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Start an audio driver
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You must be root to start this manager. |
io-audio [-d driver [opt[,opt...]]] [-m opt[,opt...]] [-o opt[,opt...]] [v[v]...]
Neutrino
All audio drivers support the following card options:
You can start more than one driver by using multiple -d command-line options. For information on the drivers and any specific options, see the entries for the deva-ctrl-* shared objects.
The default is FAHQ.
sw_mixer_samples = samples_per_frag * (hardware_rate/requested_rate) * (hardware_voices/requested_voices)
The io-audio manager provides support for dynamically loaded audio-driver modules. This utility enables you to load the audio drivers specified by the -d options when you start io-audio.
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Graphics drivers run at a higher priority than applications, but they shouldn't run at a higher priority than the audio, or else breaks in the audio occur. You can use the on command to adjust the priorities of the audio and graphics drivers. |
Once io-audio has started, you can dynamically load and unload drivers using the mount and umount commands. E.g. this command:
io-audio -dvortex -daudiopci &
gives the same result as this sequence:
io-audio & mount -T io-audio vortex mount -T io-audio audiopci
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When searching for shared objects, the io-audio manager uses the LD_LIBRARY_PATH environment variable. |
To unload a module, use a command like this:
umount /dev/snd/controlC0
Provide support for Aureal Vortex sound card, using deva-ctrl-vortex.so:
io-audio -vv -d vortex &
Load the deva-ctrl-audiopci.so shared object, specifying the size of the DMA memory pool as 500 KB:
io-audio -vv -m pool_size=500 -d audiopci &
Lock the sample rate to 8 KHz (if the hardware supports 8 KHz natively):
io-audio -o sw_mixer_rate=L8000 -d my_audio_driver
Start an audio driver, specifying the card options:
io-audio -d my_audio_driver \ cap_name=capture,play_name=playback_hw,dindex=1,play_name=playback_pcm_mixer
The /dev/snd directory will look something like this:
# ls -l /dev/snd total 0 lrw-rw-rw- 1 root root 0 May 31 11:11 capture -> pcmC0D0c -rw-rw-rw- 1 root root 0 May 31 11:11 controlC0 -rw-rw-rw- 1 root root 0 May 31 11:11 mixerC0D0 -rw-rw-rw- 1 root root 0 May 31 11:11 pcmC0D0c -rw-rw-rw- 1 root root 0 May 31 11:11 pcmC0D0p -rw-rw-rw- 1 root root 0 May 31 11:11 pcmC0D1p lrw-rw-rw- 1 root root 0 May 31 11:11 pcmPreferredc -> pcmC0D0c lrw-rw-rw- 1 root root 0 May 31 11:11 pcmPreferredp -> pcmC0D1p lrw-rw-rw- 1 root root 0 May 31 11:11 playback_pcm_mixer -> pcmC0D1p lrw-rw-rw- 1 root root 0 May 31 11:11 playback_hw -> pcmC0D0p
In addition to the deva-ctrl-* drivers, the io-audio command can load the following shared objects:
Connecting Hardware in the QNX Neutrino User's Guide
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