[alsa-devel] Access to bytes from the raw audio stream? (AC'97)
johngavingraham at googlemail.com
Wed Feb 3 17:27:05 CET 2010
> With a lot of AC97 controllers the hardware won't allow you direct
> access to the cooked wire data, you'll only be able to see decoded audio
> streams. What is it that you're actually trying to do?
Basically, we've got a problem where we think our processor is
bit-shifting the sample for some reason, and I was going to see if I
could either (i) un-bit-shift it (it looks like we're not actually
losing any data, the sound's just being multiplied by 2^4), or (ii)
reproduce the problem we see by bit-shifting the samples on a
> For embedded platforms you mostly want to look under sound/soc though
> there are a few platforms outside of there.
I know the drivers for our particular setup (UBC1400 codec/i.MX25
processor) are under sound/arm, but I'm not sure if there's anything
in there that actually sees the samples as they come through.
Would I be able to access samples quite early on in the generic AC'97
code (I don't know where that is, either, but it would be interesting
to see, at least :p)
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