Harsha priya gupta wrote:
> Hi,
>
> In the case that we dont have to make any specific
changes to sound card
> driver, implementing the DSPCodec class-does the data
path flow through
> ALSA to reach the sound card driver (snd_pcm_* path?)?
If your HW decoder can return the decoded PCM data then it
is really
easy. That data will then flow back into the renderer, from
there
into the audio services, where it is resampled and mixed if
needed,
and then finally down into the audio device code where it is
send to
ALSA/OSS/ESound or whatever.
If your HW decoder decodes the data and sends it directly to
the
speakers then it is harder since that isn't the way Helix
was
designed to work originally. However, it is still possible
following
that document.
--greg.
>
> Thanks a lot for your comments and the pointers. Really
gives me a good
> start.
>
> Thanks again,
> Harsha.
>
> On Tue, Feb 26, 2008 at 11:16 PM, Greg Wright
<gwright real.com
> <mailto:gwrightreal.com>> wrote:
>
> Harsha priya gupta wrote:
> > <<Added subject line>>
> >
> > On Mon, Feb 25, 2008 at 11:29 PM, Harsha
priya gupta
> > <harshapriyagmail.com
<mailto:harshapriyagmail.com>
> <mailto:harshapriyagmail.com
<mailto:harshapriyagmail.com>>> wrote:
> >
> > Hi
> > I am new to Helix and sound stack of
Linux. I have a sound
> card that
> > supports DSP/HW decoding. Can anyone
please give me pointers or
> > example code to include a DSP codec in
Helix client? Any help in
> > related Sound card driver (or ALSA if
required) that needs to be
> > provided for this plugin to work would be
of great help.
>
> You don't have to worry about the sound driver, it
doesn't
> need to change.
>
> We have many people who have wrapped hardware
decoders into Helix.
> This is done by wrapping a decoder-codec in our
system and letting
> a 'renderer' use it. The work required is not
terribly hard but
> it is not trivial either. I would start by reading
this document
> and if it still sounds like something you want to
proceed with
> we can start helping you along:
>
> https://client.helixcommunity.org/2004/devdocs/dsp_in
te.htm
> https://client.helixcommunity.org/files/
2004/devdocs/DSP_integration.pdf
>
> Wrapping of HW decoders are generally useful for:
>
> o Video decoding on any platform
> o audio and video decoding on cpu constrained
devices like phones
> o You have a hardware codec that Helix does not
provide.
> o As a fun hobby project
>
> If you are on a PC class machine and are looking at
just decoding
> audio it may not make much of a difference when
playing back as
> audio takes very little CPU to decode compared to
video.
>
> Anyway, we are always excited to have people code
up new functionality,
> let us know if we can help.
>
> --greg.
>
>
> >
> > Thanks in advance,
> > -Harsha
> >
> >
> >
> >
> > --
> > -Harsha
> >
> >
> >
>
------------------------------------------------------------
------------
> >
> >
_______________________________________________
> > Helix-client-dev mailing list
> > Helix-client-devhelixcommunity.org
> <mailto:Helix-client-devhelixcommunity.org>
> > http://lists.helixcommunity.org/mailman/listinf
o/helix-client-dev
>
>
>
>
> --
> -Harsha
_______________________________________________
Helix-client-dev mailing list
Helix-client-devhelixcommunity.org
http://lists.helixcommunity.org/mailman/listinf
o/helix-client-dev
|
