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Diffstat (limited to 'Documentation/sound/alsa/Audiophile-Usb.txt')
| -rw-r--r-- | Documentation/sound/alsa/Audiophile-Usb.txt | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/Documentation/sound/alsa/Audiophile-Usb.txt b/Documentation/sound/alsa/Audiophile-Usb.txt index 5b7a5487d50..2ad5e6306c4 100644 --- a/Documentation/sound/alsa/Audiophile-Usb.txt +++ b/Documentation/sound/alsa/Audiophile-Usb.txt @@ -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@supelec.fr> @@ -12,6 +12,8 @@ History - Added Low Endianness nature of 16bits-modes found by Hakan Lennestal <Hakan.Lennestal@brfsodrahamn.se> - 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 @@ way (I suppose the device's index is 1): 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 @@ Examples: % 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 @@ mode" above for an aplay command example) 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 ---------------------------------------------- |