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1 2 Sound Blaster Audigy mixer / default DSP code 3 =========================================== 4 5 This is based on SB-Live-mixer.txt. 6 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.) 11 12 The ALSA driver programs this portion of chip by default code 13 (can be altered later) which offers the following functionality: 14 15 16 1) Digital mixer controls 17 ------------------------- 18 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). 25 26 27 Explanation of used abbreviations: 28 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 35 IEC958 - S/PDIF 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. 39 40 name='PCM Front Playback Volume',index=0 41 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. 46 47 name='PCM Surround Playback Volume',index=0 48 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. 53 54 name='PCM Center Playback Volume',index=0 55 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. 59 60 name='PCM LFE Playback Volume',index=0 61 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. 65 66 name='PCM Playback Volume',index=0 67 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 71 of the Philips DAC. 72 73 name='PCM Capture Volume',index=0 74 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 78 PCM device). 79 80 name='Music Playback Volume',index=0 81 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. 85 86 name='Music Capture Volume',index=0 87 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 91 PCM device). 92 93 name='Mic Playback Volume',index=0 94 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. 99 100 name='Mic Capture Volume',index=0 101 102 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 104 PCM device). 105 106 name='Audigy CD Playback Volume',index=0 107 108 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. 111 112 name='Audigy CD Capture Volume',index=0 113 114 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). 117 118 name='IEC958 Optical Playback Volume',index=0 119 120 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 122 of the Philips DAC. 123 124 name='IEC958 Optical Capture Volume',index=0 125 126 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). 129 130 name='Line2 Playback Volume',index=0 131 132 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. 135 136 name='Line2 Capture Volume',index=1 137 138 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). 141 142 name='Analog Mix Playback Volume',index=0 143 144 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, .... 148 149 name='Analog Mix Capture Volume',index=1 150 151 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). 154 155 name='Aux2 Playback Volume',index=0 156 157 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. 160 161 name='Aux2 Capture Volume',index=1 162 163 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). 166 167 name='Front Playback Volume',index=0 168 169 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 171 this mix. 172 173 name='Surround Playback Volume',index=0 174 175 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 177 this mix. 178 179 name='Center Playback Volume',index=0 180 181 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. 183 184 name='LFE Playback Volume',index=0 185 186 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. 188 189 name='Tone Control - Switch',index=0 190 191 This control turns the tone control on or off. The samples for front, rear 192 and center / LFE outputs are affected. 193 194 name='Tone Control - Bass',index=0 195 196 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. 199 200 name='Tone Control - Treble',index=0 201 202 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. 205 206 name='Master Playback Volume',index=0 207 208 This control is used to attenuate samples for front, surround, center and 209 LFE outputs. 210 211 name='IEC958 Optical Raw Playback Switch',index=0 212 213 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. 216 217 218 2) PCM stream related controls 219 ------------------------------ 220 221 name='EMU10K1 PCM Volume',index 0-31 222 223 Channel volume attenuation in range 0-0xffff. The maximum value (no 224 attenuation) is default. The channel mapping for three values is 225 as follows: 226 227 0 - mono, default 0xffff (no attenuation) 228 1 - left, default 0xffff (no attenuation) 229 2 - right, default 0xffff (no attenuation) 230 231 name='EMU10K1 PCM Send Routing',index 0-31 232 233 This control specifies the destination - FX-bus accumulators. There 24 234 values with this mapping: 235 236 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 0 260 261 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). 263 264 name='EMU10K1 PCM Send Volume',index 0-31 265 266 It specifies the attenuation (amount) for given destination in range 0-255. 267 The channel mapping is following: 268 269 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) 293 294 295 296 4) MANUALS/PATENTS: 297 ------------------- 298 299 ftp://opensource.creative.com/pub/doc 300 ------------------------------------- 301 302 Files: 303 LM4545.pdf AC97 Codec 304 305 m2049.pdf The EMU10K1 Digital Audio Processor 306 307 hog63.ps FX8010 - A DSP Chip Architecture for Audio Effects 308 309 310 WIPO Patents 311 ------------ 312 Patent numbers: 313 WO 9901813 (A1) Audio Effects Processor with multiple asynchronous (Jan. 14, 1999) 314 streams 315 316 WO 9901814 (A1) Processor with Instruction Set for Audio Effects (Jan. 14, 1999) 317 318 WO 9901953 (A1) Audio Effects Processor having Decoupled Instruction 319 Execution and Audio Data Sequencing (Jan. 14, 1999) 320 321 322 US Patents (http://www.uspto.gov/) 323 ---------------------------------- 324 325 US 5925841 Digital Sampling Instrument employing cache memory (Jul. 20, 1999) 326 327 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 330 331 US 5930158 Processor with Instruction Set for Audio Effects (Jul. 27, 1999) 332 333 US 6032235 Memory initialization circuit (Tram) (Feb. 29, 2000) 334 335 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 338 339 US 6151670 Method for conserving memory storage using a (Nov. 21, 2000) 340 pool of short term memory registers 341 342 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