[置顶] 基于Gstreamer和Gtk的一个简单的MP3播放器

安装Gstreamer插件，配置好环境，代码如下：

/*myplayer.c*/ #include <gtk/gtk.h> #include <gst/gst.h> #include <signal.h> #include <string.h> GstElement *pipeline, *source,*decoder,*sink; GMainLoop *loop = NULL; //暂停恢复开关按钮回调 void toggle_button_callback(GtkWidget *widget,gpointer data) { if(gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(widget))) { gst_element_set_state(pipeline,GST_STATE_PAUSED); GstStateChangeReturn statechange; statechange = gst_element_set_state(pipeline, GST_STATE_PAUSED); g_print("Pause\n"); } else { g_print("pause was pressed\n"); gst_element_set_state(pipeline,GST_STATE_PLAYING); g_print("恢复播放\n"); } } //play回调 void callback_play(GtkWidget *widget,gpointer data) { if(!GST_IS_ELEMENT(pipeline)) { pipeline = gst_pipeline_new ("gst-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"); } g_print("play was pressed\n"); gst_element_set_state(pipeline,GST_STATE_PLAYING); g_print("Running\n"); g_main_loop_run(loop); } //stop回调 void callback_stop(GtkWidget *widget,gpointer data) { GtkWidget *tgbt=data; g_print("stop was pressed\n"); gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(tgbt), FALSE); gst_element_set_state(pipeline,GST_STATE_NULL); g_main_loop_quit(loop); //退出循环 // gst_object_unref(GST_OBJECT(pipeline));//不用销毁管道 g_print("Deleting pipeline\n"); g_print("stop\n"); } //关闭回调 void delete_event(GtkWidget *widget,GdkEvent *event,gpointer data) { if(GST_IS_ELEMENT(pipeline)) { g_main_loop_quit(loop); gst_element_set_state(pipeline,GST_STATE_NULL); } gtk_main_quit(); g_print("quit was pressed\n"); g_print("quit\n"); } //菜单基本回调 static void print_hello(GtkWidget *w,gpointer data) { g_message("Hello\n"); } GtkWidget *FileSelection; GtkWidget *ok_button; char str[100]; //文件选择窗口回调 //Open void OpenFile(GtkWidget *FileSelection,gpointer data) { //先关闭文件 gst_element_set_state(pipeline,GST_STATE_NULL); g_main_loop_quit(loop); GtkWidget *widget =(GtkWidget*)data; g_print("%s\n",gtk_file_selection_get_filename(GTK_FILE_SELECTION(widget))); strcpy(str,gtk_file_selection_get_filename(GTK_FILE_SELECTION(widget))); gtk_widget_destroy(widget); g_object_set (G_OBJECT (source),"location",(char*)str,NULL); g_print("fileselection was pressed\n"); } //Cancel void callback_fileselection_cancel(GtkWidget *FileSelection,gpointer data) { GtkWidget * widget = (GtkWidget*)data; gtk_widget_destroy(widget); g_print("fileselection cancel was pressed\n"); g_print("fileselection quit\n"); } //文件选择构件 void button_event(GtkWidget *widget,gpointer *data) { FileSelection=gtk_file_selection_new("select file"); gtk_file_selection_set_filename(GTK_FILE_SELECTION(FileSelection),"*.mp3"); g_signal_connect(G_OBJECT(((GtkFileSelection*)FileSelection)->ok_button),"clicked",G_CALLBACK(OpenFile),FileSelection); g_signal_connect(G_OBJECT(((GtkFileSelection*)FileSelection)->cancel_button),"clicked",G_CALLBACK(callback_fileselection_cancel),FileSelection); gtk_widget_show(FileSelection); } //MENU static GtkItemFactoryEntry menu_items[]={ { "/_File", NULL, NULL,0,"<Branch>"}, { "/File/_Open", "<control>O", button_event,0,NULL}, { "/File/_Quit", "<control>Q", delete_event,0,NULL}, { "/_Help", NULL, NULL,0,"<Branch>"}, { "/_Help/About", NULL, NULL,0,NULL}, }; void get_main_menu(GtkWidget *window,GtkWidget **menubar) { GtkItemFactory *item_factory; GtkAccelGroup *accel_group; gint nmenu_items=sizeof(menu_items)/sizeof(menu_items[0]); accel_group=gtk_accel_group_new(); item_factory=gtk_item_factory_new(GTK_TYPE_MENU_BAR,"<main>",accel_group); gtk_item_factory_create_items(item_factory,nmenu_items,menu_items,NULL); gtk_window_add_accel_group(GTK_WINDOW(window),accel_group); if(menubar) *menubar=gtk_item_factory_get_widget(item_factory,"<main>"); } static gboolean bus_call(GstBus *bus,GstMessage *msg,gpointer data) { GMainLoop *loop=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 *err; gst_message_parse_error(msg,&err,&debug); g_free(debug); g_print("Error: %s\n",err->message); g_error_free(err); g_main_loop_quit(loop); break; } default: break; } return TRUE; } static void new_pad(GstElement *element,GstPad *pad,gpointer data) { GstPad *sinkpad; g_print ("Dynamic pad created,linking parser/decoder\n"); sinkpad=gst_element_get_pad(decoder,"sink"); gst_pad_link(pad,sinkpad); gst_object_unref(sinkpad); } int main(int argc,char *argv[]) { GtkWidget *window; GtkWidget *button; GtkWidget *table; GtkWidget *toggle_button; gtk_init(&argc,&argv); window=gtk_window_new(GTK_WINDOW_TOPLEVEL); gtk_window_set_title(GTK_WINDOW(window),"MP3 Player"); gtk_widget_set_size_request(GTK_WIDGET(window),300,60); g_signal_connect(G_OBJECT(window),"delete_event",G_CALLBACK(delete_event),NULL); //menu创建 GtkWidget *main_vbox; GtkWidget *menubar; main_vbox=gtk_vbox_new(FALSE,1); gtk_container_add(GTK_CONTAINER(window),main_vbox); get_main_menu(window,&menubar); gtk_box_pack_start(GTK_BOX(main_vbox),menubar,FALSE,TRUE,0); gtk_widget_show(menubar); gtk_widget_show(main_vbox); table = gtk_hbox_new(0, 3); gtk_box_pack_start_defaults(GTK_BOX(main_vbox), table); gtk_widget_set_size_request(GTK_WIDGET(table),300,30); button=gtk_button_new_with_label("播放"); g_signal_connect(G_OBJECT(button),"clicked",G_CALLBACK(callback_play),(gpointer)"播放"); gtk_box_pack_start_defaults(GTK_BOX(table), button); gtk_widget_show(button); toggle_button=gtk_toggle_button_new_with_label("暂停/恢复"); g_signal_connect(G_OBJECT(toggle_button),"clicked",G_CALLBACK(toggle_button_callback),(gpointer)"暂停/恢复"); gtk_box_pack_start_defaults(GTK_BOX(table), toggle_button); gtk_widget_show(toggle_button); button=gtk_button_new_with_label("停止"); g_signal_connect(G_OBJECT(button),"clicked",G_CALLBACK(callback_stop),(gpointer)toggle_button); gtk_box_pack_start_defaults(GTK_BOX(table), button); gtk_widget_show(button); gtk_widget_show(table); gtk_widget_show(window); //gst部分 GstBus *bus; //初始化 gst_init (&argc,&argv); loop=g_main_loop_new(NULL,FALSE); /* //检查输入 if(argc!=2) { g_print("Usage: %s<Mp3/Vorbis filename>\n",argv[0]); return -1; } */ //创建元件 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"); //gst_element_factory_make("alsasink","alsa-output"); //异常处理 if(!pipeline||!source||!decoder||!sink) { g_print("One element could not be created\n"); return -1; } //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); 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 g_print("Running\n"); g_signal_connect(decoder,"pad_added",G_CALLBACK(new_pad),NULL); gtk_main(); return 0; }
终端里编译：

gcc -o myplayer myplayer.c `pkg-config --cflags --libs gtk+-2.0` `pkg-config --cflags --libs gstreamer-0.10`
运行：

./myplayer
运行结果如图：