Subject: Re: [linux-audio-user] Playback slow from burned CD's
From: Michael L Welles (mike_AT_bangstate.com)
Date: Wed Dec 04 2002 - 22:03:02 EET
look into using sox for downsampling -- it has enough configuration
options that you can really fine tune the quality. I've used it for a
ton of projecst -- it's the swiss army knife of audio tools.
Mark Knecht wrote:
> This problem can occur (a bit more in Linux than Windows since Linux
>gives us more freedom but requires more study) if you actually recorded your
>session at 48K, but are putting it on CD at 44.1K. If the notes are off by
>about 1 whole note (a recorded C became a B flat on the CD) then this is
>likely what you're hearing.
> If your wave files are really 48K (no matter what they say they are) then
>look into resampling them down to 44.1K before writing the CD. There is open
>source software to do that, but I haven't used any yet.
> I've been burned by this problem a couple of times. The most interesting
>one was when I was doing a 48K Pro Tools session and sending an ADAT sync to
>a GigaStudio box, but using 44.1K libraries. In that case I had to play a
>whole note low because the libraries were getting played back too fast.
> It happens...
>[mailto:linux-audio-user-admin_AT_music.columbia.edu]On Behalf Of Speaker
>Sent: Wednesday, December 04, 2002 8:20 AM
>Subject: Re: [linux-audio-user] Playback slow from burned CD's
>The 44100 Hz sample rate is absolutely the only one ever used for CD's,
>but high end audio cards like the Hammerfall tend to be more flexible.
>So probably a bug or misconfiguration of the audio card or driver is
>causing the wavs to be recorded (and played back) at a faster sample
>rate. "arecord" thinks it is getting 44100 Hz data, so that's what it
>puts in the header, but it is evidently mistaken. "cdrecord" only knows
>what is in the header, so it doesn't realize the data is at the wrong
>sample rate. Look for a way to tell the Hammerfall what sample rate to
>use, either a module option, ALSA config file option, or a
>Hammerfall-specific utility program. Sorry to be so vague, but I've
>reached (if not passed) the limit of my knowledge.
>On Tuesday 03 December 2002 03:17 pm, patrick reardon wrote:
>>i don't know if this is the right forum for my question, but here
>>i'm running on Intel PIII with kernel 2.4.18, ALSA, and a Hammerfall
>>9632 card. CD quality WAV files recorded with ALSA from live
>>performances play back with no problem via "aplay".
>>a Yamaha CRW8424S scsi burner was recently installed and i burned the
>>WAV files to CD with both "cdrecord" and "cdrdao". data is actually
>>transferred but when i play the CD's with a CD player, the tunes are
>>too slow and too low by about a minor third.
>>i tried burning at various speeds from 1x to 8x, but always the same
>>problem. have also tried a variety of other options to "cdrecord,"
>>like using a really big buffer, etc. the commands "file" and "aplay"
>>give the following information:
>>$ file blues1.wav
>>blues1.wav: RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16
>>bit, stereo 44100 Hz
>>$ aplay blues1.wav
>>Playing WAVE 'blues1.wav' : Signed 16 bit Little Endian, Rate 44100
>>Hz, Stereo --------snip-----------
>>i wrote to Jorg Schilling who developed "cdrecord", but he only said
>>i need to use 44100 Hz data and that if ALSA wrote incorrect headers,
>>i should write the ALSA group instead. i doubt it's a problem with
>>at any rate, i'm out of ideas. has anyone experienced a similar
>>problem? any pointers would be greatly appreciated.
>"Can you remember the future? Forget it!"
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