[gst-devel] Need help with first gstreamer program.

[Ognen Bezanov]

Hello all, 

I'm trying to write a gstreamer program to transcode a video into
another format (ogg theora with vorbis audio), but I can't get it to
work. When I run it with debug commands I get the following:

0:00:00.556658600  4539  0x981f920 INFO            GST_STATES
gstelement.c:2163:gst_element_continue_state:<Abuffer> posting
state-changed READY to PAUSED
0:00:00.556698920  4539  0x981f920 INFO            GST_STATES
gstbin.c:2194:gst_bin_change_state_func:<videopipeline> child 'Abuffer'
changed state to 3(PAUSED) successfully
0:00:00.556770600  4539  0x981f920 INFO            GST_STATES
gstelement.c:2150:gst_element_continue_state:<demux> completed state
change to PAUSED
0:00:00.556797720  4539  0x981f920 INFO            GST_STATES
gstelement.c:2163:gst_element_continue_state:<demux> posting
state-changed READY to PAUSED
0:00:00.556834680  4539  0x981f920 INFO            GST_STATES
gstbin.c:2194:gst_bin_change_state_func:<videopipeline> child 'demux'
changed state to 3(PAUSED) successfully
0:00:00.556879560  4539  0x981f920 INFO               filesrc
gstfilesrc.c:947:gst_file_src_start:<filesrc> opening file testmovie.mpg
0:00:00.556992080  4539  0x981f920 INFO             GST_EVENT
gstevent.c:563:gst_event_new_new_segment_full: creating newsegment
update 0, rate 1.000000, format bytes, start 0, stop 831340544, position
0
0:00:00.557376160  4539  0x9bf2b70 INFO             GST_EVENT
gstevent.c:557:gst_event_new_new_segment_full: creating newsegment
update 0, rate 1.000000, format GST_FORMAT_TIME, start
0:00:00.001622222, stop 99:99:99.999999999, position 0:00:00.001622222
0:00:00.557623280  4539  0x9bf2b70 INFO      GST_ELEMENT_PADS
gstelement.c:639:gst_element_add_pad:<demux> adding pad 'video_00'
0:00:00.640338920  4539  0x9bf2b70 INFO      GST_ELEMENT_PADS
gstelement.c:885:gst_element_get_static_pad: found pad Vbuffer:sink
0:00:00.640405200  4539  0x9bf2b70 INFO              GST_PADS
gstpad.c:1796:gst_pad_link_prepare: trying to link demux:video_00 and
Vbuffer:sink
0:00:00.640504520  4539  0x9bf2b70 INFO              GST_PADS
gstpad.c:1933:gst_pad_link: linked demux:video_00 and Vbuffer:sink,
successful
0:00:00.640556640  4539  0x9bf2b70 INFO             GST_EVENT
gstevent.c:557:gst_event_new_new_segment_full: creating newsegment
update 0, rate 1.000000, format GST_FORMAT_TIME, start
0:00:00.001622222, stop 99:99:99.999999999, position 0:00:00.001622222
0:00:00.640972360  4539  0x9bef930 INFO              GST_PADS
gstpad.c:3222:gst_pad_event_default_dispatch:<mux:sink_437196908>
Sending event 0x97e28c8 (tag) to all internally linked pads
0:00:00.557662760  4539  0x981f920 INFO            GST_STATES
gstelement.c:2150:gst_element_continue_state:<filesrc> completed state
change to PAUSED
0:00:00.665778000  4539  0x9bf2b70 INFO      GST_ELEMENT_PADS
gstelement.c:639:gst_element_add_pad:<demux> adding pad 'private_1'
0:00:00.665980680  4539  0x9bf2b70 INFO             GST_EVENT
gstevent.c:557:gst_event_new_new_segment_full: creating newsegment
update 0, rate 1.000000, format GST_FORMAT_TIME, start
0:00:00.001622222, stop 99:99:99.999999999, position 0:00:00.001622222
0:00:00.680987680  4539  0x981f920 INFO            GST_STATES
gstelement.c:2163:gst_element_continue_state:<filesrc> posting
state-changed READY to PAUSED
0:00:00.681131000  4539  0x981f920 INFO            GST_STATES
gstbin.c:2194:gst_bin_change_state_func:<videopipeline> child 'filesrc'
changed state to 3(PAUSED) successfully


Everything stays paused. If I tell it to do the video on it's own, it
converts fine, but if I tell it to do the audio by itself, it also
pauses. I'm not quite sure what I'm doing wrong (probably audio
related), so if anyone can point out my mistakes, it would be very
appreciated!


The code:


#!/usr/bin/env python

import sys, os
import pygtk, gtk, gobject
import pygst,time
pygst.require("0.10")
import gst
import gtk 

class Main:
    def __init__(self):
        self.vidline = gst.Pipeline("videopipeline") #This deals with
video processing
        #self.audline = gst.Pipeline("audiopipeline") #This deals with
audio processing
        
        #The below are generic works, mpeg2 -> theora (ogg mux)
conversion
        #With mp3 -> vorbis audio conversion
        
        #Decoding
        self.demuxer = gst.element_factory_make("mpegdemux", "demux")
        self.vdecoder = gst.element_factory_make("mpeg2dec", "mpeg2dec")
#vdecoder = video decoder
        self.adecoder = gst.element_factory_make("mad","mad") #adecoder
= audio decoder
        #Encoding
        self.muxer = gst.element_factory_make("oggmux", "mux")
        self.vencoder = gst.element_factory_make("theoraenc",
"video_enc") #video encoder
        self.aencoder =
gst.element_factory_make("vorbisenc","audio_enc") #audio encoder
        self.aconv =
gst.element_factory_make("audioconvert","audio_convert") #you need this
after decoding and before encoding stage 
        
        #File I/O
        self.filesrc = gst.element_factory_make("filesrc","filesrc") #
file input
        self.filesink = gst.element_factory_make("filesink", "file
sink")# file output
        
        #File details (hardcoded for now)
        self.filesrc.set_property("location", "testmovie.mpg")
        self.filesink.set_property("location","test.ogg")
        
        #buffers
        #input
        self.aqueue = gst.element_factory_make("queue", "Abuffer")
        self.vqueue = gst.element_factory_make("queue", "Vbuffer")
        #output
        self.aqueueout = gst.element_factory_make("queue", "AbufferOut")
        self.vqueueout = gst.element_factory_make("queue", "VbufferOut")
        
        #Build the pipeline(s)!
        self.demuxer.connect("pad-added", self.demuxer_callback)
        self.muxer.connect("pad-added", self.muxer_callback) 
              
        #Video Encoding Pipeline
        self.vidline.add(self.filesrc)
        self.vidline.add(self.demuxer)
        ##Temporarily removed till we get audio working  
        self.vidline.add(self.vqueue)
        self.vidline.add(self.vqueueout)
        self.vidline.add(self.vdecoder)
        self.vidline.add(self.vencoder)
        self.vidline.add(self.muxer)
        self.vidline.add(self.filesink)
        
        
        #Audio Encoding Pipeline
        self.vidline.add(self.aqueue)
        self.vidline.add(self.adecoder)
        self.vidline.add(self.aconv)
        self.vidline.add(self.aencoder)
        self.vidline.add(self.aqueueout)
        #self.vidline.add(self.audiosink)
       
        #Link it all together 
        gst.element_link_many(self.filesrc,self.demuxer)

gst.element_link_many(self.vqueue,self.vdecoder,self.vencoder,self.vqueueout)

gst.element_link_many(self.aqueue,self.adecoder,self.aconv,self.aencoder,self.aqueueout)   
        gst.element_link_many(self.vqueueout, self.muxer)
        gst.element_link_many(self.aqueueout, self.muxer)
        gst.element_link_many(self.muxer,self.filesink)
      
        self.vidline.set_state(gst.STATE_PLAYING)
        
        #bus = self.vidline.get_bus()
        #bus.add_signal_watch()
        #bus.connect("message::eos", self.onEndOfStream)
        #bus.connect("message::state-changed", self.onStateChanged) 
        
        
    def demuxer_callback(self, demuxer, pad):
        if pad.get_property("template").name_template == "video_%02d":
            qv_pad = self.vqueue.get_pad("sink")
            pad.link(qv_pad)
        elif pad.get_property("template").name_template == "audio_%02d":
            qa_pad = self.aqueue.get_pad("sink")
            pad.link(qa_pad)
            
    def muxer_callback(self, muxer, pad):
        if pad.get_property("template").name_template == "video_%02d":
            qv_pad = self.vqueueout.get_pad("src")
            pad.link(qv_pad)
        elif pad.get_property("template").name_template == "audio_%02d":
            qa_pad = self.aqueueout.get_pad("src")
            pad.link(qa_pad)

        
start=Main()
gtk.main()