src/com/android/speechrecorder/WaveHeader.java - platform/packages/apps/SpeechRecorder - Git at Google

 /*
  * Copyright (C) 2009 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.android.speechrecorder;

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

 /**
  * This class represents the header of a WAVE format audio file, which usually
  * have a .wav suffix.  The following integer valued fields are contained:
  * <ul>
  * <li> format - usually PCM, ALAW or ULAW.
  * <li> numChannels - 1 for mono, 2 for stereo.
  * <li> sampleRate - usually 8000, 11025, 16000, 22050, or 44100 hz.
  * <li> bitsPerSample - usually 16 for PCM, 8 for ALAW, or 8 for ULAW.
  * <li> numBytes - size of audio data after this header, in bytes.
  * </ul>
  *
  * 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 String TAG = "WaveHeader";

     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");
         int numBytes = readInt(in) - 36;
         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);
     }

 }
	/*
	* Copyright (C) 2009 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.speechrecorder;

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

	/**
	* This class represents the header of a WAVE format audio file, which usually
	* have a .wav suffix. The following integer valued fields are contained:
	* <ul>
	* <li> format - usually PCM, ALAW or ULAW.
	* <li> numChannels - 1 for mono, 2 for stereo.
	* <li> sampleRate - usually 8000, 11025, 16000, 22050, or 44100 hz.
	* <li> bitsPerSample - usually 16 for PCM, 8 for ALAW, or 8 for ULAW.
	* <li> numBytes - size of audio data after this header, in bytes.
	* </ul>
	*
	* 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 String TAG = "WaveHeader";

	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");
	int numBytes = readInt(in) - 36;
	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);
	}

	}