MATLAB：GUI按钮调用函数.m(MATLAB : GUI pushbutton call function .m)

 level元素最适合这个任务（正如@ensonic已经提到过的）它的目的正是你所需要的...... 
 
 所以基本上你添加到名为“level”的管道元素，然后启用消息触发。 
 
 然后，Level元素发出包含RMS Peak和Decay值的消息。 RMS是您所需要的。 
 
 您可以设置连接到此类消息事件的回调函数： 
 
audio_level = gst_element_factory_make ("level", "audiolevel");
g_object_set(audio_level, "message", TRUE, NULL);
...
g_signal_connect (bus, "message::element", G_CALLBACK (callback_function), this);
 
 总线变量是GstBus类型..我希望你知道如何使用总线 
 
 然后在回调函数中检查元素名称并获得如此处所述的RMS 
 
 还有使用pow（）函数的规范化算法，可以转换为0.0 - > 1.0之间的值，您可以使用它转换为％，如您在问题中所述。 

The level element is best for this task (as @ensonic already mentioned) its intended for exactly what you need..
 
So basically you add to your pipe element called "level", then enable the messages triggering. 
 
Level element then emits messages which contains values of RMS Peak and Decay. RMS is what you need.
 
You can setup callback function connected to such message event:
 
audio_level = gst_element_factory_make ("level", "audiolevel");
g_object_set(audio_level, "message", TRUE, NULL);
...
g_signal_connect (bus, "message::element", G_CALLBACK (callback_function), this);
 
bus variable is of type GstBus.. I hope you know how to work with buses
 
Then in callback function check for the element name and get the RMS like is described here
 
There is also normalization algorithm with pow() function to convert to value between 0.0 -> 1.0 which you can use to convert to % as you stated in your question.