever itunes uses) format. There were like 2 that weren't purchased that are mp3.
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Old Apr 30, 2009 | 04:36 PM
  #52  
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Originally Posted by kapusta' post='864633
I am not burning MP3 CD's. I think MP3's do not suffer from quality loss but audio CD's do.
I might be wrong though...
MP3s are compressed audio, they are innately lower quality that a pure CD quality audio file. When you record them to CD you are converting them to a uncompressed audio stream with artifacts from the MP3 encoding still there. If the burning process introduces errors then you are only compounding the problem.
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Old Apr 30, 2009 | 04:40 PM
  #53  
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You misunderstood me.

Audio CDs are uncompressed.
Your audio files on your hard drive most likely are. (mp3 etc.)
When you're burning an audio CD, the burning software has to decode your compressed audio files while it's writing them to disk. If you're burning them at 48x then the software has to decode them at 48x their playback speed, and depending on your CPU speed and decoder efficiency, the software may decide to decode at lower quality to keep up with the burn speed.

My suggestion - decode them into WAV files prior to burning.
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Old Apr 30, 2009 | 04:49 PM
  #54  
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Originally Posted by kapusta' post='864681' date='Apr 30 2009, 08:40 PM
You misunderstood me.

Audio CDs are uncompressed.
Your audio files on your hard drive most likely are. (mp3 etc.)
When you're burning an audio CD, the burning software has to decode your compressed audio files while it's writing them to disk. If you're burning them at 48x then the software has to decode them at 48x their playback speed, and depending on your CPU speed and decoder efficiency, the software may decide to decode at lower quality to keep up with the burn speed.

My suggestion - decode them into WAV files prior to burning.
Oh ok I get it. But if I burn them at 1x, then I don't have to convert them to WAV before to get the highest quality, right?
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Old Apr 30, 2009 | 04:59 PM
  #55  
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Originally Posted by kapusta' post='864681' date='Apr 30 2009, 08:40 PM
You misunderstood me.

Audio CDs are uncompressed.
Your audio files on your hard drive most likely are. (mp3 etc.)
When you're burning an audio CD, the burning software has to decode your compressed audio files while it's writing them to disk. If you're burning them at 48x then the software has to decode them at 48x their playback speed, and depending on your CPU speed and decoder efficiency, the software may decide to decode at lower quality to keep up with the burn speed.

My suggestion - decode them into WAV files prior to burning.
The Redbook Audio CD format requires a 720 kbit/s audio stream, you can't really 'decode' at a lower quality because you still need a data stream at this rate, there's no shortcut to decoding, if your computer is slow you might have buffer underrun problems. If your CD burner buffer underrun protection this type of problem should not happen. CD burning software does the conversion to WAV format while it sends data to the buffer.
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Old Apr 30, 2009 | 05:01 PM
  #56  
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Originally Posted by Krozi' post='864694' date='Apr 30 2009, 08:49 PM
Oh ok I get it. But if I burn them at 1x, then I don't have to convert them to WAV before to get the highest quality, right?
Correct

or get better burning software that would vary the burn speed instead of decoding quality.
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Old Apr 30, 2009 | 05:09 PM
  #57  
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Originally Posted by kapusta' post='864712' date='Apr 30 2009, 09:01 PM
Correct

or get better burning software that would vary the burn speed instead of decoding quality.
So I was right that the sound quality is better at lower burn speed? For me at least?
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Old Apr 30, 2009 | 05:11 PM
  #58  
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Originally Posted by Brit_in_NJ' post='864707' date='Apr 30 2009, 08:59 PM
The Redbook Audio CD format requires a 720 kbit/s audio stream, you can't really 'decode' at a lower quality because you still need a data stream at this rate, there's no shortcut to decoding, if your computer is slow you might have buffer underrun problems. If your CD burner buffer underrun protection this type of problem should not happen. CD burning software does the conversion to WAV format while it sends data to the buffer.
True, but we're talking about decoding compressed audio. Most codecs allow speed vs. quality tradeoffs in decoding compressed audio and feeding the uncompressed "720 kbit/s stream" to the burn engine.
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Old Apr 30, 2009 | 05:12 PM
  #59  
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Originally Posted by kapusta' post='864717' date='Apr 30 2009, 09:11 PM
True, but we're talking about decoding compressed audio. Most codecs allow speed vs. quality tradeoffs in decoding compressed audio and feeding the uncompressed "720 kbit/s stream" to the burn engine.
I have no clue what you just said but it sounded good
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Old Apr 30, 2009 | 05:12 PM
  #60  
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Originally Posted by Krozi' post='864714' date='Apr 30 2009, 09:09 PM
So I was right that the sound quality is better at lower burn speed? For me at least?
yes.

That was the net effect. The cause was compressed audio decoding speed not burn speed.
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