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simple question about gst api

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박민석

simple question about gst api

hi.

I have some problem about constructing pipeline.

When I run gst-launch, I use it like this,(simple video/audio playback)

gst-launch-0.10.exe filesrc location="test.mp4" ! qtdemux name=demux

demux.video_00 ! { queue ! omx_mpeg4dec ! ffmpegcolorspace ! directdrawsink }

demux.audio_00 ! { queue ! faad ! directsoundsink }

I want to construct upper command with GST API!!

but how??? Below is my test code. but it doesn't work!

I'll appreciate it if you give any comment.

==========================================================================

bin = GST_BIN (gst_element_factory_make ("pipeline", NULL));

filesrc = gst_element_factory_make ("filesrc", "myapp_source");
qtdemux = gst_element_factory_make ("qtdemux", "myapp_demux");

queue_v = gst_element_factory_make ("queue", "myapp_queue_video");
mp4_dec = gst_element_factory_make ("omx_mpeg4dec", "myapp_dec");
ccv = gst_element_factory_make ("ffmpegcolorspace", "myapp_colorspace");
video_sink= gst_element_factory_make ("directdrawsink", "myapp_directdrawsink");

queue_a = gst_element_factory_make ("queue", "myapp_queue_audio");
aac_dec = gst_element_factory_make ("faad", "myapp_faad");
video_sink= gst_element_factory_make ("directsoundsink", "myapp_audiosink");

g_object_set (G_OBJECT (filesrc), "location", "iron.mp4", NULL);//filesrc location="test.mp4"
g_object_set (G_OBJECT (filesrc), "name", "demux", NULL);//qtdemux name=demux, right??

gst_bin_add_many (GST_BIN (bin), filesrc, qtdemux,
                          queue_v, mp4_dec, ccv, video_sink, //video
                          queue_a, aac_dec, audio_sink, //audio
                          NULL);//right??

gst_element_link(filesrc, qtdemux);

gst_element_link(qtdemux, queue_v);

gst_element_link_many(queue_v, mp4_dec, ccv, video_sink, NULL);//right??

gst_element_link(qtdemux, queue_a);

gst_element_link_many(queue_a, aac_dec, audio_sink, NULL);//right??

Min-Seok Park
===============================
Korea Electronics Technology Institute
Multi-Media IP
Tel.031-789-7385
Fax.031-789-7379
===============================

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Tim-Philipp Müller-2

Re: simple question about gst api

On Wed, 2009-10-14 at 18:09 +0900, 박민석 wrote:

> gst-launch-0.10.exe filesrc location="test.mp4" ! qtdemux name=demux
>
> demux.video_00 ! { queue ! omx_mpeg4dec ! ffmpegcolorspace !
> directdrawsink }
>
> demux.audio_00 ! { queue ! faad ! directsoundsink }

The { } are GStreamer 0.8 syntax, you should not use them with GStreamer
0.10. They are not needed any longer.

>
> I want to construct upper command with GST API!!
> but how??? Below is my test code. but it doesn't work!
>
> I'll appreciate it if you give any comment.

Please go easy on the ??!?!?!.

The easiest way would be to just use

pipeline = gst_parse_launch ("filesrc ....", ...);

> gst_element_link(qtdemux, queue_v);
>
> gst_element_link_many(queue_v, mp4_dec, ccv, video_sink,
> NULL);//right??
>
>
> gst_element_link(qtdemux, queue_a);
>
> gst_element_link_many(queue_a, aac_dec, audio_sink, NULL);//right??

Many of these functions have return values to indicate success or
failure. You should check the return values.

In this case, it is probably the qtdemux -> queues links that fail.
qtdemux has so-called 'dynamic pads' as source pads, which will only be
created once data flow starts. You will have to g_signal_connect() to
the 'pad-added' signal of qtdemux and then link these things in the
callback.

Cheers
-Tim

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sledge hammer

Re: simple question about gst api

In reply to this post by 박민석

You need to connect to the "pad-added" signal of the demuxer(qtdemux). The source pads of qtmux aren't available from the begining. Take a look at this section of the Gstreamer tutorial -->http://gstreamer.freedesktop.org/data/doc/gstreamer/head/manual/html/section-dynamic.html

Date: Wed, 14 Oct 2009 18:09:49 +0900
From: [hidden email]
To: [hidden email].
Subject: [gst-devel] simple question about gst api

hi.
I have some problem about constructing pipeline.

When I run gst-launch, I use it like this,(simple video/audio playback)

gst-launch-0.10.exe filesrc location="test.mp4" ! qtdemux name=demux
demux.video_00 ! { queue ! omx_mpeg4dec ! ffmpegcolorspace ! directdrawsink }
demux.audio_00 ! { queue ! faad ! directsoundsink }

I want to construct upper command with GST API!!
but how??? Below is my test code. but it doesn't work!
I'll appreciate it if you give any comment.
==========================================================================
bin = GST_BIN (gst_element_factory_make ("pipeline", NULL));
filesrc = gst_element_factory_make ("filesrc", "myapp_source");
qtdemux = gst_element_factory_make ("qtdemux", "myapp_demux");

queue_v = gst_element_factory_make ("queue", "myapp_queue_video");
mp4_dec = gst_element_factory_make ("omx_mpeg4dec", "myapp_dec");
ccv    = gst_element_factory_make ("ffmpegcolorspace", "myapp_colorspace");
video_sink= gst_element_factory_make ("directdrawsink", "myapp_directdrawsink");

queue_a = gst_element_factory_make ("queue", "myapp_queue_audio");
aac_dec = gst_element_factory_make ("faad", "myapp_faad");
video_sink= gst_element_factory_make ("directsoundsink", "myapp_audiosink");

g_object_set (G_OBJECT (filesrc), "location", "iron.mp4", NULL);//filesrc location="test.mp4"
g_object_set (G_OBJECT (filesrc), "name", "demux", NULL);//qtdemux name=demux, right??

gst_bin_add_many (GST_BIN (bin), filesrc, qtdemux,
                          queue_v, mp4_dec, ccv, video_sink, //video
                          queue_a, aac_dec, audio_sink, //audio
                          NULL);//right??
gst_element_link(filesrc, qtdemux);

gst_element_link(qtdemux, queue_v);
gst_element_link_many(queue_v, mp4_dec, ccv, video_sink, NULL);//right??

gst_element_link(qtdemux, queue_a);
gst_element_link_many(queue_a, aac_dec, audio_sink, NULL);//right??

Min-Seok Park

===============================

Korea Electronics Technology Institute

Multi-Media IP

Tel.031-789-7385

Fax.031-789-7379

===============================

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developing skills, take BlackBerry mobile applications to market and stay
ahead of the curve. Join us from November 9 - 12, 2009. Register now!
http://p.sf.net/sfu/devconference
_______________________________________________
gstreamer-devel mailing list
[hidden email]
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