2008-05-05 20:31:05     is multi-channel supported by AD1980 codec?

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2008-05-05 20:31:05     is multi-channel supported by AD1980 codec?

Ron Weiland (UNITED STATES)

Message: 55526   

 

Hi all!

 

I am running 2008r1-rc8 with ALSA and ALSA-UTILS compiled and an AD1980 sound chip installed on my own BF533 board.  Things seem to be working as expected.  My /proc/asound/devices file looks this:

 

/proc/asound/devices

  0: [ 0]   : control

16: [ 0- 0]: digital audio playback

24: [ 0- 0]: digital audio capture

33:        : timer

 

Is there a way I can get to the surround channels and / or the LFE channel on this chip?  Does the current ad1980.c driver support those channels?  It looks like the driver is only opening one PCM stream.

 

If I have an AD1981 chip installed, the driver warns me "Found AD1981 - only 2/2 IN/OUT Channels supported" which I would expect, but I don't see that more channels are supported for the AD1980.

 

I am totally new to ALSA, so it could be I just don't know how. Ultimately I would like to be able to send different audio files to the front and back channels .  I can do it via the left / right channels if I have to, but I would like to use the hardware mixer as well.

 

Thanks for any help you can give!

 

 

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2008-05-06 01:20:21     回复: is multi-channel supported by AD1980 codec?

Cliff Cai (CHINA)

Message: 55529   

 

Hi Ron,

 

I think you just need to add the relevant slots in struct ac97_frame,and copy the data to these  slots as

 

what driver does for PCM  L/R

 

Cliff

 

 

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2008-05-06 21:42:29     Re: 回复: is multi-channel supported by AD1980 codec?

Ron Weiland (UNITED STATES)

Message: 55587   

 

Hi, Cliff!  Thanks for responding.

 

I think I would still need to define the PCM stream definitions all through the ALSA structures, wouldn't I?  I'm on a short time frame and don't have the time to learn the ALSA drivers as well as I would like.  I'm thinking of going with either the WM9712 or the AD1836 (3 separate stereo mode), both of which seem to already have the PCM streams set up.  Don't know yet if they support full duplex though.  Any suggestions?

 

Thanks again!

 

Ron

 

 

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2008-05-08 22:39:15     回复: Re: 回复: is multi-channel supported by AD1980 codec?

Cliff Cai (CHINA)

Message: 55655   

 

Hi Ron,

 

The driver for AD1836 does support multi PCM streams (up to 5.1 channels) and support full duplex as well.

 

Cliff

 

 

 

 

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2008-05-09 19:38:30     Re: 回复: Re: 回复: is multi-channel supported by AD1980 codec?

Ron Weiland (UNITED STATES)

Message: 55697   

 

Hi Cliff.

 

I decided to follow your original suggestion.  I took the old (2.6.19.3) AD1981b driver and added the ac97_frames for the back channels of the AD1980.

 

I'm able to play one ivorbisfile_example to /dev/dsp and another to /dev/dsp1 while recording from the front channels, all at 48k stereo.   May not be ALSA, but works for my needs!   Once I get the hardware out to the layout guy, maybe I can tackle a more "official" extension rather than a total hack.

 

Thanks again!

 

Ron

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