Automatic sound dedection in Slack?

drkstr · 07-09-2006, 12:26 AM

I'm putting together a Slackware live CD which needs to work out of the box with most computers. I have a generic Slack install which auto detects all of my hardware but the sound. The knoppix CD I have can detect it just fine, so I was wondering what goes into detecting and configuring sound devices. I know I can just run 'alsaconf' but this will not be an option since it will configure the sound to my specific hardware. What kind of files get created by 'alsaconf', and is there a way to make them generic like the xorg.conf is?

On the flip side, has anyone had their sound work out of the box? Maybe Slackware just doesn't like my specific hardware?

Intel AC97 w/ 2.4.31 (default) kernel.

thanks!
...aaron

**edit**
great, I typo'd the title. oh well, I'll just pretend I don't know english very well

willysr · 07-09-2006, 02:18 AM

Intel AC 97 can be detected by alsaconf, but you still have to execute the command first.

Daga · 07-09-2006, 02:35 AM

I have a live-cd that I release (100+ downloads in the last month

), and have allowed the kernel and standard Slackware startup scripts to detect the soundcard -- which they seem to do a decent job of. All that is left after that is to unmute the sound channels. To achieve that, I created a quick startup script to run these commands:

Code:

/usr/bin/amixer -q set Master 50%,50% unmute 2>/dev/null
/usr/bin/amixer -q set PCM 100% unmute 2>/dev/null
/usr/bin/amixer -q set Headphone 100% unmute 2>/dev/null

Some laptops only have "Headphone" instead of "PCM," so it is a good idea to hit both.

drkstr · 07-09-2006, 11:59 AM

Quote:

have a live-cd that I release (100+ downloads in the last month ), and have allowed the kernel and standard Slackware startup scripts to detect the soundcard -- which they seem to do a decent job of.

This is exactly what I am looking for; glad to know it's possible! So are you saying that the standard Slackware scripts should auto-detect most sound devices?

Quote:

To achieve that, I created a quick startup script to run these commands:

This will definatly be usefull, thanks!

Quote:

Intel AC 97 can be detected by alsaconf, but you still have to execute the command first.

What does alsaconf do when it auto-detects the device? What files does it modify, and what commands does it use to figure out the correct device? I think Daga is claiming that the default Slackware startup files should automatically detect and configure the sound device, why does the AC97 require the extra step?

Thanks for the help everybody!
...aaron

chrisortiz · 07-09-2006, 01:56 PM

Quote:

What does alsaconf do when it auto-detects the device? What files does it modify, and what commands does it use to figure out the correct device? I think Daga is claiming that the default Slackware startup files should automatically detect and configure the sound device, why does the AC97 require the extra step

as far as i know it only modifies /etc/modules.conf

Daga · 07-09-2006, 02:35 PM

Quote:

Originally Posted by drkstr

What does alsaconf do when it auto-detects the device? What files does it modify, and what commands does it use to figure out the correct device? I think Daga is claiming that the default Slackware startup files should automatically detect and configure the sound device, why does the AC97 require the extra step?

The AC97 driver has worked correctly on the systems I've tested my live-cd on. I don't think any extra setup should be required... alsaconf is a bash script, but it does make for some fun reading

I believe it sets the order of sound cards in /etc/modules.conf (as chrisortiz said) to the order it found sound devices, and then it unmutes the main sound channels. There could be more, but that should be the gist of the script. It has been a little while since I've taken a look at it

drkstr · 07-09-2006, 05:25 PM

I see, I didn't realize it was a script; I just assumed it was a binary. Reading it will defiantly answer my questions! Well I think I have enough information to try and get something going here. Thank you everybody for the help!

...aaron

Daga · 07-09-2006, 10:39 PM

That's why we love Bash

drkstr · 07-11-2006, 02:16 AM

Well I am still pretty new to bash scripting, but for the most part, I was able to understand it all. The only part that I didn't really get was when the list of found devices is displayed and the user picks one from a list. I am trying to eliminate all dialog so I need it to just pick the first one (or configure all of them if possible). Here is the code to display the dialog and pick the device to configure:

Code:

#from /usr/sbin/alsaconf
<snip>
devs_found=("${devs_found[@]}" "legacy" "Probe legacy ISA (non-PnP) chips")
    title=$(gettext "Soundcard Selection")
    msg=$(gettext "
         Following card(s) are found on your system.
         Choose a soundcard to configure:
")
    $DIALOG --title "$title" --menu "$msg" 17 76 8 "${devs_found[@]}" 2> $FOUND || acex 0
    card=`head -n 1 $FOUND`
    if [ "$card" = "legacy" ]; then
	ac_config_legacy
    else
	ac_config_card "$card"
    fi
    exit 0
else
<snip>

Any suggestions on the best way to remove the dialog from this and to automatically assign $card?

thanks for your time!
...drkstr

Daga · 07-12-2006, 01:51 AM

Quote:

Originally Posted by drkstr

I am trying to eliminate all dialog so I need it to just pick the first one (or configure all of them if possible). Here is the code to display the dialog and pick the device to configure:

Code:

#from /usr/sbin/alsaconf
<snip>
devs_found=("${devs_found[@]}" "legacy" "Probe legacy ISA (non-PnP) chips")
    title=$(gettext "Soundcard Selection")    msg=$(gettext "
         Following card(s) are found on your system.
         Choose a soundcard to configure:
")
    $DIALOG --title "$title" --menu "$msg" 17 76 8 "${devs_found[@]}" 2> $FOUND || acex 0
    card=`head -n 1 $FOUND`
    if [ "$card" = "legacy" ]; then
	ac_config_legacy
    else
	ac_config_card "$card"
    fi
    exit 0
else
<snip>

If you scroll up from this (I love using '/' and '?' in vim), you will find that $devs_found[] is set up as an array -- the first element is the device, the second is a description of it, the third is another device, the fourth a description of it, etc. $devs_found[@] expands the array to all of the elements in it. This might help you understand a little better what is going on:

Code:

dialog --title "example" --menu "Some random menu text" 17 76 8 "one" "First element" "two" "second element" "three" "Et cetera" 2>choice
cat choice

Now, for practicality, in the adoption you might as well skip the "card description" and just iterate through the array.

HTH, and I'd like to see the finished script when you are done

Wim Sturkenboom · 07-12-2006, 10:56 AM

Quote:

Originally Posted by drkstr

**edit**
great, I typo'd the title. oh well, I'll just pretend I don't know english very well

Just edit your post, go to advanced and change the title. Problem solved

drkstr · 07-13-2006, 11:23 AM

Quote:

If you scroll up from this (I love using '/' and '?' in vim), you will find that $devs_found[] is set up as an array -- the first element is the device, the second is a description of it, the third is another device, the fourth a description of it, etc. $devs_found[@] expands the array to all of the elements in it. This might help you understand a little better what is going on:

Thanks, I see it now! I've haven't had the chance to work on this since I need to finish a project by friday, but I'll give it another go this weekend and post back with the results.

Quote:

Just edit your post, go to advanced and change the title. Problem solved

This only changes it in the thread. The title displayed in the forum will not change unless you ask a moderator to do it.

regards,
...drkstr