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基於Gstreamer和Gtk的一個簡單的MP3播放器

安裝Gstreamer插件，配置好環境

相關閱讀：一個基於Gstreamer的Linux下的簡單媒體播放器 http://www.linuxidc.com/Linux/2012-02/54980.htm

代碼如下：

[cpp]

/*myplayer.c*/
#include <gtk/gtk.h>
#include <gst/gst.h>
#include <signal.h>
#include <string.h>
GstElement *pipeline, *source,*decoder,*sink;
GMainLoop *loop = NULL;
//暫停恢復開關按鈕回調
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("恢復播放\n");
}
}
//play回調
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回調
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); //退出循環
// gst_object_unref(GST_OBJECT(pipeline));//不用銷毀管道
g_print("Deleting pipeline\n");
g_print("stop\n");
}
//關閉回調
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");
}
//菜單基本回調
static void print_hello(GtkWidget *w,gpointer data)
{
g_message("Hello\n");
}
GtkWidget *FileSelection;
GtkWidget *ok_button;
char str[100];
//文件選擇窗口回調
//Open
void OpenFile(GtkWidget *FileSelection,gpointer data)
{
//先關閉文件
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");
}
//文件選擇構件
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創建
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("暫停/恢復");
g_signal_connect(G_OBJECT(toggle_button),"clicked",G_CALLBACK(toggle_button_callback),(gpointer)"暫停/恢復");
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);
/*
//檢查輸入
if(argc!=2)
{
g_print("Usage: %s<Mp3/Vorbis filename>\n",argv[0]);
return -1;
}
*/
//創建元件
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");
//異常處理
if(!pipeline||!source||!decoder||!sink)
{
g_print("One element could not be created\n");
return -1;
}
//得到管道的消息總線
bus = gst_pipeline_get_bus(GST_PIPELINE(pipeline));
//添加消息監視器 www.linuxidc.com
gst_bus_add_watch(bus,bus_call,loop);
gst_object_unref(bus);
//把組件添加到管道中.管道是一個特殊的組件，可以更好的讓數據流動
gst_bin_add_many(GST_BIN(pipeline),source,decoder,sink,NULL);
//依次連接組件
gst_element_link_many(source,decoder,sink,NULL);
//開始播放
g_print("Running\n");
g_signal_connect(decoder,"pad_added",G_CALLBACK(new_pad),NULL);
gtk_main();
return 0;
}