Unable to extract audio cd tracks

[David Demelier]

On 19/12/2010 15:41, Polytropon wrote:
> On Sun, 19 Dec 2010 14:41:50 +0100, David Demelier<demelier.david at gmail.com>  wrote:
>> Thanks,
>>
>> The handbook says we must `taste' the media, it works but it prints a
>> warning
>>
>> markand at Melon ~ $ dd if=/dev/acd0 of=/dev/null count=1
>> dd: /dev/acd0: Invalid argument
>> 0+0 records in
>> 0+0 records out
>> 0 bytes transferred in 0.000132 secs (0 bytes/sec)
>>
>> I just realized that using the block size for the same thing works :
>>
>> markand at Melon ~ $ dd if=/dev/acd0 of=/dev/null count=1 bs=2352
>> 1+0 records in
>> 1+0 records out
>> 2352 bytes transferred in 2.893379 secs (813 bytes/sec)
>>
>> I propose modifying the following :
>>
>> http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/creating-cds.html
>>
>> Make sure the appropriate files exist in /dev. If the entries are
>> missing, force the system to retaste the media:
>>
>> # dd if=/dev/acd0 of=/dev/null count=1 *bs=2352
>>
>> Then people who try that won't be surprised by the Invalid argument error.
>
> A good idea - again one step into the right direction
> of providing high-quality documentation.
>
> In fact, I have never needed to "taste" the media in my
> extraction scripts, but I now do realize WHY: Before using
> dd bs=2352 to get the data, I did
>
> 	cdcontrol -f /dev/acd0 info
>
> which prints out the TOC of the audio CD and, I assume,
> makes sure the corresponding /dev/acd0tNN track files
> get created; cdcontrol is part of the base system so it
> should be possible to rely on its presence, at least on
> FreeBSD.
>

I didn't know this one! I think it's even better to use that, it prints 
information on every tracks.

Cheers,