Sound

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Microphone, speaker, ringtone speaker and stereo headset are all attached to PCAP2

The motorola kernel uses an OSS sound driver to access these. There are three sound devices: /dev/dsp, /dev/dsp16 and /dev/audio. I do not know, if /dev/audio has any purpose. /dev/dsp can only output stereo, and /dev/dsp16 can only output mono. Both use signed 16-bit (2'complements) integers. You set /dev/dsp to 8000 or 44100Hz, and /dev/dsp16 only to 8000Hz. (See The Opensound Programmers Guide for a quick howto). You can write raw audio or PCM wave file to the devices and read raw audio from them.

To select the input or output source, open /dev/mixer and ioctl SOUND_MIXER_WRITE_OUTSRC or SOUND_MIXER_RECSRC. OUTSRC can be HEADSET_OUT (mono), LOUDERSPEAKER_OUT, EARPIECE_OUT or HEADJACK_OUT (see ezx-common.h in the kernel). SOUND_MIXER_RECSRC doesnt accept all values it should according to the kernel header file. Setting it to 2 should enable the builtin mono microphone.

For more information on audio support on openezx please refer to PCAP2 Sound

Retrieved from "http://wiki.openezx.org/Sound"
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