Android:Creating Wave file using Raw PCM, wave file不播放

Posted 2023-02-25

【中文标题】Android:Creating Wave file using Raw PCM, wave file不播放

【英文标题】：Android:Creating Wave file using Raw PCM, the wave file does not play

【发布时间】：2015-01-07 18:54:09

【问题描述】：

我已经为wave文件创建了header，但是创建的wave文件没有播放。

我使用这个https://ccrma.stanford.edu/courses/422/projects/WaveFormat/ 作为参考来创建波头。

    public void WriteWaveFileHeader() throws IOException 
    File f = new File(Environment.getExternalStorageDirectory().getAbsolutePath()+"/aaa.wav");
    f.createNewFile();
    FileOutputStream fos = new FileOutputStream(f);
    long longSampleRate=44100;
    int channels= AudioFormat.CHANNEL_IN_MONO;
    long totalAudioLen=fos.getChannel().size();
    long byteRate=(16 * 44100)/8;
    long totalDataLen=totalAudioLen+36;
    byte[] header = new byte[44];

    header[0] = 'R';  // RIFF/WAVE header
    header[1] = 'I';
    header[2] = 'F';
    header[3] = 'F';
    header[4] = (byte) (totalDataLen & 0xff);
    header[5] = (byte) ((totalDataLen >> 8) & 0xff);
    header[6] = (byte) ((totalDataLen >> 16) & 0xff);
    header[7] = (byte) ((totalDataLen >> 24) & 0xff);
    header[8] = 'W';
    header[9] = 'A';
    header[10] = 'V';
    header[11] = 'E';
    header[12] = 'f';  // 'fmt ' chunk
    header[13] = 'm';
    header[14] = 't';
    header[15] = ' ';
    header[16] = 16;  // 4 bytes: size of 'fmt ' chunk
    header[17] = 0;
    header[18] = 0;
    header[19] = 0;
    header[20] = 1;  // format = 1
    header[21] = 0;
    header[22] = (byte) channels;
    header[23] = 0;
    header[24] = (byte) (longSampleRate & 0xff);
    header[25] = (byte) ((longSampleRate >> 8) & 0xff);
    header[26] = (byte) ((longSampleRate >> 16) & 0xff);
    header[27] = (byte) ((longSampleRate >> 24) & 0xff);
    header[28] = (byte) (byteRate & 0xff);
    header[29] = (byte) ((byteRate >> 8) & 0xff);
    header[30] = (byte) ((byteRate >> 16) & 0xff);
    header[31] = (byte) ((byteRate >> 24) & 0xff);
    header[32] = (byte) (2 * 16 / 8);  // block align
    header[33] = 0;
    header[34] = 16;  // bits per sample
    header[35] = 0;
    header[36] = 'd';
    header[37] = 'a';
    header[38] = 't';
    header[39] = 'a';
    header[40] = (byte) (totalAudioLen & 0xff);
    header[41] = (byte) ((totalAudioLen >> 8) & 0xff);
    header[42] = (byte) ((totalAudioLen >> 16) & 0xff);
    header[43] = (byte) ((totalAudioLen >> 24) & 0xff);

    fos.write(header, 0, 44);
    File l = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/Notate/" + MainActivity.filepath);
    FileInputStream fis = new FileInputStream(Environment.getExternalStorageDirectory().getAbsolutePath() + "/Notate/" + MainActivity.filepath);
    byte[] buffer = new byte[(int) l.length()];

    int intSize = android.media.AudioTrack.getMinBufferSize(44100, AudioFormat.CHANNEL_OUT_MONO,
            AudioFormat.ENCODING_PCM_16BIT);
    AudioTrack at = new AudioTrack(AudioManager.STREAM_MUSIC, 44100, AudioFormat.CHANNEL_OUT_MONO,
            AudioFormat.ENCODING_PCM_16BIT, intSize, AudioTrack.MODE_STREAM);
    at.write(buffer,0,(int)l.length());
    fos.write(buffer);
    fos.flush();
    fos.close();

【问题讨论】：

您应该使用十六进制编辑器将您编写的标题与正在播放的文件的标题进行比较。

【参考方案1】：

试试下面的代码：

private void rawToWave(final File rawFile, final File waveFile) throws IOException 

    byte[] rawData = new byte[(int) rawFile.length()];
    DataInputStream input = null;
    try 
        input = new DataInputStream(new FileInputStream(rawFile));
        input.read(rawData);
     finally 
        if (input != null) 
            input.close();
        
    

    DataOutputStream output = null;
    try 
        output = new DataOutputStream(new FileOutputStream(waveFile));
        // WAVE header
        // see http://ccrma.stanford.edu/courses/422/projects/WaveFormat/
        output.writeChars("RIFF"); // chunk id
        output.writeInt(36 + rawData.length); // chunk size
        output.writeChars("WAVE"); // format
        output.writeChars("fmt "); // subchunk 1 id
        output.writeInt(16); // subchunk 1 size
        output.writeShort((short) 1); // audio format (1 = PCM)
        output.writeShort((short) 1); // number of channels
        output.writeInt(SAMPLE_RATE); // sample rate
        output.writeInt(SAMPLE_RATE * 2); // byte rate
        output.writeShort((short) 2); // block align
        output.writeShort((short) 16); // bits per sample
        output.writeChars(output, "data"); // subchunk 2 id
        output.writeInt(output, rawData.length); // subchunk 2 size
        // Audio data (conversion big endian -> little endian)
        short[] shorts = new short[rawData.length / 2];
        ByteBuffer.wrap(rawData).order(ByteOrder.LITTLE_ENDIAN).asShortBuffer().get(shorts);
        ByteBuffer bytes = ByteBuffer.allocate(shorts.length * 2);
        for (short s : shorts) 
            bytes.putShort(s);
        
        output.write(bytes.array());
     finally 
        if (output != null) 
            output.close();
        
    

【讨论】：

@Robert Rowntree 如果原始文件超过 80MB，此代码会崩溃。

我只是得到白噪声。有什么解决办法吗？

@AdvaitS 我也只是得到白噪声。我相信这与一些参数设置有关。你能解决这个问题吗？

@filipebarretto 我确实解决了这个问题。我相信白噪声的原因是最后一个标头中的数据已损坏。你为什么不把它作为一个问题发布？

@AdvaitS 我已经发布了一个问题，但仍然没有成功。你能帮我在那里回答吗？ ***.com/questions/37281430/…