public static byte[] Decompress(byte[] input, SnmVideoFrame video, Blocky16Context context)
{
if (input == null)
{
throw new ArgumentNullException(nameof(input));
}
if (video == null)
{
throw new ArgumentNullException(nameof(video));
}
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (video.Sequence == 0)
{
context.Clear(video.BackgroundColor);
}
switch (video.SubcodecId)
{
case 0:
Array.Copy(input, 0, context.Buffer0, 0, context.BufferSize);
break;
case 1:
throw new NotImplementedException("SubcodecId 1");
case 2:
{
int hblocks = (int)((video.Height + 7) & 0xFFFFFFF8);
int wblocks = (int)((video.Width + 7) & 0xFFFFFFF8);
int inputPos = 0;
for (int cy = 0; cy < hblocks; cy += 8)
{
for (int cx = 0; cx < wblocks; cx += 8)
{
Level(8, input, ref inputPos, video, context, cx, cy);
}
}
break;
}
case 3:
Array.Copy(context.Buffer2, 0, context.Buffer0, 0, context.BufferSize);
break;
case 4:
Array.Copy(context.Buffer1, 0, context.Buffer0, 0, context.BufferSize);
break;
case 5:
for (int pos = 0, inputPos = 0; pos < video.RleOutputSize;)
{
byte code = input[inputPos];
inputPos++;
int length = (code >> 1) + 1;
if ((code & 1) != 0)
{
byte color = input[inputPos];
inputPos++;
for (int i = 0; i < length; i++)
{
context.Buffer0[pos + i] = color;
}
}
else
{
Array.Copy(input, inputPos, context.Buffer0, pos, length);
inputPos += length;
}
pos += length;
}
break;
case 6:
for (int pos = 0, inputPos = 0; pos < context.BufferSize; pos += 2)
{
byte index = input[inputPos];
inputPos++;
ushort color = video.Codebook[index];
context.Buffer0[pos] = (byte)color;
context.Buffer0[pos + 1] = (byte)(color >> 8);
}
break;
case 7:
throw new NotImplementedException("SubcodecId 7");
case 8:
for (int pos = 0, inputPos = 0; pos < video.RleOutputSize;)
{
byte code = input[inputPos];
inputPos++;
int length2 = ((code >> 1) + 1) * 2;
if ((code & 1) != 0)
{
byte index = input[inputPos];
inputPos++;
ushort color = video.Codebook[index];
for (int i = 0; i < length2; i += 2)
{
context.Buffer0[pos + i] = (byte)color;
context.Buffer0[pos + i + 1] = (byte)(color >> 8);
}
}
else
{
for (int i = 0; i < length2; i += 2)
{
byte index = input[inputPos];
inputPos++;
ushort color = video.Codebook[index];
context.Buffer0[pos + i] = (byte)color;
context.Buffer0[pos + i + 1] = (byte)(color >> 8);
}
}
pos += length2;
}
break;
default:
throw new NotSupportedException();
}
byte[] output = context.Buffer0;
context.RotateBuffers(video.DiffBufferRotateCode);
return(output);
}
private static void Level(int param, byte[] input, ref int inputPos, SnmVideoFrame video, Blocky16Context context, int cx, int cy)
{
byte opcode = input[inputPos];
inputPos++;
int stride = video.Width * 2;
int pos = cy * stride + cx * 2;
if (opcode <= 0xF4)
{
int x = _motion_vectors[opcode * 2];
int y = _motion_vectors[opcode * 2 + 1];
int offset = y * stride + x * 2;
for (int i = 0; i < param; i++)
{
if (pos + offset + param * 2 > context.BufferSize)
{
break;
}
Array.Copy(context.Buffer2, pos + offset, context.Buffer0, pos, param * 2);
pos += stride;
}
}
else if (opcode == 0xF5)
{
int motion_vector = BitConverter.ToInt16(input, inputPos);
inputPos += 2;
int x = motion_vector % video.Width;
int y = motion_vector / video.Width;
int offset = y * stride + x * 2;
for (int i = 0; i < param; i++)
{
if (pos + offset + param * 2 > context.BufferSize)
{
break;
}
Array.Copy(context.Buffer2, pos + offset, context.Buffer0, pos, param * 2);
pos += stride;
}
}
else if (opcode == 0xF6)
{
for (int i = 0; i < param; i++)
{
if (pos + param * 2 > context.BufferSize)
{
break;
}
Array.Copy(context.Buffer1, pos, context.Buffer0, pos, param * 2);
pos += stride;
}
}
else if (opcode == 0xF7)
{
if (param > 2)
{
byte glyph_index = input[inputPos++];
byte fg_index = input[inputPos++];
byte bg_index = input[inputPos++];
ushort fg_color = video.Codebook[fg_index];
ushort bg_color = video.Codebook[bg_index];
byte[] glyph;
int glyphWidth;
if (param == 8)
{
glyph = _glyph8_cb[glyph_index];
glyphWidth = 8;
}
else
{
glyph = _glyph4_cb[glyph_index];
glyphWidth = 4;
}
byte bgLow = (byte)bg_color;
byte bgHigh = (byte)(bg_color >> 8);
byte fgLow = (byte)fg_color;
byte fgHigh = (byte)(fg_color >> 8);
for (int i = 0; i < param; i++)
{
for (int j = 0; j < param; j++)
{
if (glyph[i * glyphWidth + j] == 0)
{
context.Buffer0[pos + j * 2] = bgLow;
context.Buffer0[pos + j * 2 + 1] = bgHigh;
}
else
{
context.Buffer0[pos + j * 2] = fgLow;
context.Buffer0[pos + j * 2 + 1] = fgHigh;
}
}
pos += stride;
}
}
else
{
for (int i = 0; i < 2; i++)
{
for (int j = 0; j < 2 * 2; j += 2)
{
byte index = input[inputPos++];
ushort color = video.Codebook[index];
context.Buffer0[pos + j] = (byte)color;
context.Buffer0[pos + j + 1] = (byte)(color >> 8);
}
pos += stride;
}
}
}
else if (opcode == 0xF8)
{
if (param > 2)
{
byte glyph_index = input[inputPos++];
ushort fg_color = BitConverter.ToUInt16(input, inputPos);
inputPos += 2;
ushort bg_color = BitConverter.ToUInt16(input, inputPos);
inputPos += 2;
byte[] glyph;
int glyphWidth;
if (param == 8)
{
glyph = _glyph8_cb[glyph_index];
glyphWidth = 8;
}
else
{
glyph = _glyph4_cb[glyph_index];
glyphWidth = 4;
}
byte bgLow = (byte)bg_color;
byte bgHigh = (byte)(bg_color >> 8);
byte fgLow = (byte)fg_color;
byte fgHigh = (byte)(fg_color >> 8);
for (int i = 0; i < param; i++)
{
for (int j = 0; j < param; j++)
{
if (glyph[i * glyphWidth + j] == 0)
{
context.Buffer0[pos + j * 2] = bgLow;
context.Buffer0[pos + j * 2 + 1] = bgHigh;
}
else
{
context.Buffer0[pos + j * 2] = fgLow;
context.Buffer0[pos + j * 2 + 1] = fgHigh;
}
}
pos += stride;
}
}
else
{
for (int i = 0; i < 2; i++)
{
for (int j = 0; j < 2 * 2; j += 2)
{
context.Buffer0[pos + j] = input[inputPos++];
context.Buffer0[pos + j + 1] = input[inputPos++];
}
pos += stride;
}
}
}
else if (opcode >= 0xF9 && opcode <= 0xFC)
{
ushort color = video.SmallCodebook[opcode - 0xF9];
byte lowColor = (byte)color;
byte highColor = (byte)(color >> 8);
for (int i = 0; i < param; i++)
{
for (int j = 0; j < param * 2; j += 2)
{
context.Buffer0[pos + j] = lowColor;
context.Buffer0[pos + j + 1] = highColor;
}
pos += stride;
}
}
else if (opcode == 0xFD)
{
byte index = input[inputPos++];
ushort color = video.Codebook[index];
byte lowColor = (byte)color;
byte highColor = (byte)(color >> 8);
for (int i = 0; i < param; i++)
{
for (int j = 0; j < param * 2; j += 2)
{
context.Buffer0[pos + j] = lowColor;
context.Buffer0[pos + j + 1] = highColor;
}
pos += stride;
}
}
else if (opcode == 0xFE)
{
ushort color = BitConverter.ToUInt16(input, inputPos);
inputPos += 2;
byte lowColor = (byte)color;
byte highColor = (byte)(color >> 8);
for (int i = 0; i < param; i++)
{
for (int j = 0; j < param * 2; j += 2)
{
context.Buffer0[pos + j] = lowColor;
context.Buffer0[pos + j + 1] = highColor;
}
pos += stride;
}
}
else if (opcode == 0xFF)
{
if (param > 2)
{
int nextLevel = param / 2;
Level(nextLevel, input, ref inputPos, video, context, cx, cy);
Level(nextLevel, input, ref inputPos, video, context, cx + nextLevel, cy);
Level(nextLevel, input, ref inputPos, video, context, cx, cy + nextLevel);
Level(nextLevel, input, ref inputPos, video, context, cx + nextLevel, cy + nextLevel);
}
else
{
for (int i = 0; i < 2; i++)
{
for (int j = 0; j < 2 * 2; j += 2)
{
context.Buffer0[pos + j] = input[inputPos++];
context.Buffer0[pos + j + 1] = input[inputPos++];
}
pos += stride;
}
}
}
}
