linux/Documentation/sound/alsa/SB-Live-mixer.txt
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   2                Sound Blaster Live mixer / default DSP code
   3                ===========================================
   4
   5
   6The EMU10K1 chips have a DSP part which can be programmed to support
   7various ways of sample processing, which is described here.
   8(This article does not deal with the overall functionality of the 
   9EMU10K1 chips. See the manuals section for further details.)
  10
  11The ALSA driver programs this portion of chip by default code
  12(can be altered later) which offers the following functionality:
  13
  14
  151) IEC958 (S/PDIF) raw PCM
  16--------------------------
  17
  18This PCM device (it's the 4th PCM device (index 3!) and first subdevice
  19(index 0) for a given card) allows to forward 48kHz, stereo, 16-bit
  20little endian streams without any modifications to the digital output
  21(coaxial or optical). The universal interface allows the creation of up
  22to 8 raw PCM devices operating at 48kHz, 16-bit little endian. It would
  23be easy to add support for multichannel devices to the current code,
  24but the conversion routines exist only for stereo (2-channel streams)
  25at the time. 
  26
  27Look to tram_poke routines in lowlevel/emu10k1/emufx.c for more details.
  28
  29
  302) Digital mixer controls
  31-------------------------
  32
  33These controls are built using the DSP instructions. They offer extended
  34functionality. Only the default build-in code in the ALSA driver is described
  35here. Note that the controls work as attenuators: the maximum value is the 
  36neutral position leaving the signal unchanged. Note that if the  same destination 
  37is mentioned in multiple controls, the signal is accumulated and can be wrapped 
  38(set to maximal or minimal value without checking of overflow).
  39
  40
  41Explanation of used abbreviations:
  42
  43DAC    - digital to analog converter
  44ADC    - analog to digital converter
  45I2S    - one-way three wire serial bus for digital sound by Philips Semiconductors
  46         (this standard is used for connecting standalone DAC and ADC converters)
  47LFE    - low frequency effects (subwoofer signal)
  48AC97   - a chip containing an analog mixer, DAC and ADC converters
  49IEC958 - S/PDIF
  50FX-bus - the EMU10K1 chip has an effect bus containing 16 accumulators.
  51         Each of the synthesizer voices can feed its output to these accumulators
  52         and the DSP microcontroller can operate with the resulting sum.
  53
  54
  55name='Wave Playback Volume',index=0
  56
  57This control is used to attenuate samples for left and right PCM FX-bus
  58accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples.
  59The result samples are forwarded to the front DAC PCM slots of the AC97 codec.
  60
  61name='Wave Surround Playback Volume',index=0
  62
  63This control is used to attenuate samples for left and right PCM FX-bus
  64accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples.
  65The result samples are forwarded to the rear I2S DACs. These DACs operates
  66separately (they are not inside the AC97 codec).
  67
  68name='Wave Center Playback Volume',index=0
  69
  70This control is used to attenuate samples for left and right PCM FX-bus
  71accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples.
  72The result is mixed to mono signal (single channel) and forwarded to
  73the ??rear?? right DAC PCM slot of the AC97 codec.
  74
  75name='Wave LFE Playback Volume',index=0
  76
  77This control is used to attenuate samples for left and right PCM FX-bus
  78accumulators. ALSA uses accumulators 0 and 1 for left and right PCM.
  79The result is mixed to mono signal (single channel) and forwarded to
  80the ??rear?? left DAC PCM slot of the AC97 codec.
  81
  82name='Wave Capture Volume',index=0
  83name='Wave Capture Switch',index=0
  84
  85These controls are used to attenuate samples for left and right PCM FX-bus
  86accumulator. ALSA uses accumulators 0 and 1 for left and right PCM.
  87The result is forwarded to the ADC capture FIFO (thus to the standard capture
  88PCM device).
  89
  90name='Synth Playback Volume',index=0
  91
  92This control is used to attenuate samples for 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 front DAC PCM slots of the AC97 codec.
  95
  96name='Synth Capture Volume',index=0
  97name='Synth Capture Switch',index=0
  98
  99These controls are used to attenuate samples for left and right MIDI FX-bus
 100accumulator. ALSA uses accumulators 4 and 5 for left and right PCM.
 101The result is forwarded to the ADC capture FIFO (thus to the standard capture
 102PCM device).
 103
 104name='Surround Playback Volume',index=0
 105
 106This control is used to attenuate samples for left and right rear PCM FX-bus
 107accumulators. ALSA uses accumulators 2 and 3 for left and right rear PCM samples.
 108The result samples are forwarded to the rear I2S DACs. These DACs operate
 109separately (they are not inside the AC97 codec).
 110
 111name='Surround Capture Volume',index=0
 112name='Surround Capture Switch',index=0
 113
 114These controls are used to attenuate samples for left and right rear PCM FX-bus
 115accumulators. ALSA uses accumulators 2 and 3 for left and right rear PCM samples.
 116The result is forwarded to the ADC capture FIFO (thus to the standard capture
 117PCM device).
 118
 119name='Center Playback Volume',index=0
 120
 121This control is used to attenuate sample for center PCM FX-bus accumulator.
 122ALSA uses accumulator 6 for center PCM sample. The result sample is forwarded
 123to the ??rear?? right DAC PCM slot of the AC97 codec.
 124
 125name='LFE Playback Volume',index=0
 126
 127This control is used to attenuate sample for center PCM FX-bus accumulator.
 128ALSA uses accumulator 6 for center PCM sample. The result sample is forwarded
 129to the ??rear?? left DAC PCM slot of the AC97 codec.
 130
 131name='AC97 Playback Volume',index=0
 132
 133This control is used to attenuate samples for left and right front ADC PCM slots
 134of the AC97 codec. The result samples are forwarded to the front DAC PCM
 135slots of the AC97 codec.
 136********************************************************************************
 137*** Note: This control should be zero for the standard operations, otherwise ***
 138*** a digital loopback is activated.                                         ***
 139********************************************************************************
 140
 141name='AC97 Capture Volume',index=0
 142
 143This control is used to attenuate samples for left and right front ADC PCM slots
 144of the AC97 codec. The result is forwarded to the ADC capture FIFO (thus to
 145the standard capture PCM device).
 146********************************************************************************
 147*** Note: This control should be 100 (maximal value), otherwise no analog    ***
 148*** inputs of the AC97 codec can be captured (recorded).                     ***
 149********************************************************************************
 150
 151name='IEC958 TTL Playback Volume',index=0
 152
 153This control is used to attenuate samples from left and right IEC958 TTL
 154digital inputs (usually used by a CDROM drive). The result samples are
 155forwarded to the front DAC PCM slots of the AC97 codec.
 156
 157name='IEC958 TTL Capture Volume',index=0
 158
 159This control is used to attenuate samples from left and right IEC958 TTL
 160digital inputs (usually used by a CDROM drive). The result samples are
 161forwarded to the ADC capture FIFO (thus to the standard capture PCM device).
 162
 163name='Zoom Video Playback Volume',index=0
 164
 165This control is used to attenuate samples from left and right zoom video
 166digital inputs (usually used by a CDROM drive). The result samples are
 167forwarded to the front DAC PCM slots of the AC97 codec.
 168
 169name='Zoom Video Capture Volume',index=0
 170
 171This control is used to attenuate samples from left and right zoom video
 172digital inputs (usually used by a CDROM drive). The result samples are
 173forwarded to the ADC capture FIFO (thus to the standard capture PCM device).
 174
 175name='IEC958 LiveDrive Playback Volume',index=0
 176
 177This control is used to attenuate samples from left and right IEC958 optical
 178digital input. The result samples are forwarded to the front DAC PCM slots
 179of the AC97 codec.
 180
 181name='IEC958 LiveDrive Capture Volume',index=0
 182
 183This control is used to attenuate samples from left and right IEC958 optical
 184digital inputs. The result samples are forwarded to the ADC capture FIFO
 185(thus to the standard capture PCM device).
 186
 187name='IEC958 Coaxial Playback Volume',index=0
 188
 189This control is used to attenuate samples from left and right IEC958 coaxial
 190digital inputs. The result samples are forwarded to the front DAC PCM slots
 191of the AC97 codec.
 192
 193name='IEC958 Coaxial Capture Volume',index=0
 194
 195This control is used to attenuate samples from left and right IEC958 coaxial
 196digital inputs. The result samples are forwarded to the ADC capture FIFO
 197(thus to the standard capture PCM device).
 198
 199name='Line LiveDrive Playback Volume',index=0
 200name='Line LiveDrive Playback Volume',index=1
 201
 202This control is used to attenuate samples from left and right I2S ADC
 203inputs (on the LiveDrive). The result samples are forwarded to the front
 204DAC PCM slots of the AC97 codec.
 205
 206name='Line LiveDrive Capture Volume',index=1
 207name='Line LiveDrive Capture Volume',index=1
 208
 209This control is used to attenuate samples from left and right I2S ADC
 210inputs (on the LiveDrive). The result samples are forwarded to the ADC
 211capture FIFO (thus to the standard capture PCM device).
 212
 213name='Tone Control - Switch',index=0
 214
 215This control turns the tone control on or off. The samples for front, rear
 216and center / LFE outputs are affected.
 217
 218name='Tone Control - Bass',index=0
 219
 220This control sets the bass intensity. There is no neutral value!!
 221When the tone control code is activated, the samples are always modified.
 222The closest value to pure signal is 20.
 223
 224name='Tone Control - Treble',index=0
 225
 226This control sets the treble intensity. There is no neutral value!!
 227When the tone control code is activated, the samples are always modified.
 228The closest value to pure signal is 20.
 229
 230name='IEC958 Optical Raw Playback Switch',index=0
 231
 232If this switch is on, then the samples for the IEC958 (S/PDIF) digital
 233output are taken only from the raw FX8010 PCM, otherwise standard front
 234PCM samples are taken.
 235
 236name='Headphone Playback Volume',index=1
 237
 238This control attenuates the samples for the headphone output.
 239
 240name='Headphone Center Playback Switch',index=1
 241
 242If this switch is on, then the sample for the center PCM is put to the
 243left headphone output (useful for SB Live cards without separate center/LFE
 244output).
 245
 246name='Headphone LFE Playback Switch',index=1
 247
 248If this switch is on, then the sample for the center PCM is put to the
 249right headphone output (useful for SB Live cards without separate center/LFE
 250output).
 251
 252
 2533) PCM stream related controls
 254------------------------------
 255
 256name='EMU10K1 PCM Volume',index 0-31
 257
 258Channel volume attenuation in range 0-0xffff. The maximum value (no
 259attenuation) is default. The channel mapping for three values is
 260as follows:
 261
 262        0 - mono, default 0xffff (no attenuation)
 263        1 - left, default 0xffff (no attenuation)
 264        2 - right, default 0xffff (no attenuation)
 265
 266name='EMU10K1 PCM Send Routing',index 0-31
 267
 268This control specifies the destination - FX-bus accumulators. There are
 269twelve values with this mapping:
 270
 271         0 -  mono, A destination (FX-bus 0-15), default 0
 272         1 -  mono, B destination (FX-bus 0-15), default 1
 273         2 -  mono, C destination (FX-bus 0-15), default 2
 274         3 -  mono, D destination (FX-bus 0-15), default 3
 275         4 -  left, A destination (FX-bus 0-15), default 0
 276         5 -  left, B destination (FX-bus 0-15), default 1
 277         6 -  left, C destination (FX-bus 0-15), default 2
 278         7 -  left, D destination (FX-bus 0-15), default 3
 279         8 - right, A destination (FX-bus 0-15), default 0
 280         9 - right, B destination (FX-bus 0-15), default 1
 281        10 - right, C destination (FX-bus 0-15), default 2
 282        11 - right, D destination (FX-bus 0-15), default 3
 283
 284Don't forget that it's illegal to assign a channel to the same FX-bus accumulator 
 285more than once (it means 0=0 && 1=0 is an invalid combination).
 286 
 287name='EMU10K1 PCM Send Volume',index 0-31
 288
 289It specifies the attenuation (amount) for given destination in range 0-255.
 290The channel mapping is following:
 291
 292         0 -  mono, A destination attn, default 255 (no attenuation)
 293         1 -  mono, B destination attn, default 255 (no attenuation)
 294         2 -  mono, C destination attn, default 0 (mute)
 295         3 -  mono, D destination attn, default 0 (mute)
 296         4 -  left, A destination attn, default 255 (no attenuation)
 297         5 -  left, B destination attn, default 0 (mute)
 298         6 -  left, C destination attn, default 0 (mute)
 299         7 -  left, D destination attn, default 0 (mute)
 300         8 - right, A destination attn, default 0 (mute)
 301         9 - right, B destination attn, default 255 (no attenuation)
 302        10 - right, C destination attn, default 0 (mute)
 303        11 - right, D destination attn, default 0 (mute)
 304
 305
 306
 3074) MANUALS/PATENTS:
 308-------------------
 309
 310ftp://opensource.creative.com/pub/doc
 311-------------------------------------
 312
 313        Files:
 314        LM4545.pdf      AC97 Codec
 315
 316        m2049.pdf       The EMU10K1 Digital Audio Processor
 317
 318        hog63.ps        FX8010 - A DSP Chip Architecture for Audio Effects
 319
 320
 321WIPO Patents
 322------------
 323        Patent numbers:
 324        WO 9901813 (A1) Audio Effects Processor with multiple asynchronous (Jan. 14, 1999)
 325                        streams
 326
 327        WO 9901814 (A1) Processor with Instruction Set for Audio Effects (Jan. 14, 1999)
 328
 329        WO 9901953 (A1) Audio Effects Processor having Decoupled Instruction
 330                        Execution and Audio Data Sequencing (Jan. 14, 1999)
 331
 332
 333US Patents (http://www.uspto.gov/)
 334----------------------------------
 335
 336        US 5925841      Digital Sampling Instrument employing cache memory (Jul. 20, 1999)
 337
 338        US 5928342      Audio Effects Processor integrated on a single chip (Jul. 27, 1999)
 339                        with a multiport memory onto which multiple asynchronous
 340                        digital sound samples can be concurrently loaded
 341
 342        US 5930158      Processor with Instruction Set for Audio Effects (Jul. 27, 1999)
 343
 344        US 6032235      Memory initialization circuit (Tram) (Feb. 29, 2000)
 345
 346        US 6138207      Interpolation looping of audio samples in cache connected to    (Oct. 24, 2000)
 347                        system bus with prioritization and modification of bus transfers
 348                        in accordance with loop ends and minimum block sizes
 349
 350        US 6151670      Method for conserving memory storage using a (Nov. 21, 2000)
 351                        pool of  short term memory registers
 352
 353        US 6195715      Interrupt control for multiple programs communicating with      (Feb. 27, 2001)
 354                        a common interrupt by associating programs to GP registers,
 355                        defining interrupt register, polling GP registers, and invoking
 356                        callback routine associated with defined interrupt register
 357
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