package net.dev123.yibo.widget;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.util.concurrent.locks.ReentrantLock;
import net.dev123.yibo.common.Constants;
import net.dev123.yibo.common.MemoryManager;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.util.Log;
public class GifDecoder extends Thread {
private static final String TAG = "GifDecoder";
/**解析状态*/
public static final int STATUS_PARSING = 0; //状态：正在解码中
public static final int STATUS_FORMAT_ERROR = 1; //状态：图片格式错误
public static final int STATUS_OPEN_ERROR = 2; //状态：打开失败
public static final int STATUS_INTERRUPT = 3; //状态: 解析中断
public static final int STATUS_FINISH = -1; //状态：解码成功
private static final long MAX_HEAP_SIZE;
private static final int MaxStackSize = 4096; // max decoder pixel stack size
static {
MAX_HEAP_SIZE = Runtime.getRuntime().maxMemory() / 2; //16M用8M
}
/**gif global attribute*/
private int bgColor; // gif background color
private int frameCount; // gif frame count
private GifFrame gifFrame; // gif head frame
private int[] framePixels; // gif pixels
//private int[] lastFramePixels; // last gif pixels;
public static ReentrantLock lock = new ReentrantLock();
private boolean isFree = false; //free resource;
/**Logical Screen Descriptor*/
public int width; // full image width
public int height; // full image height
private boolean lsdGctFlag; // global color table used
private int lsdCr; // Color ResoluTion
private int lsdSf; // Sort Flag;
private int lsdGctSize; // size of global color table
private int lsdBgColorIndex; // background color index
private int lsdPar; // pixel aspect radio
private int loopCount = 1; // iterations; 0 = repeat forever
/**color table**/
private int[] gct; // global color table
private GifImageDescriptor currentImgDescriptor;
private GifGraphicControlExt currentGCExt;
private byte[] block = new byte[256]; // current data block
private int blockSize = 0; // block size
// LZW decoder working arrays
private short[] prefix;
private byte[] suffix;
private byte[] pixelStack;
private InputStream gifStream;
private int status;
private GifAction action = null;
private boolean isShow = false;
private Bitmap image; // current frame
private GifFrame currentFrame;
private GifFrame lastFrame;
public GifDecoder(byte[] gifDatabyte, GifAction action) {
this.gifStream = new ByteArrayInputStream(gifDatabyte);
this.action = action;
}
public GifDecoder(InputStream gifStream, GifAction action) {
this.gifStream = gifStream;
this.action = action;
}
@Override
public void run() {
if (gifStream != null) {
decodeGif();
}
}
/**
* 释放资源
*/
public void free() {
lock.lock();
if (status == STATUS_PARSING) {
status = STATUS_INTERRUPT;
}
GifFrame fg = gifFrame;
GifFrame temp;
while (fg != null) {
fg.image = null;
temp = fg.nextFrame;
fg.nextFrame = null;
fg.pixels = null;
fg = temp;
}
if (gifStream != null) {
try {
gifStream.close();
} catch (Exception ex) {}
gifStream = null;
}
if (image != null && !image.isRecycled()) {
image.recycle();
}
image = null;
framePixels = null;
isFree = true;
lock.unlock();
}
/**
* 当前状态
* @return
*/
public int getStatus() {
return status;
}
/**
* 解码是否成功，成功返回true
* @return 成功返回true，否则返回false
*/
public boolean parseOk() {
return status == STATUS_FINISH;
}
/**
* 取某帧的延时时间
* @param n 第几帧
* @return 延时时间，毫秒
*/
public int getDelay(int n) {
int delay = -1;
if ((n >= 0) && (n < frameCount)) {
// delay = ((GifFrame) frames.elementAt(n)).delay;
GifFrame f = getFrame(n);
if (f != null)
delay = f.delay;
}
return delay;
}
/**
* 取所有帧的延时时间
* @return
*/
public int[] getDelays() {
GifFrame f = gifFrame;
int[] d = new int[frameCount];
int i = 0;
while (f != null && i < frameCount) {
d[i] = f.delay;
f = f.nextFrame;
i++;
}
return d;
}
/**
* 取总帧 数
* @return 图片的总帧数
*/
public int getFrameCount() {
return frameCount;
}
/**
* 取第一帧图片
* @return
*/
public Bitmap getImage() {
return getFrameImage(0);
}
public int getLoopCount() {
return loopCount;
}
/**
* 取第几帧的图片
* @param n 帧数
* @return 可画的图片，如果没有此帧或者出错，返回null
*/
public Bitmap getFrameImage(int n) {
GifFrame frame = getFrame(n);
if (frame == null)
return null;
else
return frame.image;
}
/**
* 取当前帧图片
* @return 当前帧可画的图片
*/
public GifFrame getCurrentFrame() {
return currentFrame;
}
/**
* 取第几帧，每帧包含了可画的图片和延时时间
* @param n 帧数
* @return
*/
public GifFrame getFrame(int n) {
GifFrame frame = gifFrame;
int i = 0;
while (frame != null) {
if (i == n) {
return frame;
} else {
frame = frame.nextFrame;
}
i++;
}
return null;
}
/**
* 重置，进行本操作后，会直接到第一帧
*/
public void reset() {
currentFrame = gifFrame;
}
/**
* 下一帧，进行本操作后，通过getCurrentFrame得到的是下一帧
* @return 返回下一帧
*/
public GifFrame next() {
GifFrame frame = null;
if (status != STATUS_FINISH && status != STATUS_PARSING) {
return frame;
}
boolean isMove = false;
if (isShow == false || currentFrame == null) {
isShow = true;
frame = gifFrame;
if (frame != null) {
isMove = true;
}
} else {
//预数据缓冲;
//prepareFrames();
frame = currentFrame.nextFrame;
if (status == STATUS_PARSING) {
if (frame != null) {
isMove = true;
}
//currentFrame = gifFrame;
} else {
if (frame == null) {
frame = gifFrame;
}
isMove = true;
}
if (Constants.DEBUG) {
int frameIndex = currentFrame.frameIndex;
int delay = currentFrame.delay;
Log.d(TAG, "display currentFrame index->" + frameIndex + " delay->" + delay);
}
}
if (isMove && frame != null) {
currentFrame = frame;
fillFramePixels(frame);
image = createBitmap();
if (!(image == null || image.isRecycled() || framePixels == null)) {
image.setPixels(framePixels, 0, width, 0, 0, width, height);
frame.image = image;
}
}
return currentFrame;
}
private int decodeGif() {
init();
if (gifStream == null) {
status = STATUS_OPEN_ERROR;
action.parseOk(false, -1);
return status;
}
readHeader();
if (!err()) {
readContents();
if (frameCount <= 0) {
status = STATUS_FORMAT_ERROR;
action.parseOk(false, -1);
} else {
status = STATUS_FINISH;
action.parseOk(true, -1);
}
}
try {
if (gifStream != null) {
gifStream.close();
}
} catch (Exception e) {
if (Constants.DEBUG) Log.d(TAG, TAG, e);
}
return status;
}
private void init() {
status = STATUS_PARSING;
frameCount = 0;
gifFrame = null;
gct = null;
//lct = null;
}
private void readHeader() {
StringBuilder id = new StringBuilder("");
for (int i = 0; i < 6; i++) {
id.append((char) readByte());
}
if (!id.toString().startsWith("GIF")) {
status = STATUS_FORMAT_ERROR;
return;
}
readLSD();
if (lsdGctFlag && !err()) {
gct = readColorTable(lsdGctSize);
bgColor = gct[lsdBgColorIndex];
}
}
private void readLSD() {
// logical screen size
width = readShort();
height = readShort();
// packed fields
int packed = readByte();
lsdGctFlag = (packed & 0x80) != 0; // 1 : global color table flag
lsdCr = (packed & 0x70); // 2-4 : color resolution
lsdSf = (packed & 0x08); // 5 : gct sort flag
//TODO: 文档上说gct size = 2(n+1)，其中n是包装域（packed）的后三位
lsdGctSize = 2 << (packed & 0x07); // 6-8 : gct size
// 实际数量是2 << (packed & 0x07),由于数组从0开始
lsdBgColorIndex = readByte(); // background color index
lsdPar = readByte(); // pixel aspect radio
}
private void readContents() {
// read GIF file content blocks
boolean isDone = false;
while (!(isDone || err())) {
int code = readByte();
switch (code) {
case 0x2C: // image separator
readImage();
break;
case 0x21: // extension
code = readByte();
switch (code) {
case 0xf9: // graphics control extension
currentGCExt = readGraphicControlExt();
break;
case 0xff: // application extension
readBlock();
StringBuilder app = new StringBuilder("");
for (int i = 0; i < 11; i++) {
app.append((char) block[i]);
}
if ("NETSCAPE2.0".equals(app.toString())) {
readNetscapeExt();
} else {
skip(); // don't care
}
break;
default: // uninteresting extension
skip();
}
break;
case 0x3b: // terminator
isDone = true;
break;
case 0x00: // bad byte, but keep going and see what happens
break;
default:
status = STATUS_FORMAT_ERROR;
}
}
}
private void readImage() {
if (currentGCExt == null) {
//status = STATUS_FORMAT_ERROR;
currentGCExt = new GifGraphicControlExt();
}
if (err()) {
return;
}
currentImgDescriptor = readImageDescriptor();
if (currentImgDescriptor == null) {
status = STATUS_FORMAT_ERROR;
return;
}
int[] colorTable;
if (currentImgDescriptor.lctFlag) {
colorTable = readColorTable(currentImgDescriptor.lctSize); // read table
} else {
colorTable = gct; // use make global table
}
int tempColor = 0;
if (currentGCExt.transparentColorFlag) {
tempColor = colorTable[currentGCExt.transparentColorIndex];
colorTable[currentGCExt.transparentColorIndex] = 0; // set transparent color if specified
}
if (colorTable == null) {
status = STATUS_FORMAT_ERROR; // no color table defined
}
if (err()) {
return;
}
GifImageData imgData = readImageData(currentImgDescriptor); // decode pixel data
if (imgData != null) {
imgData.colorTable = colorTable;
}
skip();
if (err()) {
return;
}
frameCount++;
if (currentGCExt.delay < 10) {
currentGCExt.delay = 80;
}
GifFrame newFrame = createFrame(imgData, frameCount, currentGCExt.delay);
if (newFrame == null) {
return;
}
newFrame.gcExt = currentGCExt;
newFrame.imgData = imgData;
newFrame.imgDescriptor = currentImgDescriptor;
if (gifFrame == null) {
gifFrame = newFrame;
} else {
GifFrame f = gifFrame;
while(f.nextFrame != null) {
f = f.nextFrame;
}
f.nextFrame = newFrame;
}
if (currentGCExt.transparentColorFlag) {
colorTable[currentGCExt.transparentColorIndex] = tempColor;
}
resetFrame();
action.parseOk(true, frameCount);
}
private GifImageDescriptor readImageDescriptor() {
GifImageDescriptor imgDescriptor = new GifImageDescriptor();
imgDescriptor.offX = readShort(); // (sub)image position & size
imgDescriptor.offY = readShort();
imgDescriptor.width = readShort();
imgDescriptor.height = readShort();
int packed = readByte();
imgDescriptor.lctFlag = (packed & 0x80) != 0; // 1 - local color table flag
imgDescriptor.interlaceFlag = (packed & 0x40) != 0; // 2 - interlace flag
//TODO: 没有设置Sort Flag(设置 彩色表排序标志)和Reserved(保留)？
// 3 - sort flag
// 4-5 - reserved
imgDescriptor.lctSize = 2 << (packed & 0x07); // 6-8 - local color table size
return imgDescriptor;
}
private GifImageData readImageData(GifImageDescriptor imgDescriptor) {
int NullCode = -1;
int npix = imgDescriptor.width * imgDescriptor.height;
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;
GifImageData imageData = new GifImageData();
//if ((pixels == null) || (pixels.length < npix)) {
byte[] pixels = new byte[npix]; // allocate new pixel array
//}
if (prefix == null) {
prefix = new short[MaxStackSize];
}
if (suffix == null) {
suffix = new byte[MaxStackSize];
}
if (pixelStack == null) {
pixelStack = new byte[MaxStackSize + 1];
}
// Initialize GIF data stream decoder.
data_size = readByte();
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++) {
prefix[code] = 0;
suffix[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) block[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) {
pixelStack[top++] = suffix[code];
old_code = code;
first = code;
continue;
}
in_code = code;
if (code == available) {
pixelStack[top++] = (byte) first;
code = old_code;
}
while (code > clear) {
pixelStack[top++] = suffix[code];
code = prefix[code];
}
first = ((int) suffix[code]) & 0xff;
// Add a new string to the string table,
if (available >= MaxStackSize) {
break;
}
pixelStack[top++] = (byte) first;
prefix[available] = (short) old_code;
suffix[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--;
pixels[pi++] = pixelStack[top];
i++;
}
for (i = pi; i < npix; i++) {
pixels[i] = 0; // clear missing pixels
}
imageData.pixels = pixels;
return imageData;
}
private GifFrame createFrame(GifImageData imgData, int frameCount, int delay) {
GifFrame newFrame = null;
long frameHeapSize = width * height * 1; //只存储像素索引
if (Constants.DEBUG) MemoryManager.trace();
if (frameHeapSize * (frameCount + 1) > MAX_HEAP_SIZE) {
return newFrame;
}
newFrame = new GifFrame(frameCount, delay);
return newFrame;
}
private void fillFramePixels(GifFrame frame) {
lock.lock();
if (isFree || frame == null) {
lock.unlock();
return;
}
if (framePixels == null) {
framePixels = new int[width * height];
}
if (frame.frameIndex == 0 || frame.frameIndex == 1) {
initPixels(framePixels, bgColor);
}
GifGraphicControlExt gcExt = frame.gcExt;
GifImageDescriptor imgDescriptor = frame.imgDescriptor;
GifImageData imgData = frame.imgData;
if (gcExt == null || imgDescriptor == null || imgData == null) {
status = STATUS_FORMAT_ERROR;
return;
}
// fill in starting image contents based on last image's dispose code
switch(gcExt.disposal) {
case 0: break;
case 1: break;
case 2:
GifImageDescriptor lastImgDescriptor = null;
if (lastFrame != null) {
lastImgDescriptor = lastFrame.imgDescriptor;
}
if (lastImgDescriptor == null) {
break;
}
// fill last image rect area with background color
int color = 0;
if (!gcExt.transparentColorFlag) {
color = bgColor;
}
int lastHeight = lastImgDescriptor.height;
for (int i = 0; i < lastHeight; i++) {
int n1 = (lastImgDescriptor.offY + i) * width + lastImgDescriptor.offX;
int n2 = n1 + lastImgDescriptor.width;
for (int k = n1; k < n2; k++) {
framePixels[k] = color;
}
}
break;
case 3:
//System.arraycopy(lastFramePixels, 0, framePixels, 0, width * height);
break;
default: break;
}
if (Constants.DEBUG) Log.d(TAG, "graphic control disposal:" + gcExt.disposal);
int tempColor = 0;
if (gcExt.transparentColorFlag) {
tempColor = imgData.colorTable[gcExt.transparentColorIndex];
imgData.colorTable[gcExt.transparentColorIndex] = 0; // set transparent color if specified
}
// 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 < imgDescriptor.height; i++) {
int line = i;
if (imgDescriptor.interlaceFlag) {
if (iline >= imgDescriptor.height) {
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 += imgDescriptor.offY;
if (line < height) {
int k = line * width;
int dx = k + imgDescriptor.offX; // start of line in dest
int dlim = dx + imgDescriptor.width; // end of dest line
if ((k + width) < dlim) {
dlim = k + width; // past dest edge
}
int sx = i * imgDescriptor.width; // start of line in source
while (dx < dlim) {
// map color and insert in destination
int index = ((int) imgData.pixels[sx++]) & 0xff;
int c = imgData.colorTable[index];
if (c != 0) {
framePixels[dx] = c;
}
dx++;
}
}
}
if (gcExt.transparentColorFlag) {
imgData.colorTable[gcExt.transparentColorIndex] = tempColor;
}
lastFrame = frame;
lock.unlock();
}
private void initPixels(int[] pixels, int color) {
if (pixels == null) {
return;
}
for (int i = 0; i < pixels.length; i++) {
pixels[i] = color;
}
}
private boolean err() {
return status != STATUS_PARSING;
}
private int readByte() {
int curByte = 0;
try {
// read 8-bit value
curByte = gifStream.read();
} catch (Exception e) {
status = STATUS_FORMAT_ERROR;
}
return curByte;
}
private int readBlock() {
blockSize = readByte();
int n = 0;
if (blockSize > 0) {
try {
int count = 0;
while (n < blockSize) {
count = gifStream.read(block, n, blockSize - n);
if (count == -1) {
break;
}
n += count;
}
} catch (Exception e) {
e.printStackTrace();
}
if (n < blockSize) {
status = 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 = gifStream.read(c);
} catch (Exception e) {
e.printStackTrace();
}
if (n < nbytes) {
status = STATUS_FORMAT_ERROR;
} else {
tab = new int[256]; // max size to avoid bounds checks
int i = 0;
int j = 0;
while (i < ncolors) {
//TODO: 这里是否需要和0xff做“与”操作？
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 GifGraphicControlExt readGraphicControlExt() {
GifGraphicControlExt ext = new GifGraphicControlExt();
readByte(); // block size
int packed = readByte(); // packed fields
ext.disposal = (packed & 0x1c) >> 2; // disposal method
if (ext.disposal == 0) {
ext.disposal = 1; // elect to keep old image if discretionary
}
ext.transparentColorFlag = (packed & 1) != 0;
ext.delay = readShort() * 10; // delay in milliseconds
ext.transparentColorIndex = readByte(); // transparent color index
readByte(); // block terminator
return ext;
}
private void readNetscapeExt() {
do {
readBlock();
if (block[0] == 1) {
// loop count sub-block
int b1 = ((int) block[1]) & 0xff;
int b2 = ((int) block[2]) & 0xff;
loopCount = (b2 << 8) | b1;
}
} while ((blockSize > 0) && !err());
}
private int readShort() {
// read 16-bit value, LSB first
return readByte() | (readByte() << 8);
}
private void resetFrame() {
currentImgDescriptor = null;
currentGCExt = null;
}
/**
* Skips variable length blocks up to and including next zero length block.
*/
private void skip() {
do {
readBlock();
} while ((blockSize > 0) && !err());
}
private Bitmap createBitmap() {
if (image == null || image.isRecycled()) {
image = Bitmap.createBitmap(width, height, Config.ARGB_8888);
}
return image;
}
}