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ALSA: doc: ReSTize CMIPCI document 

A simple conversion from a plain text file.
Put to cards subdirectory.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2016-11-09 17:12:34 +01:00
parent f59c3c6d87
commit 95ee717a89
2 changed files with 41 additions and 22 deletions
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50
Documentation/sound/alsa/CMIPCI.txt → Documentation/sound/cards/cmipci.rst
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@ -1,3 +1,4 @@
=================================================
Brief Notes on C-Media 8338/8738/8768/8770 Driver
=================================================
@ -30,19 +31,20 @@ The rear output can be heard only when "Four Channel Mode" switch is
disabled. Otherwise no signal will be routed to the rear speakers.
As default it's turned on.
*** WARNING ***
.. WARNING::
When "Four Channel Mode" switch is off, the output from rear speakers
will be FULL VOLUME regardless of Master and PCM volumes.
will be FULL VOLUME regardless of Master and PCM volumes [#]_.
This might damage your audio equipment. Please disconnect speakers
before your turn off this switch.
*** WARNING ***
[ Well.. I once got the output with correct volume (i.e. same with the
.. [#]
Well.. I once got the output with correct volume (i.e. same with the
front one) and was so excited. It was even with "Four Channel" bit
on and "double DAC" mode. Actually I could hear separate 4 channels
from front and rear speakers! But.. after reboot, all was gone.
It's a very pity that I didn't save the register dump at that
time.. Maybe there is an unknown register to achieve this... ]
time.. Maybe there is an unknown register to achieve this...
If your card has an extra output jack for the rear output, the rear
playback should be routed there as default. If not, there is a
@ -73,12 +75,14 @@ cannot operate with full-duplex.
The 4.0 and 5.1 modes are defined as the pcm "surround40" and "surround51"
in alsa-lib. For example, you can play a WAV file with 6 channels like
::
% aplay -Dsurround51 sixchannels.wav
For programming the 4/6 channel playback, you need to specify the PCM
channels as you like and set the format S16LE. For example, for playback
with 4 channels,
::
snd_pcm_hw_params_set_access(pcm, hw, SND_PCM_ACCESS_RW_INTERLEAVED);
// or mmap if you like
@ -89,13 +93,15 @@ and use the interleaved 4 channel data.
There are some control switches affecting to the speaker connections:
"Line-In Mode" - an enum control to change the behavior of line-in
Line-In Mode
an enum control to change the behavior of line-in
jack. Either "Line-In", "Rear Output" or "Bass Output" can
be selected. The last item is available only with model 039
or newer.
When "Rear Output" is chosen, the surround channels 3 and 4
are output to line-in jack.
"Mic-In Mode" - an enum control to change the behavior of mic-in
Mic-In Mode
an enum control to change the behavior of mic-in
jack. Either "Mic-In" or "Center/LFE Output" can be
selected.
When "Center/LFE Output" is chosen, the center and bass
@ -111,11 +117,14 @@ The SPDIF playback and capture are done via the third PCM device
(hw:0,2). Usually this is assigned to the PCM device "spdif".
The available rates are 44100 and 48000 Hz.
For playback with aplay, you can run like below:
::
% aplay -Dhw:0,2 foo.wav
or
::
% aplay -Dspdif foo.wav
24bit format is also supported experimentally.
@ -140,31 +149,40 @@ off. (Also don't forget to turn on "IEC958 Output Switch", too.)
Additionally there are relevant control switches:
"IEC958 Mix Analog" - Mix analog PCM playback and FM-OPL/3 streams and
IEC958 Mix Analog
Mix analog PCM playback and FM-OPL/3 streams and
output through SPDIF. This switch appears only on old chip
models (CM8738 033 and 037).
Note: without this control you can output PCM to SPDIF.
This is "mixing" of streams, so e.g. it's not for AC3 output
(see the next section).
"IEC958 In Select" - Select SPDIF input, the internal CD-in (false)
IEC958 In Select
Select SPDIF input, the internal CD-in (false)
and the external input (true).
"IEC958 Loop" - SPDIF input data is loop back into SPDIF
IEC958 Loop
SPDIF input data is loop back into SPDIF
output (aka bypass)
"IEC958 Copyright" - Set the copyright bit.
IEC958 Copyright
Set the copyright bit.
"IEC958 5V" - Select 0.5V (coax) or 5V (optical) interface.
IEC958 5V
Select 0.5V (coax) or 5V (optical) interface.
On some cards this doesn't work and you need to change the
configuration with hardware dip-switch.
"IEC958 In Monitor" - SPDIF input is routed to DAC.
IEC958 In Monitor
SPDIF input is routed to DAC.
"IEC958 In Phase Inverse" - Set SPDIF input format as inverse.
IEC958 In Phase Inverse
Set SPDIF input format as inverse.
[FIXME: this doesn't work on all chips..]
"IEC958 In Valid" - Set input validity flag detection.
IEC958 In Valid
Set input validity flag detection.
Note: When "PCM Playback Switch" is on, you'll hear the digital output
stream through analog line-out.
@ -217,7 +235,7 @@ to enable MIDI support. Valid I/O ports are 0x300, 0x310, 0x320 and
With CMI8738 and newer chips, the MIDI interface is enabled by default
and the driver automatically chooses a port address.
There is _no_ hardware wavetable function on this chip (except for
There is *no* hardware wavetable function on this chip (except for
OPL3 synth below).
What's said as MIDI synth on Windows is a software synthesizer
emulation. On Linux use TiMidity or other softsynth program for

1
Documentation/sound/cards/index.rst
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@ -5,3 +5,4 @@ Card-Specific Information
:maxdepth: 2
joystick
cmipci