Re: Audio-out test implementation

[Josef S. <jos...@ge...>]

Hi Markus,


> ...
> [init -> test-audio_out] C++ runtime: Genode::Parent::Service_denied
> ...
>
> To me it looks as if the build/bin/config file was misconfigured. It
> looks like
>
> <config>
>       <parent-provides>
>               <service name="CAP"/>
>               <service name="LOG"/>
>               <service name="RM"/>
>               <service name="SIGNAL"/>
>       </parent-provides>
>       <default-route>
>               <any-service><parent/><any-child/></any-service>
>       </default-route>
>       <start name="audio_out_drv">name>               <resource
name="RAM" quantum="8M"/>
>               <provides><service name="Audio_out"/></provides>
>       </start>
>
>       <start name="test-audio_out">test>              <resource
name="RAM" quantum="1M"/>
>               <config>
>                       <filename>audio1.raw</filename>
>                       <filename>audio2.raw</filename>
>               </config>
>       </start>start>   </config>
>
> Do you have any idea for what I need to correct ?

I'm afraid you are missing a few essential services (which ones exactly
depends on the platform you are running Genode on).

> Moreover, there is another issue. The audio files needed to run the
> audio-out test are missing and the README file provided simply states
> 'The raw data must comply the Audio_out standard format.'

> Where can I get information regarding the aforementioned Audio_out
> standard format and are there any tools for converting audio files
> such as WAVs into Genode?s raw format ?

The currently used raw format is simply stereo float32 with a sample
rate of 44.1kHz. Amongst others, this information can be obtained by
looking at the 'os/include/audio_out_session/audio_out_session.h'
header file.

As mentioned in 'dde_oss/README' you can create a usable raw audio file
from a given audio file by yourself by execuing 'sox(1)':

  'sox -c 2 -r 44100 foo.mp3 foo.f32'

I have attached a working runscript that can be used to play such a file
on Linux as well as on e.g. NOVA by using dde_oss. (Note, that Using
Qemu's ICH driver results in some what disorted sound which is a known
issue.)

Cheers
Josef