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Make the lossless predictors work on a batch of pixels.

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Change-Id: Ieaee34f1f97c375b9e97ef7e9df60aed353dffa1
This commit is contained in:
Vincent Rabaud 2016-11-28 17:12:05 +01:00
parent bc18ebad2e
commit 4239a1489c
8 changed files with 236 additions and 105 deletions
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89
src/dsp/lossless.c
View File

@ -27,11 +27,6 @@
//------------------------------------------------------------------------------
// Image transforms.
// In-place sum of each component with mod 256.
static WEBP_INLINE void AddPixelsEq(uint32_t* a, uint32_t b) {
*a = VP8LAddPixels(*a, b);
}
static WEBP_INLINE uint32_t Average2(uint32_t a0, uint32_t a1) {
return (((a0 ^ a1) & 0xfefefefeu) >> 1) + (a0 & a1);
}
@ -172,21 +167,33 @@ static uint32_t Predictor13(uint32_t left, const uint32_t* const top) {
return pred;
}
GENERATE_PREDICTOR_ADD(0)
GENERATE_PREDICTOR_ADD(1)
GENERATE_PREDICTOR_ADD(2)
GENERATE_PREDICTOR_ADD(3)
GENERATE_PREDICTOR_ADD(4)
GENERATE_PREDICTOR_ADD(5)
GENERATE_PREDICTOR_ADD(6)
GENERATE_PREDICTOR_ADD(7)
GENERATE_PREDICTOR_ADD(8)
GENERATE_PREDICTOR_ADD(9)
GENERATE_PREDICTOR_ADD(10)
GENERATE_PREDICTOR_ADD(11)
GENERATE_PREDICTOR_ADD(12)
GENERATE_PREDICTOR_ADD(13)
//------------------------------------------------------------------------------
// Inverse prediction.
static void PredictorInverseTransform(const VP8LTransform* const transform,
int y_start, int y_end, uint32_t* data) {
int y_start, int y_end,
const uint32_t* in, uint32_t* out) {
const int width = transform->xsize_;
if (y_start == 0) { // First Row follows the L (mode=1) mode.
int x;
const uint32_t pred0 = Predictor0(data[-1], NULL);
AddPixelsEq(data, pred0);
for (x = 1; x < width; ++x) {
const uint32_t pred1 = Predictor1(data[x - 1], NULL);
AddPixelsEq(data + x, pred1);
}
data += width;
PredictorAdd0(in, NULL, 1, out);
PredictorAdd1(in + 1, NULL, width - 1, out + 1);
in += width;
out += width;
++y_start;
}
@ -194,36 +201,26 @@ static void PredictorInverseTransform(const VP8LTransform* const transform,
int y = y_start;
const int tile_width = 1 << transform->bits_;
const int mask = tile_width - 1;
const int safe_width = width & ~mask;
const int tiles_per_row = VP8LSubSampleSize(width, transform->bits_);
const uint32_t* pred_mode_base =
transform->data_ + (y >> transform->bits_) * tiles_per_row;
while (y < y_end) {
const uint32_t pred2 = Predictor2(data[-1], data - width);
const uint32_t* pred_mode_src = pred_mode_base;
VP8LPredictorFunc pred_func;
int x = 1;
int t = 1;
// First pixel follows the T (mode=2) mode.
AddPixelsEq(data, pred2);
PredictorAdd2(in, out - width, 1, out);
// .. the rest:
while (x < safe_width) {
pred_func = VP8LPredictors[((*pred_mode_src++) >> 8) & 0xf];
for (; t < tile_width; ++t, ++x) {
const uint32_t pred = pred_func(data[x - 1], data + x - width);
AddPixelsEq(data + x, pred);
}
t = 0;
while (x < width) {
const VP8LPredictorAddSubFunc pred_func =
VP8LPredictorsAdd[((*pred_mode_src++) >> 8) & 0xf];
int x_end = (x & ~mask) + tile_width;
if (x_end > width) x_end = width;
pred_func(in + x, out + x - width, x_end - x, out + x);
x = x_end;
}
if (x < width) {
pred_func = VP8LPredictors[((*pred_mode_src++) >> 8) & 0xf];
for (; x < width; ++x) {
const uint32_t pred = pred_func(data[x - 1], data + x - width);
AddPixelsEq(data + x, pred);
}
}
data += width;
in += width;
out += width;
++y;
if ((y & mask) == 0) { // Use the same mask, since tiles are squares.
pred_mode_base += tiles_per_row;
@ -375,11 +372,7 @@ void VP8LInverseTransform(const VP8LTransform* const transform,
VP8LAddGreenToBlueAndRed(in, (row_end - row_start) * width, out);
break;
case PREDICTOR_TRANSFORM:
// TODO(vrabaud): parallelize transform predictors.
if (in != out) {
memcpy(out, in, (row_end - row_start) * width * sizeof(*out));
}
PredictorInverseTransform(transform, row_start, row_end, out);
PredictorInverseTransform(transform, row_start, row_end, in, out);
if (row_end != transform->ysize_) {
// The last predicted row in this iteration will be the top-pred row
// for the first row in next iteration.
@ -566,6 +559,7 @@ void VP8LConvertFromBGRA(const uint32_t* const in_data, int num_pixels,
//------------------------------------------------------------------------------
VP8LProcessDecBlueAndRedFunc VP8LAddGreenToBlueAndRed;
VP8LPredictorAddSubFunc VP8LPredictorsAdd[16];
VP8LPredictorFunc VP8LPredictors[16];
VP8LTransformColorInverseFunc VP8LTransformColorInverse;
@ -607,6 +601,23 @@ WEBP_TSAN_IGNORE_FUNCTION void VP8LDspInit(void) {
VP8LPredictors[14] = Predictor0; // <- padding security sentinels
VP8LPredictors[15] = Predictor0;
VP8LPredictorsAdd[0] = PredictorAdd0;
VP8LPredictorsAdd[1] = PredictorAdd1;
VP8LPredictorsAdd[2] = PredictorAdd2;
VP8LPredictorsAdd[3] = PredictorAdd3;
VP8LPredictorsAdd[4] = PredictorAdd4;
VP8LPredictorsAdd[5] = PredictorAdd5;
VP8LPredictorsAdd[6] = PredictorAdd6;
VP8LPredictorsAdd[7] = PredictorAdd7;
VP8LPredictorsAdd[8] = PredictorAdd8;
VP8LPredictorsAdd[9] = PredictorAdd9;
VP8LPredictorsAdd[10] = PredictorAdd10;
VP8LPredictorsAdd[11] = PredictorAdd11;
VP8LPredictorsAdd[12] = PredictorAdd12;
VP8LPredictorsAdd[13] = PredictorAdd13;
VP8LPredictorsAdd[14] = PredictorAdd0; // <- padding security sentinels
VP8LPredictorsAdd[15] = PredictorAdd0;
VP8LAddGreenToBlueAndRed = VP8LAddGreenToBlueAndRed_C;
VP8LTransformColorInverse = VP8LTransformColorInverse_C;

6
src/dsp/lossless.h
View File

@ -34,6 +34,10 @@ extern "C" {
typedef uint32_t (*VP8LPredictorFunc)(uint32_t left, const uint32_t* const top);
extern VP8LPredictorFunc VP8LPredictors[16];
typedef void (*VP8LPredictorAddSubFunc)(const uint32_t* in,
const uint32_t* upper, int num_pixels,
uint32_t* out);
extern VP8LPredictorAddSubFunc VP8LPredictorsAdd[16];
typedef void (*VP8LProcessDecBlueAndRedFunc)(const uint32_t* src,
int num_pixels, uint32_t* dst);
@ -143,6 +147,8 @@ void VP8LCollectColorBlueTransforms_C(const uint32_t* argb, int stride,
int green_to_blue, int red_to_blue,
int histo[]);
extern VP8LPredictorAddSubFunc VP8LPredictorsSub[16];
// -----------------------------------------------------------------------------
// Huffman-cost related functions.

28
src/dsp/lossless_common.h
View File

@ -174,6 +174,34 @@ uint32_t VP8LSubPixels(uint32_t a, uint32_t b) {
}
//------------------------------------------------------------------------------
// Transform-related functions use din both encoding and decoding.
// Macros used to create a batch predictor that iteratively uses a
// one-pixel predictor.
// The predictor is added to the output pixel (which
// is therefore considered as a residual) to get the final prediction.
#define GENERATE_PREDICTOR_ADD(X) \
static void PredictorAdd##X(const uint32_t* in, const uint32_t* upper, \
int num_pixels, uint32_t* out) { \
int x; \
for (x = 0; x < num_pixels; ++x) { \
const uint32_t pred = VP8LPredictors[(X)](out[x - 1], upper + x); \
out[x] = VP8LAddPixels(in[x], pred); \
} \
}
// It subtracts the prediction from the input pixel and stores the residual
// in the output pixel.
#define GENERATE_PREDICTOR_SUB(X) \
static void PredictorSub##X(const uint32_t* in, const uint32_t* upper, \
int num_pixels, uint32_t* out) { \
int x; \
for (x = 0; x < num_pixels; ++x) { \
const uint32_t pred = VP8LPredictors[(X)](in[x - 1], upper + x); \
out[x] = VP8LSubPixels(in[x], pred); \
} \
}
#ifdef __cplusplus
} // extern "C"

34
src/dsp/lossless_enc.c
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@ -665,6 +665,21 @@ static void HistogramAdd(const VP8LHistogram* const a,
//------------------------------------------------------------------------------
GENERATE_PREDICTOR_SUB(0)
GENERATE_PREDICTOR_SUB(1)
GENERATE_PREDICTOR_SUB(2)
GENERATE_PREDICTOR_SUB(3)
GENERATE_PREDICTOR_SUB(4)
GENERATE_PREDICTOR_SUB(5)
GENERATE_PREDICTOR_SUB(6)
GENERATE_PREDICTOR_SUB(7)
GENERATE_PREDICTOR_SUB(8)
GENERATE_PREDICTOR_SUB(9)
GENERATE_PREDICTOR_SUB(10)
GENERATE_PREDICTOR_SUB(11)
GENERATE_PREDICTOR_SUB(12)
GENERATE_PREDICTOR_SUB(13)
VP8LProcessEncBlueAndRedFunc VP8LSubtractGreenFromBlueAndRed;
VP8LTransformColorFunc VP8LTransformColor;
@ -686,6 +701,8 @@ VP8LHistogramAddFunc VP8LHistogramAdd;
VP8LVectorMismatchFunc VP8LVectorMismatch;
VP8LPredictorAddSubFunc VP8LPredictorsSub[16];
extern void VP8LEncDspInitSSE2(void);
extern void VP8LEncDspInitSSE41(void);
extern void VP8LEncDspInitNEON(void);
@ -722,6 +739,23 @@ WEBP_TSAN_IGNORE_FUNCTION void VP8LEncDspInit(void) {
VP8LVectorMismatch = VectorMismatch;
VP8LPredictorsSub[0] = PredictorSub0;
VP8LPredictorsSub[1] = PredictorSub1;
VP8LPredictorsSub[2] = PredictorSub2;
VP8LPredictorsSub[3] = PredictorSub3;
VP8LPredictorsSub[4] = PredictorSub4;
VP8LPredictorsSub[5] = PredictorSub5;
VP8LPredictorsSub[6] = PredictorSub6;
VP8LPredictorsSub[7] = PredictorSub7;
VP8LPredictorsSub[8] = PredictorSub8;
VP8LPredictorsSub[9] = PredictorSub9;
VP8LPredictorsSub[10] = PredictorSub10;
VP8LPredictorsSub[11] = PredictorSub11;
VP8LPredictorsSub[12] = PredictorSub12;
VP8LPredictorsSub[13] = PredictorSub13;
VP8LPredictorsSub[14] = PredictorSub0; // <- padding security sentinels
VP8LPredictorsSub[15] = PredictorSub0;
// If defined, use CPUInfo() to overwrite some pointers with faster versions.
if (VP8GetCPUInfo != NULL) {
#if defined(WEBP_USE_SSE2)

22
src/dsp/lossless_sse2.c
View File

@ -17,6 +17,7 @@
#include "./common_sse2.h"
#include "./lossless.h"
#include "./lossless_common.h"
#include <assert.h>
#include <emmintrin.h>
@ -154,6 +155,17 @@ static uint32_t Predictor13(uint32_t left, const uint32_t* const top) {
return pred;
}
// TODO(vrabaud): implement those functions in SSE.
GENERATE_PREDICTOR_ADD(5)
GENERATE_PREDICTOR_ADD(6)
GENERATE_PREDICTOR_ADD(7)
GENERATE_PREDICTOR_ADD(8)
GENERATE_PREDICTOR_ADD(9)
GENERATE_PREDICTOR_ADD(10)
GENERATE_PREDICTOR_ADD(11)
GENERATE_PREDICTOR_ADD(12)
GENERATE_PREDICTOR_ADD(13)
//------------------------------------------------------------------------------
// Subtract-Green Transform
@ -394,6 +406,16 @@ WEBP_TSAN_IGNORE_FUNCTION void VP8LDspInitSSE2(void) {
VP8LPredictors[12] = Predictor12;
VP8LPredictors[13] = Predictor13;
VP8LPredictorsAdd[5] = PredictorAdd5;
VP8LPredictorsAdd[6] = PredictorAdd6;
VP8LPredictorsAdd[7] = PredictorAdd7;
VP8LPredictorsAdd[8] = PredictorAdd8;
VP8LPredictorsAdd[9] = PredictorAdd9;
VP8LPredictorsAdd[10] = PredictorAdd10;
VP8LPredictorsAdd[11] = PredictorAdd11;
VP8LPredictorsAdd[12] = PredictorAdd12;
VP8LPredictorsAdd[13] = PredictorAdd13;
VP8LAddGreenToBlueAndRed = AddGreenToBlueAndRed;
VP8LTransformColorInverse = TransformColorInverse;

152
src/enc/predictor.c
View File

@ -66,16 +66,27 @@ static WEBP_INLINE void UpdateHisto(int histo_argb[4][256], uint32_t argb) {
//------------------------------------------------------------------------------
// Spatial transform functions.
static WEBP_INLINE uint32_t Predict(VP8LPredictorFunc pred_func,
int x, int y,
const uint32_t* current_row,
const uint32_t* upper_row) {
static WEBP_INLINE void PredictBatch(int mode, int x_start, int y,
int num_pixels, const uint32_t* current,
const uint32_t* upper, uint32_t* out) {
if (x_start == 0) {
if (y == 0) {
// ARGB_BLACK.
VP8LPredictorsSub[0](current, NULL, 1, out);
} else {
// Top one.
VP8LPredictorsSub[2](current, upper, 1, out);
}
++x_start;
++out;
--num_pixels;
}
if (y == 0) {
return (x == 0) ? ARGB_BLACK : current_row[x - 1]; // Left.
} else if (x == 0) {
return upper_row[x]; // Top.
// Left one.
VP8LPredictorsSub[1](current + x_start, NULL, num_pixels, out);
} else {
return pred_func(current_row[x - 1], upper_row + x);
VP8LPredictorsSub[mode](current + x_start, upper + x_start, num_pixels,
out);
}
}
@ -208,42 +219,59 @@ static uint32_t NearLossless(uint32_t value, uint32_t predict,
return ((uint32_t)a << 24) | ((uint32_t)r << 16) | ((uint32_t)g << 8) | b;
}
// Returns the difference between the pixel and its prediction. In case of a
// lossy encoding, updates the source image to avoid propagating the deviation
// further to pixels which depend on the current pixel for their predictions.
static WEBP_INLINE uint32_t GetResidual(int width, int height,
uint32_t* const upper_row,
uint32_t* const current_row,
const uint8_t* const max_diffs,
int mode, VP8LPredictorFunc pred_func,
int x, int y, int max_quantization,
int exact, int used_subtract_green) {
const uint32_t predict = Predict(pred_func, x, y, current_row, upper_row);
uint32_t residual;
if (max_quantization == 1 || mode == 0 || y == 0 || y == height - 1 ||
x == 0 || x == width - 1) {
residual = VP8LSubPixels(current_row[x], predict);
// Stores the difference between the pixel and its prediction in "out".
// In case of a lossy encoding, updates the source image to avoid propagating
// the deviation further to pixels which depend on the current pixel for their
// predictions.
static WEBP_INLINE void GetResidual(
int width, int height, uint32_t* const upper_row,
uint32_t* const current_row, const uint8_t* const max_diffs, int mode,
int x_start, int x_end, int y, int max_quantization, int exact,
int used_subtract_green, uint32_t* const out) {
if (exact) {
PredictBatch(mode, x_start, y, x_end - x_start, current_row, upper_row,
out);
} else {
residual = NearLossless(current_row[x], predict, max_quantization,
max_diffs[x], used_subtract_green);
// Update the source image.
current_row[x] = VP8LAddPixels(predict, residual);
// x is never 0 here so we do not need to update upper_row like below.
const VP8LPredictorFunc pred_func = VP8LPredictors[mode];
int x;
for (x = x_start; x < x_end; ++x) {
uint32_t predict;
uint32_t residual;
if (y == 0) {
predict = (x == 0) ? ARGB_BLACK : current_row[x - 1]; // Left.
} else if (x == 0) {
predict = upper_row[x]; // Top.
} else {
predict = pred_func(current_row[x - 1], upper_row + x);
}
if (mode == 0 || y == 0 || y == height - 1 || x == 0 || x == width - 1) {
residual = VP8LSubPixels(current_row[x], predict);
} else {
residual = NearLossless(current_row[x], predict, max_quantization,
max_diffs[x], used_subtract_green);
// Update the source image.
current_row[x] = VP8LAddPixels(predict, residual);
// x is never 0 here so we do not need to update upper_row like below.
}
if ((current_row[x] & kMaskAlpha) == 0) {
// If alpha is 0, cleanup RGB. We can choose the RGB values of the
// residual for best compression. The prediction of alpha itself can be
// non-zero and must be kept though. We choose RGB of the residual to be
// 0.
residual &= kMaskAlpha;
// Update the source image.
current_row[x] = predict & ~kMaskAlpha;
// The prediction for the rightmost pixel in a row uses the leftmost
// pixel
// in that row as its top-right context pixel. Hence if we change the
// leftmost pixel of current_row, the corresponding change must be
// applied
// to upper_row as well where top-right context is being read from.
if (x == 0 && y != 0) upper_row[width] = current_row[0];
}
out[x - x_start] = residual;
}
}
if (!exact && (current_row[x] & kMaskAlpha) == 0) {
// If alpha is 0, cleanup RGB. We can choose the RGB values of the residual
// for best compression. The prediction of alpha itself can be non-zero and
// must be kept though. We choose RGB of the residual to be 0.
residual &= kMaskAlpha;
// Update the source image.
current_row[x] = predict & ~kMaskAlpha;
// The prediction for the rightmost pixel in a row uses the leftmost pixel
// in that row as its top-right context pixel. Hence if we change the
// leftmost pixel of current_row, the corresponding change must be applied
// to upper_row as well where top-right context is being read from.
if (x == 0 && y != 0) upper_row[width] = current_row[0];
}
return residual;
}
// Returns best predictor and updates the accumulated histogram.
@ -293,9 +321,11 @@ static int GetBestPredictorForTile(int width, int height,
int (*histo_argb)[256] = histo_stack_1;
int (*best_histo)[256] = histo_stack_2;
int i, j;
uint32_t residuals[1 << MAX_TRANSFORM_BITS];
assert(bits <= MAX_TRANSFORM_BITS);
assert(max_x <= (1 << MAX_TRANSFORM_BITS));
for (mode = 0; mode < kNumPredModes; ++mode) {
const VP8LPredictorFunc pred_func = VP8LPredictors[mode];
float cur_diff;
int relative_y;
memset(histo_argb, 0, sizeof(histo_stack_1));
@ -326,12 +356,11 @@ static int GetBestPredictorForTile(int width, int height,
max_diffs + context_start_x, used_subtract_green);
}
GetResidual(width, height, upper_row, current_row, max_diffs, mode,
start_x, start_x + max_x, y, max_quantization, exact,
used_subtract_green, residuals);
for (relative_x = 0; relative_x < max_x; ++relative_x) {
const int x = start_x + relative_x;
UpdateHisto(histo_argb,
GetResidual(width, height, upper_row, current_row,
max_diffs, mode, pred_func, x, y,
max_quantization, exact, used_subtract_green));
UpdateHisto(histo_argb, residuals[relative_x]);
}
}
cur_diff = PredictionCostSpatialHistogram(
@ -369,7 +398,6 @@ static void CopyImageWithPrediction(int width, int height,
int low_effort, int max_quantization,
int exact, int used_subtract_green) {
const int tiles_per_row = VP8LSubSampleSize(width, bits);
const int mask = (1 << bits) - 1;
// The width of upper_row and current_row is one pixel larger than image width
// to allow the top right pixel to point to the leftmost pixel of the next row
// when at the right edge.
@ -378,8 +406,6 @@ static void CopyImageWithPrediction(int width, int height,
uint8_t* current_max_diffs = (uint8_t*)(current_row + width + 1);
uint8_t* lower_max_diffs = current_max_diffs + width;
int y;
int mode = 0;
VP8LPredictorFunc pred_func = NULL;
for (y = 0; y < height; ++y) {
int x;
@ -390,11 +416,8 @@ static void CopyImageWithPrediction(int width, int height,
sizeof(*argb) * (width + (y + 1 < height)));
if (low_effort) {
for (x = 0; x < width; ++x) {
const uint32_t predict = Predict(VP8LPredictors[kPredLowEffort], x, y,
current_row, upper_row);
argb[y * width + x] = VP8LSubPixels(current_row[x], predict);
}
PredictBatch(kPredLowEffort, 0, y, width, current_row, upper_row,
argb + y * width);
} else {
if (max_quantization > 1) {
// Compute max_diffs for the lower row now, because that needs the
@ -408,14 +431,15 @@ static void CopyImageWithPrediction(int width, int height,
used_subtract_green);
}
}
for (x = 0; x < width; ++x) {
if ((x & mask) == 0) {
mode = (modes[(y >> bits) * tiles_per_row + (x >> bits)] >> 8) & 0xff;
pred_func = VP8LPredictors[mode];
}
argb[y * width + x] = GetResidual(
width, height, upper_row, current_row, current_max_diffs, mode,
pred_func, x, y, max_quantization, exact, used_subtract_green);
for (x = 0; x < width;) {
const int mode =
(modes[(y >> bits) * tiles_per_row + (x >> bits)] >> 8) & 0xff;
int x_end = x + (1 << bits);
if (x_end > width) x_end = width;
GetResidual(width, height, upper_row, current_row, current_max_diffs,
mode, x, x_end, y, max_quantization, exact,
used_subtract_green, argb + y * width + x);
x = x_end;
}
}
}

5
src/enc/vp8l.c
View File

@ -319,7 +319,10 @@ static int GetHistoBits(int method, int use_palette, int width, int height) {
static int GetTransformBits(int method, int histo_bits) {
const int max_transform_bits = (method < 4) ? 6 : (method > 4) ? 4 : 5;
return (histo_bits > max_transform_bits) ? max_transform_bits : histo_bits;
const int res =
(histo_bits > max_transform_bits) ? max_transform_bits : histo_bits;
assert(res <= MAX_TRANSFORM_BITS);
return res;
}
static int AnalyzeAndInit(VP8LEncoder* const enc) {

5
src/enc/vp8li.h
View File

@ -24,6 +24,9 @@
extern "C" {
#endif
// maximum value of transform_bits_ in VP8LEncoder.
#define MAX_TRANSFORM_BITS 6
typedef struct {
const WebPConfig* config_; // user configuration and parameters
const WebPPicture* pic_; // input picture.
@ -39,7 +42,7 @@ typedef struct {
// Encoding parameters derived from quality parameter.
int histo_bits_;
int transform_bits_;
int transform_bits_; // <= MAX_TRANSFORM_BITS.
int cache_bits_; // If equal to 0, don't use color cache.
// Encoding parameters derived from image characteristics.