Re: [LAU] Hideous dmix, alsa, jack, realtime and mixing mess

From: Simon Williams <simon@email-addr-hidden>
Date: Sat Sep 22 2007 - 18:06:39 EEST

cdr wrote:
> On Sat Sep 22, 2007 at 01:14:24AM +0100, Simon Williams wrote:
>> AAAARRRGGHHHH!!! FOR GOODNESS SAKE!!!!!!! Hardware manufacturers
>> are now driving me totally insane. Are they all completely brain
>> dead? How in the world is anyone actually supposed to use the
>> appalling software sound cards they put in laptops and on
>> motherboards these days?
>
> most people don't. they just use the onboard speakers to watch
> youtube clips with 8kbps compressed audio..
>
> that said, i found onboard sound completely usable with jack, from a
> technical standpoint.

jack works fine with my onboard card (apart from the occasional xrun,
but I'm working on that), but the problem is that whilst jack is running
nothing else can play sounds.

> youll definitely go insane if youre trying to use dmix ALSA apps and
> JACK stuff all at once, with a single PCM.
>
> ask yourself, do you really need those ALSA apps? which are they?
> mplayer has a jack backend, as does gstreamer, so just about any
> media player should be covered if you choose to use JACK instead of
> dmix for multiplexing your PCM

I want to use XMMS for almost all mp3 cases. Unless there is a similar
alternative. Usually I'm a hardcore command line person, but for a whole
playlist of mp3s xmms is much easier. I use mplayer if I want to play
files I've just downloaded, but once they are in my music collection I
want xmms.

>> dmix blocked the soundcard anyway, so if any one of my applications
>> didn't use dmix I was back to one at a time. (I'm looking at YOU,
>> flash plugin (which, incidentally, also comes under the category of
>> "useless ****ing ****")- more on that later as well)
>
> flash opens another PCM if the lowest one is blocked, like hw:0,0,2
> if hw:0,0,0 is in use. not sure about other cards but my echo has 8
> PCMs (and hw mixing) even tho theres only one physical out.

Exactly- your 'Echo' has hardware mixing. The onboard cards I'm using do
not. I have one PCM.

>> My initial thought was to try and get my other applications to use
>> jack directly, which would have the added bonus of mixing them
>> nicely. Great in theory, but xmms-jack didn't work and it looks
>> like most other applications will require similar hacks, which for
>> the most part are not available. I
>
> xmms-jack is pretty old. audacious played to jack fine here, before i
> stopped using GUI players entirely..
>
>> can't even get some applications to use ALSA instead of OSS, so I
>> don't really stand much chance of getting them to use jack.
>
> apps that still only support OSS? which are these?

flash, teamspeak.

> that jack-PCM for alsa is kinda nutty, and doesnt totally work.
> again, why not fix the apps causing problems to not require hacks in
> the first place?

Perhaps I should reiterate the problem. I have one PCM device. Lets
assume for the moment that I can persuade all apps to use dmix. No
problem there. But I need jack for realtime. And in order for jack to
have realtime it can't use dmix. So either jack uses the PCM or dmix
does. Not both. Which means that if I want realtime (even for just
fluidsynth), I have to get all apps to use jack. I can't see any way of
getting jack to use dmix in realtime, so that's the only option.

>> 3. How do I get proprietary software (which for some reason all
>> still uses OSS)(flash, teamspeak) to use ALSA?
>
> flash doesnt use OSS anymore. upgrade to v9

That should help.

>> 3a. Or at the very least get the flash plugin to release the sound
>> device once it's finished, without requiring the whole of firefox
>> to be restarted?
>
> gnash almost plays youtube these days, btw..

I must get round to trying that.

> ao=jack in /etc/mplayer/mplayer.conf or ~/.mplayer. xmms, try
> audacious.

> flash, good luck :)
Right, exactly. If just one of the applications I need doesn't use the
software mixer I'm trying to use then everything falls flat on it's face
because that app will hog the PCM device and stop all other apps from
playing sound.

>> The whole point of buying a midi controller instead of a normal
>> keyboard was that it was supposed to be cheaper and more portable.
>> It doesn't seem to be going that way.
>
> eh? every MIDI device i still own has usb bus power and additional
> MIDI ports (CME U-Key, Korg PadKontrol). so ive got a MidiSport and
> MOTU MIDI thing just sitting in a pile of junk

I don't think we are talking about the same thing. I bought an Evolution
MK461c (a midi controller keyboard- it requires a PC or other midi
device to actually make sounds), instead of getting some other keyboard
with it's own synth and speakers which could be played without needing a
computer.

Thanks
Simon
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Received on Sat Sep 22 20:15:02 2007

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