Hi Anders,

Thanks for your reply. I have created a /*.asoundrc*/ file in my home directory as you suggested and added the following configuration there (as you can see, these are basically the exact default configuration that the dmix plugin has) -

pcm.lol { type dmix ipc_key 1024 ipc_key_add_uid true slave { pcm "hw:0,0" period_time 125000 rate 48000 format S32_LE channels 2 } }

Now when I start my program while a media player is running, it doesn't show any /*Device or Resource busy */error. It successfully opens the device and starts to write the sine wave into it. But the problem is I can't hear its output. I should have heard two sounds simultaneously but I can only hear the song in the media player, not the output sound from the example program. Similar things happens when I start the example first and the start a media player, I can only hear sounds from the first one.

Also, when I try to run the example program on different rate (i.e., rate 8000, channel 1) it throws an error saying format doesn't match. I guess it's because of the configuration rate that I specified in the file. I tried to supply multiple values for rate using array notations ( rate [8000, 48000] ) but it threw an error telling that the /*.asoundrc */file is corrupted or old.

Actually the whole point of my exploration is this - I want to display a list of available audio cards/devices in my system to my application user who will then select the input and output audio card to record/playback audio data accordingly.

Thank you.

Regards, Sayem Ahmed

On 11/21/2011 01:41 PM, Anders Gnistrup wrote:

Hi Sayem

It's because you open the device plughw:0,0. It's actually the device hw:0,0 with a additional "plug" pluggin. The plug pluggin takes care of resampling. Devices is not mixing device by design. This is handled by plugins (the dmix plugin)

What you want is a device that can mix (and possible resample). For that you need a new virtual device. I have had the same problem myself, and the solution I have used is a .asoundrc configuration.

pcm.mydmix { type dmix ipc_key 1024 slave { pcm "hw:0,0" period_time 0 period_size 1024 buffer_size 8192 rate 44100 format "S32_LE" } }

Instead of the slave definition you could make your own. Now the device mydmix can be used as a mixing device.