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SH-3075 : Fix reversible compression for very small textures. Also supress the forcing to reversible for small textures.

master
Merov Linden 2012-05-09 17:04:02 -07:00
parent 005ce31f41
commit 7fd2290177
1 changed files with 11 additions and 13 deletions
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24
indra/llkdu/llimagej2ckdu.cpp
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@ -609,13 +609,6 @@ BOOL LLImageJ2CKDU::encodeImpl(LLImageJ2C &base, const LLImageRaw &raw_image, co
llassert (base.mRate > 0.f);
max_bytes = (U32)((F32)(max_bytes) * base.mRate);
// If the image is very small, code it in a lossless way.
// Note: it'll also have only 1 layer which is fine as there's no point reordering blocks in that case.
if (max_bytes < FIRST_PACKET_SIZE)
{
reversible = true;
}
// This code is where we specify the target number of bytes for each quality layer.
// We're using a logarithmic spacing rule that fits with our way of fetching texture data.
// Note: For more info on this layers business, read kdu_codestream::flush() doc in kdu_compressed.h
@ -626,27 +619,32 @@ BOOL LLImageJ2CKDU::encodeImpl(LLImageJ2C &base, const LLImageRaw &raw_image, co
layer_bytes[nb_layers++] = i;
i *= 4;
}
// Note: for small images, we can have (max_bytes < FIRST_PACKET_SIZE), hence the test
if (layer_bytes[nb_layers-1] < max_bytes)
{
// Set the last quality layer if necessary so to fit the preset compression ratio
// Use 0 for that last layer for reversible images so all remaining code blocks will be flushed
layer_bytes[nb_layers++] = (reversible ? 0 : max_bytes);
// Set the last quality layer so to fit the preset compression ratio
layer_bytes[nb_layers++] = max_bytes;
}
if (reversible)
{
// Use 0 for a last quality layer for reversible images so all remaining code blocks will be flushed
// Hack: KDU encoding for reversible images has a bug for small images that leads to j2c images that
// cannot be open or are very blurry. Avoiding that last layer prevents the problem to happen.
if ((base.getWidth() >= 32) || (base.getHeight() >= 32))
{
layer_bytes[nb_layers++] = 0;
}
codestream.access_siz()->parse_string("Creversible=yes");
// *TODO: we should use yuv in reversible mode
// Don't turn this on now though as it creates problems on decoding for the moment
//codestream.access_siz()->parse_string("Cycc=no");
}
std::string layer_string = llformat("Clayers=%d",nb_layers);
codestream.access_siz()->parse_string(layer_string.c_str());
// Set up data ordering, markers, etc... if precincts or blocks specified
// Note: This code is *not* used in the encoding made by the viewer. It is currently used only
// by llimage_libtest to create various j2c and test alternative compression schemes.
if ((mBlocksSize != -1) || (mPrecinctsSize != -1))
{
if (mPrecinctsSize != -1)