dany/libwebp
1
0
Fork 0
mirror of https://github.com/webmproject/libwebp.git synced 2025-07-13 06:24:27 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

Fix CopyTileWithPrediction()

Browse Source 
so that it uses original values of left, top etc for prediction rather than the
predicted values of the same. Also, do some renaming in the same to make it
more readable.

Change-Id: I2fe94e35a6700bd437f5c601e2af12323bf32445
This commit is contained in:
Urvang Joshi
2012-04-13 07:01:11 +00:00
committed by James Zern
parent 84547f540c
commit b2f99465a7
4 changed files with 57 additions and 40 deletions
Download Patch File Download Diff File Expand all files Collapse all files

30
src/enc/vp8l.c
View File

@ -928,7 +928,8 @@ static int ApplyPredictFilter(VP8LBitWriter* const bw,
const int transform_width = VP8LSubSampleSize(width, pred_bits);
const int transform_height = VP8LSubSampleSize(height, pred_bits);
VP8LResidualImage(width, height, pred_bits, enc->argb_, enc->transform_data_);
VP8LResidualImage(width, height, pred_bits, enc->argb_, enc->argb_scratch_,
enc->transform_data_);
VP8LWriteBits(bw, 1, 1);
VP8LWriteBits(bw, 2, 0);
VP8LWriteBits(bw, 4, pred_bits);
@ -1020,9 +1021,7 @@ static WebPEncodingError WriteImage(VP8LEncoder* const enc,
static VP8LEncoder* InitVP8LEncoder(const WebPConfig* const config,
WebPPicture* const picture) {
VP8LEncoder* enc;
enc = (VP8LEncoder*)malloc(sizeof(*enc));
VP8LEncoder* enc = (VP8LEncoder*)malloc(sizeof(*enc));
if (enc == NULL) {
WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
return NULL;
@ -1034,8 +1033,6 @@ static VP8LEncoder* InitVP8LEncoder(const WebPConfig* const config,
enc->use_lz77_ = 1;
enc->palette_bits_ = 7;
enc->argb_ = NULL;
// TODO: Use config.quality to initialize histo_bits_ and transform_bits_.
enc->histo_bits_ = 4;
enc->transform_bits_ = 4;
@ -1058,25 +1055,28 @@ static void DeleteVP8LEncoder(VP8LEncoder* enc) {
free(enc);
}
// Allocates the memory for argb (W x H) buffer and transform data.
// Former buffer (argb_) will hold the argb data from successive image
// transformtions and later corresponds to prediction data (uint32) used
// for every image tile corresponding to the transformed argb_.
// The dimension of this square tile is 2^transform_bits_.
// Allocates the memory for argb (W x H) buffer, 2 rows of context for
// prediction and transform data.
static WebPEncodingError AllocateTransformBuffer(VP8LEncoder* const enc,
int height, int width) {
WebPEncodingError err = VP8_ENC_OK;
const size_t image_size = height * width;
const size_t argb_scratch_size = 2 * width;
const size_t transform_data_size =
VP8LSubSampleSize(height, enc->transform_bits_) *
VP8LSubSampleSize(width, enc->transform_bits_);
const size_t total_size = image_size + transform_data_size;
enc->argb_ = (uint32_t*)malloc(total_size * sizeof(*enc->argb_));
if (enc->argb_ == NULL) {
const size_t total_size =
image_size + argb_scratch_size + transform_data_size;
uint32_t* mem = (uint32_t*)malloc(total_size * sizeof(*mem));
if (mem == NULL) {
err = VP8_ENC_ERROR_OUT_OF_MEMORY;
goto Error;
}
enc->transform_data_ = enc->argb_ + image_size;
enc->argb_ = mem;
mem += image_size;
enc->argb_scratch_ = mem;
mem += argb_scratch_size;
enc->transform_data_ = mem;
enc->current_width_ = width;
Error:

2
src/enc/vp8li.h
View File

@ -38,6 +38,8 @@ typedef struct {
WebPPicture* pic_; // input picture.
uint32_t* argb_; // Transformed argb image data.
uint32_t* argb_scratch_; // Scratch memory for current and top row.
// (used for prediction).
uint32_t* transform_data_; // Scratch memory for transform data.
int current_width_; // Corresponds to packed image width.