[alsa-devel] HDMI with more than 2ch ?
Hi,
I'm using HDMI output on an HD 2600, using KMS from kernel 2.6.37: http://www.alsa-project.org/db/?f=b3f67a0890f9878b7b3f345578e24eda0aaa59ac The problem is that only 2ch are supported (not 1, not 3 or more). I tested with speaker-test, it only works with -c 2.
So how can I access the other PCM channels ? There are 8 of them available in the HDMI standard, I thought the card should be able to drive all of them.
Thanks, Xav
On Mon, 2011-01-24 at 10:16 +0100, Xavier Bestel wrote:
Hi,
I'm using HDMI output on an HD 2600, using KMS from kernel 2.6.37: http://www.alsa-project.org/db/?f=b3f67a0890f9878b7b3f345578e24eda0aaa59ac The problem is that only 2ch are supported (not 1, not 3 or more). I tested with speaker-test, it only works with -c 2.
Just in case: [root@awak:~]$ speaker-test -Dhw:1,3 -c6 -twav
speaker-test 1.0.23
Playback device is hw:1,3 Stream parameters are 48000Hz, S16_LE, 6 channels WAV file(s) Channels count (6) not available for playbacks: Argument invalide Setting of hwparams failed: Argument invalide
On 2011-01-24 10:16, Xavier Bestel wrote:
Hi,
I'm using HDMI output on an HD 2600, using KMS from kernel 2.6.37: http://www.alsa-project.org/db/?f=b3f67a0890f9878b7b3f345578e24eda0aaa59ac The problem is that only 2ch are supported (not 1, not 3 or more). I tested with speaker-test, it only works with -c 2.
So how can I access the other PCM channels ? There are 8 of them available in the HDMI standard, I thought the card should be able to drive all of them.
According to your HDMI codec it only supports stereo output, not 8-channel PCM. This is a limitation in your hardware, not in the HDMI standard.
That is, if you want more channels, you probably want to ac3-encode the audio data.
Le mardi 25 janvier 2011 à 02:17 +0100, David Henningsson a écrit :
According to your HDMI codec it only supports stereo output, not 8-channel PCM. This is a limitation in your hardware, not in the HDMI standard.
That is, if you want more channels, you probably want to ac3-encode the audio data.
I've found it's a driver problem. Please read the thread titled "ALSA multichannel through HDMI" for the gory details.
Xav
participants (2)
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David Henningsson -
Xavier Bestel