AndroidでGIFアニメーションが動いたんだもんね!!

ついにっ

動きました!
GIFアニメーションがっ!
追記 2010-04-22 21:06
ごく一部に正常に表示されないgifアニメーションが存在することが分かりました。
原因はまだ分かっていません。
GWあたりにでも調べてみます。
追記 2010-04-22 21:41
原因が分かりました。
gifをバラバラにする部分にバグがあります。
修正したバージョンは後日公開します。
追記 2010-04-26 16:41
こちらをご利用ください
AndroidでGIFアニメーションが動いたんだもんね(バグフィックス) - 明日の鍵

言い訳とか

以前やった方法はMovieクラスに任せてGifアニメーションをバラバラにしていたんですが
offsetが指定されているGifアニメーションだと正常に表示されないバグがありました。
じゃぁ、自分でバイナリ読んでバラバラにしてImageViewに順番に表示すればいいんじゃね?って思ったので
自分で書いてたのですが、作ったプログラムだとどうも効率が悪かったのでインターネットで探してたんです
Gifをバラバラにするプログラムなんて腐るほどあったので、いろいろ見てたら、
あるじゃないですか!Android版が!
で、よく読んでみるとそのままでGifアニメーションの表示までしてくれそーなんで
動かしてみたら動きました。
以上です。

すこしだけ変更加えました

オリジナルのプログラムだと、まずMovieクラスを使って表示しようとしているので
Movieクラスのくだりを全部消しました。

動作

大きい画像だと重たいです。
GIFアニメーションを自分で用意して、それを使うのであればMovieクラスを使った方が軽いです。ネイティブですから。
デコ美の様にストレージ内のGIFアニメーションを動かすのであれば、重たいけどこのプログラム使った方がいいです。

ソース

GifView.java

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.util.Vector;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Bitmap.Config;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;

public class GifView extends View {

  private static final int DEFAULT_INTERVAL = 250;

  private GifDecoder decoder;
  private Bitmap bitmap;

  private int width;
  private int height;

  private long startTime;
  private int interval;

  private boolean decoding = false;

  private int resId;
  private String filePath;

  private GifListener listener;

  public GifView(Context context, AttributeSet attrs) {
    super(context, attrs);
    init();
  }

  /**
   * Constructor
   */
  public GifView(Context context) {
    super(context);
    init();
  }

  private void init() {
    interval = DEFAULT_INTERVAL;
  }

  public void setListener(GifListener listener) {
    this.listener = listener;
  }

  private InputStream getInputStream() {
    if (filePath != null)
      try {
        return new FileInputStream(filePath);
      } catch (FileNotFoundException e) {
      }
    if (resId > 0)
      return getContext().getResources().openRawResource(resId);
    return null;
  }

  /**
   * set gif file path
   * 
   * @param filePath
   */
  public void setGif(String filePath) {
    this.filePath = filePath;
    decode();
  }

  /**
   * set gif res id
   * 
   * @param resId
   */
  public void setGif(int resId) {
    this.resId = resId;
    decode();
  }

  private void decode() {
    release();
    decoding = true;
    if (listener != null)
      listener.statusChanged(GifListener.START_DECODE);
    new Thread() {
      @Override
      public void run() {
        try {
          GifDecoder decoder = new GifDecoder();
          decoder.read(getInputStream());
          width = decoder.width;
          height = decoder.height;
          if (width == 0 || height == 0)
            throw new Exception();
          GifView.this.decoder = decoder;
          if (listener != null)
            listener.statusChanged(GifListener.DECODE_SUCCESS);
        } catch (Throwable e) {
          Log.e("GifView", e.getMessage(), e);
          try {
            Bitmap bitmap = BitmapFactory.decodeStream(getInputStream());
            width = bitmap.getWidth();
            height = bitmap.getHeight();
            GifView.this.bitmap = bitmap;
          } catch (Exception e1) {
          }
          if (listener != null)
            listener.statusChanged(GifListener.DECODE_ERROR);
        } finally {
          postInvalidate();
          decoding = false;
        }
      }
    }.start();
  }

  /**
   * set gif frame interval
   * 
   * @param interval
   */
  public void setInterval(int interval) {
    if (interval >= 20 && interval <= 10000)
      this.interval = interval;
  }

  /*
   * @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { setMeasuredDimension(width, height); }
   */
  public void release() {
    decoder = null;
    bitmap = null;
  }

  @Override
  protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    if (decoding) {
      Paint paint = new Paint();
      paint.setColor(Color.rgb(180, 150, 150));
      canvas.drawText("Loading ...", 20, 30, paint);
      invalidate();
      return;
    }
    float left = (getWidth() - width) / 2f, top = (getHeight() - height) / 2f;

    if (bitmap != null) {
      canvas.drawBitmap(bitmap, left, top, null);
      return;
    }
    long now = System.currentTimeMillis();
    if (startTime == 0)
      startTime = now;
    int time = (int) (now - startTime);

    if (decoder == null)
      return;
    int index = time / interval;
    Bitmap bitmap = decoder.getFrame(index);
    if (bitmap != null)
      canvas.drawBitmap(bitmap, left, top, null);
    if (index == decoder.getFrameCount() && listener != null)
      listener.statusChanged(GifListener.PLAY_END);

    invalidate();
  }

  public interface GifListener {
    public static final int START_DECODE = 1;
    public static final int DECODE_SUCCESS = 2;
    public static final int DECODE_ERROR = 3;
    public static final int PLAY_END = 4;

    void statusChanged(int status);
  }

  public static class GifDecoder {
    /**
     * 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 */
    protected static final int MAX_STACK_SIZE = 4096;
    protected InputStream in;
    protected int status;
    protected int width; // full image width
    protected int height; // full image height
    protected boolean gctFlag; // global color table used
    protected int gctSize; // size of global color table
    protected int loopCount = 1; // iterations; 0 = repeat forever
    protected int[] gct; // global color table
    protected int[] lct; // local color table
    protected int[] act; // active color table
    protected int bgIndex; // background color index
    protected int bgColor; // background color
    protected int lastBgColor; // previous bg color
    protected int pixelAspect; // pixel aspect ratio
    protected boolean lctFlag; // local color table flag
    protected boolean interlace; // interlace flag
    protected int lctSize; // local color table size
    protected int ix, iy, iw, ih; // current image rectangle
    protected int lrx, lry, lrw, lrh;
    protected Bitmap image; // current frame
    protected Bitmap lastBitmap; // previous frame
    protected byte[] block = new byte[256]; // current data block
    protected int blockSize = 0; // block size last graphic control extension info
    protected int dispose = 0; // 0=no action; 1=leave in place; 2=restore to bg; 3=restore to prev
    protected int lastDispose = 0;
    protected boolean transparency = false; // use transparent color
    protected int delay = 0; // delay in milliseconds
    protected int transIndex; // transparent color index
    // LZW decoder working arrays
    protected short[] prefix;
    protected byte[] suffix;
    protected byte[] pixelStack;
    protected byte[] pixels;
    protected Vector<GifFrame> frames; // frames read from current file
    protected int frameCount;

    private static class GifFrame {
      public GifFrame(Bitmap im, int del) {
        image = im;
        delay = del;
      }

      public Bitmap image;
      public int delay;
    }

    /**
     * Gets display duration for specified frame.
     * 
     * @param n
     *          int index of frame
     * @return delay in milliseconds
     */
    public int getDelay(int n) {
      delay = -1;
      if ((n >= 0) && (n < frameCount)) {
        delay = frames.elementAt(n).delay;
      }
      return delay;
    }

    /**
     * Gets the number of frames read from file.
     * 
     * @return frame count
     */
    public int getFrameCount() {
      return frameCount;
    }

    /**
     * Gets the first (or only) image read.
     * 
     * @return BufferedBitmap containing first frame, or null if none.
     */
    public Bitmap getBitmap() {
      return getFrame(0);
    }

    /**
     * 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 loopCount;
    }

    /**
     * Creates new frame image from current data (and previous frames as specified by their disposition codes).
     */
    protected void setPixels() {
      // expose destination image's pixels as int array
      int[] dest = new int[width * height];
      // fill in starting image contents based on last image's dispose code
      if (lastDispose > 0) {
        if (lastDispose == 3) {
          // use image before last
          int n = frameCount - 2;
          if (n > 0) {
            lastBitmap = getFrame(n - 1);
          } else {
            lastBitmap = null;
          }
        }
        if (lastBitmap != null) {
          lastBitmap.getPixels(dest, 0, width, 0, 0, width, height);
          // copy pixels
          if (lastDispose == 2) {
            // fill last image rect area with background color
            int c = 0;
            if (!transparency) {
              c = lastBgColor;
            }
            for (int i = 0; i < lrh; i++) {
              int n1 = (lry + i) * width + lrx;
              int n2 = n1 + lrw;
              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 < ih; i++) {
        int line = i;
        if (interlace) {
          if (iline >= 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 += iy;
        if (line < height) {
          int k = line * width;
          int dx = k + ix; // start of line in dest
          int dlim = dx + iw; // end of dest line
          if ((k + width) < dlim) {
            dlim = k + width; // past dest edge
          }
          int sx = i * iw; // start of line in source
          while (dx < dlim) {
            // map color and insert in destination
            int index = ((int) pixels[sx++]) & 0xff;
            int c = act[index];
            if (c != 0) {
              dest[dx] = c;
            }
            dx++;
          }
        }
      }
      image = Bitmap.createBitmap(dest, width, height, Config.ARGB_4444);
    }

    /**
     * Gets the image contents of frame n.
     * 
     * @return BufferedBitmap representation of frame, or null if n is invalid.
     */
    public Bitmap getFrame(int n) {
      if (frameCount <= 0)
        return null;
      n = n % frameCount;
      return ((GifFrame) frames.elementAt(n)).image;
    }

    /**
     * Reads GIF image from stream
     * 
     * @param is
     *          containing GIF file.
     * @return read status code (0 = no errors)
     */
    public int read(InputStream is) {
      init();
      if (is != null) {
        in = is;
        readHeader();
        if (!err()) {
          readContents();
          if (frameCount < 0) {
            status = STATUS_FORMAT_ERROR;
          }
        }
      } else {
        status = STATUS_OPEN_ERROR;
      }
      try {
        is.close();
      } catch (Exception e) {
      }
      return status;
    }

    /**
     * Decodes LZW image data into pixel array. Adapted from John Cristy's BitmapMagick.
     */
    protected void decodeBitmapData() {
      int nullCode = -1;
      int npix = iw * 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 ((pixels == null) || (pixels.length < npix)) {
        pixels = 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--;
        pixels[pi++] = pixelStack[top];
        i++;
      }
      for (i = pi; i < npix; i++) {
        pixels[i] = 0; // clear missing pixels
      }
    }

    /**
     * Returns true if an error was encountered during reading/decoding
     */
    protected boolean err() {
      return status != STATUS_OK;
    }

    /**
     * Initializes or re-initializes reader
     */
    protected void init() {
      status = STATUS_OK;
      frameCount = 0;
      frames = new Vector<GifFrame>();
      gct = null;
      lct = null;
    }

    /**
     * Reads a single byte from the input stream.
     */
    protected int read() {
      int curByte = 0;
      try {
        curByte = in.read();
      } catch (Exception e) {
        status = STATUS_FORMAT_ERROR;
      }
      return curByte;
    }

    /**
     * Reads next variable length block from input.
     * 
     * @return number of bytes stored in "buffer"
     */
    protected int readBlock() {
      blockSize = read();
      int n = 0;
      if (blockSize > 0) {
        try {
          int count = 0;
          while (n < blockSize) {
            count = in.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;
    }

    /**
     * Reads color table as 256 RGB integer values
     * 
     * @param ncolors
     *          int number of colors to read
     * @return int array containing 256 colors (packed ARGB with full alpha)
     */
    protected int[] readColorTable(int ncolors) {
      int nbytes = 3 * ncolors;
      int[] tab = null;
      byte[] c = new byte[nbytes];
      int n = 0;
      try {
        n = in.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) {
          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;
    }

    /**
     * Main file parser. Reads GIF content blocks.
     */
    protected void readContents() {
      // read GIF file content blocks
      boolean done = false;
      while (!(done || err())) {
        int code = read();
        switch (code) {
        case 0x2C: // image separator
          readBitmap();
          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) block[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:
          status = STATUS_FORMAT_ERROR;
        }
      }
    }

    /**
     * Reads Graphics Control Extension values
     */
    protected void readGraphicControlExt() {
      read(); // block size
      int packed = read(); // packed fields
      dispose = (packed & 0x1c) >> 2; // disposal method
      if (dispose == 0) {
        dispose = 1; // elect to keep old image if discretionary
      }
      transparency = (packed & 1) != 0;
      delay = readShort() * 10; // delay in milliseconds
      transIndex = read(); // transparent color index
      read(); // block terminator
    }

    /**
     * Reads GIF file header information.
     */
    protected void readHeader() {
      String id = "";
      for (int i = 0; i < 6; i++) {
        id += (char) read();
      }
      if (!id.startsWith("GIF")) {
        status = STATUS_FORMAT_ERROR;
        return;
      }
      readLSD();
      if (gctFlag && !err()) {
        gct = readColorTable(gctSize);
        bgColor = gct[bgIndex];
      }
    }

    /**
     * Reads next frame image
     */
    protected void readBitmap() {
      ix = readShort(); // (sub)image position & size
      iy = readShort();
      iw = readShort();
      ih = readShort();
      int packed = read();
      lctFlag = (packed & 0x80) != 0; // 1 - local color table flag interlace
      // = (packed & 0x40) != 0; // 2 -
      // interlace flag
      // 3 - sort flag
      // 4-5 - reserved lctSize = 2 << (packed & 7); // 6-8 - local color
      // table size
      if (lctFlag) {
        lct = readColorTable(lctSize); // read table
        act = lct; // make local table active
      } else {
        act = gct; // make global table active
        if (bgIndex == transIndex) {
          bgColor = 0;
        }
      }
      int save = 0;
      if (transparency) {
        save = act[transIndex];
        act[transIndex] = 0; // set transparent color if specified
      }
      if (act == null) {
        status = STATUS_FORMAT_ERROR; // no color table defined
      }
      if (err()) {
        return;
      }
      decodeBitmapData(); // decode pixel data
      skip();
      if (err()) {
        return;
      }
      frameCount++;
      // create new image to receive frame data
      image = Bitmap.createBitmap(width, height, Config.ARGB_4444);
      setPixels(); // transfer pixel data to image
      frames.addElement(new GifFrame(image, delay)); // add image to frame
      // list
      if (transparency) {
        act[transIndex] = save;
      }
      resetFrame();
    }

    /**
     * Reads Logical Screen Descriptor
     */
    protected void readLSD() {
      // logical screen size
      width = readShort();
      height = readShort();
      // packed fields
      int packed = read();
      gctFlag = (packed & 0x80) != 0; // 1 : global color table flag
      // 2-4 : color resolution
      // 5 : gct sort flag
      gctSize = 2 << (packed & 7); // 6-8 : gct size
      bgIndex = read(); // background color index
      pixelAspect = read(); // pixel aspect ratio
    }

    /**
     * Reads Netscape extenstion to obtain iteration count
     */
    protected 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());
    }

    /**
     * Reads next 16-bit value, LSB first
     */
    protected int readShort() {
      // read 16-bit value, LSB first
      return read() | (read() << 8);
    }

    /**
     * Resets frame state for reading next image.
     */
    protected void resetFrame() {
      lastDispose = dispose;
      lrx = ix;
      lry = iy;
      lrw = iw;
      lrh = ih;
      lastBitmap = image;
      lastBgColor = bgColor;
      dispose = 0;
      transparency = false;
      delay = 0;
      lct = null;
    }

    /**
     * Skips variable length blocks up to and including next zero length block.
     */
    protected void skip() {
      do {
        readBlock();
      } while ((blockSize > 0) && !err());
    }
  }

}

サンプルプロジェクト

GifViewer.zip 直

デコメ絵文字

サンプルに含まれている画像はMovieクラスを使って表示しようとすると正常に表示されない画像です。
ちなみに自作です。
mspaintとバイナリエディタを使って描きました。


使ってください。