[Arm-netbook] A10 and all things audio

[Iain Bullard]

On 13 July 2012 07:32, Jorgen Lundman <lundman at lundman.net> wrote:
>
>> As we discussed on IRC, the a10 seems to have some timing/clock problems
>> when it comes to video.  Maybe audio suffers from the same problem and your
>> AVR has trouble locking-in on the sampling frequency of the signal.  Did
>> you test with stock Mele android 2.x image?  Back when I still had my a10
>
> Yeah I was looking at adding the frequencies for the 23 and 59 framerates
> to see how they would perform, but...
>
>
>> I'm pretty sure nobody has ever gotten audio pass-through to work on any
>> a10 device.  But it should not be difficult to pass standard ac3/dts inside
>> the PCM signal (assuming you can first fix the problems you're having with
>> PCM).  You just need to wrap the compressed audio frames in some spdif
>
> It certainly sounds like it isn't "supposed to" be able to do more than
> stereo "right now", so there is no reason for me to check my hardware etc.
>
> But as far as I can tell, I don't have access to the sources for anything
> audio (at that level), so I can't try to fix this myself.

https://github.com/amery/linux-allwinner/tree/allwinner-v3.0-android-v2/sound/soc/sun4i/spdif

That looks like the low level driver code for the spdif, I'm not aware
of any binary blobs required for the spdif output (there isn't for
hdmi), though I can't say I've actually researched the spdif output
other than glancing over the source code.

Iain.