/**
* The CodecOptions parameter should have the following fields set: {@link CodecOptions#width
* width} {@link CodecOptions#height height}
*
* @see Codec#decompress(RandomAccessInputStream, CodecOptions)
*/
@Override
public byte[] decompress(final RandomAccessInputStream in, CodecOptions options)
throws FormatException, IOException {
if (in == null) throw new IllegalArgumentException("No data to decompress.");
if (options == null) options = CodecOptions.getDefaultOptions();
in.skipBytes(8);
final int plane = options.width * options.height;
stride = options.width;
final int rowInc = stride - 4;
short opcode;
int nBlocks;
int colorA = 0, colorB;
final int[] color4 = new int[4];
int index, idx;
int ta, tb;
int blockPtr = 0;
rowPtr = pixelPtr = 0;
int pixelX, pixelY;
final int[] pixels = new int[plane];
final byte[] rtn = new byte[plane * 3];
while (in.read() != (byte) 0xe1) {
/* Read to block metadata */
}
in.skipBytes(3);
// totalBlocks = ((options.width + 3) / 4) * ((options.height + 3) / 4);
while (in.getFilePointer() + 2 < in.length()) {
opcode = in.readByte();
nBlocks = (opcode & 0x1f) + 1;
if ((opcode & 0x80) == 0) {
if (in.getFilePointer() >= in.length()) break;
colorA = (opcode << 8) | in.read();
opcode = 0;
if (in.getFilePointer() >= in.length()) break;
if ((in.read() & 0x80) != 0) {
opcode = 0x20;
nBlocks = 1;
}
in.seek(in.getFilePointer() - 1);
}
switch (opcode & 0xe0) {
case 0x80:
while (nBlocks-- > 0) {
updateBlock(options.width);
}
break;
case 0xa0:
if (in.getFilePointer() + 2 >= in.length()) break;
colorA = in.readShort();
while (nBlocks-- > 0) {
blockPtr = rowPtr + pixelPtr;
for (pixelY = 0; pixelY < 4; pixelY++) {
for (pixelX = 0; pixelX < 4; pixelX++) {
if (blockPtr >= pixels.length) break;
pixels[blockPtr] = colorA;
final short s = (short) (pixels[blockPtr] & 0x7fff);
unpack(s, rtn, blockPtr, pixels.length);
blockPtr++;
}
blockPtr += rowInc;
}
updateBlock(options.width);
}
break;
case 0xc0:
case 0x20:
if (in.getFilePointer() + 2 >= in.length()) break;
if ((opcode & 0xe0) == 0xc0) {
colorA = in.readShort();
}
colorB = in.readShort();
color4[0] = colorB;
color4[1] = 0;
color4[2] = 0;
color4[3] = colorA;
ta = (colorA >> 10) & 0x1f;
tb = (colorB >> 10) & 0x1f;
color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;
ta = (colorA >> 5) & 0x1f;
tb = (colorB >> 5) & 0x1f;
color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;
ta = colorA & 0x1f;
tb = colorB & 0x1f;
color4[1] |= (11 * ta + 21 * tb) >> 5;
color4[2] |= (21 * ta + 11 * tb) >> 5;
while (nBlocks-- > 0) {
blockPtr = rowPtr + pixelPtr;
for (pixelY = 0; pixelY < 4; pixelY++) {
if (in.getFilePointer() >= in.length()) break;
index = in.read();
for (pixelX = 0; pixelX < 4; pixelX++) {
idx = (index >> (2 * (3 - pixelX))) & 3;
if (blockPtr >= pixels.length) break;
pixels[blockPtr] = color4[idx];
final short s = (short) (pixels[blockPtr] & 0x7fff);
unpack(s, rtn, blockPtr, pixels.length);
blockPtr++;
}
blockPtr += rowInc;
}
updateBlock(options.width);
}
break;
case 0x00:
blockPtr = rowPtr + pixelPtr;
for (pixelY = 0; pixelY < 4; pixelY++) {
for (pixelX = 0; pixelX < 4; pixelX++) {
if ((pixelY != 0) || (pixelX != 0)) {
if (in.getFilePointer() + 2 >= in.length()) break;
colorA = in.readShort();
}
if (blockPtr >= pixels.length) break;
pixels[blockPtr] = colorA;
final short s = (short) (pixels[blockPtr] & 0x7fff);
unpack(s, rtn, blockPtr, pixels.length);
blockPtr++;
}
blockPtr += rowInc;
}
updateBlock(options.width);
break;
}
}
return rtn;
}
