/*
* Copyright (C) 2008 Google Inc.
*
* 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.ringdroid.soundfile;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
/**
* CheapWAV represents a standard 16-bit WAV file, splitting it into
* artificial frames of 20 ms and taking the maximum of each frame to
* get an approximation of the waveform contour.
*/
public class CheapWAV extends CheapSoundFile {
public static Factory getFactory() {
return new Factory() {
public CheapSoundFile create() {
return new CheapWAV();
}
public String[] getSupportedExtensions() {
return new String[] { "wav" };
}
};
}
// Member variables containing frame info
private int mNumFrames;
private int[] mFrameOffsets;
private int[] mFrameLens;
private int[] mFrameGains;
private int mFrameBytes;
private int mFileSize;
private int mSampleRate;
private int mChannels;
// Member variables used during initialization
private int mOffset;
public CheapWAV() {
}
public int getNumFrames() {
return mNumFrames;
}
public int getSamplesPerFrame() {
return mSampleRate / 50;
}
public int[] getFrameOffsets() {
return mFrameOffsets;
}
public int[] getFrameLens() {
return mFrameLens;
}
public int[] getFrameGains() {
return mFrameGains;
}
public int getFileSizeBytes() {
return mFileSize;
}
public int getAvgBitrateKbps() {
return mSampleRate * mChannels * 2 / 1024;
}
public int getSampleRate() {
return mSampleRate;
}
public int getChannels() {
return mChannels;
}
public String getFiletype() {
return "WAV";
}
public void ReadFile(File inputFile)
throws java.io.FileNotFoundException,
java.io.IOException {
super.ReadFile(inputFile);
mFileSize = (int)mInputFile.length();
if (mFileSize < 128) {
throw new java.io.IOException("File too small to parse");
}
FileInputStream stream = new FileInputStream(mInputFile);
byte[] header = new byte[12];
stream.read(header, 0, 12);
mOffset += 12;
if (header[0] != 'R' ||
header[1] != 'I' ||
header[2] != 'F' ||
header[3] != 'F' ||
header[8] != 'W' ||
header[9] != 'A' ||
header[10] != 'V' ||
header[11] != 'E') {
throw new java.io.IOException("Not a WAV file");
}
mChannels = 0;
mSampleRate = 0;
while (mOffset + 8 <= mFileSize) {
byte[] chunkHeader = new byte[8];
stream.read(chunkHeader, 0, 8);
mOffset += 8;
int chunkLen =
((0xff & chunkHeader[7]) << 24) |
((0xff & chunkHeader[6]) << 16) |
((0xff & chunkHeader[5]) << 8) |
((0xff & chunkHeader[4]));
if (chunkHeader[0] == 'f' &&
chunkHeader[1] == 'm' &&
chunkHeader[2] == 't' &&
chunkHeader[3] == ' ') {
if (chunkLen < 16 || chunkLen > 1024) {
throw new java.io.IOException(
"WAV file has bad fmt chunk");
}
byte[] fmt = new byte[chunkLen];
stream.read(fmt, 0, chunkLen);
mOffset += chunkLen;
int format =
((0xff & fmt[1]) << 8) |
((0xff & fmt[0]));
mChannels =
((0xff & fmt[3]) << 8) |
((0xff & fmt[2]));
mSampleRate =
((0xff & fmt[7]) << 24) |
((0xff & fmt[6]) << 16) |
((0xff & fmt[5]) << 8) |
((0xff & fmt[4]));
if (format != 1) {
throw new java.io.IOException(
"Unsupported WAV file encoding");
}
} else if (chunkHeader[0] == 'd' &&
chunkHeader[1] == 'a' &&
chunkHeader[2] == 't' &&
chunkHeader[3] == 'a') {
if (mChannels == 0 || mSampleRate == 0) {
throw new java.io.IOException(
"Bad WAV file: data chunk before fmt chunk");
}
int frameSamples = (mSampleRate * mChannels) / 50;
mFrameBytes = frameSamples * 2;
mNumFrames = (chunkLen + (mFrameBytes - 1)) / mFrameBytes;
mFrameOffsets = new int[mNumFrames];
mFrameLens = new int[mNumFrames];
mFrameGains = new int[mNumFrames];
byte[] oneFrame = new byte[mFrameBytes];
int i = 0;
int frameIndex = 0;
while (i < chunkLen) {
int oneFrameBytes = mFrameBytes;
if (i + oneFrameBytes > chunkLen) {
i = chunkLen - oneFrameBytes;
}
stream.read(oneFrame, 0, oneFrameBytes);
int maxGain = 0;
for (int j = 1; j < oneFrameBytes; j += 4 * mChannels) {
int val = java.lang.Math.abs(oneFrame[j]);
if (val > maxGain) {
maxGain = val;
}
}
mFrameOffsets[frameIndex] = mOffset;
mFrameLens[frameIndex] = oneFrameBytes;
mFrameGains[frameIndex] = maxGain;
frameIndex++;
mOffset += oneFrameBytes;
i += oneFrameBytes;
if (mProgressListener != null) {
boolean keepGoing = mProgressListener.reportProgress(
i * 1.0 / chunkLen);
if (!keepGoing) {
break;
}
}
}
} else {
stream.skip(chunkLen);
mOffset += chunkLen;
}
}
}
public void WriteFile(File outputFile, int startFrame, int numFrames)
throws java.io.IOException {
outputFile.createNewFile();
FileInputStream in = new FileInputStream(mInputFile);
FileOutputStream out = new FileOutputStream(outputFile);
long totalAudioLen = 0;
for (int i = 0; i < numFrames; i++) {
totalAudioLen += mFrameLens[startFrame + i];
}
long totalDataLen = totalAudioLen + 36;
long longSampleRate = mSampleRate;
long byteRate = mSampleRate * 2 * mChannels;
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) mChannels;
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 * mChannels); // 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);
out.write(header, 0, 44);
byte[] buffer = new byte[mFrameBytes];
int pos = 0;
for (int i = 0; i < numFrames; i++) {
int skip = mFrameOffsets[startFrame + i] - pos;
int len = mFrameLens[startFrame + i];
if (skip < 0) {
continue;
}
if (skip > 0) {
in.skip(skip);
pos += skip;
}
in.read(buffer, 0, len);
out.write(buffer, 0, len);
pos += len;
}
in.close();
out.close();
}
};