private View.OnClickListener clickListener = new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 Intent intent = new Intent();
 intent.setType("video/*");
 intent.setAction(Intent.ACTION_GET_CONTENT);
 startActivityForResult(Intent.createChooser(intent, "Select Video"), SELECT_VIDEO);
 }
};
 
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
 if (requestCode == REQUEST_SELECT_VIDEO) {
 if (resultCode == RESULT_OK) {
  Uri videoUri = data.getData();
  filePath = getRealFilePath(videoUri);
 }
 }
}

public List<Bitmap> createBitmaps(String path) {
 MediaMetadataRetriever mmr = new MediaMetadataRetriever();
 mmr.setDataSource(path);
 double inc = 1000 * 1000 / fps;
 
 for (double i = begin; i < end; i += inc) {
 Bitmap frame = mmr.getFrameAtTime((long) i, MediaMetadataRetriever.OPTION_CLOSEST);
 if (frame != null) {
  bitmaps.add(scale(frame));
 }
 }
 
 return bitmaps;
}
 
private Bitmap scale(Bitmap bitmap) {
 return Bitmap.createScaledBitmap(bitmap,
 width > 0 ? width : bitmap.getWidth(),
 height > 0 ? height : bitmap.getHeight(),
 true);
}

protected void getImagePixels() {
 int w = image.getWidth();
 int h = image.getHeight();
 pixels = new byte[w*h*3];
 for (int i = 0; i < h; i++) {
 int stride = w * 3 * i;
 for (int j = 0; j < w; j++) {
  int p = image.getPixel(j, i);
  int step = j * 3;
  int offset = stride + step;
  // blue
  pixels[offset+0] = (byte) ((p & 0x0000FF) >> 0);
  // green
  pixels[offset+1] = (byte) ((p & 0x00FF00) >> 8);
  // red
  pixels[offset+2] = (byte) ((p & 0xFF0000) >> 16); 
 }
 }
}

// 写入文件头
protected void writeHeader() throws IOException {
 writeString("GIF89a");
}
 
protected void writeString(String s) throws IOException {
 for (int i = 0; i < s.length(); i++) {
 out.write((byte) s.charAt(i));
 }
}

// 写入逻辑屏幕标识符
protected void writeLSD() throws IOException {
 writeShort(width); // 写入图像宽度
 writeShort(height); // 写入图像高度
 
 out.write((0x80 | // 全局颜色列表标志置 1
    0x70 | // 确定图象的颜色深度（7+1=8）
    0x00 | // 全局颜色列表分类排列置为 0
    0x07)); // 颜色列表的索引数（2的7+1次方）
 
 out.write(0); // 背景颜色(在全局颜色列表中的索引)
 out.write(0); // 像素宽高比默认 1:1
}
 
protected void writeShort(int value) throws IOException {
 out.write(value & 0xff);
 out.write((value >> 8) & 0xff);
}

// 写入颜色表
protected void writePalette() throws IOException {
 out.write(colorTab, 0, colorTab.length);
 int n = (3 * 256) - colorTab.length;
 for (int i = 0; i < n; i++) {
 out.write(0);
 }
}

protected void writeGraphicCtrlExt() throws IOException {
 out.write(0x21); // 扩展块标识，固定值 0x21
 out.write(0xf9); // 图形控制扩展标签，固定值 0xf9
 out.write(4); // 块大小，固定值 4
 out.write(0 | // 1:3 保留位
   0 | // 4:6 不使用处置方法
   0 | // 7 用户输入标志置 0
   0); // 8 透明色标志置 0
 
 writeShort(delay); // 延迟时间
 out.write(0);  // 透明色索引值
 out.write(0);  // 块终结器，固定值 0
}

protected void writeImageDesc() throws IOException {
 out.write(0x2c); // 图象标识符开始，固定值为 0x2c
 writeShort(0);  // x 方向偏移
 writeShort(0);  // y 方向偏移
 writeShort(width); // 图像宽度
 writeShort(height); // 图像高度
 out.write((
  0x80 |  // 局部颜色列表标志置 1
  0x00 |
  0x00 |
  0x07));  // 局部颜色列表的索引数（2的7+1次方）
}

protected void writePixels() throws IOException {
 LZWEncoder encoder = new LZWEncoder(
  width, height, indexedPixels, colorDepth);
 encoder.encode(out);
}

public void finish() throws IOException {
 out.write(0x3b);
 out.flush();
 out.close();
}