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1da177e4 LT |
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. | |
4ae0edc2 | 9 | (This article does not deal with the overall functionality of the |
1da177e4 LT |
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 |