llimagej2ckdu.cpp

	// These example weights are adapted from numbers generated by Marcus Nadenau
	// at EPFL, for a viewing distance of 15 cm and a display resolution of
	// 300 DPI.

	cod->parse_string("Cband_weights:C0="
		"{0.0901},{0.2758},{0.2758},"
		"{0.7018},{0.8378},{0.8378},{1}");
	cod->parse_string("Cband_weights:C1="
		"{0.0263},{0.0863},{0.0863},"
		"{0.1362},{0.2564},{0.2564},"
		"{0.3346},{0.4691},{0.4691},"
		"{0.5444},{0.6523},{0.6523},"
		"{0.7078},{0.7797},{0.7797},{1}");
	cod->parse_string("Cband_weights:C2="
		"{0.0773},{0.1835},{0.1835},"
		"{0.2598},{0.4130},{0.4130},"
		"{0.5040},{0.6464},{0.6464},"
		"{0.7220},{0.8254},{0.8254},"
		"{0.8769},{0.9424},{0.9424},{1}");
}

/******************************************************************************/
/*                              transfer_bytes                                */
/******************************************************************************/

void transfer_bytes(kdu_byte *dest, kdu_line_buf &src, int gap, int precision)
/* Transfers source samples from the supplied line buffer into the output
byte buffer, spacing successive output samples apart by `gap' bytes
(to allow for interleaving of colour components).  The function performs
all necessary level shifting, type conversion, rounding and truncation. */
{
	int width = src.get_width();
	if (src.get_buf32() != NULL)
	{ // Decompressed samples have a 32-bit representation (integer or float)
		assert(precision >= 8); // Else would have used 16 bit representation
		kdu_sample32 *sp = src.get_buf32();
		if (!src.is_absolute())
		{ // Transferring normalized floating point data.
			float scale16 = (float)(1<<16);
			kdu_int32 val;

			for (; width > 0; width--, sp++, dest+=gap)
			{
				val = (kdu_int32)(sp->fval*scale16);
				val = (val+128)>>8; // May be faster than true rounding
				val += 128;
				if (val & ((-1)<<8))
				{
					val = (val < 0 ? 0 : 255);
				}
				*dest = (kdu_byte) val;
			}
		}
		else
		{ // Transferring 32-bit absolute integers.
			kdu_int32 val;
			kdu_int32 downshift = precision-8;
			kdu_int32 offset = (1<<downshift)>>1;

			for (; width > 0; width--, sp++, dest+=gap)
			{
				val = sp->ival;
				val = (val+offset)>>downshift;
				val += 128;
				if (val & ((-1)<<8))
				{
					val = (val < 0 ? 0 : 255);
				}
				*dest = (kdu_byte) val;
			}
		}
	}
	else
	{ // Source data is 16 bits.
		kdu_sample16 *sp = src.get_buf16();
		if (!src.is_absolute())
		{ // Transferring 16-bit fixed point quantities
			kdu_int16 val;

			if (precision >= 8)
			{ // Can essentially ignore the bit-depth.
				for (; width > 0; width--, sp++, dest+=gap)
				{
					val = sp->ival;
					val += (1<<(KDU_FIX_POINT-8))>>1;
					val >>= (KDU_FIX_POINT-8);
					val += 128;
					if (val & ((-1)<<8))
					{
						val = (val < 0 ? 0 : 255);
					}
					*dest = (kdu_byte) val;
				}
			}
			else
			{ // Need to force zeros into one or more least significant bits.
				kdu_int16 downshift = KDU_FIX_POINT-precision;
				kdu_int16 upshift = 8-precision;
				kdu_int16 offset = 1<<(downshift-1);

				for (; width > 0; width--, sp++, dest+=gap)
				{
					val = sp->ival;
					val = (val+offset)>>downshift;
					val <<= upshift;
					val += 128;
					if (val & ((-1)<<8))
					{
						val = (val < 0 ? 0 : 256 - (1<<upshift));
					}
					*dest = (kdu_byte) val;
				}
			}
		}
		else
		{ // Transferring 16-bit absolute integers.
			kdu_int16 val;

			if (precision >= 8)
			{
				kdu_int16 downshift = precision-8;
				kdu_int16 offset = (1<<downshift)>>1;

				for (; width > 0; width--, sp++, dest+=gap)
				{
					val = sp->ival;
					val = (val+offset)>>downshift;
					val += 128;
					if (val & ((-1)<<8))
					{
						val = (val < 0 ? 0 : 255);
					}
					*dest = (kdu_byte) val;
				}
			}
			else
			{
				kdu_int16 upshift = 8-precision;

				for (; width > 0; width--, sp++, dest+=gap)
				{
					val = sp->ival;
					val <<= upshift;
					val += 128;
					if (val & ((-1)<<8))
					{
						val = (val < 0 ? 0 : 256 - (1<<upshift));
					}
					*dest = (kdu_byte) val;
				}
			}
		}
	}
}

LLKDUDecodeState::LLKDUDecodeState(kdu_tile tile, kdu_byte *buf, S32 row_gap)
{
	S32 c;

	mTile = tile;
	mBuf = buf;
	mRowGap = row_gap;

	mNumComponents = tile.get_num_components();

	llassert(mNumComponents <= 4);
	mUseYCC = tile.get_ycc();

	for (c = 0; c < 4; ++c)
	{
		mReversible[c] = false;
		mBitDepths[c] = 0;
	}

	// Open tile-components and create processing engines and resources
	for (c = 0; c < mNumComponents; c++)
	{
		mComps[c] = mTile.access_component(c);
		mReversible[c] = mComps[c].get_reversible();
		mBitDepths[c] = mComps[c].get_bit_depth();
		kdu_resolution res = mComps[c].access_resolution(); // Get top resolution
		kdu_dims comp_dims; res.get_dims(comp_dims);
		if (c == 0)
		{
			mDims = comp_dims;
		}
		else
		{
			llassert(mDims == comp_dims); // Safety check; the caller has ensured this
		}
		bool use_shorts = (mComps[c].get_bit_depth(true) <= 16);
		mLines[c].pre_create(&mAllocator,mDims.size.x,mReversible[c],use_shorts);
		if (res.which() == 0) // No DWT levels used
		{
			mEngines[c] = kdu_decoder(res.access_subband(LL_BAND),&mAllocator,use_shorts);
		}
		else
		{
			mEngines[c] = kdu_synthesis(res,&mAllocator,use_shorts);
		}
	}
	mAllocator.finalize(); // Actually creates buffering resources
	for (c = 0; c < mNumComponents; c++)
	{
		mLines[c].create(); // Grabs resources from the allocator.
	}
}

LLKDUDecodeState::~LLKDUDecodeState()
{
	// Cleanup
	for (S32 c = 0; c < mNumComponents; c++)
	{
		mEngines[c].destroy(); // engines are interfaces; no default destructors
	}
	mTile.close();
}

BOOL LLKDUDecodeState::processTileDecode(F32 decode_time, BOOL limit_time)
/* Decompresses a tile, writing the data into the supplied byte buffer.
The buffer contains interleaved image components, if there are any.
Although you may think of the buffer as belonging entirely to this tile,
the `buf' pointer may actually point into a larger buffer representing
multiple tiles.  For this reason, `row_gap' is needed to identify the
separation between consecutive rows in the real buffer. */
{
	S32 c;
	// Now walk through the lines of the buffer, recovering them from the
	// relevant tile-component processing engines.

	LLTimer decode_timer;
	while (mDims.size.y--)
	{
		for (c = 0; c < mNumComponents; c++)
		{
			mEngines[c].pull(mLines[c],true);
		}
		if ((mNumComponents >= 3) && mUseYCC)
		{
			kdu_convert_ycc_to_rgb(mLines[0],mLines[1],mLines[2]);
		}
		for (c = 0; c < mNumComponents; c++)
		{
			transfer_bytes(mBuf+c,mLines[c],mNumComponents,mBitDepths[c]);
		}
		mBuf += mRowGap;
		if (mDims.size.y % 10)
		{
			if (limit_time && decode_timer.getElapsedTimeF32() > decode_time)
			{
				return FALSE;
			}
		}
	}
	return TRUE;
}

// kdc_flow_control 

kdc_flow_control::kdc_flow_control (kdu_image_in_base *img_in, kdu_codestream codestream)
{
	int n;
	
	this->codestream = codestream;
	codestream.get_valid_tiles(valid_tile_indices);
	tile_idx = valid_tile_indices.pos;
	tile = codestream.open_tile(tile_idx,NULL);
	
	// Set up the individual components
	num_components = codestream.get_num_components(true);
	components = new kdc_component_flow_control[num_components];
	count_delta = 0;
	kdc_component_flow_control *comp = components;
	for (n = 0; n < num_components; n++, comp++)
	{
		comp->line = NULL;
		comp->reader = img_in;
		kdu_coords subsampling;  
		codestream.get_subsampling(n,subsampling,true);
		kdu_dims dims;  
		codestream.get_tile_dims(tile_idx,n,dims,true);
		comp->vert_subsampling = subsampling.y;
		if ((n == 0) || (comp->vert_subsampling < count_delta))
		{
			count_delta = comp->vert_subsampling;
		}
		comp->ratio_counter = 0;
		comp->remaining_lines = comp->initial_lines = dims.size.y;
	}
	assert(num_components >= 0);
	
	tile.set_components_of_interest(num_components);
	max_buffer_memory = engine.create(codestream,tile,false,NULL,false,1,NULL,NULL,false);
}

kdc_flow_control::~kdc_flow_control()
{
	if (components != NULL)
	{
		delete[] components;
	}
	if (engine.exists())
	{
		engine.destroy();
	}
}

bool kdc_flow_control::advance_components()
{
	bool found_line = false;
	while (!found_line)
	{
		bool all_done = true;
		kdc_component_flow_control *comp = components;
		for (int n = 0; n < num_components; n++, comp++)
		{
			assert(comp->ratio_counter >= 0);
			if (comp->remaining_lines > 0)
			{
				all_done = false;
				comp->ratio_counter -= count_delta;
				if (comp->ratio_counter < 0)
				{
					found_line = true;
					comp->line = engine.exchange_line(n,NULL,NULL);
					assert(comp->line != NULL);
					if (comp->line->get_width())
					{
						comp->reader->get(n,*(comp->line),0);
					}
				}
			}
		}
		if (all_done)
		{
			return false;
		}
	}
	return true;
}

void kdc_flow_control::process_components()
{
	kdc_component_flow_control *comp = components;
	for (int n = 0; n < num_components; n++, comp++)
	{
		if (comp->ratio_counter < 0)
		{
			comp->ratio_counter += comp->vert_subsampling;
			assert(comp->ratio_counter >= 0);
			assert(comp->remaining_lines > 0);
			comp->remaining_lines--;
			assert(comp->line != NULL);
			engine.exchange_line(n,comp->line,NULL);
			comp->line = NULL;
		}
	}
}