// N_COMP == number of components (2, 3 or 4)
// X_S_F == x/horizontal sampling factor (1 or 2)
// Y_S_F == y/vertical sampling factor (1 or 2)
void Decode2_1_1()
{
Debug.Assert(slicesW.Count < 16); // We only have 4 bits for slice number.
Debug.Assert(!(slicesW.Count > 1 && skipX != 0)); // Check if this is a valid state
Debug.Assert(frame.ComponentInfo[0].superH == 1);
Debug.Assert(frame.ComponentInfo[0].superV == 1);
Debug.Assert(frame.ComponentInfo[1].superH == 1);
Debug.Assert(frame.ComponentInfo[1].superV == 1);
Debug.Assert(frame.numComponents == 2);
HuffmanTable[] ht = new HuffmanTable[2];
for (int i = 0; i < 2; ++i)
{
ht[i] = huff[frame.ComponentInfo[i].dcTblNo];
}
// Initialize predictors
long[] p = new long[2];
for (int i = 0; i < 2; ++i)
{
p[i] = (1 << (frame.precision - Pt - 1));
}
BitPumpJPEG bitStream = new BitPumpJPEG(input);
uint pixelPitch = raw.pitch / 2; // Pitch in pixel
if (frame.numComponents != 3 && frame.width * frame.numComponents > 2 * frame.height)
{
// Fix Canon double height issue where Canon doubled the width and halfed
// the height (e.g. with 5Ds), ask Canon. frame.w needs to stay as is here
// because the number of pixels after which the predictor gets updated is
// still the doubled width.
// see: FIX_CANON_HALF_HEIGHT_DOUBLE_WIDTH
frame.height *= 2;
}
// Fix for Canon 6D raw, which has flipped width & height
// see FIX_CANON_FLIPPED_WIDTH_AND_HEIGHT
long sliceH = frame.numComponents == 3 ? Math.Min(frame.width, frame.height) : frame.height;
// inner loop decodes one group of pixels at a time
uint processedPixels = 0;
uint processedLineSlices = 0;
long nextPredictor = offX + (offY * raw.fullSize.dim.width);
foreach (uint sliceW in slicesW)
{
for (uint y = 0; y < sliceH && y + offY < raw.fullSize.dim.height; y += 1)
{
uint destX = processedLineSlices / raw.fullSize.dim.height * slicesW[0];
uint destY = processedLineSlices % raw.fullSize.dim.height;
if (destX + offX >= raw.fullSize.dim.width * raw.fullSize.cpp)
{
break;
}
long dest = (destX + offX) + (destY + offY) * raw.fullSize.dim.width;
for (uint x = 0; x < sliceW; x += 2)
{
// check if we processed one full raw row worth of pixels
if (processedPixels == frame.width)
{
p[0] = raw.fullSize.rawView[nextPredictor];
p[1] = raw.fullSize.rawView[nextPredictor + 1];
nextPredictor = dest;
processedPixels = 0;
}
p[0] += ht[0].Decode();
Debug.Assert(p[0] >= 0 && p[0] < 65536);
p[1] += ht[1].Decode();
Debug.Assert(p[1] >= 0 && p[1] < 65536);
if (x + offX < raw.fullSize.dim.width)
{
raw.fullSize.rawView[dest] = (ushort)(p[0]);
dest++;
raw.fullSize.rawView[dest] = (ushort)(p[1]);
dest++;
}
processedPixels++;
}
processedLineSlices++;
}
}
}
// N_COMP == number of components (2, 3 or 4)
// X_S_F == x/horizontal sampling factor (1 or 2)
// Y_S_F == y/vertical sampling factor (1 or 2)
void DecodeN_X_Y(int N_COMP, int X_S_F, int Y_S_F)
{
Debug.Assert(frame.ComponentInfo[0].superH == X_S_F);
Debug.Assert(frame.ComponentInfo[0].superV == Y_S_F);
Debug.Assert(frame.ComponentInfo[1].superH == 1);
Debug.Assert(frame.ComponentInfo[1].superV == 1);
Debug.Assert(frame.numComponents == N_COMP);
HuffmanTable[] ht = new HuffmanTable[N_COMP];
for (int i = 0; i < N_COMP; ++i)
{
ht[i] = huff[frame.ComponentInfo[i].dcTblNo];
}
// Initialize predictors
long[] p = new long[N_COMP];
for (int i = 0; i < N_COMP; ++i)
{
p[i] = (1 << (frame.precision - Pt - 1));
}
BitPumpJPEG bitStream = new BitPumpJPEG(input);
uint pixelPitch = raw.pitch / 2; // Pitch in pixel
if (frame.numComponents != 3 && frame.width * frame.numComponents > 2 * frame.height)
{
// Fix Canon double height issue where Canon doubled the width and halfed
// the height (e.g. with 5Ds), ask Canon. frame.w needs to stay as is here
// because the number of pixels after which the predictor gets updated is
// still the doubled width.
// see: FIX_CANON_HALF_HEIGHT_DOUBLE_WIDTH
frame.height *= 2;
}
// Fix for Canon 6D raw, which has flipped width & height
// see FIX_CANON_FLIPPED_WIDTH_AND_HEIGHT
uint sliceH = frame.numComponents == 3 ? Math.Min(frame.width, frame.height) : frame.height;
if (X_S_F == 2 && Y_S_F == 1)
{
// fix the inconsistent slice width in sRaw mode, ask Canon.
for (int i = 0; i < slicesW.Count; i++)
{
slicesW[i] *= 3 / 2;
}
}
// To understand the CR2 slice handling and sampling factor behavior, see
// https://github.com/lclevy/libcraw2/blob/master/docs/cr2_lossless.pdf?raw=true
// inner loop decodes one group of pixels at a time
// * for <N,1,1>: N = N*1*1 (full raw)
// * for <3,2,1>: 6 = 3*2*1
// * for <3,2,2>: 12 = 3*2*2
// and advances x by N_COMP*X_S_F and y by Y_S_F
int xStepSize = N_COMP * X_S_F;
int yStepSize = Y_S_F;
uint processedPixels = 0;
uint processedLineSlices = 0;
long nextPredictor = offX + (offY * raw.fullSize.dim.width);
foreach (uint sliceW in slicesW)
{
for (uint y = 0; y < sliceH && y + offY < raw.fullSize.dim.height; y += (uint)yStepSize)
{
// Fix for Canon 80D mraw format.
// In that format, `frame` is 4032x3402, while `raw` is 4536x3024.
// Consequently, the slices in `frame` wrap around plus there are few
// 'extra' sliced lines because sum(slicesW) * sliceH > raw.dim.area()
// Those would overflow, hence the break.
// see FIX_CANON_FRAME_VS_IMAGE_SIZE_MISMATCH
uint destX = processedLineSlices / raw.fullSize.dim.height * slicesW[0];
uint destY = processedLineSlices % raw.fullSize.dim.height;
if (destX + offX >= raw.fullSize.dim.width * raw.fullSize.cpp)
{
break;
}
long dest = (destX + offX) + (destY + offY) * raw.fullSize.dim.width;
for (uint x = 0; x < sliceW; x += (uint)xStepSize)
{
Debug.Assert((processedPixels <= frame.width));
// check if we processed one full raw row worth of pixels
if (processedPixels == frame.width)
{
// if yes . update predictor by going back exactly one row,
// no matter where we are right now.
// makes no sense from an image compression point of view, ask Canon.
for (int i = 0; i < N_COMP; i++)
{
p[i] = raw.fullSize.rawView[nextPredictor + i];
}
nextPredictor = dest;
processedPixels = 0;
}
if (X_S_F == 1)
{
for (int i = 0; i < N_COMP; i++)
{
p[i] += ht[i].Decode();
if (x + offX < raw.fullSize.dim.width)
{
raw.fullSize.rawView[dest] = (ushort)(p[i]);
dest++;
}
}
}
else
{
for (int i = 0; i < Y_S_F; i++)
{
p[0] += ht[0].Decode();
var t = p[0];
p[0] += ht[0].Decode();
if (x + offX < raw.fullSize.dim.width)
{
if (x + offX < raw.fullSize.dim.width)
{
raw.fullSize.rawView[dest + i * pixelPitch] = (ushort)(t);
}
if (x + offX < raw.fullSize.dim.width)
{
raw.fullSize.rawView[dest + 3 + i * pixelPitch] = (ushort)(p[0]);
}
}
}
p[1] += ht[1].Decode();
p[2] += ht[2].Decode();
if (x + offX < raw.fullSize.dim.width)
{
raw.fullSize.rawView[dest + 1] = (ushort)(p[1]);
raw.fullSize.rawView[dest + 2] = (ushort)(p[2]);
}
dest += xStepSize;
}
processedPixels += (uint)X_S_F;
}
processedLineSlices += (uint)yStepSize;
}
}
//TODO Check
//input.ReadBytes(bitStream.getBufferPosition());
}