ALSA Api: How to play two wave files simultaneously?

Question

What is the required API configuration/call for playing two independent wavefiles overlapped ? I tried to do so , I am getting resource busy error. Some pointers to solve the problem will be very helpful. Following is the error message from snd_pcm_prepare() of the second wavefile "Device or resource busy" JavaScript questions and answers, JavaScript questions pdf, JavaScript question bank, JavaScript questions and answers pdf, mcq on JavaScript pdf, JavaScript questions and solutions, JavaScript mcq Test , Interview JavaScript questions, JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)

Answer 1

You can configure ALSA's dmix plugin to allow multiple applications to share input/output devices. An example configuration to do this is below: pcm.dmixed { type dmix ipc_key 1024 ipc_key_add_uid 0 slave.pcm "hw:0,0" } pcm.dsnooped { type dsnoop ipc_key 1025 slave.pcm "hw:0,0" } pcm.duplex { type asym playback.pcm "dmixed" capture.pcm "dsnooped" } # Instruct ALSA to use pcm.duplex as the default device pcm.!default { type plug slave.pcm "duplex" } ctl.!default { type hw card 0 } This does the following: creates a new device using the dmix plugin, which allows multiple apps to share the output stream creates another using dsnoop which does the same thing for the input stream merges these into a new duplex device that will support input and output using the asym plugin tell ALSA to use the new duplex device as the default device tell ALSA to use hw:0 to control the default device (alsamixer and so on) Stick this in either ~/.asoundrc or /etc/asound.conf and you should be good to go. For more information see http://www.alsa-project.org/main/index.php/Asoundrc#Software_mixing.