Thursday, November 19, 2009

How not to configure default settings for sound applications

You're absolutely right, Martin: recordmydesktop did the wrong thing and screwed your sound experience in Ubuntu. Fortunately, it's really straightforward to fix:

--- recordmydesktop-0.3.8.1.orig/src/rmd_types.h
+++ recordmydesktop-0.3.8.1/src/rmd_types.h
@@ -39,7 +39,7 @@
#ifdef HAVE_LIBASOUND
#include

- #define DEFAULT_AUDIO_DEVICE "hw:0,0"
+ #define DEFAULT_AUDIO_DEVICE "default"
#else
#include
#include

Wednesday, November 18, 2009

Flailing against the light, or why bad things happen to good users

Seriously, Craig, I'm a bit disappointed that you didn't stop to ask members of this perceived conspiracy how to disable PulseAudio before flaming away, but as you say, it is most definitely your "right" to flame away. And, as Jordan mentioned in your blog post's comments, it was (and is) hardly MOTU's decision to tie PulseAudio more tightly into the GNOME desktop. That decision was upstream GNOME's. Not Ubuntu's. Not Fedora's. Not openSUSE's. Not Gentoo's. Not Debian's. Not Mandriva's.

In other words, it would take a non-trivial amount of work to remove the PulseAudio dependency from GNOME, and then Ubuntu would get to carry the delta *and* respond to defect reports.

Let's put this in perspective: there are two people working on audio in Ubuntu. One of them is employed by Canonical, and he isn't 100% time on audio. The other one cares enough to trawl through vitriol and drivel to respond to requests, demands, rants, and apathy -- on his lunch breaks and spare time -- to unbreak a resounding mess. If it's insufficiently clear, you're preaching to the choir, and your ultimatum is pathetically misdirected.

Now let's be constructive:

Firstly, PulseAudio *can* be made to go away in Karmic. I've written about it before, but I guess the naysayers are too busy flailing about how much PA sucks. Some caveats with the approach given: you'll need to use one of alsamixer, amixer (both command line tools shipped by default in the alsa-utils package), alsamixer-gui, aumix, and so on. You'll lose live per-application (per-stream) migration. You'll lose per-application volumes. And you'll lose other things, but they're hardly consequential enough to list here.

Secondly, the loss of system sounds is not a PulseAudio issue. It's a window manager issue. There's even a defect report about it.

Thirdly, PulseAudio *has* to use ALSA. PulseAudio is not a replacement for ALSA and never will be, because one of ALSA's primary functions is enable hardware. It's a sound driver. PulseAudio is not a sound driver; it's a program that uses sound drivers. If you're expecting PulseAudio to replace ALSA, go ahead and throw that idea out the window.

Fourthly, where are your defect reports for PulseAudio and ALSA in Karmic?

Lastly, no one is forcing you to upgrade to the latest Ubuntu hotness. Some people still use Dapper; others, Hardy. A great many people don't use Ubuntu at all. If you don't enjoy Ubuntu's direction, why not attend the Lucid developer summit and work with people there to resolve some issues?

Thursday, October 29, 2009

Caveats for audio in 9.10

Here follows an update for 9.10 to this month's earlier caveats:

If you use Ubuntu:
  • Use Karmic's kernel, not Jaunty's. A lot of you with Realtek and IDT/Sigmatel HDA codecs are being bitten by /boot/grub/grub.cfg not being updated properly, resulting in Jaunty's 2.6.28 kernel being used instead of Karmic's 2.6.31. Jaunty's kernel has pretty subpar performance for PulseAudio, and you should not incorrectly blame PulseAudio.
  • Check that slmodemd is not running if you're seeing a dummy/null sink in the volume control applet. Arguably PulseAudio's module-udev-detect should allow the device instead of bailing when detecting it, and an approach is under discussion for future versions. In the meantime, you can either instead load module-detect in /etc/pulse/default.pa (or ~/.pulse/default.pa) or kill slmodemd.
  • Install linux-backports-modules-alsa-karmic (then reboot) if you have a very new computer, because that package enables audio on quite a few very new laptop models and contains much improved support for microphone auto-switching.
  • Use a temporary alternate channel mapping for PulseAudio if you have an ice17xx-based sound card. Please be aware that the fault lies with alsa-lib not PulseAudio and will be addressed in 10.04 LTS.
  • Configure PulseAudio to ignore your sound driver's misreported dB information if you experience "overdriven" sound.
  • Attach a verbose PulseAudio runtime log to your PulseAudio bug report.
  • Attach an ALSA codec dump to your linux bug report if jack sense (e.g., connecting headphones mutes internal laptop speakers) does not seem to function properly.
As always, thank you for helping improve Ubuntu!

Tuesday, October 13, 2009

The perils of saving sound card state; and why apologizing is good.

Bad news: I broke alsa-utils in Karmic.

Good news: I fixed it tonight. Please report your results.

Honestly, I tested the previous upload on Ubuntu, Kubuntu, and Xubuntu before committing to bzr -- even on different hardware! It just goes to show that I make dumb mistakes, so, sorry about that.

Mo' bett' news: many thanks to the awesome Tim Gardner, who imported alsa-driver stable (snapshot from 20091012) into ubuntu-karmic-lbm.git, which means that all you poor saps with eeePCs and HP dvs and Dell Studios will finally have less suck for audio. Granted, it will require installing linux-backports-modules-karmic in a week or so...

In other news (what?! there're more kinds?!), it really is decent to apologize when I make mistakes. This guy is a real gem, that is all.

Thursday, October 1, 2009

Caveats for audio in Ubuntu Karmic Beta

In the wake of the Ubuntu Karmic Beta release, here are some audio gotchas on my radar:

* Volumes being erroneously set to 0 and/or muted upon reboot/shutdown
** We'll address this in Lucid by altering how alsactl store is called. For Ubuntu, there's arguably no need to actually call alsactl restore; PulseAudio handles volume state on its own. Granted, the approach will take some fleshing out, as we need to handle Kubuntu, Xubuntu, Ubuntu Studio, ...

* Default PulseAudio behaviour causes overdriven audio due to hardware inanity
** Thanks to some wonderful (sarcasm) hardware integration, we can work around this issue by using the patch mentioned in the comment. Please note that this patch will not be turned on for Karmic, because doing so will result in a very poor user experience for many more HDA users whose hardware are not quite so craptastic.

* Internal/External microphone selection is broken for many HDA users
** Well-known upstream, being addressed for Lucid, patches too invasive for Karmic, etc.

* Extremely high CPU usage by PulseAudio with third-party applications (Skype, I'm looking at you)
** Use the PulseAudio-aware beta of Skype

Finally, last post I described populating the alsactl init database. There are a few things of which one should be aware:

* Too quiet or too loud is usually a driver (i.e., linux) bug
** We can work around this in alsa-kernel/linux, so the first place we check is linux, not alsa-utils. In the rare case it is not a driver bug, we resort to alsactl init patches.

* You can clone the upstream alsa-utils git tree and submit patches directly
** (Next post, I'll cover how to do it.)

Monday, September 21, 2009

Atlanta Linux Fest 2009 and Crowdsourcing

A couple months ago, upon reading the tentative speaker schedule for Atlanta Linux Fest 2009, I was surprised at the Canonical omnipresence. There was personal trepidation regarding how such a presence may be interpreted, and sure enough, I wasn't alone. Certainly in my talk, I kept the vast majority of the physical speech focused on current FOSS and mentioned Ubuntu only in the confines of what we've done poorly and how we're resolving those shortcomings.

For instance, one of the most difficult things to "get right" in a default (clean) install is configuring various audio settings. A great analogous post by Ed Felten really made me reconsider the command line as the preferable interface for troubleshooting.

Many parts of Ubuntu are contributed by volunteers (thank you!) like myself. There seems to be a considerable amount of bad blood in the Linux community regarding what Canonical "doesn't do". We all need to do a better job of thanking our fellow volunteers and remembering that corporate overlords do not drive everything.

That said, I enjoyed the brief moments spent at this year's ALF (had to leave early to return to work), particularly the thoughtfulness of all the organizers (please thank them!) and attendees.

See you this weekend at Ohio LinuxFest!

Thursday, September 17, 2009

Limited liability, or how not to develop Karmic using Karmic

Karmic has been wonderfully jumpy these past few days. I must have some sick fascination with broken systems, as my presentation at this year's Ohio LinuxFest will focus on developing Karmic while running Karmic. Not just that, but this Saturday I'll briefly discuss Linux audio at Atlanta Linux Fest.

Now for the real meat in this post. For Karmic+1, I want Ubuntu to lead the charge in populating alsa-utils's init db.

Currently we do some pretty braindead things in alsa-utils's initscript, namely forcibly iterate over an entire set of static mixer element strings and values and attempt to set all detected audio devices to a specific state. Well, it's rather unlikely that my Logitech USB headset will have a Creative Audigy-specific "Audigy Analog/Digital Output Jack", yes?

Of course, that's just one badness, but the driving factor is to be able to conditionally set volumes on system start (for non-PulseAudio configurations) based on the machine's SSID. This approach largely resolves the "Gee, I have an Audigy X that requires the jack toggle to be muted to get audible analog output but person Y with an Audigy Z requires it to be unmuted" debacle.

So where do you come in? With current HDA codecs, using a static setting of 80% for PCM is pretty fragile. Some hardware sounds really overdriven at that setting, and others are barely audible. We need your SSID (lspci -nv|grep -A1 040[13]) and your preferred volumes! More in the following weeks.