Re: GStreamer access to raw audio data

[Torsten Schoenfeld <kaffeetisch gmx de>]

On 19.01.2012 14:01, Zach Morgan wrote:
> I took your advice and cannibalized GStreamer::Interfaces to create
> bindings for Appsink and Appsrc. I'm not clear on how you would make
> it nice and perlish, so any criticism is welcome. Also, I've never
> used xs or created bindings before. I didn't touch the set_callbacks
> methods, and the GstAppStreamType enum, which isn't even tested,
> probably could have been handled better.

First of all: fantastic work!  That was really quick.  Comments:

• For an example of how to handle callbacks, look into GstBus.xs.

• Your gst_app_sink_pull_buffer_list wrapper lacks sv_2mortal() wrapped 
around newSVGstBuffer(), but otherwise it looks fine.

• For gst_app_src_get_latency, you could use xsubpp's OUTLIST, like so:

  void gst_app_src_get_latency (GstAppSrc *appsrc,
                                OUTLIST guint64 min,
                                OUTLIST guint64 max);

But note that there are some unresolved issues on win32 that seem to 
involve OUTLIST.¹  So if you want to be on the safe side, you have to do 
it manually, as is done for gst_clock_add_observation, for example.

¹ Search for "Gtk2::TreeView get_path_at_pos doesn't return array on 
Windows".

• Your handling of GstAppStreamType looks good.  Its mention in the 
"maps" file will trigger all the magic.

> And a question: Will GStreamer buffers leak every bit of data that
> they're set with? I don't see what this comment is referring to.
> http://git.gnome.org/browse/perl-GStreamer/tree/xs/GstBuffer.xs#n100

Indeed, they do leak everything.  I never used GStreamer::Buffer, so I 
never noticed.  This commit should fix it: 
<http://git.gnome.org/browse/perl-GStreamer/commit/?id=d26bd4e433133df222b75c7ebf5b50882a15d87e>. 
 Please test.

> My GStreamer::App repo is at https://github.com/zpmorgan/GStreamer-App

Next stop: CPAN!