Linux Audio Development

JulesVD writes "There is an article from Linux Journal about the latest plans for Linux audio functionality from the first developer's conference in Germany. Developers from more than a dozen countries attended this successful conference, representing organizations such as SuSE, Linux Audio Systems, Stanford University, IRCAM and Centro Tempo Reale. Topic discussions included in-depth presentations of the rapidly evolving Linux sound system, a look at the details of programming for professional audio standards and a survey of recent applications and audio-centric Linux distributions." Mmm...interesting reading (blantant plug for cool program), but I think the most important question is will it make Scrubby happy?

Comments

Sound Support

[rf0]

ALSA is actually quite nice. It works on more cards than OSS, allows duplex on some cards and is still backwards compatible with the OSS API. However I still feel that audio support on Linux could be improved. For example in my latop Intel soundcard which seems to only play at 44 Khz if using xmms. Now I know this is a software problem but it would be nice if it worked out the box.

Not a major issue but annoying

Rus

Re:Sound Support

[0x0d0a]

ALSA is actually quite nice. It works on more cards than OSS, allows duplex on some cards and is still backwards compatible with the OSS API.

Agreed, ALSA *is* nice.

ALSA's biggest drawback is the project policy that software mixing should be done in userspace (presumably by a separate project). They feel that a user should use hardware mixing *or* software mixing provided by a sound server like arts, esd, JACK, etc. This produces less kernelspace code, which is good, but means that Linux cannot handle using hardware mixing until all channels are exhausted, then fall back to software mixing for additional channels.

Esd and arts do not provide solid enough latency and sync to be the sound server in this scenario. JACK may be enough -- haven't used it -- but it's not in common use outside of the audio content creation software area.

OSS/Free has a similar approach. Hardware or software sound mixing, no hybrid approach.

A mixer capable of supplying such mixing would need to intercept all ALSA calls and use realtime scheduling. Kinda nasty. It always seemed that adding mixing and resampling code to ALSA would be easier.

It *is* a bit of a thorny problem, though.

Re:Sound Support

[paulbd]

LSA's biggest drawback is the project policy that software mixing should be done in userspace (presumably by a separate project)

This just is not true. ALSA now has the dmix plugin that handles software mixing in user space all by itself. Its very, very efficient and has no impact on latency (though it can't offer JACK-style sample-synchronous execution). dmix makes regular software mixing "servers" irrelevant, and JACK fills the remaining needs.

A pro audio platform would be cool...

[japhar81]

Something like Logic or Cubase on Linux would absolutely kick ass. My powerbook beats the hell out of windows for music apps, but an open-sourced suite would be worth it to switch. You have no idea how often I wind up thinking, geez, if only logic had an extra slider here to control this or that or the other...

Re:A pro audio platform would be cool...

[fruey]

It's called Ardour, look for it at Sourceforge.

-Simon

the drivers need to work. period.

[Anonymous Coward]

Anything less than complete parity with Windows drivers FEATURE FOR FEATURE is unacceptable. Linux is STILL not there.

I installed Windows XP after 9 years of running Linux (various distros) because I was tired of only being able to use half the features of my hardware.

Re:the drivers need to work. period.

[QuackQuack]

I get around this problem by buying only well supported hardware.

But what's really annoying is when features aren't supported on Linux for non-technical reasons. For example, Matrox has written Linux drivers for their graphics cards, but the Linux drivers don't support TV-out. Why?

It's apparently because Linux doesn't have Macrovision support, and I guess Matrox doesn't want to be sued by the MPAA for releasing drivers that "enable piracy". So Linux users can't have a feature that has many legitimate uses, just because someone might tape a DVD onto a VHS tape with it.

Drivers?

[Drathus]

Isn't the largest issue with any support on Linux still the fact that very few companies are willing to put in the time to create Linux drivers let alone have have the decency to release the information on the chipsets to the public to allow 3rd party drivers to be created?

Maybe what should be looked into is the creation of a vested interest just to deal with sound card companies and try and negotiate accessability to chipset information to create drivers for their cards for other OSes than they're willing to develop for in-house.

Re:Drivers?

[Adnans]

Contrast with the monolithic kernel that linux has. Creative would need to participate and coordinate with linus et al from start to finish.

Erh no! Most, if not all drivers in ALSA were written without any interaction from the kernel folks. ALSA is now integrated in the 2.5.x kernel, but that doesn't mean driver developers will have to deal with Linus et al. They just deal with Jaroslav, the ALSA maintainer. All mainstream cards are already supported by ALSA. If a company doesn't want to provide docs it can always choose to write and distribute their driver on their own.

In short, the monolithic kernel is an albatross around linux' neck when it comes to wanting hardware support from the manufacturers.

Nonsense.

-adnans

Re:Drivers?

[Adnans]

And ALSA is the way every card will work from now on? Or will it change to something else with kernel 2.6?

The ALSA API in kernel 2.5.x will be the same one in kernel 2.6.

Vendors like standards and specifications. They dont like researchers and academics and expiriments.

Vendors look at the bottom line. If there's enough incentive they will write against any API (*cough* Windows *cough* :-).

-adnans

After dealing with Linux sound for 3 years.....

[mao che minh]

"Topic discussions included in-depth presentations of the rapidly evolving Linux sound system..."

I hope so. After working with Linux for three years I have come to expect little in terms of audio. Hell, I was taken completely by suprise when the Redhat 8.0 install actually had a "play sample sound" button. It was like first time I witnessed scaling effects on the SNES. Inspiring.

Mixing...

[ElGuapoGolf]

I may be wrong, but whatever. It seems to me that Linux *really* needs a decent stream mixer.

I hate not being able to play more than 2 sounds at once (and that's only because that's supported in hardware by my card, my old card could only play 1). Neither esd (does anyone use this anymore) or artsd cut it. They're too laggy to be usable for games, and in order to increase their response time, you have to increase their priority, thus slowing everything else down.

Say what you want about Windows, but at least it gets this right.

So, anyone know a soundcard that will let me play mutiple streams WITHOUT having to use esd/artsd, and is decently well supported under Linux? Anyone? BTW, can we keep it under $100 (USD) if possible?

Cool

[IamTheRealMike]

The most amazing thing about the Linux audio scene is how well organised it's been since day one. All the key players work together, and are putting together a seriously sweet pro audio architecture. The same people who write ALSA collaborate on Jack, LADSPA (which looks like an open alternative to VST plugins), write sample editors - the works.

It's too bad that the desktop audio scene is such a shambles by comparison - in 2003 there is still no standard way of mixing and resampling (sound servers). What I expect will happen at this point is simply that once 2.6 is rolled out, distros will simply start shipping with the ALSA dmix plugin which mixes at the hardware level by writing into a sound cards DMA buffer (iirc), making most desktop uses of sound servers obsolete (though they can still be useful for network transparent audio and jack style synchro).

Oh, and GStreamer kicks ass :) It's messy right now, but I think Linux multimedia could become really great.

I have to say...

[SatanicPuppy]

I've had a better audio experience with Linux than I ever did with windows.

Case in point: I recently was bequeathed a SB Audigy card (Platinum...Oooooooo.) with no driver disk.

So whay you say! I can download the driver no problem, you say!

NAY! I say, they have restricted the downloads to driver "upgrades" only. If you don't have the original, then you get NOTHING! I had to go rip off a damn copy of the original driver CD to use a physical piece of hardware. Severely annoying.

This is in windows. In LINUX, I found the driver and it worked perfectly. Took like 3 minutes. It was GREAT! No pops or crackles, just pure wonderful SOUND!

My Name is SatanicPuppy, and I'm a switcher.

=P

Re:I have a single question

[Consul]

A popular program, under active development, is Rosegarden4.

I haven't used it much, but I was able to get it to run stably, and talk to my soundcard just fine. Many people on the Linux Audio Users mailing list like it a lot.

Creative Open Sources their drivers

[brunes69]

Not only do they create drivers for their chips (SBLive! and Audigy series, OpenAL), they release the code as Open Source. The driver sin the Linux kernel came from Creative, not some 3rd party. Another reason to support Creative (as if having the best stuff wasn't enough of a reason)

http://opensource.creative.com