gpt4 book ai didi

java - AudioRecord PCM数据有没有用?

转载 作者:行者123 更新时间:2023-11-30 11:55:31 25 4
gpt4 key购买 nike

我已经在我的 android 应用程序中使用 Mic 进行了录音,当使用 AudioPlayer 类将数据流式传输进来时,它播放得非常好。我的问题是我想向该数据附加一个 wav header ,以便它可以在外部播放应用。我很确定在十六进制编辑器中播放其他音频文件后创建 header 的方法会起作用,这会导致记录的 pcm 数据不能用作 wav 文件中的原始数据?

任何人都可以阐明这一点吗?我可以将 pcm/wav 文件作为原始文件导入 audacity,它可以完美播放,但是当我尝试打开 wav 时,我只是听到噪音,再次暗示 pcm 数据有问题。

录音设置:

int frequency = 22050;
int channelConfiguration = AudioFormat.CHANNEL_CONFIGURATION_MONO;
int audioEncoding = AudioFormat.ENCODING_PCM_16BIT;

header 变量:

byte[] clipData = data;
long myDataSize = clipData.length;
long mySubChunk1Size = 16;
int myBitsPerSample= 16;
int myFormat = 1;
long myChannels = 1;
long mySampleRate = 22050;
long myByteRate = mySampleRate * myChannels * myBitsPerSample/8;
int myBlockAlign = (int) (myChannels * myBitsPerSample/8);
long myChunk2Size = myDataSize * myChannels * myBitsPerSample/8;
long myChunkSize = 36 + myChunk2Size;

try
{
File audioDirectory = new File(Environment
.getExternalStorageDirectory().getAbsolutePath()
+ "/Directory/");
audioDirectory.mkdir();
File file = new File(audioDirectory, "test.wav");
if (file.exists())
file.delete();

// Create the new file.
try {
file.createNewFile();
} catch (IOException e) {
throw new IllegalStateException("Failed to create "
+ file.toString());
}
OutputStream os = new FileOutputStream(file);
BufferedOutputStream bos = new BufferedOutputStream(os);
DataOutputStream outFile = new DataOutputStream(bos);

// write the wav file per the wav file format
outFile.writeBytes("RIFF"); // 00 - RIFF
outFile.write(intToByteArray((int)myChunkSize), 0, 4); // 04 - how big is the rest of this file?
outFile.writeBytes("WAVE"); // 08 - WAVE
outFile.writeBytes("fmt "); // 12 - fmt
outFile.write(intToByteArray((int)mySubChunk1Size), 0, 4); // 16 - size of this chunk
outFile.write(shortToByteArray((short)myFormat), 0, 2); // 20 - what is the audio format? 1 for PCM = Pulse Code Modulation
outFile.write(shortToByteArray((short)myChannels), 0, 2); // 22 - mono or stereo? 1 or 2? (or 5 or ???)
outFile.write(intToByteArray((int)mySampleRate), 0, 4); // 24 - samples per second (numbers per second)
outFile.write(intToByteArray((int)myByteRate), 0, 4); // 28 - bytes per second
outFile.write(shortToByteArray((short)myBlockAlign), 0, 2); // 32 - # of bytes in one sample, for all channels
outFile.write(shortToByteArray((short)myBitsPerSample), 0, 2); // 34 - how many bits in a sample(number)? usually 16 or 24
outFile.writeBytes("data"); // 36 - data
outFile.write(intToByteArray((int)myDataSize), 0, 4); // 40 - how big is this data chunk
outFile.write(clipData); // 44 - the actual data itself - just a long string of numbers
}

转换器

public static int byteArrayToInt(byte[] b)
{
int start = 0;
int low = b[start] & 0xff;
int high = b[start+1] & 0xff;
return (int)( high << 8 | low );
}


// these two routines convert a byte array to an unsigned integer
public static long byteArrayToLong(byte[] b)
{
int start = 0;
int i = 0;
int len = 4;
int cnt = 0;
byte[] tmp = new byte[len];
for (i = start; i < (start + len); i++)
{
tmp[cnt] = b[i];
cnt++;
}
long accum = 0;
i = 0;
for ( int shiftBy = 0; shiftBy < 32; shiftBy += 8 )
{
accum |= ( (long)( tmp[i] & 0xff ) ) << shiftBy;
i++;
}
return accum;
}


// ===========================
// CONVERT JAVA TYPES TO BYTES
// ===========================
// returns a byte array of length 4
private static byte[] intToByteArray(int i)
{
byte[] b = new byte[4];
b[0] = (byte) (i & 0x00FF);
b[1] = (byte) ((i >> 8) & 0x000000FF);
b[2] = (byte) ((i >> 16) & 0x000000FF);
b[3] = (byte) ((i >> 24) & 0x000000FF);
return b;
}

// convert a short to a byte array
public static byte[] shortToByteArray(short data)
{
return new byte[]{(byte)(data & 0xff),(byte)((data >>> 8) & 0xff)};
}

最佳答案

您可能只是错误地设置了 header 属性。 WAV 格式 header 应为 44 字节,后跟原始音频数据。以下是 WAV 格式的说明:

http://www.sonicspot.com/guide/wavefiles.html

如果您创建了一个 header 并附加了原始数据,并且生成的文件播放时没有错误但听起来像噪音,那么最可能的罪魁祸首是原始音频每个样本使用 2 个字节,但您将 Bi​​tsPerSample 属性设置为 header 到 8.

您使用的方法(在原始音频前添加 WAV header )完全有效,应该可以正常工作。

更新:咦,你的转换方式不应该是

    // convert a short to a byte array
public static byte[] shortToByteArray(short data)
{
return new byte[]{(byte)(data & 0xff),(byte)((data >> 8) & 0xff)};
}

?我不确定 >>> 在位移世界中意味着什么。

关于java - AudioRecord PCM数据有没有用?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/4960125/

25 4 0