Re: cdrdao: CRC error
Le Fri, 08 Apr 2005 21:42:18 +0200, Gerard Robin a écrit :
> the result was fine but I got some errors:
>
> cdrdao copy --on-the-fly --source-device ATA:1,0,0 --device ATA:1,1,0
>
> Cdrdao version 1.1.9 - (C) Andreas Mueller <andreas@daneb.de>
> SCSI interface library - (C) Joerg Schilling
> Paranoia DAE library - (C) Monty
> ...
> ...
> Starting on-the-fly CD copy at speed 52...
>
> Track Mode Flags Start Length
> ------------------------------------------------------------
> 1 AUDIO 0 00:00:00( 0) 04:23:00( 19725)
> .....
> .....
> 15 AUDIO 0 53:30:73(240823) 04:39:43( 20968)
> Leadout AUDIO 0 58:10:41(261791)
>
> Raw P-W sub-channel reading (audio track) is supported.
> Analyzing track 01 (AUDIO): start 00:00:00, length 04:23:00...
> Found 8 Q sub-channels with CRC errors.
> Control nibbles of track match CD-TOC settings.
> Analyzing track 02 (AUDIO): start 04:23:00, length 03:21:21...
> Found pre-gap: 00:00:14
> Found 11 Q sub-channels with CRC errors.
> Control nibbles of track match CD-TOC settings.
> ......
> ......
> Analyzing track 15 (AUDIO): start 53:30:73, length 04:39:43...
> Found pre-gap: 00:01:73
> Found 6 Q sub-channels with CRC errors.
> Control nibbles of track match CD-TOC settings.
>
> Turning BURN-Proof on
> Enabling JustSpeed.
> Executing power calibration...
> Power calibration successful.
> Writing track 01 (mode AUDIO/AUDIO )...
> ....
> ....
> Writing track 15 (mode AUDIO/AUDIO )....
> Wrote 587 of 587 MB (Buffers 100% 98%).
> Wrote 261791 blocks. Buffer fill min 3%/max 100%.
> Flushing cache...
> Writing finished successfully.
> On-the-fly CD copying finished successfully.
>
>
> can someone explain to me the meaning of the lines:
>
> Found 8 Q sub-channels with CRC errors.
> Found 11 Q sub-channels with CRC errors.
> ....
> ....
> Found 6 Q sub-channels with CRC errors.
>
I am not a guru regarding cd burning. Those are just guess from the few i
know. Cdrom have error control : this means they not only copy the data
but also data to check if it is not corrupted and a few duplicate to
survive this breakage.
Those errors would mean that cdrdao found such corruption on the media ,
tough as it does not fails to copy i guess there was enough safe "control
data" to restore it.
That s why it is told to clean cdrom from the center to the edge. If you
scratch the medium as the control data is next to it. A scratch that only
happens on a radius won't destroy the control data.
So i would say that the medium you copy from is somewhat scratched and
may not survived a few other such damages . But the copy is safe (error
corrected and new clean medium ).
Greetings
Alban
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