Re: ad1848 question

[Iain Hibbert <plunky%rya-online.net@localhost>]

On Fri, 18 Apr 2008, Cherry G. Mathew wrote:

> I'm trying to understand the audio driver subsystem. Briefly skimming
> dev/ic/ad1848.c if find:
>
> ad1848_query_encoding()
> ....
>
>     829       case 5:
>     830               strcpy(fp->name, AudioEslinear);
>     831               fp->encoding = AUDIO_ENCODING_SLINEAR;
>     832               fp->precision = 8;
>     833               fp->flags = AUDIO_ENCODINGFLAG_EMULATED;
>     834               break;
>
>
> But ad1848_set_params() doesn't seem to check for
> AUDIO_ENCODING_SLINEAR to pass down to a filter hook.

I'm not sure what this means

but, I suppose you read audio(4) and audio(9) ?

> Am I missing something, or is that a bug ? If the encoding is marked
> as EMULATED, does userspace respond in a fashion that obviates the
> need to support the encoding emulation or something like that ?

I think it relates to mmap'ed files. if its marked EMULATED then it won't
work properly there, see AUDIO_GETENC in audio(4)

iain