格式转换提供者提供格式转换服务

*从一个或多个输入格式的一个或多个输出格式。

*转换器，包括编解码器，它编码和/或解码的音频数据，

*以及转码器等格式转换器提供的方法

*确定支持什么样的转换，并获得的音频

流从转换后的数据可以被读取.-A format conversion provider provides format conversion services

* from one or more input formats to one or more output formats.

* Converters include codecs, which encode and/or decode audio data,

* as well as transcoders, etc.　Format converters provide methods for

* determining what conversions are supported and for obtaining an audio

* stream from which converted data can be read.