[alsa-devel] 6-channel output and i2s

Jon Smirl jonsmirl at gmail.com
Wed Apr 29 16:35:34 CEST 2009


On Wed, Apr 29, 2009 at 9:04 AM, Takashi Iwai <tiwai at suse.de> wrote:
> At Wed, 29 Apr 2009 08:58:52 -0400,
> Jon Smirl wrote:
>>
>> My hardware was has three stereo i2s lines. These three lines are all
>> tied to the same external clock so they are synchronized. Because
>> there are three i2s lines, each with it's own DMA queue and FIFO, I
>> need three independent output buffers. What is the correct way to set
>> this up in ALSA?
>
> So I suppose it's three streams of 2-ch interleaved format?

Yes

> If so, an easier way would be to provide three substreams in a PCM,
> and bind 6 channels with alsa-lib plugin.

How does ALSA start the streams synchronously?

>
> Another possible way would be to set up channel_info to point a proper
> offset for each channel.  But, this is less common and maybe more
> problematic.
>
>
> Takashi
>



-- 
Jon Smirl
jonsmirl at gmail.com


More information about the Alsa-devel mailing list