| package com.bumptech.glide.gifdecoder; |
| |
| |
| /** |
| * Copyright (c) 2013 Xcellent Creations, Inc. |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining |
| * a copy of this software and associated documentation files (the |
| * "Software"), to deal in the Software without restriction, including |
| * without limitation the rights to use, copy, modify, merge, publish, |
| * distribute, sublicense, and/or sell copies of the Software, and to |
| * permit persons to whom the Software is furnished to do so, subject to |
| * the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be |
| * included in all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE |
| * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION |
| * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION |
| * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| */ |
| |
| import android.graphics.Bitmap; |
| import android.graphics.Color; |
| import android.util.Log; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.nio.ByteBuffer; |
| import java.nio.ByteOrder; |
| |
| /** |
| * Reads frame data from a GIF image source and decodes it into individual frames |
| * for animation purposes. Image data can be read from either and InputStream source |
| * or a byte[]. |
| * |
| * This class is optimized for running animations with the frames, there |
| * are no methods to get individual frame images, only to decode the next frame in the |
| * animation sequence. Instead, it lowers its memory footprint by only housing the minimum |
| * data necessary to decode the next frame in the animation sequence. |
| * |
| * The animation must be manually moved forward using {@link #advance()} before requesting the next |
| * frame. This method must also be called before you request the first frame or an error will |
| * occur. |
| * |
| * Implementation adapted from sample code published in Lyons. (2004). <em>Java for Programmers</em>, |
| * republished under the MIT Open Source License |
| */ |
| public class GifDecoder { |
| private static final String TAG = GifDecoder.class.getSimpleName(); |
| |
| /** |
| * File read status: No errors. |
| */ |
| public static final int STATUS_OK = 0; |
| /** |
| * File read status: Error decoding file (may be partially decoded) |
| */ |
| public static final int STATUS_FORMAT_ERROR = 1; |
| /** |
| * File read status: Unable to open source. |
| */ |
| public static final int STATUS_OPEN_ERROR = 2; |
| /** |
| * max decoder pixel stack size |
| */ |
| private static final int MAX_STACK_SIZE = 4096; |
| |
| /** |
| * GIF Disposal Method meaning take no action |
| */ |
| private static final int DISPOSAL_UNSPECIFIED = 0; |
| /** |
| * GIF Disposal Method meaning leave canvas from previous frame |
| */ |
| private static final int DISPOSAL_NONE = 1; |
| /** |
| * GIF Disposal Method meaning clear canvas to background color |
| */ |
| private static final int DISPOSAL_BACKGROUND = 2; |
| /** |
| * GIF Disposal Method meaning clear canvas to frame before last |
| */ |
| private static final int DISPOSAL_PREVIOUS = 3; |
| |
| //Global File Header values and parsing flags |
| private int[] act; // active color table |
| |
| // Raw GIF data from input source |
| private ByteBuffer rawData; |
| |
| // Raw data read working array |
| private byte[] block = new byte[256]; // current data block |
| // LZW decoder working arrays |
| private short[] prefix; |
| private byte[] suffix; |
| private byte[] pixelStack; |
| private byte[] mainPixels; |
| private int[] mainScratch; |
| |
| private int framePointer = -1; |
| private byte[] data; |
| private GifHeader header; |
| private String id; |
| private BitmapProvider bitmapProvider; |
| |
| public interface BitmapProvider { |
| public Bitmap obtain(int width, int height, Bitmap.Config config); |
| } |
| |
| public GifDecoder(BitmapProvider provider) { |
| this.bitmapProvider = provider; |
| header = new GifHeader(); |
| } |
| |
| public int getWidth() { |
| return header.width; |
| } |
| |
| public int getHeight() { |
| return header.height; |
| } |
| |
| public boolean isTransparent() { |
| return header.isTransparent; |
| } |
| |
| public int getGifByteSize() { |
| return data.length; |
| } |
| |
| public byte[] getData() { |
| return data; |
| } |
| |
| public int getDecodedFramesByteSizeSum() { |
| // 4 == ARGB_8888, 2 == RGB_565 |
| return header.frameCount * header.width * header.height * (header.isTransparent ? 4 : 2); |
| } |
| |
| /** |
| * Move the animation frame counter forward |
| */ |
| public void advance() { |
| framePointer = (framePointer + 1) % header.frameCount; |
| } |
| |
| /** |
| * Gets display duration for specified frame. |
| * |
| * @param n int index of frame |
| * @return delay in milliseconds |
| */ |
| public int getDelay(int n) { |
| int delay = -1; |
| if ((n >= 0) && (n < header.frameCount)) { |
| delay = header.frames.get(n).delay; |
| } |
| return delay; |
| } |
| |
| /** |
| * Gets display duration for the upcoming frame |
| */ |
| public int getNextDelay() { |
| if (header.frameCount <= 0 || framePointer < 0) { |
| return -1; |
| } |
| |
| return getDelay(framePointer); |
| } |
| |
| /** |
| * Gets the number of frames read from file. |
| * |
| * @return frame count |
| */ |
| public int getFrameCount() { |
| return header.frameCount; |
| } |
| |
| /** |
| * Gets the current index of the animation frame, or -1 if animation hasn't not yet started |
| * |
| * @return frame index |
| */ |
| public int getCurrentFrameIndex() { |
| return framePointer; |
| } |
| |
| /** |
| * Gets the "Netscape" iteration count, if any. A count of 0 means repeat indefinitiely. |
| * |
| * @return iteration count if one was specified, else 1. |
| */ |
| public int getLoopCount() { |
| return header.loopCount; |
| } |
| |
| public String getId() { |
| return id; |
| } |
| |
| /** |
| * Get the next frame in the animation sequence. |
| * |
| * @return Bitmap representation of frame |
| */ |
| public Bitmap getNextFrame() { |
| if (header.frameCount <= 0 || framePointer < 0 ) { |
| return null; |
| } |
| |
| GifFrame frame = header.frames.get(framePointer); |
| |
| //Set the appropriate color table |
| if (frame.lct == null) { |
| act = header.gct; |
| } else { |
| act = frame.lct; |
| if (header.bgIndex == frame.transIndex) { |
| header.bgColor = 0; |
| } |
| } |
| |
| int save = 0; |
| if (frame.transparency) { |
| save = act[frame.transIndex]; |
| act[frame.transIndex] = 0; // set transparent color if specified |
| } |
| if (act == null) { |
| Log.w(TAG, "No Valid Color Table"); |
| header.status = STATUS_FORMAT_ERROR; // no color table defined |
| return null; |
| } |
| |
| Bitmap result = setPixels(framePointer); // transfer pixel data to image |
| |
| // Reset the transparent pixel in the color table |
| if (frame.transparency) { |
| act[frame.transIndex] = save; |
| } |
| |
| return result; |
| } |
| |
| /** |
| * Reads GIF image from stream |
| * |
| * @param is containing GIF file. |
| * @return read status code (0 = no errors) |
| */ |
| public int read(InputStream is, int contentLength) { |
| if (is != null) { |
| try { |
| int capacity = (contentLength > 0) ? (contentLength + 4096) : 16384; |
| ByteArrayOutputStream buffer = new ByteArrayOutputStream(capacity); |
| int nRead; |
| byte[] data = new byte[16384]; |
| while ((nRead = is.read(data, 0, data.length)) != -1) { |
| buffer.write(data, 0, nRead); |
| } |
| buffer.flush(); |
| |
| read(buffer.toByteArray()); |
| } catch (IOException e) { |
| Log.w(TAG, "Error reading data from stream", e); |
| } |
| } else { |
| header.status = STATUS_OPEN_ERROR; |
| } |
| |
| try { |
| if (is != null) { |
| is.close(); |
| } |
| } catch (IOException e) { |
| Log.w(TAG, "Error closing stream", e); |
| } |
| |
| return header.status; |
| } |
| |
| public void setData(String id, GifHeader header, byte[] data) { |
| this.id = id; |
| this.header = header; |
| this.data = data; |
| //Initialize the raw data buffer |
| rawData = ByteBuffer.wrap(data); |
| rawData.rewind(); |
| rawData.order(ByteOrder.LITTLE_ENDIAN); |
| |
| //Now that we know the size, init scratch arrays |
| mainPixels = new byte[header.width * header.height]; |
| mainScratch = new int[header.width * header.height]; |
| } |
| |
| /** |
| * Reads GIF image from byte array |
| * |
| * @param data containing GIF file. |
| * @return read status code (0 = no errors) |
| */ |
| public int read(byte[] data) { |
| this.data = data; |
| this.header = new GifHeaderParser(data).parseHeader(); |
| if (data != null) { |
| //Initialize the raw data buffer |
| rawData = ByteBuffer.wrap(data); |
| rawData.rewind(); |
| rawData.order(ByteOrder.LITTLE_ENDIAN); |
| |
| //Now that we know the size, init scratch arrays |
| mainPixels = new byte[header.width * header.height]; |
| mainScratch = new int[header.width * header.height]; |
| } |
| |
| return header.status; |
| } |
| |
| /** |
| * Creates new frame image from current data (and previous frames as specified by their disposition codes). |
| */ |
| private Bitmap setPixels(int frameIndex) { |
| GifFrame currentFrame = header.frames.get(frameIndex); |
| GifFrame previousFrame = null; |
| int previousIndex = frameIndex - 1; |
| if (previousIndex >= 0) { |
| previousFrame = header.frames.get(previousIndex); |
| } |
| |
| // final location of blended pixels |
| final int[] dest = mainScratch; |
| |
| // fill in starting image contents based on last image's dispose code |
| if (previousFrame != null && previousFrame.dispose > DISPOSAL_UNSPECIFIED) { |
| // if (previousFrame.dispose == DISPOSAL_NONE) { |
| // We don't need to do anything for this case, mainScratch should already have the pixels of the |
| // previous image. |
| // currentImage.getPixels(dest, 0, header.width, 0, 0, header.width, header.height); |
| // } |
| if (previousFrame.dispose == DISPOSAL_BACKGROUND) { |
| // Start with a canvas filled with the background color |
| int c = 0; |
| if (!currentFrame.transparency) { |
| c = header.bgColor; |
| } |
| for (int i = 0; i < previousFrame.ih; i++) { |
| int n1 = (previousFrame.iy + i) * header.width + previousFrame.ix; |
| int n2 = n1 + previousFrame.iw; |
| for (int k = n1; k < n2; k++) { |
| dest[k] = c; |
| } |
| } |
| } |
| } else { |
| int c = 0; |
| if (!currentFrame.transparency) { |
| c = header.bgColor; |
| } |
| for (int i = 0; i < dest.length; i++) { |
| dest[i] = c; |
| } |
| } |
| |
| // Decode pixels for this frame into the global pixels[] scratch |
| decodeBitmapData(currentFrame, mainPixels); // decode pixel data |
| |
| // 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 < currentFrame.ih; i++) { |
| int line = i; |
| if (currentFrame.interlace) { |
| if (iline >= currentFrame.ih) { |
| pass++; |
| switch (pass) { |
| case 2: |
| iline = 4; |
| break; |
| case 3: |
| iline = 2; |
| inc = 4; |
| break; |
| case 4: |
| iline = 1; |
| inc = 2; |
| break; |
| default: |
| break; |
| } |
| } |
| line = iline; |
| iline += inc; |
| } |
| line += currentFrame.iy; |
| if (line < header.height) { |
| int k = line * header.width; |
| int dx = k + currentFrame.ix; // start of line in dest |
| int dlim = dx + currentFrame.iw; // end of dest line |
| if ((k + header.width) < dlim) { |
| dlim = k + header.width; // past dest edge |
| } |
| int sx = i * currentFrame.iw; // start of line in source |
| while (dx < dlim) { |
| // map color and insert in destination |
| int index = ((int) mainPixels[sx++]) & 0xff; |
| int c = act[index]; |
| if (c != 0) { |
| dest[dx] = c; |
| } |
| dx++; |
| } |
| } |
| } |
| |
| //Set pixels for current image |
| Bitmap result = getNextBitmap(); |
| result.setPixels(dest, 0, header.width, 0, 0, header.width, header.height); |
| return result; |
| } |
| |
| /** |
| * Decodes LZW image data into pixel array. Adapted from John Cristy's BitmapMagick. |
| */ |
| private void decodeBitmapData(GifFrame frame, byte[] dstPixels) { |
| if (frame != null) { |
| //Jump to the frame start position |
| rawData.position(frame.bufferFrameStart); |
| } |
| |
| int nullCode = -1; |
| int npix = (frame == null) ? header.width * header.height : frame.iw * frame.ih; |
| 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 (dstPixels == null || dstPixels.length < npix) { |
| dstPixels = new byte[npix]; // allocate new pixel array |
| } |
| if (prefix == null) { |
| prefix = new short[MAX_STACK_SIZE]; |
| } |
| if (suffix == null) { |
| suffix = new byte[MAX_STACK_SIZE]; |
| } |
| if (pixelStack == null) { |
| pixelStack = new byte[MAX_STACK_SIZE + 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++) { |
| prefix[code] = 0; // XXX ArrayIndexOutOfBoundsException |
| 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 >= MAX_STACK_SIZE) { |
| break; |
| } |
| pixelStack[top++] = (byte) first; |
| prefix[available] = (short) old_code; |
| suffix[available] = (byte) first; |
| available++; |
| if (((available & code_mask) == 0) && (available < MAX_STACK_SIZE)) { |
| code_size++; |
| code_mask += available; |
| } |
| old_code = in_code; |
| } |
| // Pop a pixel off the pixel stack. |
| top--; |
| dstPixels[pi++] = pixelStack[top]; |
| i++; |
| } |
| |
| for (i = pi; i < npix; i++) { |
| dstPixels[i] = 0; // clear missing pixels |
| } |
| } |
| |
| /** |
| * Reads a single byte from the input stream. |
| */ |
| private int read() { |
| int curByte = 0; |
| try { |
| curByte = (rawData.get() & 0xFF); |
| } catch (Exception e) { |
| header.status = STATUS_FORMAT_ERROR; |
| } |
| return curByte; |
| } |
| |
| /** |
| * Reads next variable length block from input. |
| * |
| * @return number of bytes stored in "buffer" |
| */ |
| private int readBlock() { |
| int blockSize = read(); |
| int n = 0; |
| if (blockSize > 0) { |
| try { |
| int count; |
| while (n < blockSize) { |
| count = blockSize - n; |
| rawData.get(block, n, count); |
| |
| n += count; |
| } |
| } catch (Exception e) { |
| Log.w(TAG, "Error Reading Block", e); |
| header.status = STATUS_FORMAT_ERROR; |
| } |
| } |
| return n; |
| } |
| |
| private Bitmap getNextBitmap() { |
| Bitmap.Config targetConfig = header.isTransparent ? Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565; |
| Bitmap result = bitmapProvider.obtain(header.width, header.height, targetConfig); |
| if (result == null) { |
| result = Bitmap.createBitmap(header.width, header.height, targetConfig); |
| } else { |
| // If we're reusing a bitmap it may have other things drawn in it which we need to remove. |
| result.eraseColor(Color.TRANSPARENT); |
| } |
| return result; |
| } |
| } |