bool cineon::Reader::ReadBlock(void *data, const DataSize size, Block &block)
{
int i;
// check the block coordinates
block.Check();
// get the number of components for this element descriptor
const int numberOfComponents = this->header.NumberOfElements();
// check the widths and bit depths of the image elements
bool consistentDepth = true;
bool consistentWidth = true;
const int bitDepth = this->header.BitDepth(0);
const int width = this->header.PixelsPerLine(0);
for (i = 1; i < numberOfComponents; i++) {
if (this->header.BitDepth(i) != bitDepth) {
consistentDepth = false;
if (!consistentWidth)
break;
}
if (this->header.PixelsPerLine(i) != width) {
consistentWidth = false;
if (!consistentDepth)
break;
}
}
// lets see if this can be done in a single fast read
if (consistentDepth && consistentWidth && this->header.EndOfLinePadding() == 0 &&
((bitDepth == 8 && size == cineon::kByte) ||
(bitDepth == 16 && size == cineon::kWord) ||
(bitDepth == 32 && size == cineon::kInt) ||
(bitDepth == 64 && size == cineon::kLongLong)) &&
block.x1 == 0 && block.x2 == (int)(this->header.Width()-1))
{
// seek to the beginning of the image block
if (this->fd->Seek((this->header.ImageOffset() + (block.y1 * this->header.Width() * (bitDepth / 8) * numberOfComponents)), InStream::kStart) == false)
return false;
// size of the image
const size_t imageSize = this->header.Width() * (block.y2 - block.y1 + 1) * numberOfComponents;
const size_t imageByteSize = imageSize * bitDepth / 8;
size_t rs = this->fd->ReadDirect(data, imageByteSize);
if (rs != imageByteSize)
return false;
// swap the bytes if different byte order
if (this->header.RequiresByteSwap())
cineon::EndianSwapImageBuffer(size, data, imageSize);
return true;
}
// determine if the encoding system is loaded
if (this->codec == 0)
// this element reader has not been used
this->codec = new Codec;
// read the image block
return this->codec->Read(this->header, this->rio, block, data, size);
}
bool dpx::Reader::ReadBlock(void* data, const DataSize size, Block& block, const Descriptor desc)
{
int i;
int element;
// check the block coordinates
block.Check();
// determine which element we are viewing
for(i = 0; i < MAX_ELEMENTS; i++)
{
if(this->header.ImageDescriptor(i) == desc)
{
element = i;
break;
}
}
if(i == MAX_ELEMENTS) // was it found?
return false;
// get the number of components for this element descriptor
const int numberOfComponents = this->header.ImageElementComponentCount(element);
// bit depth of the image element
const int bitDepth = this->header.BitDepth(element);
// rle encoding?
const bool rle = (this->header.ImageEncoding(element) == kRLE);
// lets see if this can be done in a single fast read
if(!rle && this->header.EndOfLinePadding(element) == 0 &&
((bitDepth == 8 && size == dpx::kByte) || (bitDepth == 16 && size == dpx::kWord) ||
(bitDepth == 32 && size == dpx::kFloat) || (bitDepth == 64 && size == dpx::kDouble)) &&
block.x1 == 0 && block.x2 == (int)(this->header.Width() - 1))
{
// seek to the beginning of the image block
if(this->fd->Seek(
(this->header.DataOffset(element) + (block.y1 * this->header.Width() * (bitDepth / 8) * numberOfComponents)),
InStream::kStart) == false)
return false;
// size of the image
const size_t imageSize = this->header.Width() * (block.y2 - block.y1 + 1) * numberOfComponents;
const size_t imageByteSize = imageSize * bitDepth / 8;
size_t rs = this->fd->ReadDirect(data, imageByteSize);
if(rs != imageByteSize)
return false;
// swap the bytes if different byte order
if(this->header.RequiresByteSwap())
dpx::EndianSwapImageBuffer(size, data, imageSize);
return true;
}
// determine if the encoding system is loaded
if(this->codex[element] == 0)
{
// this element reader has not been used
if(rle)
// TODO
// this->codex[element] = new RunLengthEncoding;
return false;
else
this->codex[element] = new Codec;
}
// read the image block
return this->codex[element]->Read(this->header, this->rio, element, block, data, size);
}
