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-rw-r--r--Documentation/sound/alsa/Audiophile-Usb.txt22
1 files changed, 16 insertions, 6 deletions
diff --git a/Documentation/sound/alsa/Audiophile-Usb.txt b/Documentation/sound/alsa/Audiophile-Usb.txt
index 5b7a5487d505..2ad5e6306c44 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 v1.4 1 Guide to using M-Audio Audiophile USB with ALSA and Jack v1.5
2 ======================================================== 2 ========================================================
3 3
4 Thibault Le Meur <Thibault.LeMeur@supelec.fr> 4 Thibault Le Meur <Thibault.LeMeur@supelec.fr>
@@ -12,6 +12,8 @@ History
12 - Added Low Endianness nature of 16bits-modes 12 - Added Low Endianness nature of 16bits-modes
13 found by Hakan Lennestal <Hakan.Lennestal@brfsodrahamn.se> 13 found by Hakan Lennestal <Hakan.Lennestal@brfsodrahamn.se>
14 - Modifying document structure 14 - Modifying document structure
15* v1.5 - Thibault Le Meur (2007-07-12)
16 - Added AC3/DTS passthru info
15 17
16 18
171 - Audiophile USB Specs and correct usage 191 - Audiophile USB Specs and correct usage
@@ -105,9 +107,12 @@ way (I suppose the device's index is 1):
105 107
106In this mode, the device uses Big Endian byte-encoding so that 108In this mode, the device uses Big Endian byte-encoding so that
107supported audio format are S16_BE for 16-bit depth modes and S24_3BE for 109supported audio format are S16_BE for 16-bit depth modes and S24_3BE for
10824-bits depth mode. One exception is the hw:1,2 port which is reported 11024-bits depth mode.
109to be Little Endian compliant (supposedly supporting S16_LE) but processes 111
110in fact only S16_BE streams. 112One exception is the hw:1,2 port which was reported to be Little Endian
113compliant (supposedly supporting S16_LE) but processes in fact only S16_BE streams.
114This has been fixed in kernel 2.6.23 and above and now the hw:1,2 interface
115is reported to be big endian in this default driver mode.
111 116
112Examples: 117Examples:
113 * playing a S24_3BE encoded raw file to the Ao port 118 * playing a S24_3BE encoded raw file to the Ao port
@@ -116,6 +121,8 @@ Examples:
116 % arecord -D hw:1,1 -c2 -t raw -r48000 -fS24_3BE test.raw 121 % arecord -D hw:1,1 -c2 -t raw -r48000 -fS24_3BE test.raw
117 * playing a S16_BE encoded raw file to the Do port 122 * playing a S16_BE encoded raw file to the Do port
118 % aplay -D hw:1,1 -c2 -t raw -r48000 -fS16_BE test.raw 123 % aplay -D hw:1,1 -c2 -t raw -r48000 -fS16_BE test.raw
124 * playing an ac3 sample file to the Do port
125 % aplay -D hw:1,2 --channels=6 ac3_S16_BE_encoded_file.raw
119 126
120If you're happy with the default Alsa driver mode and don't experience any 127If you're happy with the default Alsa driver mode and don't experience any
121issue with this mode, then you can skip the following chapter. 128issue with this mode, then you can skip the following chapter.
@@ -205,13 +212,16 @@ mode" above for an aplay command example)
205 212
2063.2.1.3 - AC3 w/ DTS passthru mode 2133.2.1.3 - AC3 w/ DTS passthru mode
207 214
208This mode is untested, I have no AC3 compliant device to test it. I uses: 215Thanks to Hakan Lennestal, I now have a report saying that this mode works.
209 216
210 * device_setup=0x03 217 * device_setup=0x03
211 - 16bits 48kHz mode with only the Do port enabled 218 - 16bits 48kHz mode with only the Do port enabled
212 - AC3 with DTS passthru (not tested) 219 - AC3 with DTS passthru
213 - Caution with this setup the Do port is mapped to the pcm device hw:1,0 220 - Caution with this setup the Do port is mapped to the pcm device hw:1,0
214 221
222The command line used to playback the AC3/DTS encoded .wav-files in this mode:
223 % aplay -D hw:1,0 --channels=6 ac3_S16_LE_encoded_file.raw
224
2153.2.2 - How to use the device_setup parameter 2253.2.2 - How to use the device_setup parameter
216---------------------------------------------- 226----------------------------------------------
217 227