2 Sound Blaster Audigy mixer / default DSP code
3 ===========================================
5 This is based on SB-Live-mixer.txt.
7 The EMU10K2 chips have a DSP part which can be programmed to support
8 various ways of sample processing, which is described here.
9 (This article does not deal with the overall functionality of the
10 EMU10K2 chips. See the manuals section for further details.)
12 The ALSA driver programs this portion of chip by default code
13 (can be altered later) which offers the following functionality:
16 1) Digital mixer controls
17 -------------------------
19 These controls are built using the DSP instructions. They offer extended
20 functionality. Only the default build-in code in the ALSA driver is described
21 here. Note that the controls work as attenuators: the maximum value is the
22 neutral position leaving the signal unchanged. Note that if the same destination
23 is mentioned in multiple controls, the signal is accumulated and can be wrapped
24 (set to maximal or minimal value without checking of overflow).
27 Explanation of used abbreviations:
29 DAC - digital to analog converter
30 ADC - analog to digital converter
31 I2S - one-way three wire serial bus for digital sound by Philips Semiconductors
32 (this standard is used for connecting standalone DAC and ADC converters)
33 LFE - low frequency effects (subwoofer signal)
34 AC97 - a chip containing an analog mixer, DAC and ADC converters
36 FX-bus - the EMU10K2 chip has an effect bus containing 64 accumulators.
37 Each of the synthesizer voices can feed its output to these accumulators
38 and the DSP microcontroller can operate with the resulting sum.
40 name='PCM Front Playback Volume',index=0
42 This control is used to attenuate samples for left and right front PCM FX-bus
43 accumulators. ALSA uses accumulators 8 and 9 for left and right front PCM
44 samples for 5.1 playback. The result samples are forwarded to the front DAC PCM
45 slots of the Philips DAC.
47 name='PCM Surround Playback Volume',index=0
49 This control is used to attenuate samples for left and right surround PCM FX-bus
50 accumulators. ALSA uses accumulators 2 and 3 for left and right surround PCM
51 samples for 5.1 playback. The result samples are forwarded to the surround DAC PCM
52 slots of the Philips DAC.
54 name='PCM Center Playback Volume',index=0
56 This control is used to attenuate samples for center PCM FX-bus accumulator.
57 ALSA uses accumulator 6 for center PCM sample for 5.1 playback. The result sample
58 is forwarded to the center DAC PCM slot of the Philips DAC.
60 name='PCM LFE Playback Volume',index=0
62 This control is used to attenuate sample for LFE PCM FX-bus accumulator.
63 ALSA uses accumulator 7 for LFE PCM sample for 5.1 playback. The result sample
64 is forwarded to the LFE DAC PCM slot of the Philips DAC.
66 name='PCM Playback Volume',index=0
68 This control is used to attenuate samples for left and right PCM FX-bus
69 accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples for
70 stereo playback. The result samples are forwarded to the front DAC PCM slots
73 name='PCM Capture Volume',index=0
75 This control is used to attenuate samples for left and right PCM FX-bus
76 accumulator. ALSA uses accumulators 0 and 1 for left and right PCM.
77 The result is forwarded to the ADC capture FIFO (thus to the standard capture
80 name='Music Playback Volume',index=0
82 This control is used to attenuate samples for left and right MIDI FX-bus
83 accumulators. ALSA uses accumulators 4 and 5 for left and right MIDI samples.
84 The result samples are forwarded to the front DAC PCM slots of the AC97 codec.
86 name='Music Capture Volume',index=0
88 These controls are used to attenuate samples for left and right MIDI FX-bus
89 accumulator. ALSA uses accumulators 4 and 5 for left and right PCM.
90 The result is forwarded to the ADC capture FIFO (thus to the standard capture
93 name='Mic Playback Volume',index=0
95 This control is used to attenuate samples for left and right Mic input.
96 For Mic input is used AC97 codec. The result samples are forwarded to
97 the front DAC PCM slots of the Philips DAC. Samples are forwarded to Mic
98 capture FIFO (device 1 - 16bit/8KHz mono) too without volume control.
100 name='Mic Capture Volume',index=0
102 This control is used to attenuate samples for left and right Mic input.
103 The result is forwarded to the ADC capture FIFO (thus to the standard capture
106 name='Audigy CD Playback Volume',index=0
108 This control is used to attenuate samples from left and right IEC958 TTL
109 digital inputs (usually used by a CDROM drive). The result samples are
110 forwarded to the front DAC PCM slots of the Philips DAC.
112 name='Audigy CD Capture Volume',index=0
114 This control is used to attenuate samples from left and right IEC958 TTL
115 digital inputs (usually used by a CDROM drive). The result samples are
116 forwarded to the ADC capture FIFO (thus to the standard capture PCM device).
118 name='IEC958 Optical Playback Volume',index=0
120 This control is used to attenuate samples from left and right IEC958 optical
121 digital input. The result samples are forwarded to the front DAC PCM slots
124 name='IEC958 Optical Capture Volume',index=0
126 This control is used to attenuate samples from left and right IEC958 optical
127 digital inputs. The result samples are forwarded to the ADC capture FIFO
128 (thus to the standard capture PCM device).
130 name='Line2 Playback Volume',index=0
132 This control is used to attenuate samples from left and right I2S ADC
133 inputs (on the AudigyDrive). The result samples are forwarded to the front
134 DAC PCM slots of the Philips DAC.
136 name='Line2 Capture Volume',index=1
138 This control is used to attenuate samples from left and right I2S ADC
139 inputs (on the AudigyDrive). The result samples are forwarded to the ADC
140 capture FIFO (thus to the standard capture PCM device).
142 name='Analog Mix Playback Volume',index=0
144 This control is used to attenuate samples from left and right I2S ADC
145 inputs from Philips ADC. The result samples are forwarded to the front
146 DAC PCM slots of the Philips DAC. This contains mix from analog sources
147 like CD, Line In, Aux, ....
149 name='Analog Mix Capture Volume',index=1
151 This control is used to attenuate samples from left and right I2S ADC
152 inputs Philips ADC. The result samples are forwarded to the ADC
153 capture FIFO (thus to the standard capture PCM device).
155 name='Aux2 Playback Volume',index=0
157 This control is used to attenuate samples from left and right I2S ADC
158 inputs (on the AudigyDrive). The result samples are forwarded to the front
159 DAC PCM slots of the Philips DAC.
161 name='Aux2 Capture Volume',index=1
163 This control is used to attenuate samples from left and right I2S ADC
164 inputs (on the AudigyDrive). The result samples are forwarded to the ADC
165 capture FIFO (thus to the standard capture PCM device).
167 name='Front Playback Volume',index=0
169 All stereo signals are mixed together and mirrored to surround, center and LFE.
170 This control is used to attenuate samples for left and right front speakers of
173 name='Surround Playback Volume',index=0
175 All stereo signals are mixed together and mirrored to surround, center and LFE.
176 This control is used to attenuate samples for left and right surround speakers of
179 name='Center Playback Volume',index=0
181 All stereo signals are mixed together and mirrored to surround, center and LFE.
182 This control is used to attenuate sample for center speaker of this mix.
184 name='LFE Playback Volume',index=0
186 All stereo signals are mixed together and mirrored to surround, center and LFE.
187 This control is used to attenuate sample for LFE speaker of this mix.
189 name='Tone Control - Switch',index=0
191 This control turns the tone control on or off. The samples for front, rear
192 and center / LFE outputs are affected.
194 name='Tone Control - Bass',index=0
196 This control sets the bass intensity. There is no neutral value!!
197 When the tone control code is activated, the samples are always modified.
198 The closest value to pure signal is 20.
200 name='Tone Control - Treble',index=0
202 This control sets the treble intensity. There is no neutral value!!
203 When the tone control code is activated, the samples are always modified.
204 The closest value to pure signal is 20.
206 name='Master Playback Volume',index=0
208 This control is used to attenuate samples for front, surround, center and
211 name='IEC958 Optical Raw Playback Switch',index=0
213 If this switch is on, then the samples for the IEC958 (S/PDIF) digital
214 output are taken only from the raw FX8010 PCM, otherwise standard front
215 PCM samples are taken.
218 2) PCM stream related controls
219 ------------------------------
221 name='EMU10K1 PCM Volume',index 0-31
223 Channel volume attenuation in range 0-0xffff. The maximum value (no
224 attenuation) is default. The channel mapping for three values is
227 0 - mono, default 0xffff (no attenuation)
228 1 - left, default 0xffff (no attenuation)
229 2 - right, default 0xffff (no attenuation)
231 name='EMU10K1 PCM Send Routing',index 0-31
233 This control specifies the destination - FX-bus accumulators. There 24
234 values with this mapping:
236 0 - mono, A destination (FX-bus 0-63), default 0
237 1 - mono, B destination (FX-bus 0-63), default 1
238 2 - mono, C destination (FX-bus 0-63), default 2
239 3 - mono, D destination (FX-bus 0-63), default 3
240 4 - mono, E destination (FX-bus 0-63), default 0
241 5 - mono, F destination (FX-bus 0-63), default 0
242 6 - mono, G destination (FX-bus 0-63), default 0
243 7 - mono, H destination (FX-bus 0-63), default 0
244 8 - left, A destination (FX-bus 0-63), default 0
245 9 - left, B destination (FX-bus 0-63), default 1
246 10 - left, C destination (FX-bus 0-63), default 2
247 11 - left, D destination (FX-bus 0-63), default 3
248 12 - left, E destination (FX-bus 0-63), default 0
249 13 - left, F destination (FX-bus 0-63), default 0
250 14 - left, G destination (FX-bus 0-63), default 0
251 15 - left, H destination (FX-bus 0-63), default 0
252 16 - right, A destination (FX-bus 0-63), default 0
253 17 - right, B destination (FX-bus 0-63), default 1
254 18 - right, C destination (FX-bus 0-63), default 2
255 19 - right, D destination (FX-bus 0-63), default 3
256 20 - right, E destination (FX-bus 0-63), default 0
257 21 - right, F destination (FX-bus 0-63), default 0
258 22 - right, G destination (FX-bus 0-63), default 0
259 23 - right, H destination (FX-bus 0-63), default 0
261 Don't forget that it's illegal to assign a channel to the same FX-bus accumulator
262 more than once (it means 0=0 && 1=0 is an invalid combination).
264 name='EMU10K1 PCM Send Volume',index 0-31
266 It specifies the attenuation (amount) for given destination in range 0-255.
267 The channel mapping is following:
269 0 - mono, A destination attn, default 255 (no attenuation)
270 1 - mono, B destination attn, default 255 (no attenuation)
271 2 - mono, C destination attn, default 0 (mute)
272 3 - mono, D destination attn, default 0 (mute)
273 4 - mono, E destination attn, default 0 (mute)
274 5 - mono, F destination attn, default 0 (mute)
275 6 - mono, G destination attn, default 0 (mute)
276 7 - mono, H destination attn, default 0 (mute)
277 8 - left, A destination attn, default 255 (no attenuation)
278 9 - left, B destination attn, default 0 (mute)
279 10 - left, C destination attn, default 0 (mute)
280 11 - left, D destination attn, default 0 (mute)
281 12 - left, E destination attn, default 0 (mute)
282 13 - left, F destination attn, default 0 (mute)
283 14 - left, G destination attn, default 0 (mute)
284 15 - left, H destination attn, default 0 (mute)
285 16 - right, A destination attn, default 0 (mute)
286 17 - right, B destination attn, default 255 (no attenuation)
287 18 - right, C destination attn, default 0 (mute)
288 19 - right, D destination attn, default 0 (mute)
289 20 - right, E destination attn, default 0 (mute)
290 21 - right, F destination attn, default 0 (mute)
291 22 - right, G destination attn, default 0 (mute)
292 23 - right, H destination attn, default 0 (mute)
299 ftp://opensource.creative.com/pub/doc
300 -------------------------------------
303 LM4545.pdf AC97 Codec
305 m2049.pdf The EMU10K1 Digital Audio Processor
307 hog63.ps FX8010 - A DSP Chip Architecture for Audio Effects
313 WO 9901813 (A1) Audio Effects Processor with multiple asynchronous (Jan. 14, 1999)
316 WO 9901814 (A1) Processor with Instruction Set for Audio Effects (Jan. 14, 1999)
318 WO 9901953 (A1) Audio Effects Processor having Decoupled Instruction
319 Execution and Audio Data Sequencing (Jan. 14, 1999)
322 US Patents (http://www.uspto.gov/)
323 ----------------------------------
325 US 5925841 Digital Sampling Instrument employing cache memory (Jul. 20, 1999)
327 US 5928342 Audio Effects Processor integrated on a single chip (Jul. 27, 1999)
328 with a multiport memory onto which multiple asynchronous
329 digital sound samples can be concurrently loaded
331 US 5930158 Processor with Instruction Set for Audio Effects (Jul. 27, 1999)
333 US 6032235 Memory initialization circuit (Tram) (Feb. 29, 2000)
335 US 6138207 Interpolation looping of audio samples in cache connected to (Oct. 24, 2000)
336 system bus with prioritization and modification of bus transfers
337 in accordance with loop ends and minimum block sizes
339 US 6151670 Method for conserving memory storage using a (Nov. 21, 2000)
340 pool of short term memory registers
342 US 6195715 Interrupt control for multiple programs communicating with (Feb. 27, 2001)
343 a common interrupt by associating programs to GP registers,
344 defining interrupt register, polling GP registers, and invoking
345 callback routine associated with defined interrupt register