音频参数获取：采样率、比特率，通道数

获取音频文件采样率、比特率，通道数的一种方法：

 MediaExtractor mex = new MediaExtractor();
        try {
            mex.setDataSource(mp3Path);
        } catch (IOException e ) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        MediaFormat mf = mex.getTrackFormat(0);
        int bitRate = mf.getInteger(MediaFormat.KEY_BIT_RATE);//比特率
        int sampleRate = mf.getInteger(MediaFormat.KEY_SAMPLE_RATE);//采样率
        int channelCount = mf.getInteger(MediaFormat.KEY_CHANNEL_COUNT);//通道数
        int digit = bitRate*8/(sampleRate*channelCount);//采样位
        Log.d("TAG", "getSampleRate: bitRate:"+bitRate);
        Log.d("TAG", "getSampleRate: sampleRate:"+sampleRate);
        Log.d("TAG", "getSampleRate: channelCount:"+channelCount);
        Log.d("TAG", "getSampleRate: digit:"+digit);

参考：
多媒体提取器MediaExtractor详解_入门篇