At Fri, 30 Mar 2007 11:22:27 -0700, John Utz wrote: > > as usual, plz forgive my poor citing. > > -----Original Message----- > From: rlrevell@xxxxxxxxx on behalf of Lee Revell > Sent: Thu 3/29/2007 7:10 PM > To: John Utz > Cc: Takashi Iwai; alsa-devel@xxxxxxxxxxxxxxxx > Subject: Re: how does hw:0, 1 eventually get mapped to /dev/snd/controlC0 > and company? is this on the wiki somewhere? > > Hello Lee; > > Thankyou for taking the time to respond, i appreciate it! > > On 3/29/07, John Utz <John.Utz@xxxxxxx> wrote: > > since i dont need a generic solution, it would be very helpful to me to not use > alsa-lib and just use the alsa modules the way that our current version of the player > uses /dev/dsp from the alsa oss-compat kernel modules. > > > > i'd like to open and playback to /dev/snd/pcmC0D0p and /dev/snd/pcmC0D1p directly if > it's a reasonable thing to do. > > * The alsa-lib <-> kernel interface is intentionally undocumented. The > * only officially supported interface to ALSA is via alsa-lib. > > you can still document things even if you dont support them! > > most app writers will use the lib because it does a very good job of dealing with all > the inscrutable mandatory details of getting sound out of an arbitrary device. > > but it's not the best fit for everybody! > > what if you have a very teensy tiny filesystem and you dont want to fill your limited > space with text configuration files and executable code that reads the conf files and > executes test calls that you as a developer already know the answer to because you are > the guy that also wrote the driver for the only hardware that you will ever use? > > The lib code is in front of me and i have a compiler and a debugger and i will figure > it out in the fullness of time. I know of demands on recent many embedded systems. Now alsa-lib can be built in fairly small size by choosing appropriate components via configure options. Of course, it would be more smaller if the interface is rewritten somehow, though. > Make no mistake, it will be kind of a fun adventure! > > But having fun is supposed to be just a side effect of doing a good job for my > employer and to do a good job for my employer i need to meet a rather short deadline! > > Thus i am executing my responsibility as an effective employee by asking for help on > this matter. > > * If you really refuse to use alsa-lib (it's not that big, I've used it > * in embedded projects), > > 'refuse' is much too strong of a term! > > i seek to minimize: > > 1. the filesystem space required > 2. the build complexity involved in building our product. > > i have to cross-compile *everything!* and currently i am the *only* guy in the whole > company that's doing this job, i wish to provide as simple a build process as possible > for my future self or my windows centric coworkers. > > * then just enable ALSA's OSS emulation and continue to use /dev/dsp. > > does /dev/dsp support use of 4 channel output? how would one create 4 individual mono > streams with /dev/dsp? > > i dont think this is possible. am i mistaken? Not impossible but much harder if you cope with ALSA drivers... At least, the current OSS emulation won't work easily for such a purpose as it is. Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
