Hardware: Sony CRX140S CD ReWritable Recorder
Software RH 7.2 kernel 2.4.9-13 sox-12.17.1-4 cdrecord-1.10-4 cdrecord-devel-1.10-4
Using cdrtoaster-1.12 to burn an MP3 to an audio cd results in never recorded before "chipmunks" coaster. The audio sounds like a 33rpm record played at 45rpm. This may be a bad analogy for the CD exposed generation. Analyzing the script from cdrtoaster the creation of a CD takes place in two steps. One step converts the mp3 to wav the next step burns the cd.
Audio convert: mpg123 -s sample1.mp3|sox -t raw -w -s -c 2 -r 44100 - -t wav sample1.wav
CD burn: cdrecord -v -eject dev=/dev/sg0 speed=4 -audio -pad /home/username/sample1.wav
I have tried doing the audio convert manually an it produces a chipmunks wav file. If I change the rate parameter to -r 22050 the wav file is produced correctly. The new file is not in the correct format for cdrecord to handle and produces an error message "Inappropiate audio coding". According to my reading a wav file must be created with 16bit 44100hz sample rate. I have also tried changing the mp3 player to the GPL version mpg321-0.1.5-1 with no success. I have found no indication at the SOX site of any problems with the software.
This is my first foray into CD burning using Linux. The burner works fine under windows95 and its software. I have made a decision to eliminate as many windows machines as I can. My project is the burner/scanner box.
Sean
While cleaning up my mailbox, I came across this message from Jan 3, which I don't think was ever answered. My apologies if this isn't news to anyone...
According to S/C Conway:
Using cdrtoaster-1.12 to burn an MP3 to an audio cd results in never recorded before "chipmunks" coaster. The audio sounds like a 33rpm record played at 45rpm. This may be a bad analogy for the CD exposed generation. Analyzing the script from cdrtoaster the creation of a CD takes place in two steps. One step converts the mp3 to wav the next step burns the cd.
Audio convert: mpg123 -s sample1.mp3|sox -t raw -w -s -c 2 -r 44100 - -t wav sample1.wav
CD burn: cdrecord -v -eject dev=/dev/sg0 speed=4 -audio -pad /home/username/sample1.wav
It appears cdrtoaster assumes the MP3 file will be sampled at 44.1 KHz, which is why it puts the -r 44100 before the input filename, "-".
I have tried doing the audio convert manually an it produces a chipmunks wav file. If I change the rate parameter to -r 22050 the wav file is produced correctly. The new file is not in the correct format for cdrecord to handle and produces an error message "Inappropiate audio coding". According to my reading a wav file must be created with 16bit 44100hz sample rate.
WAVE files can support a number of sampling rates, but for burning to audio CDs they must be 16 bit stereo at 44.1 KHz. If the WAVE file you produce at 22.05k play correctly, this must be the sampling rate of your MP3 (surely there must be an easy way to query the MP3 for this info). If you want sox to resample to a different rate, you must specify -r options on both the input and output sides of the command line (before and after the input file name). You may want to read up on polyphase, rate and resample effects in sox(1) and experiment with what works best. The default is "rate", which does quick linear interpolation, and isn't usually ideal if sound quality matters.
I have also tried changing the mp3 player to the GPL version mpg321-0.1.5-1 with no success. I have found no indication at the SOX site of any problems with the software.
This is my first foray into CD burning using Linux. The burner works fine under windows95 and its software. I have made a decision to eliminate as many windows machines as I can. My project is the burner/scanner box.
Sean
Near as I can tell, it's not a problem with the burner or any of the software components you're using. Just a bad assumption by cdrtoaster's handling of MP3s - it really should enquire about the actual sampling rate used in the MP3, or even in WAVE files, and get sox to resample accordingly.
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Gilles Detillieux -
S/C Conway