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1275 |
phoenix |
/proc/sound, /dev/sndstat
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-------------------------
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/proc/sound and /dev/sndstat is not supported by the
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driver. To find out whether the driver succeeded loading,
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check the kernel log (dmesg).
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ALaw/uLaw sample formats
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------------------------
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This driver does not support the ALaw/uLaw sample formats.
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ALaw is the default mode when opening a sound device
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using OSS/Free. The reason for the lack of support is
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that the hardware does not support these formats, and adding
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conversion routines to the kernel would lead to very ugly
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code in the presence of the mmap interface to the driver.
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And since xquake uses mmap, mmap is considered important :-)
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and no sane application uses ALaw/uLaw these days anyway.
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In short, playing a Sun .au file as follows:
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cat my_file.au > /dev/dsp
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does not work. Instead, you may use the play script from
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Chris Bagwell's sox-12.14 package (available from the URL
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below) to play many different audio file formats.
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The script automatically determines the audio format
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and does do audio conversions if necessary.
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http://home.sprynet.com/sprynet/cbagwell/projects.html
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Blocking vs. nonblocking IO
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---------------------------
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Unlike OSS/Free this driver honours the O_NONBLOCK file flag
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not only during open, but also during read and write.
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This is an effort to make the sound driver interface more
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regular. Timidity has problems with this; a patch
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is available from http://www.ife.ee.ethz.ch/~sailer/linux/pciaudio.html.
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(Timidity patched will also run on OSS/Free).
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MIDI UART
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---------
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The driver supports a simple MIDI UART interface, with
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no ioctl's supported.
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MIDI synthesizer
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----------------
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This soundcard does not have any hardware MIDI synthesizer;
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MIDI synthesis has to be done in software. To allow this
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the driver/soundcard supports two PCM (/dev/dsp) interfaces.
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There is a freely available software package that allows
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MIDI file playback on this soundcard called Timidity.
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See http://www.cgs.fi/~tt/timidity/.
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Thomas Sailer
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t.sailer@alumni.ethz.ch
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