[gst-devel] Wavparse - getting to blockalign, format, etc.

[Edward Averill]

Thanks ensonic, I have it "kind of" working now...

In my set_caps() function, I'm doing this:

------------ start code -----------

  GstpalmADPCM *filter;
  GstStructure *ins;

  filter = GST_PALMADPCM (gst_pad_get_parent (pad));

  ins = gst_caps_get_structure(caps, 0);

  if (gst_structure_get_int (ins, "channels", &filter->channels)) {
	printf("channels: %d\n", filter->channels);
  }

  if (gst_structure_get_int (ins, "rate", &filter->rate)) {
	printf("rate: %d\n", filter->rate);
  }

  if (gst_structure_get_int (ins, "format", &filter->format)) {
	printf("format: %d\n", filter->format);
  }
------------------- end code -------------------

I see rate and channels, but no format - even though I see wavparse print 
the information out!  I need the format, among other bits of info.. and from 
poking around in gstwavparse.c it looks like it's there.. somewhere.. but 
I'm not sure the above mechanism is proper (or maybe I just am not using the 
Right Names(tm) for things)..

Any suggestions, recommendations, or examples I can pilfer from?

All info appreciated! :-)

...ed..

>Message: 3
>Date: Thu, 18 Jan 2007 09:03:54 +0100
>From: "ensonic" <ensonic at hora-obscura.de>
>Subject: Re: [gst-devel] Wavparse to rip apart compressed audio?
>	Newbie Q.
>To: " Edward Averill " <edaverill at hotmail.com>
>Cc: gstreamer-devel at lists.sourceforge.net
>Message-ID: <5ea9f03ca39308b15e30f7ab307f807e at hora-obscura.de>
>Content-Type: text/plain; charset=us-ascii
>
>hi,
>
>On 1:02:09 am 18/01/2007 "Edward Averill" <edaverill at hotmail.com> wrote:
> > Ok, I have some RIFF-format files I need to get the fmt info from.
> > The data inside is compressed, but I have an element that will handle
> > that...
> >
> > What I'm wondering is: is there any reason I can't use the data
> > output from the wavparse element to feed my decoder?  And is there an
> > example of how to get the channels/bit depth/etc. information out of
> > the wavparse element, or will I need to write my own wavparse-like
> > library that will give me access to that information? I see that I
> > can use the gstriff library to help with this, if needed.
> >
>wavparse acts as a demuxer. it parses the riff-wav container and emits data
>packets. the meta data of the stream is parts of the caps. additional
>metadata might be send as tags.
>
>what format is it that you need to decode? if you run 'gst-inspect
>wavparse' you see that it already knows about lot of formats (like
>audio/ms-gsm, audio/x-mulaw, audio/x-adpcm, ...). If your format is not
>among this, we need to add a fourcc mapping.
>
>Is the decoder you want to use already a gstreamer element? Once the output
>caps are fine, you should be able to plug it in.
>
>Stefan
>
> > Sorry if this is a newbie type question, my last element was
> > standalone and I'm trying to Use What's There this time rather than
> > Re-Invent The Wheel.
> >
> > ...ed..