Use GStreamer to develop a simple MP3 player under Ubuntu

First, GStreamer installation
$ sudo apt-get install Libgstreamer0.10-dev gstreamer-tools gstreamer0.10-tools Gstreamer0.10-doc
$ sudo apt-get install gstreamer0.10-plugins-base gstreamer0.10-plugins-good gstreamer0.10-plugins-ugly Gstreamer0.10-plugins-bad Gstreamer0.10-plugins-bad-multiverse

You can also install the following GST plugins:
Gstreamer0.10-tools
Gstreamer0.10-x
Gstreamer0.10-plugins-base
Gstreamer0.10-plugins-good
gstreamer0.10-plugins-ugly
Gstreamer0.10-plugins-bad
Gstreamer0.10-ffmpeg
Gstreamer0.10-alsa
Gstreamer0.10-schroedinger
Gstreamer0.10-pulseaudio

There may be software that needs to be installed:
sudo apt-get install Bison
sudo apt-get install Flex
sudo apt-get install zlib1g
Mad Decode Plugin
Apt-get Install Libmad0-dev
Apt-get Install gstreamer0.10-plugins-ugly

Second, GStreamer test code
#include <stdio.h>
#include <gst/gst.h>

int main (int argc, char *argv[])
{
Const Gchar *NANO_STR;
Guint major, minor, Micro, nano;

Gst_init (&AMP;ARGC, &AMP;ARGV);

Gst_version (&major, &minor,µ, &nano);

if (nano = = 1)
Nano_str = "(CVS)";
else if (nano = = 2)
Nano_str = "(prerelease)";
Else
Nano_str = "";

printf ("This program is linked against GStreamer%d.%d.%d%s\n",
Major, minor, Micro, NANO_STR);

return 0;
}


Compile run
# Gcc-wall $ (pkg-config--cflags--libs gstreamer-0.10) hello.c-o Hello
./hello
Operation Result:


This program is linked against GStreamer 0.10.22


Third, command line MP3 player test
#include <gst/gst.h>
#include <glib.h>
Define the message handler function,
Static Gboolean Bus_call (Gstbus *bus,gstmessage *msg,gpointer data)
{
Gmainloop *loop = (Gmainloop *) data;//This is a pointer to the main loop that exits the loop when the EOS message is accepted
Switch (Gst_message_type (msg))
{
Case Gst_message_eos:
G_print ("End of stream\n");
G_main_loop_quit (loop);
Break
Case GST_MESSAGE_ERROR:
{
Gchar *debug;
Gerror *error;
Gst_message_parse_error (Msg,&error,&debug);
G_free (Debug);
G_printerr ("error:%s\n", error->message);
G_error_free (Error);
G_main_loop_quit (loop);

Break
}
Default
Break
}
return TRUE;
}

int main (int argc,char *argv[])
{
Gmainloop *loop;
Gstelement *pipeline,*source,*decoder,*sink;//Defining components
Gstbus *bus;

Gst_init (&AMP;ARGC,&AMP;ARGV);
loop = G_main_loop_new (null,false);//create main loop, formally start loop after executing G_main_loop_run

if (argc! = 2)
{
G_printerr ("usage:%s <mp3 filename>\n", argv[0]);
return-1;
}

Creating Pipelines and Components
Pipeline = gst_pipeline_new ("Audio-player");
Source = Gst_element_factory_make ("Filesrc", "File-source");
Decoder = Gst_element_factory_make ("Mad", "Mad-decoder");
Sink = Gst_element_factory_make ("Autoaudiosink", "audio-output");

if (!pipeline| |! source| |! decoder| |! Sink) {
G_printerr ("one element could not being created. Exiting.\n ");
return-1;
}


Sets the location parameter of the source. That is, the file address.
G_object_set (G_object (source), "location", argv[1],null);


Get the message bus for the pipeline
Bus = Gst_pipeline_get_bus (Gst_pipeline (pipeline));

Add Message Monitor
Gst_bus_add_watch (Bus,bus_call,loop);
Gst_object_unref (bus);


Add components to the pipeline. A pipeline is a special component that allows for better flow of data
Gst_bin_add_many (Gst_bin (pipeline), source,decoder,sink,null);


Connecting components in turn
Gst_element_link_many (Source,decoder,sink,null);