2023-08-30 17:31:07 +02:00
|
|
|
===========================================
|
|
|
|
|
Sound Blaster Live mixer / default DSP code
|
|
|
|
|
===========================================
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
The EMU10K1 chips have a DSP part which can be programmed to support
|
|
|
|
|
various ways of sample processing, which is described here.
|
|
|
|
|
(This article does not deal with the overall functionality of the
|
|
|
|
|
EMU10K1 chips. See the manuals section for further details.)
|
|
|
|
|
|
|
|
|
|
The ALSA driver programs this portion of chip by default code
|
|
|
|
|
(can be altered later) which offers the following functionality:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
IEC958 (S/PDIF) raw PCM
|
|
|
|
|
=======================
|
|
|
|
|
|
2023-10-24 12:59:35 +02:00
|
|
|
This PCM device (it's the 3rd PCM device (index 2!) and first subdevice
|
2023-08-30 17:31:07 +02:00
|
|
|
(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
|
|
|
|
|
to 8 raw PCM devices operating at 48kHz, 16-bit little endian. It would
|
|
|
|
|
be easy to add support for multichannel devices to the current code,
|
|
|
|
|
but the conversion routines exist only for stereo (2-channel streams)
|
|
|
|
|
at the time.
|
|
|
|
|
|
|
|
|
|
Look to tram_poke routines in lowlevel/emu10k1/emufx.c for more details.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Digital mixer controls
|
|
|
|
|
======================
|
|
|
|
|
|
|
|
|
|
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
|
2023-10-24 12:59:35 +02:00
|
|
|
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).
|
2023-08-30 17:31:07 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
Explanation of used abbreviations:
|
|
|
|
|
|
|
|
|
|
DAC
|
|
|
|
|
digital to analog converter
|
|
|
|
|
ADC
|
|
|
|
|
analog to digital converter
|
|
|
|
|
I2S
|
|
|
|
|
one-way three wire serial bus for digital sound by Philips Semiconductors
|
2023-10-24 12:59:35 +02:00
|
|
|
(this standard is used for connecting standalone D/A and A/D converters)
|
2023-08-30 17:31:07 +02:00
|
|
|
LFE
|
2023-10-24 12:59:35 +02:00
|
|
|
low frequency effects (used as subwoofer signal)
|
2023-08-30 17:31:07 +02:00
|
|
|
AC97
|
2023-10-24 12:59:35 +02:00
|
|
|
a chip containing an analog mixer, D/A and A/D converters
|
2023-08-30 17:31:07 +02:00
|
|
|
IEC958
|
|
|
|
|
S/PDIF
|
|
|
|
|
FX-bus
|
|
|
|
|
the EMU10K1 chip has an effect bus containing 16 accumulators.
|
|
|
|
|
Each of the synthesizer voices can feed its output to these accumulators
|
|
|
|
|
and the DSP microcontroller can operate with the resulting sum.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
``name='Wave Playback Volume',index=0``
|
|
|
|
|
---------------------------------------
|
|
|
|
|
This control is used to attenuate samples for left and right PCM FX-bus
|
|
|
|
|
accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples.
|
|
|
|
|
The result samples are forwarded to the front DAC PCM slots of the AC97 codec.
|
|
|
|
|
|
|
|
|
|
``name='Wave Surround Playback Volume',index=0``
|
|
|
|
|
------------------------------------------------
|
|
|
|
|
This control is used to attenuate samples for left and right PCM FX-bus
|
|
|
|
|
accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples.
|
|
|
|
|
The result samples are forwarded to the rear I2S DACs. These DACs operates
|
|
|
|
|
separately (they are not inside the AC97 codec).
|
|
|
|
|
|
|
|
|
|
``name='Wave Center Playback Volume',index=0``
|
|
|
|
|
----------------------------------------------
|
|
|
|
|
This control is used to attenuate samples for left and right PCM FX-bus
|
|
|
|
|
accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples.
|
|
|
|
|
The result is mixed to mono signal (single channel) and forwarded to
|
|
|
|
|
the ??rear?? right DAC PCM slot of the AC97 codec.
|
|
|
|
|
|
|
|
|
|
``name='Wave LFE Playback Volume',index=0``
|
|
|
|
|
-------------------------------------------
|
|
|
|
|
This control is used to attenuate samples for left and right PCM FX-bus
|
|
|
|
|
accumulators. ALSA uses accumulators 0 and 1 for left and right PCM.
|
|
|
|
|
The result is mixed to mono signal (single channel) and forwarded to
|
|
|
|
|
the ??rear?? left DAC PCM slot of the AC97 codec.
|
|
|
|
|
|
|
|
|
|
``name='Wave Capture Volume',index=0``, ``name='Wave Capture Switch',index=0``
|
|
|
|
|
------------------------------------------------------------------------------
|
|
|
|
|
These controls are used to attenuate samples for left and right PCM FX-bus
|
|
|
|
|
accumulator. ALSA uses accumulators 0 and 1 for left and right PCM.
|
|
|
|
|
The result is forwarded to the ADC capture FIFO (thus to the standard capture
|
|
|
|
|
PCM device).
|
|
|
|
|
|
|
|
|
|
``name='Synth Playback Volume',index=0``
|
|
|
|
|
----------------------------------------
|
|
|
|
|
This control is used to attenuate samples for left and right MIDI FX-bus
|
|
|
|
|
accumulators. ALSA uses accumulators 4 and 5 for left and right MIDI samples.
|
|
|
|
|
The result samples are forwarded to the front DAC PCM slots of the AC97 codec.
|
|
|
|
|
|
|
|
|
|
``name='Synth Capture Volume',index=0``, ``name='Synth Capture Switch',index=0``
|
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
|
These controls are used to attenuate samples for left and right MIDI FX-bus
|
|
|
|
|
accumulator. ALSA uses accumulators 4 and 5 for left and right PCM.
|
|
|
|
|
The result is forwarded to the ADC capture FIFO (thus to the standard capture
|
|
|
|
|
PCM device).
|
|
|
|
|
|
|
|
|
|
``name='Surround Playback Volume',index=0``
|
|
|
|
|
-------------------------------------------
|
|
|
|
|
This control is used to attenuate samples for left and right rear PCM FX-bus
|
|
|
|
|
accumulators. ALSA uses accumulators 2 and 3 for left and right rear PCM samples.
|
|
|
|
|
The result samples are forwarded to the rear I2S DACs. These DACs operate
|
|
|
|
|
separately (they are not inside the AC97 codec).
|
|
|
|
|
|
|
|
|
|
``name='Surround Capture Volume',index=0``, ``name='Surround Capture Switch',index=0``
|
|
|
|
|
--------------------------------------------------------------------------------------
|
|
|
|
|
These controls are used to attenuate samples for left and right rear PCM FX-bus
|
|
|
|
|
accumulators. ALSA uses accumulators 2 and 3 for left and right rear PCM samples.
|
|
|
|
|
The result is forwarded to the ADC capture FIFO (thus to the standard capture
|
|
|
|
|
PCM device).
|
|
|
|
|
|
|
|
|
|
``name='Center Playback Volume',index=0``
|
|
|
|
|
-----------------------------------------
|
|
|
|
|
This control is used to attenuate sample for center PCM FX-bus accumulator.
|
|
|
|
|
ALSA uses accumulator 6 for center PCM sample. The result sample is forwarded
|
|
|
|
|
to the ??rear?? right DAC PCM slot of the AC97 codec.
|
|
|
|
|
|
|
|
|
|
``name='LFE Playback Volume',index=0``
|
|
|
|
|
--------------------------------------
|
|
|
|
|
This control is used to attenuate sample for center PCM FX-bus accumulator.
|
|
|
|
|
ALSA uses accumulator 6 for center PCM sample. The result sample is forwarded
|
|
|
|
|
to the ??rear?? left DAC PCM slot of the AC97 codec.
|
|
|
|
|
|
|
|
|
|
``name='AC97 Playback Volume',index=0``
|
|
|
|
|
---------------------------------------
|
|
|
|
|
This control is used to attenuate samples for left and right front ADC PCM slots
|
|
|
|
|
of the AC97 codec. The result samples are forwarded to the front DAC PCM
|
|
|
|
|
slots of the AC97 codec.
|
|
|
|
|
|
|
|
|
|
.. note::
|
|
|
|
|
This control should be zero for the standard operations, otherwise
|
|
|
|
|
a digital loopback is activated.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
``name='AC97 Capture Volume',index=0``
|
|
|
|
|
--------------------------------------
|
|
|
|
|
This control is used to attenuate samples for left and right front ADC PCM slots
|
|
|
|
|
of the AC97 codec. The result is forwarded to the ADC capture FIFO (thus to
|
|
|
|
|
the standard capture PCM device).
|
|
|
|
|
|
|
|
|
|
.. note::
|
|
|
|
|
This control should be 100 (maximal value), otherwise no analog
|
|
|
|
|
inputs of the AC97 codec can be captured (recorded).
|
|
|
|
|
|
|
|
|
|
``name='IEC958 TTL Playback Volume',index=0``
|
|
|
|
|
---------------------------------------------
|
|
|
|
|
This control is used to attenuate samples from left and right IEC958 TTL
|
|
|
|
|
digital inputs (usually used by a CDROM drive). The result samples are
|
|
|
|
|
forwarded to the front DAC PCM slots of the AC97 codec.
|
|
|
|
|
|
|
|
|
|
``name='IEC958 TTL Capture Volume',index=0``
|
|
|
|
|
--------------------------------------------
|
|
|
|
|
This control is used to attenuate samples from left and right IEC958 TTL
|
|
|
|
|
digital inputs (usually used by a CDROM drive). The result samples are
|
|
|
|
|
forwarded to the ADC capture FIFO (thus to the standard capture PCM device).
|
|
|
|
|
|
|
|
|
|
``name='Zoom Video Playback Volume',index=0``
|
|
|
|
|
---------------------------------------------
|
|
|
|
|
This control is used to attenuate samples from left and right zoom video
|
|
|
|
|
digital inputs (usually used by a CDROM drive). The result samples are
|
|
|
|
|
forwarded to the front DAC PCM slots of the AC97 codec.
|
|
|
|
|
|
|
|
|
|
``name='Zoom Video Capture Volume',index=0``
|
|
|
|
|
--------------------------------------------
|
|
|
|
|
This control is used to attenuate samples from left and right zoom video
|
|
|
|
|
digital inputs (usually used by a CDROM drive). The result samples are
|
|
|
|
|
forwarded to the ADC capture FIFO (thus to the standard capture PCM device).
|
|
|
|
|
|
|
|
|
|
``name='IEC958 LiveDrive Playback Volume',index=0``
|
|
|
|
|
---------------------------------------------------
|
|
|
|
|
This control is used to attenuate samples from left and right IEC958 optical
|
|
|
|
|
digital input. The result samples are forwarded to the front DAC PCM slots
|
|
|
|
|
of the AC97 codec.
|
|
|
|
|
|
|
|
|
|
``name='IEC958 LiveDrive Capture Volume',index=0``
|
|
|
|
|
--------------------------------------------------
|
|
|
|
|
This control is used to attenuate samples from left and right IEC958 optical
|
|
|
|
|
digital inputs. The result samples are forwarded to the ADC capture FIFO
|
|
|
|
|
(thus to the standard capture PCM device).
|
|
|
|
|
|
|
|
|
|
``name='IEC958 Coaxial Playback Volume',index=0``
|
|
|
|
|
-------------------------------------------------
|
|
|
|
|
This control is used to attenuate samples from left and right IEC958 coaxial
|
|
|
|
|
digital inputs. The result samples are forwarded to the front DAC PCM slots
|
|
|
|
|
of the AC97 codec.
|
|
|
|
|
|
|
|
|
|
``name='IEC958 Coaxial Capture Volume',index=0``
|
|
|
|
|
------------------------------------------------
|
|
|
|
|
This control is used to attenuate samples from left and right IEC958 coaxial
|
|
|
|
|
digital inputs. The result samples are forwarded to the ADC capture FIFO
|
|
|
|
|
(thus to the standard capture PCM device).
|
|
|
|
|
|
|
|
|
|
``name='Line LiveDrive Playback Volume',index=0``, ``name='Line LiveDrive Playback Volume',index=1``
|
|
|
|
|
----------------------------------------------------------------------------------------------------
|
|
|
|
|
This control is used to attenuate samples from left and right I2S ADC
|
|
|
|
|
inputs (on the LiveDrive). The result samples are forwarded to the front
|
|
|
|
|
DAC PCM slots of the AC97 codec.
|
|
|
|
|
|
|
|
|
|
``name='Line LiveDrive Capture Volume',index=1``, ``name='Line LiveDrive Capture Volume',index=1``
|
|
|
|
|
--------------------------------------------------------------------------------------------------
|
|
|
|
|
This control is used to attenuate samples from left and right I2S ADC
|
|
|
|
|
inputs (on the LiveDrive). The result samples are forwarded to the ADC
|
|
|
|
|
capture FIFO (thus to the standard capture PCM device).
|
|
|
|
|
|
|
|
|
|
``name='Tone Control - Switch',index=0``
|
|
|
|
|
----------------------------------------
|
|
|
|
|
This control turns the tone control on or off. The samples for front, rear
|
|
|
|
|
and center / LFE outputs are affected.
|
|
|
|
|
|
|
|
|
|
``name='Tone Control - Bass',index=0``
|
|
|
|
|
--------------------------------------
|
|
|
|
|
This control sets the bass intensity. There is no neutral value!!
|
|
|
|
|
When the tone control code is activated, the samples are always modified.
|
|
|
|
|
The closest value to pure signal is 20.
|
|
|
|
|
|
|
|
|
|
``name='Tone Control - Treble',index=0``
|
|
|
|
|
----------------------------------------
|
|
|
|
|
This control sets the treble intensity. There is no neutral value!!
|
|
|
|
|
When the tone control code is activated, the samples are always modified.
|
|
|
|
|
The closest value to pure signal is 20.
|
|
|
|
|
|
|
|
|
|
``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.
|
|
|
|
|
|
|
|
|
|
``name='Headphone Playback Volume',index=1``
|
|
|
|
|
--------------------------------------------
|
|
|
|
|
This control attenuates the samples for the headphone output.
|
|
|
|
|
|
|
|
|
|
``name='Headphone Center Playback Switch',index=1``
|
|
|
|
|
---------------------------------------------------
|
|
|
|
|
If this switch is on, then the sample for the center PCM is put to the
|
|
|
|
|
left headphone output (useful for SB Live cards without separate center/LFE
|
|
|
|
|
output).
|
|
|
|
|
|
|
|
|
|
``name='Headphone LFE Playback Switch',index=1``
|
|
|
|
|
------------------------------------------------
|
|
|
|
|
If this switch is on, then the sample for the center PCM is put to the
|
|
|
|
|
right headphone output (useful for SB Live cards without separate center/LFE
|
|
|
|
|
output).
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
PCM stream related controls
|
|
|
|
|
===========================
|
|
|
|
|
|
|
|
|
|
``name='EMU10K1 PCM Volume',index 0-31``
|
|
|
|
|
----------------------------------------
|
2023-10-24 12:59:35 +02:00
|
|
|
Channel volume attenuation in range 0-0x1fffd. The middle value (no
|
2023-08-30 17:31:07 +02:00
|
|
|
attenuation) is default. The channel mapping for three values is
|
|
|
|
|
as follows:
|
|
|
|
|
|
|
|
|
|
* 0 - mono, default 0xffff (no attenuation)
|
|
|
|
|
* 1 - left, default 0xffff (no attenuation)
|
|
|
|
|
* 2 - right, default 0xffff (no attenuation)
|
|
|
|
|
|
|
|
|
|
``name='EMU10K1 PCM Send Routing',index 0-31``
|
|
|
|
|
----------------------------------------------
|
|
|
|
|
This control specifies the destination - FX-bus accumulators. There are
|
|
|
|
|
twelve values with this mapping:
|
|
|
|
|
|
|
|
|
|
* 0 - mono, A destination (FX-bus 0-15), default 0
|
|
|
|
|
* 1 - mono, B destination (FX-bus 0-15), default 1
|
|
|
|
|
* 2 - mono, C destination (FX-bus 0-15), default 2
|
|
|
|
|
* 3 - mono, D destination (FX-bus 0-15), default 3
|
|
|
|
|
* 4 - left, A destination (FX-bus 0-15), default 0
|
|
|
|
|
* 5 - left, B destination (FX-bus 0-15), default 1
|
|
|
|
|
* 6 - left, C destination (FX-bus 0-15), default 2
|
|
|
|
|
* 7 - left, D destination (FX-bus 0-15), default 3
|
|
|
|
|
* 8 - right, A destination (FX-bus 0-15), default 0
|
|
|
|
|
* 9 - right, B destination (FX-bus 0-15), default 1
|
|
|
|
|
* 10 - right, C destination (FX-bus 0-15), default 2
|
|
|
|
|
* 11 - right, D destination (FX-bus 0-15), default 3
|
|
|
|
|
|
|
|
|
|
Don't forget that it's illegal to assign a channel to the same FX-bus accumulator
|
|
|
|
|
more than once (it means 0=0 && 1=0 is an invalid combination).
|
|
|
|
|
|
|
|
|
|
``name='EMU10K1 PCM Send Volume',index 0-31``
|
|
|
|
|
---------------------------------------------
|
|
|
|
|
It specifies the attenuation (amount) for given destination in range 0-255.
|
|
|
|
|
The channel mapping is following:
|
|
|
|
|
|
|
|
|
|
* 0 - mono, A destination attn, default 255 (no attenuation)
|
|
|
|
|
* 1 - mono, B destination attn, default 255 (no attenuation)
|
|
|
|
|
* 2 - mono, C destination attn, default 0 (mute)
|
|
|
|
|
* 3 - mono, D destination attn, default 0 (mute)
|
|
|
|
|
* 4 - left, A destination attn, default 255 (no attenuation)
|
|
|
|
|
* 5 - left, B destination attn, default 0 (mute)
|
|
|
|
|
* 6 - left, C destination attn, default 0 (mute)
|
|
|
|
|
* 7 - left, D destination attn, default 0 (mute)
|
|
|
|
|
* 8 - right, A destination attn, default 0 (mute)
|
|
|
|
|
* 9 - right, B destination attn, default 255 (no attenuation)
|
|
|
|
|
* 10 - right, C destination attn, default 0 (mute)
|
|
|
|
|
* 11 - right, D destination attn, default 0 (mute)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
MANUALS/PATENTS
|
|
|
|
|
===============
|
|
|
|
|
|
|
|
|
|
ftp://opensource.creative.com/pub/doc
|
|
|
|
|
-------------------------------------
|
|
|
|
|
|
2023-10-24 12:59:35 +02:00
|
|
|
Note that the site is defunct, but the documents are available
|
|
|
|
|
from various other locations.
|
|
|
|
|
|
2023-08-30 17:31:07 +02:00
|
|
|
LM4545.pdf
|
|
|
|
|
AC97 Codec
|
|
|
|
|
m2049.pdf
|
|
|
|
|
The EMU10K1 Digital Audio Processor
|
|
|
|
|
hog63.ps
|
|
|
|
|
FX8010 - A DSP Chip Architecture for Audio Effects
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
WIPO Patents
|
|
|
|
|
------------
|
|
|
|
|
|
|
|
|
|
WO 9901813 (A1)
|
|
|
|
|
Audio Effects Processor with multiple asynchronous streams
|
|
|
|
|
(Jan. 14, 1999)
|
|
|
|
|
|
|
|
|
|
WO 9901814 (A1)
|
|
|
|
|
Processor with Instruction Set for Audio Effects (Jan. 14, 1999)
|
|
|
|
|
|
|
|
|
|
WO 9901953 (A1)
|
|
|
|
|
Audio Effects Processor having Decoupled Instruction
|
|
|
|
|
Execution and Audio Data Sequencing (Jan. 14, 1999)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
US Patents (https://www.uspto.gov/)
|
|
|
|
|
-----------------------------------
|
|
|
|
|
|
|
|
|
|
US 5925841
|
|
|
|
|
Digital Sampling Instrument employing cache memory (Jul. 20, 1999)
|
|
|
|
|
|
|
|
|
|
US 5928342
|
|
|
|
|
Audio Effects Processor integrated on a single chip
|
|
|
|
|
with a multiport memory onto which multiple asynchronous
|
|
|
|
|
digital sound samples can be concurrently loaded
|
|
|
|
|
(Jul. 27, 1999)
|
|
|
|
|
|
|
|
|
|
US 5930158
|
|
|
|
|
Processor with Instruction Set for Audio Effects (Jul. 27, 1999)
|
|
|
|
|
|
|
|
|
|
US 6032235
|
|
|
|
|
Memory initialization circuit (Tram) (Feb. 29, 2000)
|
|
|
|
|
|
|
|
|
|
US 6138207
|
|
|
|
|
Interpolation looping of audio samples in cache connected to
|
|
|
|
|
system bus with prioritization and modification of bus transfers
|
|
|
|
|
in accordance with loop ends and minimum block sizes
|
|
|
|
|
(Oct. 24, 2000)
|
|
|
|
|
|
|
|
|
|
US 6151670
|
|
|
|
|
Method for conserving memory storage using a
|
|
|
|
|
pool of short term memory registers
|
|
|
|
|
(Nov. 21, 2000)
|
|
|
|
|
|
|
|
|
|
US 6195715
|
|
|
|
|
Interrupt control for multiple programs communicating with
|
|
|
|
|
a common interrupt by associating programs to GP registers,
|
|
|
|
|
defining interrupt register, polling GP registers, and invoking
|
|
|
|
|
callback routine associated with defined interrupt register
|
|
|
|
|
(Feb. 27, 2001)
|
