[gst-devel] getting an accurate frame number from pipeline

[mapping at sheerman-chase.org.uk]

Hi,

Thanks again people for help with gdkpixbufsink. I am now trying to  
get an accurate video frame number from a pipeline. I can change the  
format I am requesting but only GST_FORMAT_TIME and GST_FORMAT_PERCENT  
work as expected. When I ask for GST_FORMAT_BUFFERS, the query returns  
with the same result as GST_FORMAT_PERCENT.

int video_get_pos(GstFormat fmt, const char *text)
{
	GstQuery *query;
	 gboolean res;
	 query = gst_query_new_position (fmt);
	 res = gst_element_query (pipeline, query);
	 if (res) {
	   gint64 pos;
	   gst_query_parse_position (query, &fmt, &pos);
	   printf ("position %s \t= %lld\n", text, (pos));
	 }
	 else {
	   printf ("position query failed...\n");
	 }
	 gst_query_unref (query);
	return 0;
}

And I am querying with different formats like this:

	video_get_pos(GST_FORMAT_DEFAULT,"default");
	video_get_pos(GST_FORMAT_TIME,"time   ");
	video_get_pos(GST_FORMAT_BUFFERS,"buffers");
	video_get_pos(GST_FORMAT_PERCENT,"percent");

I get a result along these lines:

position default 	= 11040000000
position time    	= 10882214000
position buffers 	= 11040000000
position percent 	= 11040000000

Is this a good approach to get an accurate frame number? Or do I have  
to work around and get the time in nanoseconds and multiply it by the  
frame rate?

I also have problems seeking using frame numbers. Is gstreamer trying  
to tell me something?

full code:  
http://www.sheerman-chase.org.uk/temp/gst-player-pixel2009-01-12d.tar.gz

Thanks,

Tim