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package com.android.gallery3d.util;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.util.Log;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
public class GifDecoder {
public static final int STATUS_PARSING = 0;
public static final int STATUS_FORMAT_ERROR = 1;
public static final int STATUS_OPEN_ERROR = 2;
public static final int STATUS_FINISH = -1;
private InputStream mIS;
private int mStatus;
public int mWidth; // full image width
public int mHeight; // full image height
private boolean mGctFlag; // global color table used
private int mGctSize; // size of global color table
private int mLoopCount = 1; // iterations; 0 = repeat forever
private int[] mGct; // global color table
private int[] mLct; // local color table
private int[] mAct; // active color table
private int mBgIndex; // background color index
private int mBgColor; // background color
private int mLastBgColor; // previous bg color
private int mPixelAspect; // pixel aspect ratio
private boolean mLctFlag; // local color table flag
private boolean mInterlace; // interlace flag
private int mLctSize; // local color table size
private int mIx, mIy, mIw, mIh; // current image rectangle
private int mLrx, mLry, mLrw, mLrh;
private Bitmap mImage; // current frame
private Bitmap mLastImage; // previous frame
private GifFrame mCurrentFrame = null;
private boolean mIsShow = false;
private byte[] mBlock = new byte[256]; // current data block
private int mBlockSize = 0; // block size
private int mDispose = 0;
private int mLastDispose = 0;
private boolean mTransparency = false; // use transparent color
private int mDelay = 0; // delay in milliseconds
private int mTransIndex; // transparent color index
// max decoder pixel stack size
private static final int MaxStackSize = 4096;
// LZW decoder working arrays
private short[] mPrefix;
private byte[] mSuffix;
private byte[] mPixelStack;
private byte[] mPixels;
private GifFrame mGifFrame; // frames read from current file
private int mFrameCount;
private GifAction mGifAction = null;
private byte[] mGifData = null;
public GifDecoder(byte[] data, GifAction act) {
mGifData = data;
mGifAction = act;
startDecoder();
}
public GifDecoder(InputStream is, GifAction act) {
mIS = is;
mGifAction = act;
startDecoder();
}
public void startDecoder() {
if (mIS != null) {
readStream();
} else if (mGifData != null) {
readByte();
}
}
public void free() {
freeFrame();
freeIS();
freeImage();
}
public int getStatus() {
return mStatus;
}
public boolean parseOk() {
return mStatus == STATUS_FINISH;
}
public int getDelay(int n) {
mDelay = -1;
if ((n >= 0) && (n < mFrameCount)) {
GifFrame f = getFrame(n);
if (f != null) {
mDelay = f.mDelayInMs;
}
}
return mDelay;
}
public int[] getDelays() {
GifFrame f = mGifFrame;
int[] d = new int[mFrameCount];
int i = 0;
while (f != null && i < mFrameCount) {
d[i] = f.mDelayInMs;
f = f.mNextFrame;
i++;
}
return d;
}
public int getFrameCount() {
return mFrameCount;
}
public Bitmap getImage() {
return getFrameImage(0);
}
public int getLoopCount() {
return mLoopCount;
}
private void setPixels() {
int[] dest = new int[mWidth * mHeight];
// fill in starting image contents based on last image's dispose code
if (mLastDispose > 0) {
if (mLastDispose == 3) {
// use image before last
int n = mFrameCount - 2;
if (n > 0) {
mLastImage = getPreUndisposedImage(n - 1);
} else {
mLastImage = null;
}
}
if (mLastImage != null) {
mLastImage.getPixels(dest, 0, mWidth, 0, 0, mWidth, mHeight);
// copy pixels
if (mLastDispose == 2) {
// fill last image rect area with background color
int c = 0;
if (!mTransparency) {
c = mLastBgColor;
}
for (int i = 0; i < mLrh; i++) {
int n1 = (mLry + i) * mWidth + mLrx;
int n2 = n1 + mLrw;
for (int k = n1; k < n2; k++) {
dest[k] = c;
}
}
}
}
}
// copy each source line to the appropriate place in the destination
int pass = 1;
int inc = 8;
int iline = 0;
for (int i = 0; i < mIh; i++) {
int line = i;
if (mInterlace) {
if (iline >= mIh) {
pass++;
switch (pass) {
case 2:
iline = 4;
break;
case 3:
iline = 2;
inc = 4;
break;
case 4:
iline = 1;
inc = 2;
}
}
line = iline;
iline += inc;
}
line += mIy;
if (line < mHeight) {
int k = line * mWidth;
int dx = k + mIx; // start of line in dest
int dlim = dx + mIw; // end of dest line
if ((k + mWidth) < dlim) {
dlim = k + mWidth; // past dest edge
}
int sx = i * mIw; // start of line in source
while (dx < dlim) {
// map color and insert in destination
int index = ((int) mPixels[sx++]) & 0xff;
int c = mAct[index];
if (c != 0) {
dest[dx] = c;
}
dx++;
}
}
}
mImage = Bitmap.createBitmap(dest, mWidth, mHeight, Config.ARGB_4444);
}
public Bitmap getFrameImage(int n) {
GifFrame frame = getFrame(n);
if (frame == null) {
return null;
} else {
return frame.mImage;
}
}
public GifFrame getCurrentFrame() {
return mCurrentFrame;
}
public GifFrame getFrame(int n) {
GifFrame frame = mGifFrame;
int i = 0;
while (frame != null) {
if (i == n) {
return frame;
} else {
frame = frame.mNextFrame;
}
i++;
}
return null;
}
private Bitmap getPreUndisposedImage(int n) {
Bitmap preUndisposedImage = null;
GifFrame frame = mGifFrame;
int i = 0;
while (frame != null && i <= n) {
if (frame.mDispose == 1) {
preUndisposedImage = frame.mImage;
} else {
frame = frame.mNextFrame;
}
i++;
}
return preUndisposedImage;
}
public void reset() {
mCurrentFrame = mGifFrame;
}
public GifFrame next() {
if (mIsShow == false) {
mIsShow = true;
return mGifFrame;
} else {
if (mStatus == STATUS_PARSING) {
if (mCurrentFrame.mNextFrame != null) {
mCurrentFrame = mCurrentFrame.mNextFrame;
}
} else {
mCurrentFrame = mCurrentFrame.mNextFrame;
if (mCurrentFrame == null) {
mCurrentFrame = mGifFrame;
}
}
return mCurrentFrame;
}
}
private int readByte() {
mIS = new ByteArrayInputStream(mGifData);
mGifData = null;
return readStream();
}
private int readStream() {
init();
if (mIS != null) {
readHeader();
if (!err()) {
readContents();
if (mFrameCount < 0) {
mStatus = STATUS_FORMAT_ERROR;
if (mGifAction != null) {
mGifAction.parseOk(false, -1);
}
} else {
mStatus = STATUS_FINISH;
if (mGifAction != null) {
mGifAction.parseOk(true, -1);
}
}
}
try {
mIS.close();
} catch (Exception e) {
e.printStackTrace();
}
} else {
mStatus = STATUS_OPEN_ERROR;
if (mGifAction != null) {
mGifAction.parseOk(false, -1);
}
}
return mStatus;
}
private void decodeImageData() {
int NullCode = -1;
int npix = mIw * mIh;
int available, clear, code_mask, code_size, end_of_information, in_code, old_code,
bits, code, count, i, datum, data_size, first, top, bi, pi;
if ((mPixels == null) || (mPixels.length < npix)) {
mPixels = new byte[npix]; // allocate new pixel array
}
if (mPrefix == null) {
mPrefix = new short[MaxStackSize];
}
if (mSuffix == null) {
mSuffix = new byte[MaxStackSize];
}
if (mPixelStack == null) {
mPixelStack = new byte[MaxStackSize + 1];
}
// Initialize GIF data stream decoder.
data_size = read();
clear = 1 << data_size;
end_of_information = clear + 1;
available = clear + 2;
old_code = NullCode;
code_size = data_size + 1;
code_mask = (1 << code_size) - 1;
for (code = 0; code < clear; code++) {
mPrefix[code] = 0;
mSuffix[code] = (byte) code;
}
// Decode GIF pixel stream.
datum = bits = count = first = top = pi = bi = 0;
for (i = 0; i < npix;) {
if (top == 0) {
if (bits < code_size) {
// Load bytes until there are enough bits for a code.
if (count == 0) {
// Read a new data block.
count = readBlock();
if (count <= 0) {
break;
}
bi = 0;
}
datum += (((int) mBlock[bi]) & 0xff) << bits;
bits += 8;
bi++;
count--;
continue;
}
// Get the next code.
code = datum & code_mask;
datum >>= code_size;
bits -= code_size;
// Interpret the code
if ((code > available) || (code == end_of_information)) {
break;
}
if (code == clear) {
// Reset decoder.
code_size = data_size + 1;
code_mask = (1 << code_size) - 1;
available = clear + 2;
old_code = NullCode;
continue;
}
if (old_code == NullCode) {
mPixelStack[top++] = mSuffix[code];
old_code = code;
first = code;
continue;
}
in_code = code;
if (code == available) {
mPixelStack[top++] = (byte) first;
code = old_code;
}
while (code > clear) {
mPixelStack[top++] = mSuffix[code];
code = mPrefix[code];
}
first = ((int) mSuffix[code]) & 0xff;
// Add a new string to the string table,
if (available >= MaxStackSize) {
break;
}
mPixelStack[top++] = (byte) first;
mPrefix[available] = (short) old_code;
mSuffix[available] = (byte) first;
available++;
if (((available & code_mask) == 0)
&& (available < MaxStackSize)) {
code_size++;
code_mask += available;
}
old_code = in_code;
}
// Pop a pixel off the pixel stack.
top--;
mPixels[pi++] = mPixelStack[top];
i++;
}
for (i = pi; i < npix; i++) {
mPixels[i] = 0; // clear missing pixels
}
}
private boolean err() {
return mStatus != STATUS_PARSING;
}
private void init() {
mStatus = STATUS_PARSING;
mFrameCount = 0;
mGifFrame = null;
mGct = null;
mLct = null;
}
private int read() {
int curByte = 0;
try {
curByte = mIS.read();
} catch (Exception e) {
mStatus = STATUS_FORMAT_ERROR;
}
return curByte;
}
private int readBlock() {
mBlockSize = read();
int n = 0;
if (mBlockSize > 0) {
try {
int count = 0;
while (n < mBlockSize) {
count = mIS.read(mBlock, n, mBlockSize - n);
if (count == -1) {
break;
}
n += count;
}
} catch (Exception e) {
e.printStackTrace();
}
if (n < mBlockSize) {
mStatus = STATUS_FORMAT_ERROR;
}
}
return n;
}
private int[] readColorTable(int ncolors) {
int nbytes = 3 * ncolors;
int[] tab = null;
byte[] c = new byte[nbytes];
int n = 0;
try {
n = mIS.read(c);
} catch (Exception e) {
e.printStackTrace();
}
if (n < nbytes) {
mStatus = STATUS_FORMAT_ERROR;
} else {
tab = new int[256]; // max size to avoid bounds checks
int i = 0;
int j = 0;
while (i < ncolors) {
int r = ((int) c[j++]) & 0xff;
int g = ((int) c[j++]) & 0xff;
int b = ((int) c[j++]) & 0xff;
tab[i++] = 0xff000000 | (r << 16) | (g << 8) | b;
}
}
return tab;
}
private void readContents() {
// read GIF file content blocks
boolean done = false;
while (!(done || err())) {
int code = read();
switch (code) {
case 0x2C: // image separator
readImage();
break;
case 0x21: // extension
code = read();
switch (code) {
case 0xf9: // graphics control extension
readGraphicControlExt();
break;
case 0xff: // application extension
readBlock();
String app = "";
for (int i = 0; i < 11; i++) {
app += (char) mBlock[i];
}
if (app.equals("NETSCAPE2.0")) {
readNetscapeExt();
} else {
skip(); // don't care
}
break;
default: // uninteresting extension
skip();
}
break;
case 0x3b: // terminator
done = true;
break;
case 0x00: // bad byte, but keep going and see what happens
break;
default:
mStatus = STATUS_FORMAT_ERROR;
}
}
}
private void readGraphicControlExt() {
read(); // block size
int packed = read(); // packed fields
mDispose = (packed & 0x1c) >> 2; // disposal method
if (mDispose == 0) {
mDispose = 1; // elect to keep old image if discretionary
}
mTransparency = (packed & 1) != 0;
mDelay = readShort() * 10; // delay in milliseconds
mTransIndex = read(); // transparent color index
read(); // block terminator
}
private void readHeader() {
String id = "";
for (int i = 0; i < 6; i++) {
id += (char) read();
}
if (!id.startsWith("GIF")) {
mStatus = STATUS_FORMAT_ERROR;
return;
}
readLSD();
if (mGctFlag && !err()) {
mGct = readColorTable(mGctSize);
mBgColor = mGct[mBgIndex];
}
}
private void readImage() {
mIx = readShort(); // (sub)image position & size
mIy = readShort();
mIw = readShort();
mIh = readShort();
int packed = read();
mLctFlag = (packed & 0x80) != 0; // 1 - local color table flag
mInterlace = (packed & 0x40) != 0; // 2 - interlace flag
// 3 - sort flag
// 4-5 - reserved
mLctSize = 2 << (packed & 7); // 6-8 - local color table size
if (mLctFlag) {
mLct = readColorTable(mLctSize); // read table
mAct = mLct; // make local table active
} else {
mAct = mGct; // make global table active
if (mBgIndex == mTransIndex) {
mBgColor = 0;
}
}
int save = 0;
if (mTransparency) {
save = mAct[mTransIndex];
mAct[mTransIndex] = 0; // set transparent color if specified
}
if (mAct == null) {
mStatus = STATUS_FORMAT_ERROR; // no color table defined
}
if (err()) {
return;
}
try {
decodeImageData(); // decode pixel data
skip();
if (err()) {
return;
}
mFrameCount++;
// create new image to receive frame data
mImage = Bitmap.createBitmap(mWidth, mHeight, Config.ARGB_4444);
// createImage(mWidth, mHeight);
setPixels(); // transfer pixel data to image
if (mGifFrame == null) {
mGifFrame = new GifFrame(mImage, mDelay, mDispose);
mCurrentFrame = mGifFrame;
} else {
GifFrame f = mGifFrame;
while (f.mNextFrame != null) {
f = f.mNextFrame;
}
f.mNextFrame = new GifFrame(mImage, mDelay, mDispose);
}
// frames.addElement(new GifFrame(image, delay)); // add image to
// frame
// list
if (mTransparency) {
mAct[mTransIndex] = save;
}
resetFrame();
if (mGifAction != null) {
mGifAction.parseOk(true, mFrameCount);
}
} catch (OutOfMemoryError e) {
Log.e("GifDecoder", ">>> log : " + e.toString());
e.printStackTrace();
}
}
private void readLSD() {
// logical screen size
mWidth = readShort();
mHeight = readShort();
// packed fields
int packed = read();
mGctFlag = (packed & 0x80) != 0; // 1 : global color table flag
// 2-4 : color resolution
// 5 : gct sort flag
mGctSize = 2 << (packed & 7); // 6-8 : gct size
mBgIndex = read(); // background color index
mPixelAspect = read(); // pixel aspect ratio
}
private void readNetscapeExt() {
do {
readBlock();
if (mBlock[0] == 1) {
// loop count sub-block
int b1 = ((int) mBlock[1]) & 0xff;
int b2 = ((int) mBlock[2]) & 0xff;
mLoopCount = (b2 << 8) | b1;
}
} while ((mBlockSize > 0) && !err());
}
private int readShort() {
// read 16-bit value, LSB first
return read() | (read() << 8);
}
private void resetFrame() {
mLastDispose = mDispose;
mLrx = mIx;
mLry = mIy;
mLrw = mIw;
mLrh = mIh;
mLastImage = mImage;
mLastBgColor = mBgColor;
mDispose = 0;
mTransparency = false;
mDelay = 0;
mLct = null;
}
/**
* Skips variable length blocks up to and including next zero length block.
*/
private void skip() {
do {
readBlock();
} while ((mBlockSize > 0) && !err());
}
private void freeFrame() {
GifFrame fg = mGifFrame;
while (fg != null) {
if (fg.mImage != null) {
fg.mImage.recycle();
}
fg.mImage = null;
fg = null;
mGifFrame = mGifFrame.mNextFrame;
fg = mGifFrame;
}
}
private void freeIS() {
if (mIS != null) {
try {
mIS.close();
} catch (Exception ex) {
ex.printStackTrace();
}
mIS = null;
}
mGifData = null;
}
private void freeImage() {
if (mImage != null) {
mImage.recycle();
mImage = null;
}
if (mLastImage != null) {
mLastImage.recycle();
mLastImage = null;
}
}
}
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