-
Summary: Audiophile-usb fix (corrects little-endianness in 16bit
modes, resets interfaces at device initialization, and updates the
documentation)
Signed-Of-By: Thibault Le Meur <Thibault.LeMeur@xxxxxxxxxx>
Thanks, applied now.
Takashi
Hi,
Hakan reported to me (off-list) that the AC3 function works correctly
with the device except in device_setup=0x00 mode because the interface
is reported to be little endian whereas it is in fact big-endian (in
this mode only).
With the help of Hakan I made a fix and updated the doc accordingly.
Hakan could you test this fix (to be applied after my last one) and
report if it is ok for you ?
Takashi, in case everything is ok and you want to apply the patch:
Summary: Fixed AC3 interface in device_setup=0x00 mode thanks to Hakan
Lennestal and updated documentation
Signed-Of-By: Thibault Le Meur <Thibault.LeMeur@xxxxxxxxxx>
Thanks in advance,
Thibault
--- alsa-kernel/Documentation/Audiophile-Usb.txt 2007-07-12 23:15:04.000000000 +0200
+++ new/alsa-kernel/Documentation/Audiophile-Usb.txt 2007-07-12 23:00:04.000000000 +0200
@@ -1,4 +1,4 @@
- Guide to using M-Audio Audiophile USB with ALSA and Jack v1.4
+ Guide to using M-Audio Audiophile USB with ALSA and Jack v1.5
========================================================
Thibault Le Meur <Thibault.LeMeur@xxxxxxxxxx>
@@ -12,6 +12,8 @@
- Added Low Endianness nature of 16bits-modes
found by Hakan Lennestal <Hakan.Lennestal@xxxxxxxxxxxxxxx>
- Modifying document structure
+* v1.5 - Thibault Le Meur (2007-07-12)
+ - Added AC3/DTS passthru info
1 - Audiophile USB Specs and correct usage
@@ -105,9 +107,12 @@
In this mode, the device uses Big Endian byte-encoding so that
supported audio format are S16_BE for 16-bit depth modes and S24_3BE for
-24-bits depth mode. One exception is the hw:1,2 port which is reported
-to be Little Endian compliant (supposedly supporting S16_LE) but processes
-in fact only S16_BE streams.
+24-bits depth mode.
+
+One exception is the hw:1,2 port which was reported to be Little Endian
+compliant (supposedly supporting S16_LE) but processes in fact only S16_BE streams.
+This has been fixed in kernel 2.6.23 and above and now the hw:1,2 interface
+is reported to be big endian in this default driver mode.
Examples:
* playing a S24_3BE encoded raw file to the Ao port
@@ -116,6 +121,8 @@
% arecord -D hw:1,1 -c2 -t raw -r48000 -fS24_3BE test.raw
* playing a S16_BE encoded raw file to the Do port
% aplay -D hw:1,1 -c2 -t raw -r48000 -fS16_BE test.raw
+ * playing an ac3 sample file to the Do port
+ % aplay -D hw:1,2 --channels=6 ac3_S16_BE_encoded_file.raw
If you're happy with the default Alsa driver mode and don't experience any
issue with this mode, then you can skip the following chapter.
@@ -205,13 +212,16 @@
3.2.1.3 - AC3 w/ DTS passthru mode
-This mode is untested, I have no AC3 compliant device to test it. I uses:
+Thanks to Hakan Lennestal, I now have a report saying that this mode works.
* device_setup=0x03
- 16bits 48kHz mode with only the Do port enabled
- - AC3 with DTS passthru (not tested)
+ - AC3 with DTS passthru
- Caution with this setup the Do port is mapped to the pcm device hw:1,0
+The command line used to playback the AC3/DTS encoded .wav-files in this mode:
+ % aplay -D hw:1,0 --channels=6 ac3_S16_LE_encoded_file.raw
+
3.2.2 - How to use the device_setup parameter
----------------------------------------------
--- alsa-kernel/usb/usbaudio.c 2007-07-12 23:15:05.000000000 +0200
+++ new/alsa-kernel/usb/usbaudio.c 2007-07-12 22:33:32.000000000 +0200
@@ -2532,7 +2532,18 @@
* but we give normal PCM format to get the existing
* apps working...
*/
- pcm_format = SNDRV_PCM_FORMAT_S16_LE;
+ switch (chip->usb_id) {
+
+ case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
+ if (device_setup[chip->index] == 0x00 &&
+ fp->altsetting == 6)
+ pcm_format = SNDRV_PCM_FORMAT_S16_BE;
+ else
+ pcm_format = SNDRV_PCM_FORMAT_S16_LE;
+ break;
+ default:
+ pcm_format = SNDRV_PCM_FORMAT_S16_LE;
+ }
} else {
pcm_format = parse_audio_format_i_type(chip, fp, format, fmt);
if (pcm_format < 0)
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