Re: [Alsa-devel] stupid question about pcm devices
>I have seen that alsa provides nice pcm devices in /dev/snd directory > >*They are split in playback and capture devices :) nice idea. >In Oss I was able to pipe data from and to them and therfore was >recording/playing back at a certain sample rate. >With alsa this is not possible anymore. it says the descriptor was in a bad >state. Is it possible ??? jaroslav answered this in one way. i'd like to add this: under OSS, most people understand that cat > /dev/dspN requires that the data match the "default" format for the "dsp" device. any mismatch will result in noise. the same is true for ALSA. however, under ALSA, the devices are not that simple. specifically, OSS required opening+closing devices to reset the parameters, whereas ALSA instead allows the devices to remain open, but stopped, reconfigured, then restarted. these are all done by ioctl(2) calls. this means that, in terms of system calls, there is always at least one ioctl(2) call required to get the device started after it is opened. as a result of this, "cat > /dev/snd/pcmC0D0" or equivalent will never work, since cat merely calls open(2) on the device - it does not start it (i.e. make the ioctl(2) call). i suspect that some people in the kernel community will object to this design, noting that it violates The Unix Way. however, there are many devices that require ioctl(2)'s to get them set up for use, so ALSA will not be the first. i doubt, for example, if "cat > /dev/scanner" will work, and "cat > /dev/modem" normally results in garbage someplace. >*Is there something like aconnect for pcm devices > >when I do a sfxload, it operates on /dev/sequencer, which makes the seq-oss >module automatically to load. Is there a way to load the patches in native als >a >??? rewrite sfxload. --p ___ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
Re: [Alsa-devel] stupid question about pcm devices
On Fri, 8 Feb 2002, Guenther Sohler wrote: > I have seen that alsa provides nice pcm devices in /dev/snd directory > > *They are split in playback and capture devices :) nice idea. > In Oss I was able to pipe data from and to them and therfore was > recording/playing back at a certain sample rate. > With alsa this is not possible anymore. it says the descriptor was in a bad > state. Is it possible ??? Yes: arecord | aplay > *Is there something like aconnect for pcm devices Nope. > when I do a sfxload, it operates on /dev/sequencer, which makes the seq-oss > module automatically to load. Is there a way to load the patches in native alsa > ??? No, it's under slow development. Jaroslav - Jaroslav Kysela <[EMAIL PROTECTED]> SuSE Linuxhttp://www.suse.com ALSA Project http://www.alsa-project.org ___ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
Re: [Alsa-devel] stupid question about pcm devices
--- Guenther Sohler <[EMAIL PROTECTED]> wrote: >I have seen that alsa provides nice pcm devices in /dev/snd directory > >*They are split in playback and capture devices :) nice idea. >In Oss I was able to pipe data from and to them and therfore was >recording/playing back at a certain sample rate. >With alsa this is not possible anymore. it says the descriptor was in a bad >state. Is it possible ??? > >*Is there something like aconnect for pcm devices > That is on it's way but is part of the jack api. checkout http://jackit.sourceforge.net >when I do a sfxload, it operates on /dev/sequencer, which makes the seq-oss >module automatically to load. Is there a way to load the patches in native alsa >??? > >rds guenther > >___ >Alsa-devel mailing list >[EMAIL PROTECTED] >https://lists.sourceforge.net/lists/listinfo/alsa-devel -- Patrick Shirkey - Boost Hardware Ltd For the discerning hardware connoisseur Http://www.boosthardware.com Http://www.boosthardware.com/LAU/Linux_Audio_Users_Guide/ _ Want a new web-based email account ? ---> http://www.firstlinux.net ___ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
Re: [Alsa-devel] stupid question
On Thu, 6 Dec 2001, Kyle Centers wrote:
> I hate to be nit picky, but I have been trying to figure something out, and am at a
>complete loss.
>
> In alsa-drivers, the file card-emu10k1.c, line 79 or there about reads:
>
> static struct pci_device_id snd_emu10k1_ids[] __devinitdata = {
>
> After an hour of searching, I finally discovered that __devinitdata is
> an empty #define from compat_22.h. What I'm lost on, is what purpose
> it serves. I'm sorry to waste your time on someting so trivial, but
> its driving me nuts.
Look to /usr/src/linux/include/linux/init.h for more details (2.4
kernels).
Jaroslav
-
Jaroslav Kysela <[EMAIL PROTECTED]>
SuSE Linuxhttp://www.suse.com
ALSA Project http://www.alsa-project.org
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