[gst-devel] source plugin blocked in PAUSE state

[Riccardo Corona]

Hi,
thank's for the tips. When I told that I've started from GstPluginTemplate I
mean something like this:

GST_BOILERPLATE (GstPluginTemplate, gst_plugin_template, GstBaseSrc,
    GST_TYPE_ELEMENT);

Is it what did you mean?


2007/6/28, René Stadler <mail at renestadler.de>:
>
> Am Donnerstag, den 28.06.2007, 13:09 +0200 schrieb Riccardo Corona:
> > Hi,
> > I'm writing a source plugin, I'm started from GstPluginTemplate to
> > make a simple plugin that generate only B&W frames...
> > The problem is that with this pipeline:
> >
> I strongly suggest deriving from GstBaseSrc instead.
>
>
> > mysrc ! ffmpegcolorspace ! directdrawsink
> >
> > the pipeline is blocked on PREROLLING and in debug mode I can see that
> > the last state of my plugin is PAUSED.
> > Here the snipped of code in which I set the buffer:
> >
> >
> >
> > /* get_range function
> >  * makes it a source of a stream
> >  */
> > static gboolean gst_plugin_template_get_range (GstPad *pad, guint64
> > offset, guint lenght, GstBuffer **buf)
> > {
> >     static  gboolean white=1;
> >
> >     GstPluginTemplate *plug= GST_PLUGIN_TEMPLATE (GST_OBJECT_PARENT
> > (pad) );
> >
> >      GstBuffer *buffer;
> >       gint size, width, height, bpp;
> >       width = 320; height = 240; bpp = 16;
> >       size = width * height * bpp;
> >       buffer = gst_buffer_new();
> >       GST_BUFFER_SIZE (buffer) = size;
> >
> >     if (white)GST_BUFFER_MALLOCDATA (buffer) =  g_memdup (0xff,size);
> >         else GST_BUFFER_MALLOCDATA (buffer) =  g_memdup (0x0,size);
> >
> >     white=!white;
> >
> >       GST_BUFFER_DATA (buffer) = GST_BUFFER_MALLOCDATA (buffer);
> >
> >
> >     ts = gst_util_uint64_scale_int (frame_num * GST_SECOND, FPS_DEN,
> > FPS_NUM);
> >     next_ts = gst_util_uint64_scale_int ((frame_num + 1) * GST_SECOND,
> > FPS_DEN,  FPS_NUM);
> >
> >     GST_BUFFER_TIMESTAMP (buffer) = ts;
> >     GST_BUFFER_DURATION (buffer) = next_ts-ts;
> >
> >     frame_num++;
> >
> >
> >     return gst_pad_push (plug->srcpad, buffer);
> >
> > }
> >
> This is completely wrong.  In a get_range function, you are supposed to
> return the buffer to the supplied location!  Take a look at
> gstreamer/docs/design/part-scheduling.txt [1] and other docs in that
> directory to get some insight.
>
> [1]:
>
> http://webcvs.freedesktop.org/gstreamer/gstreamer/docs/design/part-scheduling.txt?view=markup
> >
> > I thought that setting the timestamp is enough to have continuosly a
> > stream of images but it seems that I'm wrong.
> > Do I must force the state of the plugin in PLAY mode?
> > Or maybe I'm wrong with the buffer management?
> >
> > Any help will be very appreciate becouse I'm new to plugin writing...
> >
> >
> > Best Regards.
> >
> >
> >
> > --
> > Riccardo Corona
>
> --
> Regards,
>   René Stadler
>
>


-- 
Riccardo Corona
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