Re: [linux-audio-dev] ok, jump on slashdot right now, ALSA story in progress

Paul Davis <paul(a)linuxaudiosystems.com> wrote: What a coincidence: I've had brewing in my mind in the last two days an ALSA usability project. It would be pointless to post to /. about it, so let me braindump here since I could actually get informed replies. :-) Here are my primary goals: 1. Work on getting discover [0] to work with ALSA. discover is a project developed by Progeny, designed to detect what hardware is available and provide that information to userspace programs via the library libdiscover. It works reasonably well, but at this point only supports OSS. I wrote to the mailing list yesterday asking questions about how ALSA could be supported [1]. I believe this is a very promising project: here is an example of the output on my machine: $ sudo discover all Silicon Integrated Systems (SiS) SG85C503 Unknown LITEON DVD-ROM LTD163D Silicon Integrated Systems (SiS) SiS900 10/100 Ethernet Realtek Semiconductor Co., Ltd. RTL-8139 Silicon Integrated Systems (SiS) 5513 [IDE] Linux IDE-SCSI emulation layer Creative Labs SB Live! EMU10000 Silicon Integrated Systems (SiS) 7001 Silicon Integrated Systems (SiS) 7001 Silicon Integrated Systems (SiS) SG86C201 NVIDIA Corporation GeForce [NV11] Unknown WDC WD1200AB-00CBA1 Unknown ST360021A $ sudo discover --module all | sort -u emu10k1 ide-scsi rtl8139 sis900 usb-ohci 2. Modify the ALSA drivers to put something useful in the card ID. Right now you get card0, card1, etc., which is completely useless: if you wanted to refer to the card by number, you'd just write hw:0. Why is the card ID important? Because it can be used to enumerate and select cards, the way other audio APIs will let you do! Using the syntax hw:CARD=cardid you can select a device based on human-readable strings. Today I get: $ cat /proc/asound/cards 0 [card0 ]: EMU10K1 - Sound Blaster Live! Sound Blaster Live! at 0xcc00, irq 11 1 [card1 ]: ICH - SiS SI7012 SiS SI7012 at 0xd800, irq 11 My goal is: $ cat /proc/asound/cards 0 [SBLive ]: EMU10K1 - Sound Blaster Live! Sound Blaster Live! at 0xcc00, irq 11 1 [SiS SI7012 ]: ICH - SiS SI7012 SiS SI7012 at 0xd800, irq 11 It is possible to set these with arguments to modprobe, but that's no reason why they shouldn't be useful by default. 3. Documentation on how to write user-friendly device selection for ALSA. If common apps started getting this right, ALSA would provide a directly visible value-add for end-users, since OSS can only let you choose between /dev/dsp1, /dev/dsp2, etc (AFAIK). Alternatively, encourage people to use PortAudio since it will provide this transparently. Alternatively, investigate the possibility of being able to run more than one jackd at a time, one for each sound card. Running a single jackd for more than one sound card is infeasable since two cards can never be perfectly synced. The point of this being that the user would again see the advange of being able to easily select the desired sound card for output, with the added advantage of being able to share the sound card. I believe that these things alone would make ALSA *much* more usable for simple, stereo users that perhaps have more than one sound card. The hw:0 stuff is a drag, as is trying to find out what module goes with your card and modprobing it. I'm interested in input from multichannel users regarding what kind of usability improvements ALSA could use in this arena. To be honest, I have no idea how ALSA works with multichannel cards since I don't have any. Comments welcome. Josh [0] http://hackers.progeny.com/discover/ [1] http://lists.progeny.com/archive/discover-workers/200211/msg00000.html -- "Only Angels can sing that high, and only dogs can hear it." -- James Evans