#include <gst/gst.h>
#include <glib.h>
//定义消息处理函数
static gboolean bus_call(GstBus * bus, GstMessage * msg, gpointer data)
{
GMainLoop *loop = (GMainLoop *) data;
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; //定义组件
GstBus *bus;
gst_init(&argc, &argv);
loop = g_main_loop_new(NULL, FALSE); //创建主循环,在执行 g_main_loop_run后正式开始循环
if (argc != 2) {
g_printerr("Usage:%s <mp3 filename>\n", argv[0]);
return -1;
}
//创建管道和组件
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 be created.Exiting.\n");
return -1;
}
//设置source的location参数,即文件地址
g_object_set(G_OBJECT(source), "location", argv[1], NULL);
//得到管道的消息总线
bus = gst_pipeline_get_bus(GST_PIPELINE(pipeline));
//添加消息监视器
gst_bus_add_watch(bus, bus_call, loop); //等同于callback处理函数
gst_object_unref(bus);
//把组件添加到管道中.管道是一个特殊的组件,可以更好的让数据流动
gst_bin_add_many(GST_BIN(pipeline), source, decoder, sink, NULL);
//依次连接组件
gst_element_link_many(source, decoder, sink, NULL);
//开始播放
gst_element_set_state(pipeline, GST_STATE_PLAYING);
g_print("Running\n");
//开始循环
g_main_loop_run(loop);
g_print("Returned,stopping playback\n");
gst_element_set_state(pipeline, GST_STATE_NULL);
gst_object_unref(GST_OBJECT(pipeline));
return 0;
}
$ gcc -Wall $(pkg-config --cflags --libs gstreamer-0.10) test.c -o test `pkg-config --libs glib-2.0` `pkg-config --libs gstreamer-0.10`
$ ./test test.mp3