These controls are built using the DSP instructions. They offer extended
functionality. Only the default built-in code in the ALSA driver is described
here. Note that the controls work as attenuators: the maximum value is the
-neutral position leaving the signal unchanged. Note that if the same destination
-is mentioned in multiple controls, the signal is accumulated and can be wrapped
-(set to maximal or minimal value without checking of overflow).
+neutral position leaving the signal unchanged. Note that if the same destination
+is mentioned in multiple controls, the signal is accumulated and can be clipped
+(set to maximal or minimal value without checking for overflow).
Explanation of used abbreviations:
analog to digital converter
I2S
one-way three wire serial bus for digital sound by Philips Semiconductors
- (this standard is used for connecting standalone DAC and ADC converters)
+ (this standard is used for connecting standalone D/A and A/D converters)
LFE
- low frequency effects (subwoofer signal)
+ low frequency effects (used as subwoofer signal)
AC97
- a chip containing an analog mixer, DAC and ADC converters
+ a chip containing an analog mixer, D/A and A/D converters
IEC958
S/PDIF
FX-bus
the EMU10K2 chip has an effect bus containing 64 accumulators.
- Each of the synthesizer voices can feed its output to these accumulators
- and the DSP microcontroller can operate with the resulting sum.
+ Each of the synthesizer voices can feed its output to these accumulators
+ and the DSP microcontroller can operate with the resulting sum.
name='PCM Front Playback Volume',index=0
----------------------------------------
name='IEC958 Optical Raw Playback Switch',index=0
-------------------------------------------------
If this switch is on, then the samples for the IEC958 (S/PDIF) digital
-output are taken only from the raw FX8010 PCM, otherwise standard front
-PCM samples are taken.
+output are taken only from the raw iec958 ALSA PCM device (which uses
+accumulators 20 and 21 for left and right PCM by default).
PCM stream related controls
name='EMU10K1 PCM Send Routing',index 0-31
------------------------------------------
-This control specifies the destination - FX-bus accumulators. There 24
-values with this mapping:
+This control specifies the destination - FX-bus accumulators. There are 24
+values in this mapping:
* 0 - mono, A destination (FX-bus 0-63), default 0
* 1 - mono, B destination (FX-bus 0-63), default 1
ftp://opensource.creative.com/pub/doc
-------------------------------------
+Note that the site is defunct, but the documents are available
+from various other locations.
+
LM4545.pdf
AC97 Codec
IEC958 (S/PDIF) raw PCM
=======================
-This PCM device (it's the 4th PCM device (index 3!) and first subdevice
+This PCM device (it's the 3rd PCM device (index 2!) and first subdevice
(index 0) for a given card) allows to forward 48kHz, stereo, 16-bit
little endian streams without any modifications to the digital output
(coaxial or optical). The universal interface allows the creation of up
These controls are built using the DSP instructions. They offer extended
functionality. Only the default built-in code in the ALSA driver is described
here. Note that the controls work as attenuators: the maximum value is the
-neutral position leaving the signal unchanged. Note that if the same destination
-is mentioned in multiple controls, the signal is accumulated and can be wrapped
-(set to maximal or minimal value without checking of overflow).
+neutral position leaving the signal unchanged. Note that if the same destination
+is mentioned in multiple controls, the signal is accumulated and can be clipped
+(set to maximal or minimal value without checking for overflow).
Explanation of used abbreviations:
analog to digital converter
I2S
one-way three wire serial bus for digital sound by Philips Semiconductors
- (this standard is used for connecting standalone DAC and ADC converters)
+ (this standard is used for connecting standalone D/A and A/D converters)
LFE
- low frequency effects (subwoofer signal)
+ low frequency effects (used as subwoofer signal)
AC97
- a chip containing an analog mixer, DAC and ADC converters
+ a chip containing an analog mixer, D/A and A/D converters
IEC958
S/PDIF
FX-bus
ftp://opensource.creative.com/pub/doc
-------------------------------------
+Note that the site is defunct, but the documents are available
+from various other locations.
+
LM4545.pdf
AC97 Codec
m2049.pdf