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package be.tarsos.dsp.writer;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * this source code is copied from : https://android.googlesource.com/platform/frameworks/base.git/+/android-4.3_r2/core/java/android/speech/srec/WaveHeader.java
 */
/**
 * This class represents the header of a WAVE format audio file, which usually
 * have a .wav suffix.  The following integer valued fields are contained:
 * 
    *
  • format - usually PCM, ALAW or ULAW. *
  • numChannels - 1 for mono, 2 for stereo. *
  • sampleRate - usually 8000, 11025, 16000, 22050, or 44100 hz. *
  • bitsPerSample - usually 16 for PCM, 8 for ALAW, or 8 for ULAW. *
  • numBytes - size of audio data after this header, in bytes. *
* * Not yet ready to be supported, so * @hide */ public class WaveHeader { // follows WAVE format in http://ccrma.stanford.edu/courses/422/projects/WaveFormat private static final int HEADER_LENGTH = 44; /** Indicates PCM format. */ public static final short FORMAT_PCM = 1; /** Indicates ALAW format. */ public static final short FORMAT_ALAW = 6; /** Indicates ULAW format. */ public static final short FORMAT_ULAW = 7; private short mFormat; private short mNumChannels; private int mSampleRate; private short mBitsPerSample; private int mNumBytes; /** * Construct a WaveHeader, with all fields defaulting to zero. */ public WaveHeader() { } /** * Construct a WaveHeader, with fields initialized. * @param format format of audio data, * one of {@link #FORMAT_PCM}, {@link #FORMAT_ULAW}, or {@link #FORMAT_ALAW}. * @param numChannels 1 for mono, 2 for stereo. * @param sampleRate typically 8000, 11025, 16000, 22050, or 44100 hz. * @param bitsPerSample usually 16 for PCM, 8 for ULAW or 8 for ALAW. * @param numBytes size of audio data after this header, in bytes. */ public WaveHeader(short format, short numChannels, int sampleRate, short bitsPerSample, int numBytes) { mFormat = format; mSampleRate = sampleRate; mNumChannels = numChannels; mBitsPerSample = bitsPerSample; mNumBytes = numBytes; } /** * Get the format field. * @return format field, * one of {@link #FORMAT_PCM}, {@link #FORMAT_ULAW}, or {@link #FORMAT_ALAW}. */ public short getFormat() { return mFormat; } /** * Set the format field. * @param format * one of {@link #FORMAT_PCM}, {@link #FORMAT_ULAW}, or {@link #FORMAT_ALAW}. * @return reference to this WaveHeader instance. */ public WaveHeader setFormat(short format) { mFormat = format; return this; } /** * Get the number of channels. * @return number of channels, 1 for mono, 2 for stereo. */ public short getNumChannels() { return mNumChannels; } /** * Set the number of channels. * @param numChannels 1 for mono, 2 for stereo. * @return reference to this WaveHeader instance. */ public WaveHeader setNumChannels(short numChannels) { mNumChannels = numChannels; return this; } /** * Get the sample rate. * @return sample rate, typically 8000, 11025, 16000, 22050, or 44100 hz. */ public int getSampleRate() { return mSampleRate; } /** * Set the sample rate. * @param sampleRate sample rate, typically 8000, 11025, 16000, 22050, or 44100 hz. * @return reference to this WaveHeader instance. */ public WaveHeader setSampleRate(int sampleRate) { mSampleRate = sampleRate; return this; } /** * Get the number of bits per sample. * @return number of bits per sample, * usually 16 for PCM, 8 for ULAW or 8 for ALAW. */ public short getBitsPerSample() { return mBitsPerSample; } /** * Set the number of bits per sample. * @param bitsPerSample number of bits per sample, * usually 16 for PCM, 8 for ULAW or 8 for ALAW. * @return reference to this WaveHeader instance. */ public WaveHeader setBitsPerSample(short bitsPerSample) { mBitsPerSample = bitsPerSample; return this; } /** * Get the size of audio data after this header, in bytes. * @return size of audio data after this header, in bytes. */ public int getNumBytes() { return mNumBytes; } /** * Set the size of audio data after this header, in bytes. * @param numBytes size of audio data after this header, in bytes. * @return reference to this WaveHeader instance. */ public WaveHeader setNumBytes(int numBytes) { mNumBytes = numBytes; return this; } /** * Read and initialize a WaveHeader. * @param in {@link java.io.InputStream} to read from. * @return number of bytes consumed. * @throws IOException */ public int read(InputStream in) throws IOException { /* RIFF header */ readId(in, "RIFF"); readId(in, "WAVE"); /* fmt chunk */ readId(in, "fmt "); if (16 != readInt(in)) throw new IOException("fmt chunk length not 16"); mFormat = readShort(in); mNumChannels = readShort(in); mSampleRate = readInt(in); int byteRate = readInt(in); short blockAlign = readShort(in); mBitsPerSample = readShort(in); if (byteRate != mNumChannels * mSampleRate * mBitsPerSample / 8) { throw new IOException("fmt.ByteRate field inconsistent"); } if (blockAlign != mNumChannels * mBitsPerSample / 8) { throw new IOException("fmt.BlockAlign field inconsistent"); } /* data chunk */ readId(in, "data"); mNumBytes = readInt(in); return HEADER_LENGTH; } private static void readId(InputStream in, String id) throws IOException { for (int i = 0; i < id.length(); i++) { if (id.charAt(i) != in.read()) throw new IOException( id + " tag not present"); } } private static int readInt(InputStream in) throws IOException { return in.read() | (in.read() << 8) | (in.read() << 16) | (in.read() << 24); } private static short readShort(InputStream in) throws IOException { return (short)(in.read() | (in.read() << 8)); } /** * Write a WAVE file header. * @param out {@link java.io.OutputStream} to receive the header. * @return number of bytes written. * @throws IOException */ public int write(OutputStream out) throws IOException { /* RIFF header */ writeId(out, "RIFF"); writeInt(out, 36 + mNumBytes); writeId(out, "WAVE"); /* fmt chunk */ writeId(out, "fmt "); writeInt(out, 16); writeShort(out, mFormat); writeShort(out, mNumChannels); writeInt(out, mSampleRate); writeInt(out, mNumChannels * mSampleRate * mBitsPerSample / 8); writeShort(out, (short)(mNumChannels * mBitsPerSample / 8)); writeShort(out, mBitsPerSample); /* data chunk */ writeId(out, "data"); writeInt(out, mNumBytes); return HEADER_LENGTH; } private static void writeId(OutputStream out, String id) throws IOException { for (int i = 0; i < id.length(); i++) out.write(id.charAt(i)); } private static void writeInt(OutputStream out, int val) throws IOException { out.write(val >> 0); out.write(val >> 8); out.write(val >> 16); out.write(val >> 24); } private static void writeShort(OutputStream out, short val) throws IOException { out.write(val >> 0); out.write(val >> 8); } @Override public String toString() { return String.format( "WaveHeader format=%d numChannels=%d sampleRate=%d bitsPerSample=%d numBytes=%d", mFormat, mNumChannels, mSampleRate, mBitsPerSample, mNumBytes); } }




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