I've been working through the .asoundrc documentation and have found several errors.
This is for the "asoundrc" documentation, viewed on Jan 23 '04, using Mozilla 1.4.1, at the URL: http://www.alsa-project.org/alsa-doc/doc-php/asoundrc.php3 I am using kernel 2.6.2-rc1 with the alsa-bk-2004-01-20.patch.gz, and the 1.0.1 version of alsa-lib, alsa-tools, and alsa-utils. The hardware I used for these tests is the Intel ICH5 AC97 interface to a Realtek ALC650 chip on an ABit MAX3 motherboard. ------------------------------------------------------ 1. The "Aliases" section contains an incorrect example, missing the alias name: " For example, this gives your first soundcard an alias: pcm. { type hw card 0 device 0 } Now you can access this card by the alias ''. aplay -D test.wav " This should be something like "pcm.my_alias_name {" ... ------------------------------------------------------ 2. The Plugins section starts with an example of a very simple slave: pcm_slave.sltest { pcm } This is incorrect. It is missing the pcm device after the keyword pcm. Similarly, the pcm_slave.sl2 rate-conversion example is missing the pcm device name. ------------------------------------------------------ 3. The rate conversion plug documentation (or code?) is broken. I'm not sure if this is a documentation bug or a driver/alsa-lib bug. My .asoundrc at this point closely follows the documentation (with corrections as noted in bug#2) and looks like: pcm.ac97 { type hw card 0 device 0 } pcm_slave.sl2 { pcm ac97 rate 44100 } pcm.rate_convert { type rate slave sl2 } The documentation says: "Now you can call this newly created virtual device by: aplay -D rate_convert test.wav" But when I try that, I get this error: Playing WAVE 'test.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo aplay: set_params:805: Broken configuration for this PCM: no configurations available Note that "aplay -D ac97 test.wav" works, but plays too fast (at 48000), and gives the warning "please, try the plug plugin (-Dplug:ac97)". If I do that, it works perfectly. So I think the documentation is wrong, or at least incomplete, or rate conversion does not work. ------------------------------------------------------ 4. The "plug" plugin documentation is wrong, or at least incomplete/misleading. First of all, the "syntax" description for "type plug" is complex and not explained in this page of documentation at all. route_policy, ttable, etc. ??? The documentation goes on to say: " We can use it as follows: pcm_slave.sl3 { pcm format S16_LE channels 1 rate 16000 } pcm.complex_convert { type plug slave sl3 } By calling it with: aplay -vD complex_convert test.wav You will convert the sample during playing to the sample format: S16_LE, one channel and a sample rate of 16 kHz. As you called aplay with the verbose option -v you see this options as it appears as it comes from the original file" " First, the pcm name for the slave is missing, as in bug #2. I copied and pasted this example directly into my .asoundrc, and then filled in "ac97" for the missing pcm name. Here are the results of testing it: [EMAIL PROTECTED] thoffman]$ aplay -vD complex_convert test.wav Playing WAVE 'test.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo ALSA lib pcm_params.c:2096:(snd_pcm_hw_refine_slave) Slave PCM not usable aplay: set_params:805: Broken configuration for this PCM: no configurations available I experimented by changing the slave channels to 2 and the rate to 44100 in .asoundrc, and got exactly the same error message. Changing the slave rate to 48000 resulted in playback, but too fast of course... ------------------------------------------------------ 5. dmix documentation Following the documentation example for how to use dmix, I wrote this .asoundrc: ----cut---- pcm.ac97 { type hw card 0 device 0 } pcm.dmixer { type dmix ipc_key 1024 slave { pcm "ac97" period_time 0 period_size 1024 buffer_size 4096 rate 44100 } bindings { 0 0 1 1 } } ctl.dmixer { type hw card 0 } pcm.!default { type plug slave.pcm "dmixer" } ----cut---- When I tried "aplay -f cd -Dplug:default test.wav" as the documentation suggests, I got no error message but no sound either. When I tried "aplay -f cd -D default test.wav" instead, it worked, and I was able to start multiple instances, which were mixed together as expected. So, I think the documentation is incorrect in suggesting that the "plug" device be used from the command line. Thanks, -- Torrey Hoffman <[EMAIL PROTECTED]> ------------------------------------------------------- The SF.Net email is sponsored by EclipseCon 2004 Premiere Conference on Open Tools Development and Integration See the breadth of Eclipse activity. February 3-5 in Anaheim, CA. http://www.eclipsecon.org/osdn _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
