diff options
Diffstat (limited to 'Documentation/sound')
-rw-r--r-- | Documentation/sound/alsa/Audiophile-Usb.txt | 230 |
1 files changed, 151 insertions, 79 deletions
diff --git a/Documentation/sound/alsa/Audiophile-Usb.txt b/Documentation/sound/alsa/Audiophile-Usb.txt index e40cce83327c..5b7a5487d505 100644 --- a/Documentation/sound/alsa/Audiophile-Usb.txt +++ b/Documentation/sound/alsa/Audiophile-Usb.txt | |||
@@ -1,4 +1,4 @@ | |||
1 | Guide to using M-Audio Audiophile USB with ALSA and Jack v1.3 | 1 | Guide to using M-Audio Audiophile USB with ALSA and Jack v1.4 |
2 | ======================================================== | 2 | ======================================================== |
3 | 3 | ||
4 | Thibault Le Meur <Thibault.LeMeur@supelec.fr> | 4 | Thibault Le Meur <Thibault.LeMeur@supelec.fr> |
@@ -6,8 +6,17 @@ | |||
6 | This document is a guide to using the M-Audio Audiophile USB (tm) device with | 6 | This document is a guide to using the M-Audio Audiophile USB (tm) device with |
7 | ALSA and JACK. | 7 | ALSA and JACK. |
8 | 8 | ||
9 | History | ||
10 | ======= | ||
11 | * v1.4 - Thibault Le Meur (2007-07-11) | ||
12 | - Added Low Endianness nature of 16bits-modes | ||
13 | found by Hakan Lennestal <Hakan.Lennestal@brfsodrahamn.se> | ||
14 | - Modifying document structure | ||
15 | |||
16 | |||
9 | 1 - Audiophile USB Specs and correct usage | 17 | 1 - Audiophile USB Specs and correct usage |
10 | ========================================== | 18 | ========================================== |
19 | |||
11 | This part is a reminder of important facts about the functions and limitations | 20 | This part is a reminder of important facts about the functions and limitations |
12 | of the device. | 21 | of the device. |
13 | 22 | ||
@@ -25,18 +34,18 @@ The device has 4 audio interfaces, and 2 MIDI ports: | |||
25 | The internal DAC/ADC has the following characteristics: | 34 | The internal DAC/ADC has the following characteristics: |
26 | * sample depth of 16 or 24 bits | 35 | * sample depth of 16 or 24 bits |
27 | * sample rate from 8kHz to 96kHz | 36 | * sample rate from 8kHz to 96kHz |
28 | * Two ports can't use different sample depths at the same time. Moreover, the | 37 | * Two interfaces can't use different sample depths at the same time. |
29 | Audiophile USB documentation gives the following Warning: "Please exit any | 38 | Moreover, the Audiophile USB documentation gives the following Warning: |
30 | audio application running before switching between bit depths" | 39 | "Please exit any audio application running before switching between bit depths" |
31 | 40 | ||
32 | Due to the USB 1.1 bandwidth limitation, a limited number of interfaces can be | 41 | Due to the USB 1.1 bandwidth limitation, a limited number of interfaces can be |
33 | activated at the same time depending on the audio mode selected: | 42 | activated at the same time depending on the audio mode selected: |
34 | * 16-bit/48kHz ==> 4 channels in/4 channels out | 43 | * 16-bit/48kHz ==> 4 channels in + 4 channels out |
35 | - Ai+Ao+Di+Do | 44 | - Ai+Ao+Di+Do |
36 | * 24-bit/48kHz ==> 4 channels in/2 channels out, | 45 | * 24-bit/48kHz ==> 4 channels in + 2 channels out, |
37 | or 2 channels in/4 channels out | 46 | or 2 channels in + 4 channels out |
38 | - Ai+Ao+Do or Ai+Di+Ao or Ai+Di+Do or Di+Ao+Do | 47 | - Ai+Ao+Do or Ai+Di+Ao or Ai+Di+Do or Di+Ao+Do |
39 | * 24-bit/96kHz ==> 2 channels in, or 2 channels out (half duplex only) | 48 | * 24-bit/96kHz ==> 2 channels in _or_ 2 channels out (half duplex only) |
40 | - Ai or Ao or Di or Do | 49 | - Ai or Ao or Di or Do |
41 | 50 | ||
42 | Important facts about the Digital interface: | 51 | Important facts about the Digital interface: |
@@ -52,44 +61,53 @@ source is connected | |||
52 | synchronization error (for instance sound played at an odd sample rate) | 61 | synchronization error (for instance sound played at an odd sample rate) |
53 | 62 | ||
54 | 63 | ||
55 | 2 - Audiophile USB support in ALSA | 64 | 2 - Audiophile USB MIDI support in ALSA |
56 | ================================== | 65 | ======================================= |
57 | 66 | ||
58 | 2.1 - MIDI ports | 67 | The Audiophile USB MIDI ports will be automatically supported once the |
59 | ---------------- | ||
60 | The Audiophile USB MIDI ports will be automatically supported once the | ||
61 | following modules have been loaded: | 68 | following modules have been loaded: |
62 | * snd-usb-audio | 69 | * snd-usb-audio |
63 | * snd-seq-midi | 70 | * snd-seq-midi |
64 | 71 | ||
65 | No additional setting is required. | 72 | No additional setting is required. |
66 | 73 | ||
67 | 2.2 - Audio ports | 74 | |
68 | ----------------- | 75 | 3 - Audiophile USB Audio support in ALSA |
76 | ======================================== | ||
69 | 77 | ||
70 | Audio functions of the Audiophile USB device are handled by the snd-usb-audio | 78 | Audio functions of the Audiophile USB device are handled by the snd-usb-audio |
71 | module. This module can work in a default mode (without any device-specific | 79 | module. This module can work in a default mode (without any device-specific |
72 | parameter), or in an "advanced" mode with the device-specific parameter called | 80 | parameter), or in an "advanced" mode with the device-specific parameter called |
73 | "device_setup". | 81 | "device_setup". |
74 | 82 | ||
75 | 2.2.1 - Default Alsa driver mode | 83 | 3.1 - Default Alsa driver mode |
76 | 84 | ------------------------------ | |
77 | The default behavior of the snd-usb-audio driver is to parse the device | 85 | |
78 | capabilities at startup and enable all functions inside the device (including | 86 | The default behavior of the snd-usb-audio driver is to list the device |
79 | all ports at any supported sample rates and sample depths). This approach | 87 | capabilities at startup and activate the required mode when required |
80 | has the advantage to let the driver easily switch from sample rates/depths | 88 | by the applications: for instance if the user is recording in a |
81 | automatically according to the need of the application claiming the device. | 89 | 24bit-depth-mode and immediately after wants to switch to a 16bit-depth mode, |
82 | 90 | the snd-usb-audio module will reconfigure the device on the fly. | |
83 | In this case the Audiophile ports are mapped to alsa pcm devices in the | 91 | |
84 | following way (I suppose the device's index is 1): | 92 | This approach has the advantage to let the driver automatically switch from sample |
93 | rates/depths automatically according to the user's needs. However, those who | ||
94 | are using the device under windows know that this is not how the device is meant to | ||
95 | work: under windows applications must be closed before using the m-audio control | ||
96 | panel to switch the device working mode. Thus as we'll see in next section, this | ||
97 | Default Alsa driver mode can lead to device misconfigurations. | ||
98 | |||
99 | Let's get back to the Default Alsa driver mode for now. In this case the | ||
100 | Audiophile interfaces are mapped to alsa pcm devices in the following | ||
101 | way (I suppose the device's index is 1): | ||
85 | * hw:1,0 is Ao in playback and Di in capture | 102 | * hw:1,0 is Ao in playback and Di in capture |
86 | * hw:1,1 is Do in playback and Ai in capture | 103 | * hw:1,1 is Do in playback and Ai in capture |
87 | * hw:1,2 is Do in AC3/DTS passthrough mode | 104 | * hw:1,2 is Do in AC3/DTS passthrough mode |
88 | 105 | ||
89 | You must note as well that the device uses Big Endian byte encoding so that | 106 | In this mode, the device uses Big Endian byte-encoding so that |
90 | supported audio format are S16_BE for 16-bit depth modes and S24_3BE for | 107 | supported audio format are S16_BE for 16-bit depth modes and S24_3BE for |
91 | 24-bits depth mode. One exception is the hw:1,2 port which is Little Endian | 108 | 24-bits depth mode. One exception is the hw:1,2 port which is reported |
92 | compliant and thus uses S16_LE. | 109 | to be Little Endian compliant (supposedly supporting S16_LE) but processes |
110 | in fact only S16_BE streams. | ||
93 | 111 | ||
94 | Examples: | 112 | Examples: |
95 | * playing a S24_3BE encoded raw file to the Ao port | 113 | * playing a S24_3BE encoded raw file to the Ao port |
@@ -99,21 +117,23 @@ Examples: | |||
99 | * playing a S16_BE encoded raw file to the Do port | 117 | * playing a S16_BE encoded raw file to the Do port |
100 | % aplay -D hw:1,1 -c2 -t raw -r48000 -fS16_BE test.raw | 118 | % aplay -D hw:1,1 -c2 -t raw -r48000 -fS16_BE test.raw |
101 | 119 | ||
102 | If you're happy with the default Alsa driver setup and don't experience any | 120 | If you're happy with the default Alsa driver mode and don't experience any |
103 | issue with this mode, then you can skip the following chapter. | 121 | issue with this mode, then you can skip the following chapter. |
104 | 122 | ||
105 | 2.2.2 - Advanced module setup | 123 | 3.2 - Advanced module setup |
124 | --------------------------- | ||
106 | 125 | ||
107 | Due to the hardware constraints described above, the device initialization made | 126 | Due to the hardware constraints described above, the device initialization made |
108 | by the Alsa driver in default mode may result in a corrupted state of the | 127 | by the Alsa driver in default mode may result in a corrupted state of the |
109 | device. For instance, a particularly annoying issue is that the sound captured | 128 | device. For instance, a particularly annoying issue is that the sound captured |
110 | from the Ai port sounds distorted (as if boosted with an excessive high volume | 129 | from the Ai interface sounds distorted (as if boosted with an excessive high |
111 | gain). | 130 | volume gain). |
112 | 131 | ||
113 | For people having this problem, the snd-usb-audio module has a new module | 132 | For people having this problem, the snd-usb-audio module has a new module |
114 | parameter called "device_setup". | 133 | parameter called "device_setup" (this parameter was introduced in kernel |
134 | release 2.6.17) | ||
115 | 135 | ||
116 | 2.2.2.1 - Initializing the working mode of the Audiophile USB | 136 | 3.2.1 - Initializing the working mode of the Audiophile USB |
117 | 137 | ||
118 | As far as the Audiophile USB device is concerned, this value let the user | 138 | As far as the Audiophile USB device is concerned, this value let the user |
119 | specify: | 139 | specify: |
@@ -121,33 +141,57 @@ specify: | |||
121 | * the sample rate | 141 | * the sample rate |
122 | * whether the Di port is used or not | 142 | * whether the Di port is used or not |
123 | 143 | ||
124 | Here is a list of supported device_setup values for this device: | 144 | When initialized with "device_setup=0x00", the snd-usb-audio module has |
125 | * device_setup=0x00 (or omitted) | 145 | the same behaviour as when the parameter is omitted (see paragraph "Default |
126 | - Alsa driver default mode | 146 | Alsa driver mode" above) |
127 | - maintains backward compatibility with setups that do not use this | 147 | |
128 | parameter by not introducing any change | 148 | Others modes are described in the following subsections. |
129 | - results sometimes in corrupted sound as described earlier | 149 | |
150 | 3.2.1.1 - 16-bit modes | ||
151 | |||
152 | The two supported modes are: | ||
153 | |||
130 | * device_setup=0x01 | 154 | * device_setup=0x01 |
131 | - 16bits 48kHz mode with Di disabled | 155 | - 16bits 48kHz mode with Di disabled |
132 | - Ai,Ao,Do can be used at the same time | 156 | - Ai,Ao,Do can be used at the same time |
133 | - hw:1,0 is not available in capture mode | 157 | - hw:1,0 is not available in capture mode |
134 | - hw:1,2 is not available | 158 | - hw:1,2 is not available |
159 | |||
135 | * device_setup=0x11 | 160 | * device_setup=0x11 |
136 | - 16bits 48kHz mode with Di enabled | 161 | - 16bits 48kHz mode with Di enabled |
137 | - Ai,Ao,Di,Do can be used at the same time | 162 | - Ai,Ao,Di,Do can be used at the same time |
138 | - hw:1,0 is available in capture mode | 163 | - hw:1,0 is available in capture mode |
139 | - hw:1,2 is not available | 164 | - hw:1,2 is not available |
165 | |||
166 | In this modes the device operates only at 16bits-modes. Before kernel 2.6.23, | ||
167 | the devices where reported to be Big-Endian when in fact they were Little-Endian | ||
168 | so that playing a file was a matter of using: | ||
169 | % aplay -D hw:1,1 -c2 -t raw -r48000 -fS16_BE test_S16_LE.raw | ||
170 | where "test_S16_LE.raw" was in fact a little-endian sample file. | ||
171 | |||
172 | Thanks to Hakan Lennestal (who discovered the Little-Endiannes of the device in | ||
173 | these modes) a fix has been committed (expected in kernel 2.6.23) and | ||
174 | Alsa now reports Little-Endian interfaces. Thus playing a file now is as simple as | ||
175 | using: | ||
176 | % aplay -D hw:1,1 -c2 -t raw -r48000 -fS16_LE test_S16_LE.raw | ||
177 | |||
178 | 3.2.1.2 - 24-bit modes | ||
179 | |||
180 | The three supported modes are: | ||
181 | |||
140 | * device_setup=0x09 | 182 | * device_setup=0x09 |
141 | - 24bits 48kHz mode with Di disabled | 183 | - 24bits 48kHz mode with Di disabled |
142 | - Ai,Ao,Do can be used at the same time | 184 | - Ai,Ao,Do can be used at the same time |
143 | - hw:1,0 is not available in capture mode | 185 | - hw:1,0 is not available in capture mode |
144 | - hw:1,2 is not available | 186 | - hw:1,2 is not available |
187 | |||
145 | * device_setup=0x19 | 188 | * device_setup=0x19 |
146 | - 24bits 48kHz mode with Di enabled | 189 | - 24bits 48kHz mode with Di enabled |
147 | - 3 ports from {Ai,Ao,Di,Do} can be used at the same time | 190 | - 3 ports from {Ai,Ao,Di,Do} can be used at the same time |
148 | - hw:1,0 is available in capture mode and an active digital source must be | 191 | - hw:1,0 is available in capture mode and an active digital source must be |
149 | connected to Di | 192 | connected to Di |
150 | - hw:1,2 is not available | 193 | - hw:1,2 is not available |
194 | |||
151 | * device_setup=0x0D or 0x10 | 195 | * device_setup=0x0D or 0x10 |
152 | - 24bits 96kHz mode | 196 | - 24bits 96kHz mode |
153 | - Di is enabled by default for this mode but does not need to be connected | 197 | - Di is enabled by default for this mode but does not need to be connected |
@@ -155,34 +199,61 @@ Here is a list of supported device_setup values for this device: | |||
155 | - Only 1 port from {Ai,Ao,Di,Do} can be used at the same time | 199 | - Only 1 port from {Ai,Ao,Di,Do} can be used at the same time |
156 | - hw:1,0 is available in captured mode | 200 | - hw:1,0 is available in captured mode |
157 | - hw:1,2 is not available | 201 | - hw:1,2 is not available |
202 | |||
203 | In these modes the device is only Big-Endian compliant (see "Default Alsa driver | ||
204 | mode" above for an aplay command example) | ||
205 | |||
206 | 3.2.1.3 - AC3 w/ DTS passthru mode | ||
207 | |||
208 | This mode is untested, I have no AC3 compliant device to test it. I uses: | ||
209 | |||
158 | * device_setup=0x03 | 210 | * device_setup=0x03 |
159 | - 16bits 48kHz mode with only the Do port enabled | 211 | - 16bits 48kHz mode with only the Do port enabled |
160 | - AC3 with DTS passthru (not tested) | 212 | - AC3 with DTS passthru (not tested) |
161 | - Caution with this setup the Do port is mapped to the pcm device hw:1,0 | 213 | - Caution with this setup the Do port is mapped to the pcm device hw:1,0 |
162 | 214 | ||
163 | 2.2.2.2 - Setting and switching configurations with the device_setup parameter | 215 | 3.2.2 - How to use the device_setup parameter |
216 | ---------------------------------------------- | ||
164 | 217 | ||
165 | The parameter can be given: | 218 | The parameter can be given: |
219 | |||
166 | * By manually probing the device (as root): | 220 | * By manually probing the device (as root): |
167 | # modprobe -r snd-usb-audio | 221 | # modprobe -r snd-usb-audio |
168 | # modprobe snd-usb-audio index=1 device_setup=0x09 | 222 | # modprobe snd-usb-audio index=1 device_setup=0x09 |
223 | |||
169 | * Or while configuring the modules options in your modules configuration file | 224 | * Or while configuring the modules options in your modules configuration file |
170 | - For Fedora distributions, edit the /etc/modprobe.conf file: | 225 | - For Fedora distributions, edit the /etc/modprobe.conf file: |
171 | alias snd-card-1 snd-usb-audio | 226 | alias snd-card-1 snd-usb-audio |
172 | options snd-usb-audio index=1 device_setup=0x09 | 227 | options snd-usb-audio index=1 device_setup=0x09 |
173 | 228 | ||
174 | IMPORTANT NOTE WHEN SWITCHING CONFIGURATION: | 229 | CAUTION when initializaing the device |
175 | ------------------------------------------- | 230 | ------------------------------------- |
176 | * You may need to _first_ initialize the module with the correct device_setup | 231 | |
177 | parameter and _only_after_ turn on the Audiophile USB device | 232 | * Correct initialization on the device requires that device_setup is given to |
178 | * This is especially true when switching the sample depth: | 233 | the module BEFORE the device is turned on. So, if you use the "manual probing" |
234 | method described above, take care to power-on the device AFTER this initialization. | ||
235 | |||
236 | * Failing to respect this will lead in a misconfiguration of the device. In this case | ||
237 | turn off the device, unproble the snd-usb-audio module, then probe it again with | ||
238 | correct device_setup parameter and then (and only then) turn on the device again. | ||
239 | |||
240 | * If you've correctly initialized the device in a valid mode and then want to switch | ||
241 | to another mode (possibly with another sample-depth), please use also the following | ||
242 | procedure: | ||
179 | - first turn off the device | 243 | - first turn off the device |
180 | - de-register the snd-usb-audio module (modprobe -r) | 244 | - de-register the snd-usb-audio module (modprobe -r) |
181 | - change the device_setup parameter by changing the device_setup | 245 | - change the device_setup parameter by changing the device_setup |
182 | option in /etc/modprobe.conf | 246 | option in /etc/modprobe.conf |
183 | - turn on the device | 247 | - turn on the device |
248 | * A workaround for this last issue has been applied to kernel 2.6.23, but it may not | ||
249 | be enough to ensure the 'stability' of the device initialization. | ||
250 | |||
251 | 3.2.3 - Technical details for hackers | ||
252 | ------------------------------------- | ||
253 | This section is for hackers, wanting to understand details about the device | ||
254 | internals and how Alsa supports it. | ||
184 | 255 | ||
185 | 2.2.2.3 - Audiophile USB's device_setup structure | 256 | 3.2.3.1 - Audiophile USB's device_setup structure |
186 | 257 | ||
187 | If you want to understand the device_setup magic numbers for the Audiophile | 258 | If you want to understand the device_setup magic numbers for the Audiophile |
188 | USB, you need some very basic understanding of binary computation. However, | 259 | USB, you need some very basic understanding of binary computation. However, |
@@ -228,12 +299,12 @@ Caution: | |||
228 | - choosing b2 will prepare all interfaces for 24bits/96kHz but you'll | 299 | - choosing b2 will prepare all interfaces for 24bits/96kHz but you'll |
229 | only be able to use one at the same time | 300 | only be able to use one at the same time |
230 | 301 | ||
231 | 2.2.3 - USB implementation details for this device | 302 | 3.2.3.2 - USB implementation details for this device |
232 | 303 | ||
233 | You may safely skip this section if you're not interested in driver | 304 | You may safely skip this section if you're not interested in driver |
234 | development. | 305 | hacking. |
235 | 306 | ||
236 | This section describes some internal aspects of the device and summarize the | 307 | This section describes some internal aspects of the device and summarizes the |
237 | data I got by usb-snooping the windows and Linux drivers. | 308 | data I got by usb-snooping the windows and Linux drivers. |
238 | 309 | ||
239 | The M-Audio Audiophile USB has 7 USB Interfaces: | 310 | The M-Audio Audiophile USB has 7 USB Interfaces: |
@@ -293,43 +364,45 @@ parse_audio_endpoints function uses a quirk called | |||
293 | "audiophile_skip_setting_quirk" in order to prevent AltSettings not | 364 | "audiophile_skip_setting_quirk" in order to prevent AltSettings not |
294 | corresponding to device_setup from being registered in the driver. | 365 | corresponding to device_setup from being registered in the driver. |
295 | 366 | ||
296 | 3 - Audiophile USB and Jack support | 367 | 4 - Audiophile USB and Jack support |
297 | =================================== | 368 | =================================== |
298 | 369 | ||
299 | This section deals with support of the Audiophile USB device in Jack. | 370 | This section deals with support of the Audiophile USB device in Jack. |
300 | The main issue regarding this support is that the device is Big Endian | ||
301 | compliant. | ||
302 | 371 | ||
303 | 3.1 - Using the plug alsa plugin | 372 | There are 2 main potential issues when using Jackd with the device: |
304 | -------------------------------- | 373 | * support for Big-Endian devices in 24-bit modes |
374 | * support for 4-in / 4-out channels | ||
305 | 375 | ||
306 | Jack doesn't directly support big endian devices. Thus, one way to have support | 376 | 4.1 - Direct support in Jackd |
307 | for this device with Alsa is to use the Alsa "plug" converter. | 377 | ----------------------------- |
378 | |||
379 | Jack supports big endian devices only in recent versions (thanks to | ||
380 | Andreas Steinmetz for his first big-endian patch). I can't remember | ||
381 | extacly when this support was released into jackd, let's just say that | ||
382 | with jackd version 0.103.0 it's almost ok (just a small bug is affecting | ||
383 | 16bits Big-Endian devices, but since you've read carefully the above | ||
384 | paragraphs, you're now using kernel >= 2.6.23 and your 16bits devices | ||
385 | are now Little Endians ;-) ). | ||
386 | |||
387 | You can run jackd with the following command for playback with Ao and | ||
388 | record with Ai: | ||
389 | % jackd -R -dalsa -Phw:1,0 -r48000 -p128 -n2 -D -Chw:1,1 | ||
390 | |||
391 | 4.2 - Using Alsa plughw | ||
392 | ----------------------- | ||
393 | If you don't have a recent Jackd installed, you can downgrade to using | ||
394 | the Alsa "plug" converter. | ||
308 | 395 | ||
309 | For instance here is one way to run Jack with 2 playback channels on Ao and 2 | 396 | For instance here is one way to run Jack with 2 playback channels on Ao and 2 |
310 | capture channels from Ai: | 397 | capture channels from Ai: |
311 | % jackd -R -dalsa -dplughw:1 -r48000 -p256 -n2 -D -Cplughw:1,1 | 398 | % jackd -R -dalsa -dplughw:1 -r48000 -p256 -n2 -D -Cplughw:1,1 |
312 | 399 | ||
313 | |||
314 | However you may see the following warning message: | 400 | However you may see the following warning message: |
315 | "You appear to be using the ALSA software "plug" layer, probably a result of | 401 | "You appear to be using the ALSA software "plug" layer, probably a result of |
316 | using the "default" ALSA device. This is less efficient than it could be. | 402 | using the "default" ALSA device. This is less efficient than it could be. |
317 | Consider using a hardware device instead rather than using the plug layer." | 403 | Consider using a hardware device instead rather than using the plug layer." |
318 | 404 | ||
319 | 3.2 - Patching alsa to use direct pcm device | 405 | 4.3 - Getting 2 input and/or output interfaces in Jack |
320 | -------------------------------------------- | ||
321 | A patch for Jack by Andreas Steinmetz adds support for Big Endian devices. | ||
322 | However it has not been included in the CVS tree. | ||
323 | |||
324 | You can find it at the following URL: | ||
325 | http://sourceforge.net/tracker/index.php?func=detail&aid=1289682&group_id=39687& | ||
326 | atid=425939 | ||
327 | |||
328 | After having applied the patch you can run jackd with the following command | ||
329 | line: | ||
330 | % jackd -R -dalsa -Phw:1,0 -r48000 -p128 -n2 -D -Chw:1,1 | ||
331 | |||
332 | 3.2 - Getting 2 input and/or output interfaces in Jack | ||
333 | ------------------------------------------------------ | 406 | ------------------------------------------------------ |
334 | 407 | ||
335 | As you can see, starting the Jack server this way will only enable 1 stereo | 408 | As you can see, starting the Jack server this way will only enable 1 stereo |
@@ -339,6 +412,7 @@ This is due to the following restrictions: | |||
339 | * Jack can only open one capture device and one playback device at a time | 412 | * Jack can only open one capture device and one playback device at a time |
340 | * The Audiophile USB is seen as 2 (or three) Alsa devices: hw:1,0, hw:1,1 | 413 | * The Audiophile USB is seen as 2 (or three) Alsa devices: hw:1,0, hw:1,1 |
341 | (and optionally hw:1,2) | 414 | (and optionally hw:1,2) |
415 | |||
342 | If you want to get Ai+Di and/or Ao+Do support with Jack, you would need to | 416 | If you want to get Ai+Di and/or Ao+Do support with Jack, you would need to |
343 | combine the Alsa devices into one logical "complex" device. | 417 | combine the Alsa devices into one logical "complex" device. |
344 | 418 | ||
@@ -348,13 +422,11 @@ It is related to another device (ice1712) but can be adapted to suit | |||
348 | the Audiophile USB. | 422 | the Audiophile USB. |
349 | 423 | ||
350 | Enabling multiple Audiophile USB interfaces for Jackd will certainly require: | 424 | Enabling multiple Audiophile USB interfaces for Jackd will certainly require: |
351 | * patching Jack with the previously mentioned "Big Endian" patch | 425 | * Making sure your Jackd version has the MMAP_COMPLEX patch (see the ice1712 page) |
352 | * patching Jackd with the MMAP_COMPLEX patch (see the ice1712 page) | 426 | * (maybe) patching the alsa-lib/src/pcm/pcm_multi.c file (see the ice1712 page) |
353 | * patching the alsa-lib/src/pcm/pcm_multi.c file (see the ice1712 page) | ||
354 | * define a multi device (combination of hw:1,0 and hw:1,1) in your .asoundrc | 427 | * define a multi device (combination of hw:1,0 and hw:1,1) in your .asoundrc |
355 | file | 428 | file |
356 | * start jackd with this device | 429 | * start jackd with this device |
357 | 430 | ||
358 | I had no success in testing this for now, but this may be due to my OS | 431 | I had no success in testing this for now, if you have any success with this kind |
359 | configuration. If you have any success with this kind of setup, please | 432 | of setup, please drop me an email. |
360 | drop me an email. | ||