1 ============================================== 1 ========================================================
2 Guide to using M-Audio Audiophile USB with ALS 2 Guide to using M-Audio Audiophile USB with ALSA and Jack
3 ============================================== 3 ========================================================
4 4
5 v1.5 5 v1.5
6 6
7 Thibault Le Meur <Thibault.LeMeur@supelec.fr> 7 Thibault Le Meur <Thibault.LeMeur@supelec.fr>
8 8
9 This document is a guide to using the M-Audio 9 This document is a guide to using the M-Audio Audiophile USB (tm) device with
10 ALSA and JACK. 10 ALSA and JACK.
11 11
12 History 12 History
13 ======= 13 =======
14 14
15 * v1.4 - Thibault Le Meur (2007-07-11) 15 * v1.4 - Thibault Le Meur (2007-07-11)
16 16
17 - Added Low Endianness nature of 16bits-mode 17 - Added Low Endianness nature of 16bits-modes
18 found by Hakan Lennestal <Hakan.Lennestal@b 18 found by Hakan Lennestal <Hakan.Lennestal@brfsodrahamn.se>
19 - Modifying document structure 19 - Modifying document structure
20 20
21 * v1.5 - Thibault Le Meur (2007-07-12) 21 * v1.5 - Thibault Le Meur (2007-07-12)
22 - Added AC3/DTS passthru info 22 - Added AC3/DTS passthru info
23 23
24 24
25 Audiophile USB Specs and correct usage 25 Audiophile USB Specs and correct usage
26 ====================================== 26 ======================================
27 27
28 This part is a reminder of important facts abo 28 This part is a reminder of important facts about the functions and limitations
29 of the device. 29 of the device.
30 30
31 The device has 4 audio interfaces, and 2 MIDI 31 The device has 4 audio interfaces, and 2 MIDI ports:
32 32
33 * Analog Stereo Input (Ai) 33 * Analog Stereo Input (Ai)
34 34
35 - This port supports 2 pairs of line-level 35 - This port supports 2 pairs of line-level audio inputs (1/4" TS and RCA)
36 - When the 1/4" TS (jack) connectors are co 36 - When the 1/4" TS (jack) connectors are connected, the RCA connectors
37 are disabled 37 are disabled
38 38
39 * Analog Stereo Output (Ao) 39 * Analog Stereo Output (Ao)
40 * Digital Stereo Input (Di) 40 * Digital Stereo Input (Di)
41 * Digital Stereo Output (Do) 41 * Digital Stereo Output (Do)
42 * Midi In (Mi) 42 * Midi In (Mi)
43 * Midi Out (Mo) 43 * Midi Out (Mo)
44 44
45 The internal DAC/ADC has the following charact 45 The internal DAC/ADC has the following characteristics:
46 46
47 * sample depth of 16 or 24 bits 47 * sample depth of 16 or 24 bits
48 * sample rate from 8kHz to 96kHz 48 * sample rate from 8kHz to 96kHz
49 * Two interfaces can't use different sample de 49 * Two interfaces can't use different sample depths at the same time.
50 50
51 Moreover, the Audiophile USB documentation giv 51 Moreover, the Audiophile USB documentation gives the following Warning:
52 Please exit any audio application running be 52 Please exit any audio application running before switching between bit depths
53 53
54 Due to the USB 1.1 bandwidth limitation, a lim 54 Due to the USB 1.1 bandwidth limitation, a limited number of interfaces can be
55 activated at the same time depending on the au 55 activated at the same time depending on the audio mode selected:
56 56
57 * 16-bit/48kHz ==> 4 channels in + 4 channels 57 * 16-bit/48kHz ==> 4 channels in + 4 channels out
58 58
59 - Ai+Ao+Di+Do 59 - Ai+Ao+Di+Do
60 60
61 * 24-bit/48kHz ==> 4 channels in + 2 channels 61 * 24-bit/48kHz ==> 4 channels in + 2 channels out,
62 or 2 channels in + 4 channels out 62 or 2 channels in + 4 channels out
63 63
64 - Ai+Ao+Do or Ai+Di+Ao or Ai+Di+Do or Di+Ao 64 - Ai+Ao+Do or Ai+Di+Ao or Ai+Di+Do or Di+Ao+Do
65 65
66 * 24-bit/96kHz ==> 2 channels in _or_ 2 chann 66 * 24-bit/96kHz ==> 2 channels in _or_ 2 channels out (half duplex only)
67 67
68 - Ai or Ao or Di or Do 68 - Ai or Ao or Di or Do
69 69
70 Important facts about the Digital interface: 70 Important facts about the Digital interface:
71 -------------------------------------------- 71 --------------------------------------------
72 72
73 * The Do port additionally supports surround- 73 * The Do port additionally supports surround-encoded AC-3 and DTS passthrough,
74 though I haven't tested it under Linux 74 though I haven't tested it under Linux
75 75
76 - Note that in this setup only the Do inter 76 - Note that in this setup only the Do interface can be enabled
77 77
78 * Apart from recording an audio digital strea 78 * Apart from recording an audio digital stream, enabling the Di port is a way
79 to synchronize the device to an external sa 79 to synchronize the device to an external sample clock
80 80
81 - As a consequence, the Di port must be ena 81 - As a consequence, the Di port must be enable only if an active Digital
82 source is connected 82 source is connected
83 - Enabling Di when no digital source is con 83 - Enabling Di when no digital source is connected can result in a
84 synchronization error (for instance sound 84 synchronization error (for instance sound played at an odd sample rate)
85 85
86 86
87 Audiophile USB MIDI support in ALSA 87 Audiophile USB MIDI support in ALSA
88 =================================== 88 ===================================
89 89
90 The Audiophile USB MIDI ports will be automati 90 The Audiophile USB MIDI ports will be automatically supported once the
91 following modules have been loaded: 91 following modules have been loaded:
92 92
93 * snd-usb-audio 93 * snd-usb-audio
94 * snd-seq-midi 94 * snd-seq-midi
95 95
96 No additional setting is required. 96 No additional setting is required.
97 97
98 98
99 Audiophile USB Audio support in ALSA 99 Audiophile USB Audio support in ALSA
100 ==================================== 100 ====================================
101 101
102 Audio functions of the Audiophile USB device a 102 Audio functions of the Audiophile USB device are handled by the snd-usb-audio
103 module. This module can work in a default mode 103 module. This module can work in a default mode (without any device-specific
104 parameter), or in an "advanced" mode with the 104 parameter), or in an "advanced" mode with the device-specific parameter called
105 ``device_setup``. 105 ``device_setup``.
106 106
107 Default Alsa driver mode 107 Default Alsa driver mode
108 ------------------------ 108 ------------------------
109 109
110 The default behavior of the snd-usb-audio driv 110 The default behavior of the snd-usb-audio driver is to list the device
111 capabilities at startup and activate the requi 111 capabilities at startup and activate the required mode when required
112 by the applications: for instance if the user 112 by the applications: for instance if the user is recording in a
113 24bit-depth-mode and immediately after wants t 113 24bit-depth-mode and immediately after wants to switch to a 16bit-depth mode,
114 the snd-usb-audio module will reconfigure the 114 the snd-usb-audio module will reconfigure the device on the fly.
115 115
116 This approach has the advantage to let the dri 116 This approach has the advantage to let the driver automatically switch from sample
117 rates/depths automatically according to the us 117 rates/depths automatically according to the user's needs. However, those who
118 are using the device under windows know that t 118 are using the device under windows know that this is not how the device is meant to
119 work: under windows applications must be close 119 work: under windows applications must be closed before using the m-audio control
120 panel to switch the device working mode. Thus 120 panel to switch the device working mode. Thus as we'll see in next section, this
121 Default Alsa driver mode can lead to device mi 121 Default Alsa driver mode can lead to device misconfigurations.
122 122
123 Let's get back to the Default Alsa driver mode 123 Let's get back to the Default Alsa driver mode for now. In this case the
124 Audiophile interfaces are mapped to alsa pcm d 124 Audiophile interfaces are mapped to alsa pcm devices in the following
125 way (I suppose the device's index is 1): 125 way (I suppose the device's index is 1):
126 126
127 * hw:1,0 is Ao in playback and Di in capture 127 * hw:1,0 is Ao in playback and Di in capture
128 * hw:1,1 is Do in playback and Ai in capture 128 * hw:1,1 is Do in playback and Ai in capture
129 * hw:1,2 is Do in AC3/DTS passthrough mode 129 * hw:1,2 is Do in AC3/DTS passthrough mode
130 130
131 In this mode, the device uses Big Endian byte- 131 In this mode, the device uses Big Endian byte-encoding so that
132 supported audio format are S16_BE for 16-bit d 132 supported audio format are S16_BE for 16-bit depth modes and S24_3BE for
133 24-bits depth mode. 133 24-bits depth mode.
134 134
135 One exception is the hw:1,2 port which was rep 135 One exception is the hw:1,2 port which was reported to be Little Endian
136 compliant (supposedly supporting S16_LE) but p 136 compliant (supposedly supporting S16_LE) but processes in fact only S16_BE streams.
137 This has been fixed in kernel 2.6.23 and above 137 This has been fixed in kernel 2.6.23 and above and now the hw:1,2 interface
138 is reported to be big endian in this default d 138 is reported to be big endian in this default driver mode.
139 139
140 Examples: 140 Examples:
141 141
142 * playing a S24_3BE encoded raw file to the A 142 * playing a S24_3BE encoded raw file to the Ao port::
143 143
144 % aplay -D hw:1,0 -c2 -t raw -r48000 -fS24_ 144 % aplay -D hw:1,0 -c2 -t raw -r48000 -fS24_3BE test.raw
145 145
146 * recording a S24_3BE encoded raw file from 146 * recording a S24_3BE encoded raw file from the Ai port::
147 147
148 % arecord -D hw:1,1 -c2 -t raw -r48000 -fS 148 % arecord -D hw:1,1 -c2 -t raw -r48000 -fS24_3BE test.raw
149 149
150 * playing a S16_BE encoded raw file to the Do 150 * playing a S16_BE encoded raw file to the Do port::
151 151
152 % aplay -D hw:1,1 -c2 -t raw -r48000 -fS16_ 152 % aplay -D hw:1,1 -c2 -t raw -r48000 -fS16_BE test.raw
153 153
154 * playing an ac3 sample file to the Do port:: 154 * playing an ac3 sample file to the Do port::
155 155
156 % aplay -D hw:1,2 --channels=6 ac3_S16_BE_e 156 % aplay -D hw:1,2 --channels=6 ac3_S16_BE_encoded_file.raw
157 157
158 If you're happy with the default Alsa driver m 158 If you're happy with the default Alsa driver mode and don't experience any
159 issue with this mode, then you can skip the fo 159 issue with this mode, then you can skip the following chapter.
160 160
161 Advanced module setup 161 Advanced module setup
162 --------------------- 162 ---------------------
163 163
164 Due to the hardware constraints described abov 164 Due to the hardware constraints described above, the device initialization made
165 by the Alsa driver in default mode may result 165 by the Alsa driver in default mode may result in a corrupted state of the
166 device. For instance, a particularly annoying 166 device. For instance, a particularly annoying issue is that the sound captured
167 from the Ai interface sounds distorted (as if 167 from the Ai interface sounds distorted (as if boosted with an excessive high
168 volume gain). 168 volume gain).
169 169
170 For people having this problem, the snd-usb-au 170 For people having this problem, the snd-usb-audio module has a new module
171 parameter called ``device_setup`` (this parame 171 parameter called ``device_setup`` (this parameter was introduced in kernel
172 release 2.6.17) 172 release 2.6.17)
173 173
174 Initializing the working mode of the Audiophil 174 Initializing the working mode of the Audiophile USB
175 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 175 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
176 176
177 As far as the Audiophile USB device is concern 177 As far as the Audiophile USB device is concerned, this value let the user
178 specify: 178 specify:
179 179
180 * the sample depth 180 * the sample depth
181 * the sample rate 181 * the sample rate
182 * whether the Di port is used or not 182 * whether the Di port is used or not
183 183
184 When initialized with ``device_setup=0x00``, t 184 When initialized with ``device_setup=0x00``, the snd-usb-audio module has
185 the same behaviour as when the parameter is om 185 the same behaviour as when the parameter is omitted (see paragraph "Default
186 Alsa driver mode" above) 186 Alsa driver mode" above)
187 187
188 Others modes are described in the following su 188 Others modes are described in the following subsections.
189 189
190 16-bit modes 190 16-bit modes
191 ~~~~~~~~~~~~ 191 ~~~~~~~~~~~~
192 192
193 The two supported modes are: 193 The two supported modes are:
194 194
195 * ``device_setup=0x01`` 195 * ``device_setup=0x01``
196 196
197 - 16bits 48kHz mode with Di disabled 197 - 16bits 48kHz mode with Di disabled
198 - Ai,Ao,Do can be used at the same time 198 - Ai,Ao,Do can be used at the same time
199 - hw:1,0 is not available in capture mode 199 - hw:1,0 is not available in capture mode
200 - hw:1,2 is not available 200 - hw:1,2 is not available
201 201
202 * ``device_setup=0x11`` 202 * ``device_setup=0x11``
203 203
204 - 16bits 48kHz mode with Di enabled 204 - 16bits 48kHz mode with Di enabled
205 - Ai,Ao,Di,Do can be used at the same time 205 - Ai,Ao,Di,Do can be used at the same time
206 - hw:1,0 is available in capture mode 206 - hw:1,0 is available in capture mode
207 - hw:1,2 is not available 207 - hw:1,2 is not available
208 208
209 In this modes the device operates only at 16bi 209 In this modes the device operates only at 16bits-modes. Before kernel 2.6.23,
210 the devices where reported to be Big-Endian wh 210 the devices where reported to be Big-Endian when in fact they were Little-Endian
211 so that playing a file was a matter of using: 211 so that playing a file was a matter of using:
212 :: 212 ::
213 213
214 % aplay -D hw:1,1 -c2 -t raw -r48000 -fS16_ 214 % aplay -D hw:1,1 -c2 -t raw -r48000 -fS16_BE test_S16_LE.raw
215 215
216 where "test_S16_LE.raw" was in fact a little-e 216 where "test_S16_LE.raw" was in fact a little-endian sample file.
217 217
218 Thanks to Hakan Lennestal (who discovered the 218 Thanks to Hakan Lennestal (who discovered the Little-Endiannes of the device in
219 these modes) a fix has been committed (expecte 219 these modes) a fix has been committed (expected in kernel 2.6.23) and
220 Alsa now reports Little-Endian interfaces. Thu 220 Alsa now reports Little-Endian interfaces. Thus playing a file now is as simple as
221 using: 221 using:
222 :: 222 ::
223 223
224 % aplay -D hw:1,1 -c2 -t raw -r48000 -fS16_ 224 % aplay -D hw:1,1 -c2 -t raw -r48000 -fS16_LE test_S16_LE.raw
225 225
226 226
227 24-bit modes 227 24-bit modes
228 ~~~~~~~~~~~~ 228 ~~~~~~~~~~~~
229 229
230 The three supported modes are: 230 The three supported modes are:
231 231
232 * ``device_setup=0x09`` 232 * ``device_setup=0x09``
233 233
234 - 24bits 48kHz mode with Di disabled 234 - 24bits 48kHz mode with Di disabled
235 - Ai,Ao,Do can be used at the same time 235 - Ai,Ao,Do can be used at the same time
236 - hw:1,0 is not available in capture mode 236 - hw:1,0 is not available in capture mode
237 - hw:1,2 is not available 237 - hw:1,2 is not available
238 238
239 * ``device_setup=0x19`` 239 * ``device_setup=0x19``
240 240
241 - 24bits 48kHz mode with Di enabled 241 - 24bits 48kHz mode with Di enabled
242 - 3 ports from {Ai,Ao,Di,Do} can be used at 242 - 3 ports from {Ai,Ao,Di,Do} can be used at the same time
243 - hw:1,0 is available in capture mode and a 243 - hw:1,0 is available in capture mode and an active digital source must be
244 connected to Di 244 connected to Di
245 - hw:1,2 is not available 245 - hw:1,2 is not available
246 246
247 * ``device_setup=0x0D`` or ``0x10`` 247 * ``device_setup=0x0D`` or ``0x10``
248 248
249 - 24bits 96kHz mode 249 - 24bits 96kHz mode
250 - Di is enabled by default for this mode bu 250 - Di is enabled by default for this mode but does not need to be connected
251 to an active source 251 to an active source
252 - Only 1 port from {Ai,Ao,Di,Do} can be use 252 - Only 1 port from {Ai,Ao,Di,Do} can be used at the same time
253 - hw:1,0 is available in captured mode 253 - hw:1,0 is available in captured mode
254 - hw:1,2 is not available 254 - hw:1,2 is not available
255 255
256 In these modes the device is only Big-Endian c 256 In these modes the device is only Big-Endian compliant (see "Default Alsa driver
257 mode" above for an aplay command example) 257 mode" above for an aplay command example)
258 258
259 AC3 w/ DTS passthru mode 259 AC3 w/ DTS passthru mode
260 ~~~~~~~~~~~~~~~~~~~~~~~~ 260 ~~~~~~~~~~~~~~~~~~~~~~~~
261 261
262 Thanks to Hakan Lennestal, I now have a report 262 Thanks to Hakan Lennestal, I now have a report saying that this mode works.
263 263
264 * ``device_setup=0x03`` 264 * ``device_setup=0x03``
265 265
266 - 16bits 48kHz mode with only the Do port e 266 - 16bits 48kHz mode with only the Do port enabled
267 - AC3 with DTS passthru 267 - AC3 with DTS passthru
268 - Caution with this setup the Do port is ma 268 - Caution with this setup the Do port is mapped to the pcm device hw:1,0
269 269
270 The command line used to playback the AC3/DTS 270 The command line used to playback the AC3/DTS encoded .wav-files in this mode:
271 :: 271 ::
272 272
273 % aplay -D hw:1,0 --channels=6 ac3_S16_LE_e 273 % aplay -D hw:1,0 --channels=6 ac3_S16_LE_encoded_file.raw
274 274
275 How to use the ``device_setup`` parameter 275 How to use the ``device_setup`` parameter
276 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 276 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
277 277
278 The parameter can be given: 278 The parameter can be given:
279 279
280 * By manually probing the device (as root)::: 280 * By manually probing the device (as root):::
281 281
282 # modprobe -r snd-usb-audio 282 # modprobe -r snd-usb-audio
283 # modprobe snd-usb-audio index=1 device_set 283 # modprobe snd-usb-audio index=1 device_setup=0x09
284 284
285 * Or while configuring the modules options in 285 * Or while configuring the modules options in your modules configuration file
286 (typically a .conf file in /etc/modprobe.d/ 286 (typically a .conf file in /etc/modprobe.d/ directory:::
287 287
288 alias snd-card-1 snd-usb-audio 288 alias snd-card-1 snd-usb-audio
289 options snd-usb-audio index=1 device_se 289 options snd-usb-audio index=1 device_setup=0x09
290 290
291 CAUTION when initializing the device 291 CAUTION when initializing the device
292 ------------------------------------- 292 -------------------------------------
293 293
294 * Correct initialization on the device requir 294 * Correct initialization on the device requires that device_setup is given to
295 the module BEFORE the device is turned on. 295 the module BEFORE the device is turned on. So, if you use the "manual probing"
296 method described above, take care to power- 296 method described above, take care to power-on the device AFTER this initialization.
297 297
298 * Failing to respect this will lead to a misc 298 * Failing to respect this will lead to a misconfiguration of the device. In this case
299 turn off the device, unprobe the snd-usb-au 299 turn off the device, unprobe the snd-usb-audio module, then probe it again with
300 correct device_setup parameter and then (an 300 correct device_setup parameter and then (and only then) turn on the device again.
301 301
302 * If you've correctly initialized the device 302 * If you've correctly initialized the device in a valid mode and then want to switch
303 to another mode (possibly with another sam 303 to another mode (possibly with another sample-depth), please use also the following
304 procedure: 304 procedure:
305 305
306 - first turn off the device 306 - first turn off the device
307 - de-register the snd-usb-audio module (mod 307 - de-register the snd-usb-audio module (modprobe -r)
308 - change the device_setup parameter by chan 308 - change the device_setup parameter by changing the device_setup
309 option in ``/etc/modprobe.d/*.conf`` 309 option in ``/etc/modprobe.d/*.conf``
310 - turn on the device 310 - turn on the device
311 311
312 * A workaround for this last issue has been a 312 * A workaround for this last issue has been applied to kernel 2.6.23, but it may not
313 be enough to ensure the 'stability' of the 313 be enough to ensure the 'stability' of the device initialization.
314 314
315 Technical details for hackers 315 Technical details for hackers
316 ----------------------------- 316 -----------------------------
317 317
318 This section is for hackers, wanting to unders 318 This section is for hackers, wanting to understand details about the device
319 internals and how Alsa supports it. 319 internals and how Alsa supports it.
320 320
321 Audiophile USB's ``device_setup`` structure 321 Audiophile USB's ``device_setup`` structure
322 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 322 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
323 323
324 If you want to understand the device_setup mag 324 If you want to understand the device_setup magic numbers for the Audiophile
325 USB, you need some very basic understanding of 325 USB, you need some very basic understanding of binary computation. However,
326 this is not required to use the parameter and 326 this is not required to use the parameter and you may skip this section.
327 327
328 The device_setup is one byte long and its stru 328 The device_setup is one byte long and its structure is the following:
329 :: 329 ::
330 330
331 +---+---+---+---+---+---+---+---+ 331 +---+---+---+---+---+---+---+---+
332 | b7| b6| b5| b4| b3| b2| b1| b0| 332 | b7| b6| b5| b4| b3| b2| b1| b0|
333 +---+---+---+---+---+---+---+---+ 333 +---+---+---+---+---+---+---+---+
334 | 0 | 0 | 0 | Di|24B|96K|DTS|SET| 334 | 0 | 0 | 0 | Di|24B|96K|DTS|SET|
335 +---+---+---+---+---+---+---+---+ 335 +---+---+---+---+---+---+---+---+
336 336
337 Where: 337 Where:
338 338
339 * b0 is the ``SET`` bit 339 * b0 is the ``SET`` bit
340 340
341 - it MUST be set if device_setup is initial 341 - it MUST be set if device_setup is initialized
342 342
343 * b1 is the ``DTS`` bit 343 * b1 is the ``DTS`` bit
344 344
345 - it is set only for Digital output with DT 345 - it is set only for Digital output with DTS/AC3
346 - this setup is not tested 346 - this setup is not tested
347 347
348 * b2 is the Rate selection flag 348 * b2 is the Rate selection flag
349 349
350 - When set to ``1`` the rate range is 48.1- 350 - When set to ``1`` the rate range is 48.1-96kHz
351 - Otherwise the sample rate range is 8-48kH 351 - Otherwise the sample rate range is 8-48kHz
352 352
353 * b3 is the bit depth selection flag 353 * b3 is the bit depth selection flag
354 354
355 - When set to ``1`` samples are 24bits long 355 - When set to ``1`` samples are 24bits long
356 - Otherwise they are 16bits long 356 - Otherwise they are 16bits long
357 - Note that b2 implies b3 as the 96kHz mode 357 - Note that b2 implies b3 as the 96kHz mode is only supported for 24 bits
358 samples 358 samples
359 359
360 * b4 is the Digital input flag 360 * b4 is the Digital input flag
361 361
362 - When set to ``1`` the device assumes that 362 - When set to ``1`` the device assumes that an active digital source is
363 connected 363 connected
364 - You shouldn't enable Di if no source is s 364 - You shouldn't enable Di if no source is seen on the port (this leads to
365 synchronization issues) 365 synchronization issues)
366 - b4 is implied by b2 (since only one port 366 - b4 is implied by b2 (since only one port is enabled at a time no synch
367 error can occur) 367 error can occur)
368 368
369 * b5 to b7 are reserved for future uses, and 369 * b5 to b7 are reserved for future uses, and must be set to ``0``
370 370
371 - might become Ao, Do, Ai, for b7, b6, b4 r 371 - might become Ao, Do, Ai, for b7, b6, b4 respectively
372 372
373 Caution: 373 Caution:
374 374
375 * there is no check on the value you will giv 375 * there is no check on the value you will give to device_setup
376 376
377 - for instance choosing 0x05 (16bits 96kHz) 377 - for instance choosing 0x05 (16bits 96kHz) will fail back to 0x09 since
378 b2 implies b3. But _there_will_be_no_warn 378 b2 implies b3. But _there_will_be_no_warning_ in /var/log/messages
379 379
380 * Hardware constraints due to the USB bus lim 380 * Hardware constraints due to the USB bus limitation aren't checked
381 381
382 - choosing b2 will prepare all interfaces f 382 - choosing b2 will prepare all interfaces for 24bits/96kHz but you'll
383 only be able to use one at the same time 383 only be able to use one at the same time
384 384
385 USB implementation details for this device 385 USB implementation details for this device
386 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 386 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
387 387
388 You may safely skip this section if you're not 388 You may safely skip this section if you're not interested in driver
389 hacking. 389 hacking.
390 390
391 This section describes some internal aspects o 391 This section describes some internal aspects of the device and summarizes the
392 data I got by usb-snooping the windows and Lin 392 data I got by usb-snooping the windows and Linux drivers.
393 393
394 The M-Audio Audiophile USB has 7 USB Interface 394 The M-Audio Audiophile USB has 7 USB Interfaces:
395 a "USB interface": 395 a "USB interface":
396 396
397 * USB Interface nb.0 397 * USB Interface nb.0
398 * USB Interface nb.1 398 * USB Interface nb.1
399 399
400 - Audio Control function 400 - Audio Control function
401 401
402 * USB Interface nb.2 402 * USB Interface nb.2
403 403
404 - Analog Output 404 - Analog Output
405 405
406 * USB Interface nb.3 406 * USB Interface nb.3
407 407
408 - Digital Output 408 - Digital Output
409 409
410 * USB Interface nb.4 410 * USB Interface nb.4
411 411
412 - Analog Input 412 - Analog Input
413 413
414 * USB Interface nb.5 414 * USB Interface nb.5
415 415
416 - Digital Input 416 - Digital Input
417 417
418 * USB Interface nb.6 418 * USB Interface nb.6
419 419
420 - MIDI interface compliant with the MIDIMAN 420 - MIDI interface compliant with the MIDIMAN quirk
421 421
422 Each interface has 5 altsettings (AltSet 1,2,3 422 Each interface has 5 altsettings (AltSet 1,2,3,4,5) except:
423 423
424 * Interface 3 (Digital Out) has an extra Alse 424 * Interface 3 (Digital Out) has an extra Alset nb.6
425 * Interface 5 (Digital In) does not have Alse 425 * Interface 5 (Digital In) does not have Alset nb.3 and 5
426 426
427 Here is a short description of the AltSettings 427 Here is a short description of the AltSettings capabilities:
428 428
429 * AltSettings 1 corresponds to 429 * AltSettings 1 corresponds to
430 430
431 - 24-bit depth, 48.1-96kHz sample mode 431 - 24-bit depth, 48.1-96kHz sample mode
432 - Adaptive playback (Ao and Do), Synch captu 432 - Adaptive playback (Ao and Do), Synch capture (Ai), or Asynch capture (Di)
433 433
434 * AltSettings 2 corresponds to 434 * AltSettings 2 corresponds to
435 435
436 - 24-bit depth, 8-48kHz sample mode 436 - 24-bit depth, 8-48kHz sample mode
437 - Asynch capture and playback (Ao,Ai,Do,Di) 437 - Asynch capture and playback (Ao,Ai,Do,Di)
438 438
439 * AltSettings 3 corresponds to 439 * AltSettings 3 corresponds to
440 440
441 - 24-bit depth, 8-48kHz sample mode 441 - 24-bit depth, 8-48kHz sample mode
442 - Synch capture (Ai) and Adaptive playback ( 442 - Synch capture (Ai) and Adaptive playback (Ao,Do)
443 443
444 * AltSettings 4 corresponds to 444 * AltSettings 4 corresponds to
445 445
446 - 16-bit depth, 8-48kHz sample mode 446 - 16-bit depth, 8-48kHz sample mode
447 - Asynch capture and playback (Ao,Ai,Do,Di) 447 - Asynch capture and playback (Ao,Ai,Do,Di)
448 448
449 * AltSettings 5 corresponds to 449 * AltSettings 5 corresponds to
450 450
451 - 16-bit depth, 8-48kHz sample mode 451 - 16-bit depth, 8-48kHz sample mode
452 - Synch capture (Ai) and Adaptive playback ( 452 - Synch capture (Ai) and Adaptive playback (Ao,Do)
453 453
454 * AltSettings 6 corresponds to 454 * AltSettings 6 corresponds to
455 455
456 - 16-bit depth, 8-48kHz sample mode 456 - 16-bit depth, 8-48kHz sample mode
457 - Synch playback (Do), audio format type III 457 - Synch playback (Do), audio format type III IEC1937_AC-3
458 458
459 In order to ensure a correct initialization of 459 In order to ensure a correct initialization of the device, the driver
460 *must* *know* how the device will be used: 460 *must* *know* how the device will be used:
461 461
462 * if DTS is chosen, only Interface 2 with Alt 462 * if DTS is chosen, only Interface 2 with AltSet nb.6 must be
463 registered 463 registered
464 * if 96KHz only AltSets nb.1 of each interfac 464 * if 96KHz only AltSets nb.1 of each interface must be selected
465 * if samples are using 24bits/48KHz then AltS 465 * if samples are using 24bits/48KHz then AltSet 2 must me used if
466 Digital input is connected, and only AltSet 466 Digital input is connected, and only AltSet nb.3 if Digital input
467 is not connected 467 is not connected
468 * if samples are using 16bits/48KHz then AltS 468 * if samples are using 16bits/48KHz then AltSet 4 must me used if
469 Digital input is connected, and only AltSet 469 Digital input is connected, and only AltSet nb.5 if Digital input
470 is not connected 470 is not connected
471 471
472 When device_setup is given as a parameter to t 472 When device_setup is given as a parameter to the snd-usb-audio module, the
473 parse_audio_endpoints function uses a quirk ca 473 parse_audio_endpoints function uses a quirk called
474 ``audiophile_skip_setting_quirk`` in order to 474 ``audiophile_skip_setting_quirk`` in order to prevent AltSettings not
475 corresponding to device_setup from being regis 475 corresponding to device_setup from being registered in the driver.
476 476
477 Audiophile USB and Jack support 477 Audiophile USB and Jack support
478 =============================== 478 ===============================
479 479
480 This section deals with support of the Audioph 480 This section deals with support of the Audiophile USB device in Jack.
481 481
482 There are 2 main potential issues when using J 482 There are 2 main potential issues when using Jackd with the device:
483 483
484 * support for Big-Endian devices in 24-bit mod 484 * support for Big-Endian devices in 24-bit modes
485 * support for 4-in / 4-out channels 485 * support for 4-in / 4-out channels
486 486
487 Direct support in Jackd 487 Direct support in Jackd
488 ----------------------- 488 -----------------------
489 489
490 Jack supports big endian devices only in recen 490 Jack supports big endian devices only in recent versions (thanks to
491 Andreas Steinmetz for his first big-endian pat 491 Andreas Steinmetz for his first big-endian patch). I can't remember
492 exactly when this support was released into ja 492 exactly when this support was released into jackd, let's just say that
493 with jackd version 0.103.0 it's almost ok (jus 493 with jackd version 0.103.0 it's almost ok (just a small bug is affecting
494 16bits Big-Endian devices, but since you've re 494 16bits Big-Endian devices, but since you've read carefully the above
495 paragraphs, you're now using kernel >= 2.6.23 495 paragraphs, you're now using kernel >= 2.6.23 and your 16bits devices
496 are now Little Endians ;-) ). 496 are now Little Endians ;-) ).
497 497
498 You can run jackd with the following command f 498 You can run jackd with the following command for playback with Ao and
499 record with Ai: 499 record with Ai:
500 :: 500 ::
501 501
502 % jackd -R -dalsa -Phw:1,0 -r48000 -p128 -n2 502 % jackd -R -dalsa -Phw:1,0 -r48000 -p128 -n2 -D -Chw:1,1
503 503
504 Using Alsa plughw 504 Using Alsa plughw
505 ----------------- 505 -----------------
506 506
507 If you don't have a recent Jackd installed, yo 507 If you don't have a recent Jackd installed, you can downgrade to using
508 the Alsa ``plug`` converter. 508 the Alsa ``plug`` converter.
509 509
510 For instance here is one way to run Jack with 510 For instance here is one way to run Jack with 2 playback channels on Ao and 2
511 capture channels from Ai: 511 capture channels from Ai:
512 :: 512 ::
513 513
514 % jackd -R -dalsa -dplughw:1 -r48000 -p256 - 514 % jackd -R -dalsa -dplughw:1 -r48000 -p256 -n2 -D -Cplughw:1,1
515 515
516 However you may see the following warning mess 516 However you may see the following warning message:
517 You appear to be using the ALSA software "pl 517 You appear to be using the ALSA software "plug" layer, probably a result of
518 using the "default" ALSA device. This is les 518 using the "default" ALSA device. This is less efficient than it could be.
519 Consider using a hardware device instead rat 519 Consider using a hardware device instead rather than using the plug layer.
520 520
521 Getting 2 input and/or output interfaces in Ja 521 Getting 2 input and/or output interfaces in Jack
522 ---------------------------------------------- 522 ------------------------------------------------
523 523
524 As you can see, starting the Jack server this 524 As you can see, starting the Jack server this way will only enable 1 stereo
525 input (Di or Ai) and 1 stereo output (Ao or Do 525 input (Di or Ai) and 1 stereo output (Ao or Do).
526 526
527 This is due to the following restrictions: 527 This is due to the following restrictions:
528 528
529 * Jack can only open one capture device and on 529 * Jack can only open one capture device and one playback device at a time
530 * The Audiophile USB is seen as 2 (or three) A 530 * The Audiophile USB is seen as 2 (or three) Alsa devices: hw:1,0, hw:1,1
531 (and optionally hw:1,2) 531 (and optionally hw:1,2)
532 532
533 If you want to get Ai+Di and/or Ao+Do support 533 If you want to get Ai+Di and/or Ao+Do support with Jack, you would need to
534 combine the Alsa devices into one logical "com 534 combine the Alsa devices into one logical "complex" device.
535 535
536 If you want to give it a try, I recommend read 536 If you want to give it a try, I recommend reading the information from
537 this page: http://www.sound-man.co.uk/linuxaud 537 this page: http://www.sound-man.co.uk/linuxaudio/ice1712multi.html
538 It is related to another device (ice1712) but 538 It is related to another device (ice1712) but can be adapted to suit
539 the Audiophile USB. 539 the Audiophile USB.
540 540
541 Enabling multiple Audiophile USB interfaces fo 541 Enabling multiple Audiophile USB interfaces for Jackd will certainly require:
542 542
543 * Making sure your Jackd version has the MMAP_ 543 * Making sure your Jackd version has the MMAP_COMPLEX patch (see the ice1712 page)
544 * (maybe) patching the alsa-lib/src/pcm/pcm_mu 544 * (maybe) patching the alsa-lib/src/pcm/pcm_multi.c file (see the ice1712 page)
545 * define a multi device (combination of hw:1,0 545 * define a multi device (combination of hw:1,0 and hw:1,1) in your .asoundrc
546 file 546 file
547 * start jackd with this device 547 * start jackd with this device
548 548
549 I had no success in testing this for now, if y 549 I had no success in testing this for now, if you have any success with this kind
550 of setup, please drop me an email. 550 of setup, please drop me an email.
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