android AudioRecord 类来录制音频并播放

Question

我想录制音频并以 WAV 格式播放。我必须使用 AudioRecord 来完成。有人可以帮我吗？

我经历了这个例子，

http://androidsourcecode.blogspot.com.au/2013/07/android-audio-demo-audiotrack.html

我不明白通话模式和扬声器模式的作用。有人可以解释一下吗？

在该链接中使用这部分代码，

private void recordAndPlay() {
    short[] lin = new short[1024];
    int num = 0;
    am = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
    am.setMode(AudioManager.MODE_IN_COMMUNICATION);
    record.startRecording();
    track.play();
    while (true) {
        num = record.read(lin, 0, 1024); 
        track.write(lin, 0, num);
    }
}

num = record.read(lin, 0, 1024); is recording the audio.

track.play(); -- Plays the audio.
track.write(lin, 0, num); -- streams the audio

不知道我理解的对不对，但是我的理解是

record.startRecording(); -- Audio is recording
track.play(); -- playing the audio
while (true) {
    num = record.read(lin, 0, 1024); -- Record gets stored
    track.write(lin, 0, num); -- play the audio
}

录制流和播放流是同时发生的吗？我该如何测试？

Answer 1

我想自己回答我的问题。

在上面的代码中，recordAndPlay 方法，同时录制和播放声音。

我拆分了代码。我先把声音录下来存到文件里，然后打开存好的文件处理播放。

    private void startRecording() {
            final int CHANNELCONFIG = AudioFormat.CHANNEL_IN_MONO;
            String filename = getTempFilename();
            OutputStream os = null;

            try {
                os = new FileOutputStream(filename);
            } catch(FileNotFoundException e) {
                e.printStackTrace();
            }

            bufferSize =                 AudioRecord.getMinBufferSize(FREQUENCY,CHANNELCONFIG,AUDIO_FORMAT);
            audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC,FREQUENCY,CHANNELCONFIG,AUDIO_FORMAT,bufferSize);

            audioData = new byte[bufferSize];

            audioRecord.startRecording();

            int read = 0;

            while (recording) {
                read = audioRecord.read(audioData,0,bufferSize);
                if(AudioRecord.ERROR_INVALID_OPERATION != read){
                    try {
                        os.write(audioData);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }

            try {
                os.close();
            } catch (IOException io) {
                io.printStackTrace();
            }

        }

        private void playRecording() {

            String fileName = getFilename();
            File file = new File(fileName);

            byte[] audioData = null;

            try {
                InputStream inputStream = new FileInputStream(fileName);

                int minBufferSize =         AudioTrack.getMinBufferSize(44100,AudioFormat.CHANNEL_OUT_MONO,         AudioFormat.ENCODING_PCM_16BIT);
                audioData = new byte[minBufferSize];

                AudioTrack audioTrack = new         AudioTrack(AudioManager.STREAM_MUSIC,FREQUENCY,AudioFormat.CHANNEL_OUT_MONO,AUDI        O_FORMAT,minBufferSize,AudioTrack.MODE_STREAM);
                audioTrack.play();
                int i=0;

                while((i = inputStream.read(audioData)) != -1) {
                    audioTrack.write(audioData,0,i);
                }

            } catch(FileNotFoundException fe) {
                Log.e(LOG_TAG,"File not found");
            } catch(IOException io) {
                Log.e(LOG_TAG,"IO Exception");
            }
        }