1============================================= 2Sound Blaster Audigy mixer / default DSP code 3============================================= 4 5This is based on sb-live-mixer.rst. 6 7The EMU10K2 chips have a DSP part which can be programmed to support 8various ways of sample processing, which is described here. 9(This article does not deal with the overall functionality of the 10EMU10K2 chips. See the manuals section for further details.) 11 12The ALSA driver programs this portion of chip by default code 13(can be altered later) which offers the following functionality: 14 15 16Digital mixer controls 17====================== 18 19These controls are built using the DSP instructions. They offer extended 20functionality. Only the default built-in code in the ALSA driver is described 21here. Note that the controls work as attenuators: the maximum value is the 22neutral position leaving the signal unchanged. Note that if the same destination 23is mentioned in multiple controls, the signal is accumulated and can be clipped 24(set to maximal or minimal value without checking for overflow). 25 26 27Explanation of used abbreviations: 28 29DAC 30 digital to analog converter 31ADC 32 analog to digital converter 33I2S 34 one-way three wire serial bus for digital sound by Philips Semiconductors 35 (this standard is used for connecting standalone D/A and A/D converters) 36LFE 37 low frequency effects (used as subwoofer signal) 38AC97 39 a chip containing an analog mixer, D/A and A/D converters 40IEC958 41 S/PDIF 42FX-bus 43 the EMU10K2 chip has an effect bus containing 64 accumulators. 44 Each of the synthesizer voices can feed its output to these accumulators 45 and the DSP microcontroller can operate with the resulting sum. 46 47name='PCM Front Playback Volume',index=0 48---------------------------------------- 49This control is used to attenuate samples from left and right front PCM FX-bus 50accumulators. ALSA uses accumulators 8 and 9 for left and right front PCM 51samples for 5.1 playback. The result samples are forwarded to the front speakers. 52 53name='PCM Surround Playback Volume',index=0 54------------------------------------------- 55This control is used to attenuate samples from left and right surround PCM FX-bus 56accumulators. ALSA uses accumulators 2 and 3 for left and right surround PCM 57samples for 5.1 playback. The result samples are forwarded to the surround (rear) 58speakers. 59 60name='PCM Side Playback Volume',index=0 61--------------------------------------- 62This control is used to attenuate samples from left and right side PCM FX-bus 63accumulators. ALSA uses accumulators 14 and 15 for left and right side PCM 64samples for 7.1 playback. The result samples are forwarded to the side speakers. 65 66name='PCM Center Playback Volume',index=0 67----------------------------------------- 68This control is used to attenuate samples from center PCM FX-bus accumulator. 69ALSA uses accumulator 6 for center PCM samples for 5.1 playback. The result 70samples are forwarded to the center speaker. 71 72name='PCM LFE Playback Volume',index=0 73-------------------------------------- 74This control is used to attenuate sample for LFE PCM FX-bus accumulator. 75ALSA uses accumulator 7 for LFE PCM samples for 5.1 playback. The result 76samples are forwarded to the subwoofer. 77 78name='PCM Playback Volume',index=0 79---------------------------------- 80This control is used to attenuate samples from left and right PCM FX-bus 81accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples for 82stereo playback. The result samples are forwarded to the front speakers. 83 84name='PCM Capture Volume',index=0 85--------------------------------- 86This control is used to attenuate samples from left and right PCM FX-bus 87accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples for 88stereo playback. The result is forwarded to the standard capture PCM device. 89 90name='Music Playback Volume',index=0 91------------------------------------ 92This control is used to attenuate samples from left and right MIDI FX-bus 93accumulators. ALSA uses accumulators 4 and 5 for left and right MIDI samples. 94The result samples are forwarded to the virtual stereo mixer. 95 96name='Music Capture Volume',index=0 97----------------------------------- 98These controls are used to attenuate samples from left and right MIDI FX-bus 99accumulator. ALSA uses accumulators 4 and 5 for left and right MIDI samples. 100The result is forwarded to the standard capture PCM device. 101 102name='Mic Playback Volume',index=0 103---------------------------------- 104This control is used to attenuate samples from left and right Mic input of 105the AC97 codec. The result samples are forwarded to the virtual stereo mixer. 106 107name='Mic Capture Volume',index=0 108--------------------------------- 109This control is used to attenuate samples from left and right Mic input of 110the AC97 codec. The result is forwarded to the standard capture PCM device. 111 112The original samples are also forwarded to the Mic capture PCM device (device 1; 11316bit/8KHz mono) without volume control. 114 115name='Audigy CD Playback Volume',index=0 116---------------------------------------- 117This control is used to attenuate samples from left and right IEC958 TTL 118digital inputs (usually used by a CDROM drive). The result samples are 119forwarded to the virtual stereo mixer. 120 121name='Audigy CD Capture Volume',index=0 122--------------------------------------- 123This control is used to attenuate samples from left and right IEC958 TTL 124digital inputs (usually used by a CDROM drive). The result is forwarded 125to the standard capture PCM device. 126 127name='IEC958 Optical Playback Volume',index=0 128--------------------------------------------- 129This control is used to attenuate samples from left and right IEC958 optical 130digital input. The result samples are forwarded to the virtual stereo mixer. 131 132name='IEC958 Optical Capture Volume',index=0 133-------------------------------------------- 134This control is used to attenuate samples from left and right IEC958 optical 135digital inputs. The result is forwarded to the standard capture PCM device. 136 137name='Line2 Playback Volume',index=0 138------------------------------------ 139This control is used to attenuate samples from left and right I2S ADC 140inputs (on the AudigyDrive). The result samples are forwarded to the virtual 141stereo mixer. 142 143name='Line2 Capture Volume',index=1 144----------------------------------- 145This control is used to attenuate samples from left and right I2S ADC 146inputs (on the AudigyDrive). The result is forwarded to the standard capture 147PCM device. 148 149name='Analog Mix Playback Volume',index=0 150----------------------------------------- 151This control is used to attenuate samples from left and right I2S ADC 152inputs from Philips ADC. The result samples are forwarded to the virtual 153stereo mixer. This contains mix from analog sources like CD, Line In, Aux, .... 154 155name='Analog Mix Capture Volume',index=1 156---------------------------------------- 157This control is used to attenuate samples from left and right I2S ADC 158inputs Philips ADC. The result is forwarded to the standard capture PCM device. 159 160name='Aux2 Playback Volume',index=0 161----------------------------------- 162This control is used to attenuate samples from left and right I2S ADC 163inputs (on the AudigyDrive). The result samples are forwarded to the virtual 164stereo mixer. 165 166name='Aux2 Capture Volume',index=1 167---------------------------------- 168This control is used to attenuate samples from left and right I2S ADC 169inputs (on the AudigyDrive). The result is forwarded to the standard capture 170PCM device. 171 172name='Front Playback Volume',index=0 173------------------------------------ 174This control is used to attenuate samples from the virtual stereo mixer. 175The result samples are forwarded to the front speakers. 176 177name='Surround Playback Volume',index=0 178--------------------------------------- 179This control is used to attenuate samples from the virtual stereo mixer. 180The result samples are forwarded to the surround (rear) speakers. 181 182name='Side Playback Volume',index=0 183----------------------------------- 184This control is used to attenuate samples from the virtual stereo mixer. 185The result samples are forwarded to the side speakers. 186 187name='Center Playback Volume',index=0 188------------------------------------- 189This control is used to attenuate samples from the virtual stereo mixer. 190The result samples are forwarded to the center speaker. 191 192name='LFE Playback Volume',index=0 193---------------------------------- 194This control is used to attenuate samples from the virtual stereo mixer. 195The result samples are forwarded to the subwoofer. 196 197name='Tone Control - Switch',index=0 198------------------------------------ 199This control turns the tone control on or off. The samples forwarded to 200the speaker outputs are affected. 201 202name='Tone Control - Bass',index=0 203---------------------------------- 204This control sets the bass intensity. There is no neutral value!! 205When the tone control code is activated, the samples are always modified. 206The closest value to pure signal is 20. 207 208name='Tone Control - Treble',index=0 209------------------------------------ 210This control sets the treble intensity. There is no neutral value!! 211When the tone control code is activated, the samples are always modified. 212The closest value to pure signal is 20. 213 214name='Master Playback Volume',index=0 215------------------------------------- 216This control is used to attenuate samples forwarded to the speaker outputs. 217 218name='IEC958 Optical Raw Playback Switch',index=0 219------------------------------------------------- 220If this switch is on, then the samples for the IEC958 (S/PDIF) digital 221output are taken only from the raw iec958 ALSA PCM device (which uses 222accumulators 20 and 21 for left and right PCM by default). 223 224 225PCM stream related controls 226=========================== 227 228name='EMU10K1 PCM Volume',index 0-31 229------------------------------------ 230Channel volume attenuation in range 0-0x1fffd. The middle value (no 231attenuation) is default. The channel mapping for three values is 232as follows: 233 234* 0 - mono, default 0xffff (no attenuation) 235* 1 - left, default 0xffff (no attenuation) 236* 2 - right, default 0xffff (no attenuation) 237 238name='EMU10K1 PCM Send Routing',index 0-31 239------------------------------------------ 240This control specifies the destination - FX-bus accumulators. There are 24 241values in this mapping: 242 243* 0 - mono, A destination (FX-bus 0-63), default 0 244* 1 - mono, B destination (FX-bus 0-63), default 1 245* 2 - mono, C destination (FX-bus 0-63), default 2 246* 3 - mono, D destination (FX-bus 0-63), default 3 247* 4 - mono, E destination (FX-bus 0-63), default 4 248* 5 - mono, F destination (FX-bus 0-63), default 5 249* 6 - mono, G destination (FX-bus 0-63), default 6 250* 7 - mono, H destination (FX-bus 0-63), default 7 251* 8 - left, A destination (FX-bus 0-63), default 0 252* 9 - left, B destination (FX-bus 0-63), default 1 253* 10 - left, C destination (FX-bus 0-63), default 2 254* 11 - left, D destination (FX-bus 0-63), default 3 255* 12 - left, E destination (FX-bus 0-63), default 4 256* 13 - left, F destination (FX-bus 0-63), default 5 257* 14 - left, G destination (FX-bus 0-63), default 6 258* 15 - left, H destination (FX-bus 0-63), default 7 259* 16 - right, A destination (FX-bus 0-63), default 0 260* 17 - right, B destination (FX-bus 0-63), default 1 261* 18 - right, C destination (FX-bus 0-63), default 2 262* 19 - right, D destination (FX-bus 0-63), default 3 263* 20 - right, E destination (FX-bus 0-63), default 4 264* 21 - right, F destination (FX-bus 0-63), default 5 265* 22 - right, G destination (FX-bus 0-63), default 6 266* 23 - right, H destination (FX-bus 0-63), default 7 267 268Don't forget that it's illegal to assign a channel to the same FX-bus accumulator 269more than once (it means 0=0 && 1=0 is an invalid combination). 270 271name='EMU10K1 PCM Send Volume',index 0-31 272----------------------------------------- 273It specifies the attenuation (amount) for given destination in range 0-255. 274The channel mapping is following: 275 276* 0 - mono, A destination attn, default 255 (no attenuation) 277* 1 - mono, B destination attn, default 255 (no attenuation) 278* 2 - mono, C destination attn, default 0 (mute) 279* 3 - mono, D destination attn, default 0 (mute) 280* 4 - mono, E destination attn, default 0 (mute) 281* 5 - mono, F destination attn, default 0 (mute) 282* 6 - mono, G destination attn, default 0 (mute) 283* 7 - mono, H destination attn, default 0 (mute) 284* 8 - left, A destination attn, default 255 (no attenuation) 285* 9 - left, B destination attn, default 0 (mute) 286* 10 - left, C destination attn, default 0 (mute) 287* 11 - left, D destination attn, default 0 (mute) 288* 12 - left, E destination attn, default 0 (mute) 289* 13 - left, F destination attn, default 0 (mute) 290* 14 - left, G destination attn, default 0 (mute) 291* 15 - left, H destination attn, default 0 (mute) 292* 16 - right, A destination attn, default 0 (mute) 293* 17 - right, B destination attn, default 255 (no attenuation) 294* 18 - right, C destination attn, default 0 (mute) 295* 19 - right, D destination attn, default 0 (mute) 296* 20 - right, E destination attn, default 0 (mute) 297* 21 - right, F destination attn, default 0 (mute) 298* 22 - right, G destination attn, default 0 (mute) 299* 23 - right, H destination attn, default 0 (mute) 300 301 302 303MANUALS/PATENTS 304=============== 305 306See sb-live-mixer.rst. 307