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Change the predictor function to pass left pixel

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instead of pointer to the source.

Change-Id: Ia2c8e17c3140709a825c2f85a88c5e31bd6e462f
This commit is contained in:
Vikas Arora 2012-04-13 07:13:15 +00:00 committed by James Zern
parent b2f99465a7
commit d673b6b9a0
1 changed files with 35 additions and 50 deletions
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85
src/dsp/lossless.c
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@ -208,82 +208,67 @@ static WEBP_INLINE uint32_t Select(uint32_t a, uint32_t b, uint32_t c) {
//------------------------------------------------------------------------------ //------------------------------------------------------------------------------
// Predictors // Predictors
static uint32_t Predictor0(const uint32_t* const src, static uint32_t Predictor0(uint32_t left, const uint32_t* const top) {
const uint32_t* const top) {
(void)top; (void)top;
(void)src; (void)left;
return ARGB_BLACK; return ARGB_BLACK;
} }
static uint32_t Predictor1(const uint32_t* const src, static uint32_t Predictor1(uint32_t left, const uint32_t* const top) {
const uint32_t* const top) {
(void)top; (void)top;
return src[-1]; return left;
} }
static uint32_t Predictor2(const uint32_t* const src, static uint32_t Predictor2(uint32_t left, const uint32_t* const top) {
const uint32_t* const top) { (void)left;
(void)src;
return top[0]; return top[0];
} }
static uint32_t Predictor3(const uint32_t* const src, static uint32_t Predictor3(uint32_t left, const uint32_t* const top) {
const uint32_t* const top) { (void)left;
(void)src;
return top[1]; return top[1];
} }
static uint32_t Predictor4(const uint32_t* const src, static uint32_t Predictor4(uint32_t left, const uint32_t* const top) {
const uint32_t* const top) { (void)left;
(void)src;
return top[-1]; return top[-1];
} }
static uint32_t Predictor5(const uint32_t* const src, static uint32_t Predictor5(uint32_t left, const uint32_t* const top) {
const uint32_t* const top) { const uint32_t pred = Average3(left, top[0], top[1]);
const uint32_t pred = Average3(src[-1], top[0], top[1]);
return pred; return pred;
} }
static uint32_t Predictor6(const uint32_t* const src, static uint32_t Predictor6(uint32_t left, const uint32_t* const top) {
const uint32_t* const top) { const uint32_t pred = Average2(left, top[-1]);
const uint32_t pred = Average2(src[-1], top[-1]);
return pred; return pred;
} }
static uint32_t Predictor7(const uint32_t* const src, static uint32_t Predictor7(uint32_t left, const uint32_t* const top) {
const uint32_t* const top) { const uint32_t pred = Average2(left, top[0]);
const uint32_t pred = Average2(src[-1], top[0]);
return pred; return pred;
} }
static uint32_t Predictor8(const uint32_t* const src, static uint32_t Predictor8(uint32_t left, const uint32_t* const top) {
const uint32_t* const top) {
const uint32_t pred = Average2(top[-1], top[0]); const uint32_t pred = Average2(top[-1], top[0]);
(void)src; (void)left;
return pred; return pred;
} }
static uint32_t Predictor9(const uint32_t* const src, static uint32_t Predictor9(uint32_t left, const uint32_t* const top) {
const uint32_t* const top) {
const uint32_t pred = Average2(top[0], top[1]); const uint32_t pred = Average2(top[0], top[1]);
(void)src; (void)left;
return pred; return pred;
} }
static uint32_t Predictor10(const uint32_t* const src, static uint32_t Predictor10(uint32_t left, const uint32_t* const top) {
const uint32_t* const top) { const uint32_t pred = Average4(left, top[-1], top[0], top[1]);
const uint32_t pred = Average4(src[-1], top[-1], top[0], top[1]);
return pred; return pred;
} }
static uint32_t Predictor11(const uint32_t* const src, static uint32_t Predictor11(uint32_t left, const uint32_t* const top) {
const uint32_t* const top) { const uint32_t pred = Select(top[0], left, top[-1]);
const uint32_t pred = Select(top[0], src[-1], top[-1]);
return pred; return pred;
} }
static uint32_t Predictor12(const uint32_t* const src, static uint32_t Predictor12(uint32_t left, const uint32_t* const top) {
const uint32_t* const top) { const uint32_t pred = ClampedAddSubtractFull(left, top[0], top[-1]);
const uint32_t pred = ClampedAddSubtractFull(src[-1], top[0], top[-1]);
return pred; return pred;
} }
static uint32_t Predictor13(const uint32_t* const src, static uint32_t Predictor13(uint32_t left, const uint32_t* const top) {
const uint32_t* const top) { const uint32_t pred = ClampedAddSubtractHalf(left, top[0], top[-1]);
const uint32_t pred = ClampedAddSubtractHalf(src[-1], top[0], top[-1]);
return pred; return pred;
} }
typedef uint32_t (*PredictorFunc)(const uint32_t* const src, typedef uint32_t (*PredictorFunc)(uint32_t left, const uint32_t* const top);
const uint32_t* const top);
static const PredictorFunc kPredictors[16] = { static const PredictorFunc kPredictors[16] = {
Predictor0, Predictor1, Predictor2, Predictor3, Predictor0, Predictor1, Predictor2, Predictor3,
Predictor4, Predictor5, Predictor6, Predictor7, Predictor4, Predictor5, Predictor6, Predictor7,
@ -380,7 +365,7 @@ static int GetBestPredictorForTile(int tile_x, int tile_y, int max_tile_size,
predict = argb[(all_y - 1) * xsize]; // First Col: Pick Top Element. predict = argb[(all_y - 1) * xsize]; // First Col: Pick Top Element.
} else { } else {
const uint32_t* src = argb + all_y * xsize + all_x; const uint32_t* src = argb + all_y * xsize + all_x;
predict = pred_func(src, src - xsize); predict = pred_func(src[-1], src - xsize);
} }
predict_diff = VP8LSubPixels(argb[all_y * xsize + all_x], predict); predict_diff = VP8LSubPixels(argb[all_y * xsize + all_x], predict);
++histo[0][predict_diff >> 24]; ++histo[0][predict_diff >> 24];
@ -437,7 +422,7 @@ static void CopyTileWithPrediction(int width, int height,
const uint32_t top = top_row[col]; const uint32_t top = top_row[col];
predict = top; predict = top;
} else { } else {
predict = pred_func(argb + pix, top_row + col); predict = pred_func(argb[pix - 1], top_row + col);
} }
argb[pix] = VP8LSubPixels(argb[pix], predict); argb[pix] = VP8LSubPixels(argb[pix], predict);
} }
@ -497,10 +482,10 @@ static void PredictorInverseTransform(const VP8LTransform* const transform,
const int width = transform->xsize_; const int width = transform->xsize_;
if (y_start == 0) { // First Row follows the L (mode=1) mode. if (y_start == 0) { // First Row follows the L (mode=1) mode.
int x; int x;
const uint32_t pred = Predictor0(data, NULL); const uint32_t pred = Predictor0(data[-1], NULL);
AddPixelsEq(data, pred); AddPixelsEq(data, pred);
for (x = 1; x < width; ++x) { for (x = 1; x < width; ++x) {
const uint32_t pred = Predictor1(data + x, NULL); const uint32_t pred = Predictor1(data[x - 1], NULL);
AddPixelsEq(data + x, pred); AddPixelsEq(data + x, pred);
} }
data += width; data += width;
@ -521,7 +506,7 @@ static void PredictorInverseTransform(const VP8LTransform* const transform,
PredictorFunc pred_func; PredictorFunc pred_func;
// First pixel follows the T (mode=2) mode. // First pixel follows the T (mode=2) mode.
pred = Predictor2(data, data - width); pred = Predictor2(data[-1], data - width);
AddPixelsEq(data, pred); AddPixelsEq(data, pred);
// .. the rest: // .. the rest:
@ -531,7 +516,7 @@ static void PredictorInverseTransform(const VP8LTransform* const transform,
if ((x & mask) == 0) { // start of tile. Read predictor function. if ((x & mask) == 0) { // start of tile. Read predictor function.
pred_func = kPredictors[((*pred_mode_src++) >> 8) & 0xf]; pred_func = kPredictors[((*pred_mode_src++) >> 8) & 0xf];
} }
pred = pred_func(data + x, data + x - width); pred = pred_func(data[x - 1], data + x - width);
AddPixelsEq(data + x, pred); AddPixelsEq(data + x, pred);
} }
data += width; data += width;