[gst-devel] Autoplugging Problem

[张 帆]

Hi, all
I met a problem when I try to use autoplugging in GStreamer.
My program is based on the example in Chapter 17 of Gstreamer Application 
guide with minor modification. I tried to play a mp3, so the 'typefinder'
in the pipeline will call the typefindfunctions in the system to determine
the media type. There are 3 typefindfunctions in my system regarding to mp3
typefindfunctions: audio/mpeg: mp3, mp2, mp1, mpga
typefindfunctions: application/x-id3v1: mp3, mp2, mp1, ....
typefindfunctions: application/x-id3v2: mp3, mp2, mp1, .....
It seems audio/mpeg has the first rank and it report to typefinder element
that the stream is audio/mpeg with probability of 100%. So the typefinder
will not call the latter two functions anymore and issued a HAVE-TYPE 
signal
with type audio/mpeg.
The problem is I found the caps of source pad on ffdemux_mp3(and other mp3 
parser)
are all application/id3, so after checking all the element factories, the 
program
report there is no element in the system can be plugged with audio/mpeg, 
the autoplugging
process fails. 
So what should I do? Can I let the typefinder to looking for other possible 
media type
instead of just finding the first one and return?

Thanks!

Fan