1,设置环境变量

export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig:$PKG_CONFIG_PATH
export LD_LIBRARY_PATH=/usr/local/lib

2,安装mad插件

下载libmad-0.15.1b.tar.gz
http://sourceforge.net/project/showfiles.php?group_id=12349

./configure --prefix=/usr/local/

make

make install

下载libid3tag-0.15.1b.tar.gz
http://sourceforge.net/project/showfiles.php?group_id=12349

./configure --prefix=/usr/local/

make

make install

下载gst-plugins-ugly-0.10.9.tar.bz2   2008.8.26
http://gstreamer.freedesktop.org/src/

./configure

make

make install

这样，在/usr/local/lib/gstreamer-0.10目录下就出现了

libgstmad.a libgstmad.la libgstmad.so

mad插件也就安装成功了!

检测mad插件是否安装上的命令

gst-inspect mad

会显示已安装的mad插件的详细信息

3,用gst-launch测试播放mp3

gst-launch filesrc location="beyond.mp3" ! mad ! audioconvert ! alsasink

可以听到音乐了。

4,用mp3_dec.c文件测试

----------------
#include <gst/gst.h>

int
main(int argc,char *argv[])
{
GstElement *pipeline,*filesrc,*decoder,*convert,*audiosink;

gst_init(&argc,&argv);

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

pipeline=gst_pipeline_new("pipeline");

if(!pipeline)
{
   g_print("Maybe pipeline cann't be created!\n");
   exit(-1);
}

filesrc=gst_element_factory_make("filesrc","disk_source");

if(!filesrc)
{
   g_print("Maybe filesrc cann't be created!\n");
   exit(-1);
}
g_object_set(G_OBJECT(filesrc),"location",argv[1],NULL);

decoder=gst_element_factory_make("mad","decoder-audio");
if(!decoder)
{
   g_print("Maybe decoder cann't be created!\n");
   exit(-1);
}

convert = gst_element_factory_make("audioconvert", "a-convert");
if(! convert)
{
   g_print("Maybe convert cann't be created!\n");
   exit(-1);
}

audiosink=gst_element_factory_make("osssink","play_audio");
if(! audiosink)
{
   g_print("Maybe audiosink cann't be created!\n");
   exit(-1);
}

gst_bin_add_many(GST_BIN(pipeline),filesrc,decoder,convert,audiosink,NULL);

gst_element_link_many(filesrc,decoder,convert,audiosink,NULL);

gst_element_set_state(pipeline,GST_STATE_PLAYING);

while(gst_bin_iterate_recurse(GST_BIN(pipeline)));

gst_element_set_state(pipeline,GST_STATE_NULL);

gst_object_unref(GST_OBJECT(pipeline));

exit(0);
}
----------------

编译命令

gcc -Wall $(pkg-config --cflags --libs gstreamer-0.10)mp3_dec.c -o mp3_dec

生成可执行文件

mp3_dec

播放mp3

./mp3_dec beyond.mp3

就可以听到音乐了!

note: