[Alsa-devel] Re: [linux-audio-dev] alsa/usb
On Thu, 17 Jan 2002, Paul Davis wrote: What's going to happen with usb audio/midi support ? Since alsa should become the kernel standard driver for audio/midi/seq devices and all the work the usb people have done to support the audio class is based on the oss-api does that mean with 2.5 or 2.6 I'll no since the POSIX API is used, there's no way to route around this (without LD_PRELOAD anyway). so my question is: are these drivers actually part of OSS/Free (i.e. .../src/linux/drivers/char/sound), or At least the driver handling the standard USB Audio Device Class is located in the USB kernel directory, ie. linux/drivers/usb. All code is in the big (~4000loc) audio.c file. It implements the OSS ioctls, plus OSS-style mmap() (and of course read()/write()). But it does register itself to the OSS subsystem (to drivers/sound/sound_core.c) like all other sound drivers, so it _is_ part of OSS. But basicly if ALSA provides (does it?) the soundcore services (combined with ALSA's own OSS-emulation layer) you should be able to continue to use the USB drivers. Oh well, let's cc this to alsa-devel.. -- http://www.eca.cx Audio software for Linux! ___ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
Re: [Alsa-devel] Re: [linux-audio-dev] alsa/usb
But it does register itself to the OSS subsystem (to drivers/sound/sound_core.c) like all other sound drivers, so it _is_ part of OSS. no. sound_core is NOT part of OSS. ALSA attaches to it as well. Alan Cox wrote that so that OSS and ALSA could (theoretically) co-exist. Now I'm nitpicking, but actually only part of ALSA registering to soundcore is the OSS-emulation layer. thats true. but it still means that sound_core.c is not part of OSS. its funny. looking over that code again, its amazing how much of a flashback it gives me to when i first started tinkering with audio on linux, and how utterly out-of-date and absurd it looks now. DSP16? bwahahaha! And wasn't soundcore written to allow OSS/kernel and OSS/commercial coexists (OSS/commercial drivers register to soundcore)...? alan explicitly wrote soundcore to support distinct, incompatible sound driver APIs. both OSS/Free and OSS/commercial use the same major device numbers the last time i looked, and so they cannot be used together. the source says: * Top level handler for the sound subsystem. Various devices can * plug into this. The fact they dont all go via OSS doesn't mean * they don't have to implement the OSS API. There is a lot of logic * to keeping much of the OSS weight out of the code in a compatibility * module, but its up to the driver to rember to load it... * * The code provides a set of functions for registration of devices * by type. This is done rather than providing a single call so that * we can hide any future changes in the internals (eg when we go to * 32bit dev_t) from the modules and their interface. * even so, its still totally out of date. --p ___ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
