Re: bug/request: multi-processing for CD devices

Re: bug/request: multi-processing for CD devices

[Michael Buesch]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Saturday 06 September 2003 21:45, Max O'Shea wrote:
> Hello,

Hi,

> Summary: request for multi-processing for CD devices (I think the word is
> 'multi-processing' - ie. so that you can play an audio CD and browse the
> audio CD using a program such as konqueror at the same time)
>
> Full description: At the moment, if you are playing an audio CD with one
> program and you start accessing the audio CD with another program, the
> music will stop playing.

As far as I know that should be impossible, because audio-playing
runs 100% on the cd-rom hardware itself. The OS has nothing to do
with it.
So your request should go to the device manufacturers and ask
them if they could build devices, that are "multithreaded". :)
(But it maybe, that this was total crap and I better had thrown
this mail to /dev/null. I'm not 100% sure. 8-) )

- -- 
Regards Michael Buesch  [ http://www.tuxsoft.de.vu ]
Animals on this machine: some GNUs and Penguin 2.6.0-test4-bk2

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.2 (GNU/Linux)

iD8DBQE/Wi3PoxoigfggmSgRAv7nAJ9FWCFjuLcrSgqfxWWaOXvWZ7A3wACZAf3r
X1KNMtG5lO0ptS7/cVt4qV8=
=NZoP
-----END PGP SIGNATURE-----

bug/request: multi-processing for CD devices

[Max O'Shea]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hello,

I don't know if this would be considered a 'bug', maybe more of a feature 
request?

Summary: request for multi-processing for CD devices (I think the word is 
'multi-processing' - ie. so that you can play an audio CD and browse the 
audio CD using a program such as konqueror at the same time)

Full description: At the moment, if you are playing an audio CD with one 
program and you start accessing the audio CD with another program, the music 
will stop playing.

Keywords: audio, sound, /dev/hdc , /dev/ide0, alsa, oss

Here's a little bit of system information if it helps:

Kernel Version: Linux version 2.4.21-0.13mdkcustom (root@tuxmachine) (gcc 
version 3.2.2 (Mandrake Linux 9.1 3.2.2-3mdk)) #1 Sat Jul 5 12:27:17 BST 2003

- --------------------------------------
Processor information: processor
: 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 6
model name      : Celeron (Mendocino)
stepping        : 5
cpu MHz         : 498.495
cache size      : 128 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca 
cmov pat pse36 mmx fxsr
bogomips        : 992.87

- --------------------------------------
Module information:

ppp_deflate             4536   0 (autoclean)
zlib_inflate           21348   0 (autoclean) [ppp_deflate]
zlib_deflate           21624   0 (autoclean) [ppp_deflate]
bsd_comp                5336   0 (autoclean)
binfmt_misc             7404   1
ide-cd                 35776   1 (autoclean)
parport_pc             27208   1 (autoclean)
lp                      8480   0 (autoclean)
parport                36960   1 (autoclean) [parport_pc lp]
i810                   65440  23
agpgart                43680   7 (autoclean)
es1371                 30472   0
soundcore               6628   0 [es1371]
ac97_codec             13576   0 [es1371]
gameport                3412   0 [es1371]
ppp_async               9408   1
ppp_generic            24636   3 [ppp_deflate bsd_comp ppp_async]
slhc                    6628   0 [ppp_generic]
af_packet              15528   0 (autoclean)
floppy                 57148   0
eepro100               22836   1 (autoclean)
mii                     3992   0 (autoclean) [eepro100]
nls_iso8859-15          4092   1 (autoclean)
nls_cp850               4316   1 (autoclean)
vfat                   12780   1 (autoclean)
fat                    39224   0 (autoclean) [vfat]
supermount             16480   3 (autoclean)
sr_mod                 17976   0
cdrom                  33920   0 [ide-cd sr_mod]
scsimon                 9824   0 (unused)
usb-storage            78648   0
scsi_mod              106548   3 [sr_mod scsimon usb-storage]
usb-uhci               26220   0 (unused)
usbcore                77760   1 [usb-storage usb-uhci]
rtc                     8412   0 (autoclean)
ext3                   59916   2
jbd                    38972   2 [ext3]

- --------------------------------------
Output of /proc/devices :

Character devices:
  1 mem
  2 pty/m%d
  3 pty/s%d
  4 tts/%d
  5 cua/%d
  6 lp
  7 vcs
 10 misc
 14 sound
 29 fb
108 ppp
128 ptm
136 pts/%d
162 raw
180 usb
226 drm

Block devices:
  1 ramdisk
  2 fd
  3 ide0
  9 md
 11 sr
 22 ide1

- --------------------------------------

Output of /proc/mounts :

rootfs / rootfs rw 0 0
/dev/root / ext3 rw 0 0
none /dev devfs rw 0 0
none /proc proc rw 0 0
none /proc/bus/usb usbdevfs rw 0 0
none /dev/pts devpts rw 0 0
/dev/hda7 /home ext3 rw 0 0
none /mnt/cdrom supermount ro 0 0
none /mnt/cdrw supermount ro 0 0
none /mnt/floppy supermount rw,sync 0 0
/dev/hda1 /mnt/windows vfat rw 0 0
none /proc/sys/fs/binfmt_misc binfmt_misc rw 0 0


I am not subscribed to the linux-kernel list (well, I was, but after I had to 
delete 100000 messages and my email account was ready to be closed, I had to 
unsubscribe) so if you could possibly cc: me if you can be bothered to or if 
you really need to.

Many thanks :-)

- --Max.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.1 (GNU/Linux)

iD8DBQE/WjlZJs1Ztj8KHd8RAmkdAJ9EW18dsWBnRdvGhH/k77nHVosmegCgt64d
ob5EEFx65Wo27awaRIGJTM8=
=UPe9
-----END PGP SIGNATURE-----

RE: bug/request: multi-processing for CD devices

[Mehmet Ceyran]

>> Summary: request for multi-processing for CD devices (I 
>> think the word is 'multi-processing' - ie. so that you can
>> play an audio CD and browse the audio CD using a program
>> such as konqueror at the same time)
>> [...]
> As far as I know that should be impossible, because 
> audio-playing runs 100% on the cd-rom hardware itself. The OS 
> has nothing to do with it. So your request should go to the 
> device manufacturers and ask them if they could build 
> devices, that are "multithreaded". :)

Well that depends. The classic audio CD access is through hardware. The
drive spins down to 1x speed and dumps the data over its private line to
the soundcard's CDDA input channel. So in this case you're right.

The other way to do it is ripping the data through the drive's data bus,
like DAC tools do, and play the music on the fly. This way
'multi-processing' is possible.

So what you have to do is to find an audio player that plays CDDA with
the second method.

	Mehmet