godotengine
/
godot
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
godot/drivers/webp/enc/picture.c

1325 lines
44 KiB
C
Raw Normal View History

GODOT IS OPEN SOURCE
2014-02-10 01:10:30 +00:00
// Copyright 2011 Google Inc. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the COPYING file in the root of the source
// tree. An additional intellectual property rights grant can be found
// in the file PATENTS. All contributing project authors may
// be found in the AUTHORS file in the root of the source tree.
// -----------------------------------------------------------------------------
//
// WebPPicture utils: colorspace conversion, crop, ...
//
// Author: Skal (pascal.massimino@gmail.com)
#include <assert.h>
#include <stdlib.h>
#include <math.h>
#include "./vp8enci.h"
#include "../utils/alpha_processing.h"
#include "../utils/random.h"
#include "../utils/rescaler.h"
#include "../utils/utils.h"
#include "../dsp/dsp.h"
#include "../dsp/yuv.h"
// Uncomment to disable gamma-compression during RGB->U/V averaging
#define USE_GAMMA_COMPRESSION
#define HALVE(x) (((x) + 1) >> 1)
#define IS_YUV_CSP(csp, YUV_CSP) (((csp) & WEBP_CSP_UV_MASK) == (YUV_CSP))
static const union {
uint32_t argb;
uint8_t bytes[4];
} test_endian = { 0xff000000u };
#define ALPHA_IS_LAST (test_endian.bytes[3] == 0xff)
static WEBP_INLINE uint32_t MakeARGB32(int r, int g, int b) {
return (0xff000000u | (r << 16) | (g << 8) | b);
}
//------------------------------------------------------------------------------
// WebPPicture
//------------------------------------------------------------------------------
int WebPPictureAlloc(WebPPicture* picture) {
if (picture != NULL) {
const WebPEncCSP uv_csp = picture->colorspace & WEBP_CSP_UV_MASK;
const int has_alpha = picture->colorspace & WEBP_CSP_ALPHA_BIT;
const int width = picture->width;
const int height = picture->height;
if (!picture->use_argb) {
const int y_stride = width;
const int uv_width = HALVE(width);
const int uv_height = HALVE(height);
const int uv_stride = uv_width;
int uv0_stride = 0;
int a_width, a_stride;
uint64_t y_size, uv_size, uv0_size, a_size, total_size;
uint8_t* mem;
// U/V
switch (uv_csp) {
case WEBP_YUV420:
break;
#ifdef WEBP_EXPERIMENTAL_FEATURES
case WEBP_YUV400: // for now, we'll just reset the U/V samples
break;
case WEBP_YUV422:
uv0_stride = uv_width;
break;
case WEBP_YUV444:
uv0_stride = width;
break;
#endif
default:
return 0;
}
uv0_size = height * uv0_stride;
// alpha
a_width = has_alpha ? width : 0;
a_stride = a_width;
y_size = (uint64_t)y_stride * height;
uv_size = (uint64_t)uv_stride * uv_height;
a_size = (uint64_t)a_stride * height;
total_size = y_size + a_size + 2 * uv_size + 2 * uv0_size;
// Security and validation checks
if (width <= 0 || height <= 0 || // luma/alpha param error
uv_width < 0 || uv_height < 0) { // u/v param error
return 0;
}
// Clear previous buffer and allocate a new one.
WebPPictureFree(picture); // erase previous buffer
mem = (uint8_t*)WebPSafeMalloc(total_size, sizeof(*mem));
if (mem == NULL) return 0;
// From now on, we're in the clear, we can no longer fail...
picture->memory_ = (void*)mem;
picture->y_stride = y_stride;
picture->uv_stride = uv_stride;
picture->a_stride = a_stride;
picture->uv0_stride = uv0_stride;
// TODO(skal): we could align the y/u/v planes and adjust stride.
picture->y = mem;
mem += y_size;
picture->u = mem;
mem += uv_size;
picture->v = mem;
mem += uv_size;
if (a_size) {
picture->a = mem;
mem += a_size;
}
if (uv0_size) {
picture->u0 = mem;
mem += uv0_size;
picture->v0 = mem;
mem += uv0_size;
}
(void)mem; // makes the static analyzer happy
} else {
void* memory;
const uint64_t argb_size = (uint64_t)width * height;
if (width <= 0 || height <= 0) {
return 0;
}
// Clear previous buffer and allocate a new one.
WebPPictureFree(picture); // erase previous buffer
memory = WebPSafeMalloc(argb_size, sizeof(*picture->argb));
if (memory == NULL) return 0;
// TODO(skal): align plane to cache line?
picture->memory_argb_ = memory;
picture->argb = (uint32_t*)memory;
picture->argb_stride = width;
}
}
return 1;
}
// Remove reference to the ARGB buffer (doesn't free anything).
static void PictureResetARGB(WebPPicture* const picture) {
picture->memory_argb_ = NULL;
picture->argb = NULL;
picture->argb_stride = 0;
}
// Remove reference to the YUVA buffer (doesn't free anything).
static void PictureResetYUVA(WebPPicture* const picture) {
picture->memory_ = NULL;
picture->y = picture->u = picture->v = picture->a = NULL;
picture->u0 = picture->v0 = NULL;
picture->y_stride = picture->uv_stride = 0;
picture->a_stride = 0;
picture->uv0_stride = 0;
}
// Grab the 'specs' (writer, *opaque, width, height...) from 'src' and copy them
// into 'dst'. Mark 'dst' as not owning any memory.
static void WebPPictureGrabSpecs(const WebPPicture* const src,
WebPPicture* const dst) {
assert(src != NULL && dst != NULL);
*dst = *src;
PictureResetYUVA(dst);
PictureResetARGB(dst);
}
// Allocate a new argb buffer, discarding any existing one and preserving
// the other YUV(A) buffer.
static int PictureAllocARGB(WebPPicture* const picture) {
WebPPicture tmp;
free(picture->memory_argb_);
PictureResetARGB(picture);
picture->use_argb = 1;
WebPPictureGrabSpecs(picture, &tmp);
if (!WebPPictureAlloc(&tmp)) {
return WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
}
picture->memory_argb_ = tmp.memory_argb_;
picture->argb = tmp.argb;
picture->argb_stride = tmp.argb_stride;
return 1;
}
// Release memory owned by 'picture' (both YUV and ARGB buffers).
void WebPPictureFree(WebPPicture* picture) {
if (picture != NULL) {
free(picture->memory_);
free(picture->memory_argb_);
PictureResetYUVA(picture);
PictureResetARGB(picture);
}
}
//------------------------------------------------------------------------------
// Picture copying
// Not worth moving to dsp/enc.c (only used here).
static void CopyPlane(const uint8_t* src, int src_stride,
uint8_t* dst, int dst_stride, int width, int height) {
while (height-- > 0) {
memcpy(dst, src, width);
src += src_stride;
dst += dst_stride;
}
}
// Adjust top-left corner to chroma sample position.
static void SnapTopLeftPosition(const WebPPicture* const pic,
int* const left, int* const top) {
if (!pic->use_argb) {
const int is_yuv422 = IS_YUV_CSP(pic->colorspace, WEBP_YUV422);
if (IS_YUV_CSP(pic->colorspace, WEBP_YUV420) || is_yuv422) {
*left &= ~1;
if (!is_yuv422) *top &= ~1;
}
}
}
// Adjust top-left corner and verify that the sub-rectangle is valid.
static int AdjustAndCheckRectangle(const WebPPicture* const pic,
int* const left, int* const top,
int width, int height) {
SnapTopLeftPosition(pic, left, top);
if ((*left) < 0 || (*top) < 0) return 0;
if (width <= 0 || height <= 0) return 0;
if ((*left) + width > pic->width) return 0;
if ((*top) + height > pic->height) return 0;
return 1;
}
int WebPPictureCopy(const WebPPicture* src, WebPPicture* dst) {
if (src == NULL || dst == NULL) return 0;
if (src == dst) return 1;
WebPPictureGrabSpecs(src, dst);
if (!WebPPictureAlloc(dst)) return 0;
if (!src->use_argb) {
CopyPlane(src->y, src->y_stride,
dst->y, dst->y_stride, dst->width, dst->height);
CopyPlane(src->u, src->uv_stride,
dst->u, dst->uv_stride, HALVE(dst->width), HALVE(dst->height));
CopyPlane(src->v, src->uv_stride,
dst->v, dst->uv_stride, HALVE(dst->width), HALVE(dst->height));
if (dst->a != NULL) {
CopyPlane(src->a, src->a_stride,
dst->a, dst->a_stride, dst->width, dst->height);
}
#ifdef WEBP_EXPERIMENTAL_FEATURES
if (dst->u0 != NULL) {
int uv0_width = src->width;
if (IS_YUV_CSP(dst->colorspace, WEBP_YUV422)) {
uv0_width = HALVE(uv0_width);
}
CopyPlane(src->u0, src->uv0_stride,
dst->u0, dst->uv0_stride, uv0_width, dst->height);
CopyPlane(src->v0, src->uv0_stride,
dst->v0, dst->uv0_stride, uv0_width, dst->height);
}
#endif
} else {
CopyPlane((const uint8_t*)src->argb, 4 * src->argb_stride,
(uint8_t*)dst->argb, 4 * dst->argb_stride,
4 * dst->width, dst->height);
}
return 1;
}
int WebPPictureIsView(const WebPPicture* picture) {
if (picture == NULL) return 0;
if (picture->use_argb) {
return (picture->memory_argb_ == NULL);
}
return (picture->memory_ == NULL);
}
int WebPPictureView(const WebPPicture* src,
int left, int top, int width, int height,
WebPPicture* dst) {
if (src == NULL || dst == NULL) return 0;
// verify rectangle position.
if (!AdjustAndCheckRectangle(src, &left, &top, width, height)) return 0;
if (src != dst) { // beware of aliasing! We don't want to leak 'memory_'.
WebPPictureGrabSpecs(src, dst);
}
dst->width = width;
dst->height = height;
if (!src->use_argb) {
dst->y = src->y + top * src->y_stride + left;
dst->u = src->u + (top >> 1) * src->uv_stride + (left >> 1);
dst->v = src->v + (top >> 1) * src->uv_stride + (left >> 1);
dst->y_stride = src->y_stride;
dst->uv_stride = src->uv_stride;
if (src->a != NULL) {
dst->a = src->a + top * src->a_stride + left;
dst->a_stride = src->a_stride;
}
#ifdef WEBP_EXPERIMENTAL_FEATURES
if (src->u0 != NULL) {
const int left_pos =
IS_YUV_CSP(dst->colorspace, WEBP_YUV422) ? (left >> 1) : left;
dst->u0 = src->u0 + top * src->uv0_stride + left_pos;
dst->v0 = src->v0 + top * src->uv0_stride + left_pos;
dst->uv0_stride = src->uv0_stride;
}
#endif
} else {
dst->argb = src->argb + top * src->argb_stride + left;
dst->argb_stride = src->argb_stride;
}
return 1;
}
//------------------------------------------------------------------------------
// Picture cropping
int WebPPictureCrop(WebPPicture* pic,
int left, int top, int width, int height) {
WebPPicture tmp;
if (pic == NULL) return 0;
if (!AdjustAndCheckRectangle(pic, &left, &top, width, height)) return 0;
WebPPictureGrabSpecs(pic, &tmp);
tmp.width = width;
tmp.height = height;
if (!WebPPictureAlloc(&tmp)) return 0;
if (!pic->use_argb) {
const int y_offset = top * pic->y_stride + left;
const int uv_offset = (top / 2) * pic->uv_stride + left / 2;
CopyPlane(pic->y + y_offset, pic->y_stride,
tmp.y, tmp.y_stride, width, height);
CopyPlane(pic->u + uv_offset, pic->uv_stride,
tmp.u, tmp.uv_stride, HALVE(width), HALVE(height));
CopyPlane(pic->v + uv_offset, pic->uv_stride,
tmp.v, tmp.uv_stride, HALVE(width), HALVE(height));
if (tmp.a != NULL) {
const int a_offset = top * pic->a_stride + left;
CopyPlane(pic->a + a_offset, pic->a_stride,
tmp.a, tmp.a_stride, width, height);
}
#ifdef WEBP_EXPERIMENTAL_FEATURES
if (tmp.u0 != NULL) {
int w = width;
int left_pos = left;
if (IS_YUV_CSP(tmp.colorspace, WEBP_YUV422)) {
w = HALVE(w);
left_pos = HALVE(left_pos);
}
CopyPlane(pic->u0 + top * pic->uv0_stride + left_pos, pic->uv0_stride,
tmp.u0, tmp.uv0_stride, w, height);
CopyPlane(pic->v0 + top * pic->uv0_stride + left_pos, pic->uv0_stride,
tmp.v0, tmp.uv0_stride, w, height);
}
#endif
} else {
const uint8_t* const src =
(const uint8_t*)(pic->argb + top * pic->argb_stride + left);
CopyPlane(src, pic->argb_stride * 4,
(uint8_t*)tmp.argb, tmp.argb_stride * 4,
width * 4, height);
}
WebPPictureFree(pic);
*pic = tmp;
return 1;
}
//------------------------------------------------------------------------------
// Simple picture rescaler
static void RescalePlane(const uint8_t* src,
int src_width, int src_height, int src_stride,
uint8_t* dst,
int dst_width, int dst_height, int dst_stride,
int32_t* const work,
int num_channels) {
WebPRescaler rescaler;
int y = 0;
WebPRescalerInit(&rescaler, src_width, src_height,
dst, dst_width, dst_height, dst_stride,
num_channels,
src_width, dst_width,
src_height, dst_height,
work);
memset(work, 0, 2 * dst_width * num_channels * sizeof(*work));
while (y < src_height) {
y += WebPRescalerImport(&rescaler, src_height - y,
src + y * src_stride, src_stride);
WebPRescalerExport(&rescaler);
}
}
static void AlphaMultiplyARGB(WebPPicture* const pic, int inverse) {
uint32_t* ptr = pic->argb;
int y;
for (y = 0; y < pic->height; ++y) {
WebPMultARGBRow(ptr, pic->width, inverse);
ptr += pic->argb_stride;
}
}
static void AlphaMultiplyY(WebPPicture* const pic, int inverse) {
const uint8_t* ptr_a = pic->a;
if (ptr_a != NULL) {
uint8_t* ptr_y = pic->y;
int y;
for (y = 0; y < pic->height; ++y) {
WebPMultRow(ptr_y, ptr_a, pic->width, inverse);
ptr_y += pic->y_stride;
ptr_a += pic->a_stride;
}
}
}
int WebPPictureRescale(WebPPicture* pic, int width, int height) {
WebPPicture tmp;
int prev_width, prev_height;
int32_t* work;
if (pic == NULL) return 0;
prev_width = pic->width;
prev_height = pic->height;
// if width is unspecified, scale original proportionally to height ratio.
if (width == 0) {
width = (prev_width * height + prev_height / 2) / prev_height;
}
// if height is unspecified, scale original proportionally to width ratio.
if (height == 0) {
height = (prev_height * width + prev_width / 2) / prev_width;
}
// Check if the overall dimensions still make sense.
if (width <= 0 || height <= 0) return 0;
WebPPictureGrabSpecs(pic, &tmp);
tmp.width = width;
tmp.height = height;
if (!WebPPictureAlloc(&tmp)) return 0;
if (!pic->use_argb) {
work = (int32_t*)WebPSafeMalloc(2ULL * width, sizeof(*work));
if (work == NULL) {
WebPPictureFree(&tmp);
return 0;
}
// If present, we need to rescale alpha first (for AlphaMultiplyY).
if (pic->a != NULL) {
RescalePlane(pic->a, prev_width, prev_height, pic->a_stride,
tmp.a, width, height, tmp.a_stride, work, 1);
}
// We take transparency into account on the luma plane only. That's not
// totally exact blending, but still is a good approximation.
AlphaMultiplyY(pic, 0);
RescalePlane(pic->y, prev_width, prev_height, pic->y_stride,
tmp.y, width, height, tmp.y_stride, work, 1);
AlphaMultiplyY(&tmp, 1);
RescalePlane(pic->u,
HALVE(prev_width), HALVE(prev_height), pic->uv_stride,
tmp.u,
HALVE(width), HALVE(height), tmp.uv_stride, work, 1);
RescalePlane(pic->v,
HALVE(prev_width), HALVE(prev_height), pic->uv_stride,
tmp.v,
HALVE(width), HALVE(height), tmp.uv_stride, work, 1);
#ifdef WEBP_EXPERIMENTAL_FEATURES
if (tmp.u0 != NULL) {
const int s = IS_YUV_CSP(tmp.colorspace, WEBP_YUV422) ? 2 : 1;
RescalePlane(
pic->u0, (prev_width + s / 2) / s, prev_height, pic->uv0_stride,
tmp.u0, (width + s / 2) / s, height, tmp.uv0_stride, work, 1);
RescalePlane(
pic->v0, (prev_width + s / 2) / s, prev_height, pic->uv0_stride,
tmp.v0, (width + s / 2) / s, height, tmp.uv0_stride, work, 1);
}
#endif
} else {
work = (int32_t*)WebPSafeMalloc(2ULL * width * 4, sizeof(*work));
if (work == NULL) {
WebPPictureFree(&tmp);
return 0;
}
// In order to correctly interpolate colors, we need to apply the alpha
// weighting first (black-matting), scale the RGB values, and remove
// the premultiplication afterward (while preserving the alpha channel).
AlphaMultiplyARGB(pic, 0);
RescalePlane((const uint8_t*)pic->argb, prev_width, prev_height,
pic->argb_stride * 4,
(uint8_t*)tmp.argb, width, height,
tmp.argb_stride * 4,
work, 4);
AlphaMultiplyARGB(&tmp, 1);
}
WebPPictureFree(pic);
free(work);
*pic = tmp;
return 1;
}
//------------------------------------------------------------------------------
// WebPMemoryWriter: Write-to-memory
void WebPMemoryWriterInit(WebPMemoryWriter* writer) {
writer->mem = NULL;
writer->size = 0;
writer->max_size = 0;
}
int WebPMemoryWrite(const uint8_t* data, size_t data_size,
const WebPPicture* picture) {
WebPMemoryWriter* const w = (WebPMemoryWriter*)picture->custom_ptr;
uint64_t next_size;
if (w == NULL) {
return 1;
}
next_size = (uint64_t)w->size + data_size;
if (next_size > w->max_size) {
uint8_t* new_mem;
uint64_t next_max_size = 2ULL * w->max_size;
if (next_max_size < next_size) next_max_size = next_size;
if (next_max_size < 8192ULL) next_max_size = 8192ULL;
new_mem = (uint8_t*)WebPSafeMalloc(next_max_size, 1);
if (new_mem == NULL) {
return 0;
}
if (w->size > 0) {
memcpy(new_mem, w->mem, w->size);
}
free(w->mem);
w->mem = new_mem;
// down-cast is ok, thanks to WebPSafeMalloc
w->max_size = (size_t)next_max_size;
}
if (data_size > 0) {
memcpy(w->mem + w->size, data, data_size);
w->size += data_size;
}
return 1;
}
//------------------------------------------------------------------------------
// Detection of non-trivial transparency
// Returns true if alpha[] has non-0xff values.
static int CheckNonOpaque(const uint8_t* alpha, int width, int height,
int x_step, int y_step) {
if (alpha == NULL) return 0;
while (height-- > 0) {
int x;
for (x = 0; x < width * x_step; x += x_step) {
if (alpha[x] != 0xff) return 1; // TODO(skal): check 4/8 bytes at a time.
}
alpha += y_step;
}
return 0;
}
// Checking for the presence of non-opaque alpha.
int WebPPictureHasTransparency(const WebPPicture* picture) {
if (picture == NULL) return 0;
if (!picture->use_argb) {
return CheckNonOpaque(picture->a, picture->width, picture->height,
1, picture->a_stride);
} else {
int x, y;
const uint32_t* argb = picture->argb;
if (argb == NULL) return 0;
for (y = 0; y < picture->height; ++y) {
for (x = 0; x < picture->width; ++x) {
if (argb[x] < 0xff000000u) return 1; // test any alpha values != 0xff
}
argb += picture->argb_stride;
}
}
return 0;
}
//------------------------------------------------------------------------------
// RGB -> YUV conversion
static int RGBToY(int r, int g, int b, VP8Random* const rg) {
return VP8RGBToY(r, g, b, VP8RandomBits(rg, YUV_FIX));
}
static int RGBToU(int r, int g, int b, VP8Random* const rg) {
return VP8RGBToU(r, g, b, VP8RandomBits(rg, YUV_FIX + 2));
}
static int RGBToV(int r, int g, int b, VP8Random* const rg) {
return VP8RGBToV(r, g, b, VP8RandomBits(rg, YUV_FIX + 2));
}
//------------------------------------------------------------------------------
#if defined(USE_GAMMA_COMPRESSION)
// gamma-compensates loss of resolution during chroma subsampling
#define kGamma 0.80
#define kGammaFix 12 // fixed-point precision for linear values
#define kGammaScale ((1 << kGammaFix) - 1)
#define kGammaTabFix 7 // fixed-point fractional bits precision
#define kGammaTabScale (1 << kGammaTabFix)
#define kGammaTabRounder (kGammaTabScale >> 1)
#define kGammaTabSize (1 << (kGammaFix - kGammaTabFix))
static int kLinearToGammaTab[kGammaTabSize + 1];
static uint16_t kGammaToLinearTab[256];
static int kGammaTablesOk = 0;
static void InitGammaTables(void) {
if (!kGammaTablesOk) {
int v;
const double scale = 1. / kGammaScale;
for (v = 0; v <= 255; ++v) {
kGammaToLinearTab[v] =
(uint16_t)(pow(v / 255., kGamma) * kGammaScale + .5);
}
for (v = 0; v <= kGammaTabSize; ++v) {
const double x = scale * (v << kGammaTabFix);
kLinearToGammaTab[v] = (int)(pow(x, 1. / kGamma) * 255. + .5);
}
kGammaTablesOk = 1;
}
}
static WEBP_INLINE uint32_t GammaToLinear(uint8_t v) {
return kGammaToLinearTab[v];
}
// Convert a linear value 'v' to YUV_FIX+2 fixed-point precision
// U/V value, suitable for RGBToU/V calls.
static WEBP_INLINE int LinearToGamma(uint32_t base_value, int shift) {
const int v = base_value << shift; // final uplifted value
const int tab_pos = v >> (kGammaTabFix + 2); // integer part
const int x = v & ((kGammaTabScale << 2) - 1); // fractional part
const int v0 = kLinearToGammaTab[tab_pos];
const int v1 = kLinearToGammaTab[tab_pos + 1];
const int y = v1 * x + v0 * ((kGammaTabScale << 2) - x); // interpolate
return (y + kGammaTabRounder) >> kGammaTabFix; // descale
}
#else
static void InitGammaTables(void) {}
static WEBP_INLINE uint32_t GammaToLinear(uint8_t v) { return v; }
static WEBP_INLINE int LinearToGamma(uint32_t base_value, int shift) {
(void)shift;
return v;
}
#endif // USE_GAMMA_COMPRESSION
//------------------------------------------------------------------------------
#define SUM4(ptr) LinearToGamma( \
GammaToLinear((ptr)[0]) + \
GammaToLinear((ptr)[step]) + \
GammaToLinear((ptr)[rgb_stride]) + \
GammaToLinear((ptr)[rgb_stride + step]), 0) \
#define SUM2H(ptr) \
LinearToGamma(GammaToLinear((ptr)[0]) + GammaToLinear((ptr)[step]), 1)
#define SUM2V(ptr) \
LinearToGamma(GammaToLinear((ptr)[0]) + GammaToLinear((ptr)[rgb_stride]), 1)
#define SUM1(ptr) \
LinearToGamma(GammaToLinear((ptr)[0]), 2)
#define RGB_TO_UV(x, y, SUM) { \
const int src = (2 * (step * (x) + (y) * rgb_stride)); \
const int dst = (x) + (y) * picture->uv_stride; \
const int r = SUM(r_ptr + src); \
const int g = SUM(g_ptr + src); \
const int b = SUM(b_ptr + src); \
picture->u[dst] = RGBToU(r, g, b, &rg); \
picture->v[dst] = RGBToV(r, g, b, &rg); \
}
#define RGB_TO_UV0(x_in, x_out, y, SUM) { \
const int src = (step * (x_in) + (y) * rgb_stride); \
const int dst = (x_out) + (y) * picture->uv0_stride; \
const int r = SUM(r_ptr + src); \
const int g = SUM(g_ptr + src); \
const int b = SUM(b_ptr + src); \
picture->u0[dst] = RGBToU(r, g, b, &rg); \
picture->v0[dst] = RGBToV(r, g, b, &rg); \
}
static void MakeGray(WebPPicture* const picture) {
int y;
const int uv_width = HALVE(picture->width);
const int uv_height = HALVE(picture->height);
for (y = 0; y < uv_height; ++y) {
memset(picture->u + y * picture->uv_stride, 128, uv_width);
memset(picture->v + y * picture->uv_stride, 128, uv_width);
}
}
static int ImportYUVAFromRGBA(const uint8_t* const r_ptr,
const uint8_t* const g_ptr,
const uint8_t* const b_ptr,
const uint8_t* const a_ptr,
int step, // bytes per pixel
int rgb_stride, // bytes per scanline
float dithering,
WebPPicture* const picture) {
const WebPEncCSP uv_csp = picture->colorspace & WEBP_CSP_UV_MASK;
int x, y;
const int width = picture->width;
const int height = picture->height;
const int has_alpha = CheckNonOpaque(a_ptr, width, height, step, rgb_stride);
VP8Random rg;
picture->colorspace = uv_csp;
picture->use_argb = 0;
if (has_alpha) {
picture->colorspace |= WEBP_CSP_ALPHA_BIT;
}
if (!WebPPictureAlloc(picture)) return 0;
VP8InitRandom(&rg, dithering);
InitGammaTables();
// Import luma plane
for (y = 0; y < height; ++y) {
for (x = 0; x < width; ++x) {
const int offset = step * x + y * rgb_stride;
picture->y[x + y * picture->y_stride] =
RGBToY(r_ptr[offset], g_ptr[offset], b_ptr[offset], &rg);
}
}
// Downsample U/V plane
if (uv_csp != WEBP_YUV400) {
for (y = 0; y < (height >> 1); ++y) {
for (x = 0; x < (width >> 1); ++x) {
RGB_TO_UV(x, y, SUM4);
}
if (width & 1) {
RGB_TO_UV(x, y, SUM2V);
}
}
if (height & 1) {
for (x = 0; x < (width >> 1); ++x) {
RGB_TO_UV(x, y, SUM2H);
}
if (width & 1) {
RGB_TO_UV(x, y, SUM1);
}
}
#ifdef WEBP_EXPERIMENTAL_FEATURES
// Store original U/V samples too
if (uv_csp == WEBP_YUV422) {
for (y = 0; y < height; ++y) {
for (x = 0; x < (width >> 1); ++x) {
RGB_TO_UV0(2 * x, x, y, SUM2H);
}
if (width & 1) {
RGB_TO_UV0(2 * x, x, y, SUM1);
}
}
} else if (uv_csp == WEBP_YUV444) {
for (y = 0; y < height; ++y) {
for (x = 0; x < width; ++x) {
RGB_TO_UV0(x, x, y, SUM1);
}
}
}
#endif
} else {
MakeGray(picture);
}
if (has_alpha) {
assert(step >= 4);
assert(picture->a != NULL);
for (y = 0; y < height; ++y) {
for (x = 0; x < width; ++x) {
picture->a[x + y * picture->a_stride] =
a_ptr[step * x + y * rgb_stride];
}
}
}
return 1;
}
static int Import(WebPPicture* const picture,
const uint8_t* const rgb, int rgb_stride,
int step, int swap_rb, int import_alpha) {
const uint8_t* const r_ptr = rgb + (swap_rb ? 2 : 0);
const uint8_t* const g_ptr = rgb + 1;
const uint8_t* const b_ptr = rgb + (swap_rb ? 0 : 2);
const uint8_t* const a_ptr = import_alpha ? rgb + 3 : NULL;
const int width = picture->width;
const int height = picture->height;
if (!picture->use_argb) {
return ImportYUVAFromRGBA(r_ptr, g_ptr, b_ptr, a_ptr, step, rgb_stride,
0.f /* no dithering */, picture);
}
if (import_alpha) {
picture->colorspace |= WEBP_CSP_ALPHA_BIT;
} else {
picture->colorspace &= ~WEBP_CSP_ALPHA_BIT;
}
if (!WebPPictureAlloc(picture)) return 0;
if (!import_alpha) {
int x, y;
for (y = 0; y < height; ++y) {
for (x = 0; x < width; ++x) {
const int offset = step * x + y * rgb_stride;
const uint32_t argb =
MakeARGB32(r_ptr[offset], g_ptr[offset], b_ptr[offset]);
picture->argb[x + y * picture->argb_stride] = argb;
}
}
} else {
int x, y;
assert(step >= 4);
for (y = 0; y < height; ++y) {
for (x = 0; x < width; ++x) {
const int offset = step * x + y * rgb_stride;
const uint32_t argb = ((uint32_t)a_ptr[offset] << 24) |
(r_ptr[offset] << 16) |
(g_ptr[offset] << 8) |
(b_ptr[offset]);
picture->argb[x + y * picture->argb_stride] = argb;
}
}
}
return 1;
}
#undef SUM4
#undef SUM2V
#undef SUM2H
#undef SUM1
#undef RGB_TO_UV
int WebPPictureImportRGB(WebPPicture* picture,
const uint8_t* rgb, int rgb_stride) {
return Import(picture, rgb, rgb_stride, 3, 0, 0);
}
int WebPPictureImportBGR(WebPPicture* picture,
const uint8_t* rgb, int rgb_stride) {
return Import(picture, rgb, rgb_stride, 3, 1, 0);
}
int WebPPictureImportRGBA(WebPPicture* picture,
const uint8_t* rgba, int rgba_stride) {
return Import(picture, rgba, rgba_stride, 4, 0, 1);
}
int WebPPictureImportBGRA(WebPPicture* picture,
const uint8_t* rgba, int rgba_stride) {
return Import(picture, rgba, rgba_stride, 4, 1, 1);
}
int WebPPictureImportRGBX(WebPPicture* picture,
const uint8_t* rgba, int rgba_stride) {
return Import(picture, rgba, rgba_stride, 4, 0, 0);
}
int WebPPictureImportBGRX(WebPPicture* picture,
const uint8_t* rgba, int rgba_stride) {
return Import(picture, rgba, rgba_stride, 4, 1, 0);
}
//------------------------------------------------------------------------------
// Automatic YUV <-> ARGB conversions.
int WebPPictureYUVAToARGB(WebPPicture* picture) {
if (picture == NULL) return 0;
if (picture->y == NULL || picture->u == NULL || picture->v == NULL) {
return WebPEncodingSetError(picture, VP8_ENC_ERROR_NULL_PARAMETER);
}
if ((picture->colorspace & WEBP_CSP_ALPHA_BIT) && picture->a == NULL) {
return WebPEncodingSetError(picture, VP8_ENC_ERROR_NULL_PARAMETER);
}
if ((picture->colorspace & WEBP_CSP_UV_MASK) != WEBP_YUV420) {
return WebPEncodingSetError(picture, VP8_ENC_ERROR_INVALID_CONFIGURATION);
}
// Allocate a new argb buffer (discarding the previous one).
if (!PictureAllocARGB(picture)) return 0;
// Convert
{
int y;
const int width = picture->width;
const int height = picture->height;
const int argb_stride = 4 * picture->argb_stride;
uint8_t* dst = (uint8_t*)picture->argb;
const uint8_t *cur_u = picture->u, *cur_v = picture->v, *cur_y = picture->y;
WebPUpsampleLinePairFunc upsample = WebPGetLinePairConverter(ALPHA_IS_LAST);
// First row, with replicated top samples.
upsample(cur_y, NULL, cur_u, cur_v, cur_u, cur_v, dst, NULL, width);
cur_y += picture->y_stride;
dst += argb_stride;
// Center rows.
for (y = 1; y + 1 < height; y += 2) {
const uint8_t* const top_u = cur_u;
const uint8_t* const top_v = cur_v;
cur_u += picture->uv_stride;
cur_v += picture->uv_stride;
upsample(cur_y, cur_y + picture->y_stride, top_u, top_v, cur_u, cur_v,
dst, dst + argb_stride, width);
cur_y += 2 * picture->y_stride;
dst += 2 * argb_stride;
}
// Last row (if needed), with replicated bottom samples.
if (height > 1 && !(height & 1)) {
upsample(cur_y, NULL, cur_u, cur_v, cur_u, cur_v, dst, NULL, width);
}
// Insert alpha values if needed, in replacement for the default 0xff ones.
if (picture->colorspace & WEBP_CSP_ALPHA_BIT) {
for (y = 0; y < height; ++y) {
uint32_t* const argb_dst = picture->argb + y * picture->argb_stride;
const uint8_t* const src = picture->a + y * picture->a_stride;
int x;
for (x = 0; x < width; ++x) {
argb_dst[x] = (argb_dst[x] & 0x00ffffffu) | ((uint32_t)src[x] << 24);
}
}
}
}
return 1;
}
int WebPPictureARGBToYUVADithered(WebPPicture* picture, WebPEncCSP colorspace,
float dithering) {
if (picture == NULL) return 0;
if (picture->argb == NULL) {
return WebPEncodingSetError(picture, VP8_ENC_ERROR_NULL_PARAMETER);
} else {
const uint8_t* const argb = (const uint8_t*)picture->argb;
const uint8_t* const r = ALPHA_IS_LAST ? argb + 2 : argb + 1;
const uint8_t* const g = ALPHA_IS_LAST ? argb + 1 : argb + 2;
const uint8_t* const b = ALPHA_IS_LAST ? argb + 0 : argb + 3;
const uint8_t* const a = ALPHA_IS_LAST ? argb + 3 : argb + 0;
// We work on a tmp copy of 'picture', because ImportYUVAFromRGBA()
// would be calling WebPPictureFree(picture) otherwise.
WebPPicture tmp = *picture;
PictureResetARGB(&tmp); // reset ARGB buffer so that it's not free()'d.
tmp.use_argb = 0;
tmp.colorspace = colorspace & WEBP_CSP_UV_MASK;
if (!ImportYUVAFromRGBA(r, g, b, a, 4, 4 * picture->argb_stride, dithering,
&tmp)) {
return WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
}
// Copy back the YUV specs into 'picture'.
tmp.argb = picture->argb;
tmp.argb_stride = picture->argb_stride;
tmp.memory_argb_ = picture->memory_argb_;
*picture = tmp;
}
return 1;
}
int WebPPictureARGBToYUVA(WebPPicture* picture, WebPEncCSP colorspace) {
return WebPPictureARGBToYUVADithered(picture, colorspace, 0.f);
}
//------------------------------------------------------------------------------
// Helper: clean up fully transparent area to help compressibility.
#define SIZE 8
#define SIZE2 (SIZE / 2)
static int is_transparent_area(const uint8_t* ptr, int stride, int size) {
int y, x;
for (y = 0; y < size; ++y) {
for (x = 0; x < size; ++x) {
if (ptr[x]) {
return 0;
}
}
ptr += stride;
}
return 1;
}
static WEBP_INLINE void flatten(uint8_t* ptr, int v, int stride, int size) {
int y;
for (y = 0; y < size; ++y) {
memset(ptr, v, size);
ptr += stride;
}
}
void WebPCleanupTransparentArea(WebPPicture* pic) {
int x, y, w, h;
const uint8_t* a_ptr;
int values[3] = { 0 };
if (pic == NULL) return;
a_ptr = pic->a;
if (a_ptr == NULL) return; // nothing to do
w = pic->width / SIZE;
h = pic->height / SIZE;
for (y = 0; y < h; ++y) {
int need_reset = 1;
for (x = 0; x < w; ++x) {
const int off_a = (y * pic->a_stride + x) * SIZE;
const int off_y = (y * pic->y_stride + x) * SIZE;
const int off_uv = (y * pic->uv_stride + x) * SIZE2;
if (is_transparent_area(a_ptr + off_a, pic->a_stride, SIZE)) {
if (need_reset) {
values[0] = pic->y[off_y];
values[1] = pic->u[off_uv];
values[2] = pic->v[off_uv];
need_reset = 0;
}
flatten(pic->y + off_y, values[0], pic->y_stride, SIZE);
flatten(pic->u + off_uv, values[1], pic->uv_stride, SIZE2);
flatten(pic->v + off_uv, values[2], pic->uv_stride, SIZE2);
} else {
need_reset = 1;
}
}
// ignore the left-overs on right/bottom
}
}
#undef SIZE
#undef SIZE2
//------------------------------------------------------------------------------
// Blend color and remove transparency info
#define BLEND(V0, V1, ALPHA) \
((((V0) * (255 - (ALPHA)) + (V1) * (ALPHA)) * 0x101) >> 16)
#define BLEND_10BIT(V0, V1, ALPHA) \
((((V0) * (1020 - (ALPHA)) + (V1) * (ALPHA)) * 0x101) >> 18)
void WebPBlendAlpha(WebPPicture* pic, uint32_t background_rgb) {
const int red = (background_rgb >> 16) & 0xff;
const int green = (background_rgb >> 8) & 0xff;
const int blue = (background_rgb >> 0) & 0xff;
VP8Random rg;
int x, y;
if (pic == NULL) return;
VP8InitRandom(&rg, 0.f);
if (!pic->use_argb) {
const int uv_width = (pic->width >> 1); // omit last pixel during u/v loop
const int Y0 = RGBToY(red, green, blue, &rg);
// VP8RGBToU/V expects the u/v values summed over four pixels
const int U0 = RGBToU(4 * red, 4 * green, 4 * blue, &rg);
const int V0 = RGBToV(4 * red, 4 * green, 4 * blue, &rg);
const int has_alpha = pic->colorspace & WEBP_CSP_ALPHA_BIT;
if (!has_alpha || pic->a == NULL) return; // nothing to do
for (y = 0; y < pic->height; ++y) {
// Luma blending
uint8_t* const y_ptr = pic->y + y * pic->y_stride;
uint8_t* const a_ptr = pic->a + y * pic->a_stride;
for (x = 0; x < pic->width; ++x) {
const int alpha = a_ptr[x];
if (alpha < 0xff) {
y_ptr[x] = BLEND(Y0, y_ptr[x], a_ptr[x]);
}
}
// Chroma blending every even line
if ((y & 1) == 0) {
uint8_t* const u = pic->u + (y >> 1) * pic->uv_stride;
uint8_t* const v = pic->v + (y >> 1) * pic->uv_stride;
uint8_t* const a_ptr2 =
(y + 1 == pic->height) ? a_ptr : a_ptr + pic->a_stride;
for (x = 0; x < uv_width; ++x) {
// Average four alpha values into a single blending weight.
// TODO(skal): might lead to visible contouring. Can we do better?
const int alpha =
a_ptr[2 * x + 0] + a_ptr[2 * x + 1] +
a_ptr2[2 * x + 0] + a_ptr2[2 * x + 1];
u[x] = BLEND_10BIT(U0, u[x], alpha);
v[x] = BLEND_10BIT(V0, v[x], alpha);
}
if (pic->width & 1) { // rightmost pixel
const int alpha = 2 * (a_ptr[2 * x + 0] + a_ptr2[2 * x + 0]);
u[x] = BLEND_10BIT(U0, u[x], alpha);
v[x] = BLEND_10BIT(V0, v[x], alpha);
}
}
memset(a_ptr, 0xff, pic->width);
}
} else {
uint32_t* argb = pic->argb;
const uint32_t background = MakeARGB32(red, green, blue);
for (y = 0; y < pic->height; ++y) {
for (x = 0; x < pic->width; ++x) {
const int alpha = (argb[x] >> 24) & 0xff;
if (alpha != 0xff) {
if (alpha > 0) {
int r = (argb[x] >> 16) & 0xff;
int g = (argb[x] >> 8) & 0xff;
int b = (argb[x] >> 0) & 0xff;
r = BLEND(red, r, alpha);
g = BLEND(green, g, alpha);
b = BLEND(blue, b, alpha);
argb[x] = MakeARGB32(r, g, b);
} else {
argb[x] = background;
}
}
}
argb += pic->argb_stride;
}
}
}
#undef BLEND
#undef BLEND_10BIT
//------------------------------------------------------------------------------
// local-min distortion
//
// For every pixel in the *reference* picture, we search for the local best
// match in the compressed image. This is not a symmetrical measure.
// search radius. Shouldn't be too large.
#define RADIUS 2
static float AccumulateLSIM(const uint8_t* src, int src_stride,
const uint8_t* ref, int ref_stride,
int w, int h) {
int x, y;
double total_sse = 0.;
for (y = 0; y < h; ++y) {
const int y_0 = (y - RADIUS < 0) ? 0 : y - RADIUS;
const int y_1 = (y + RADIUS + 1 >= h) ? h : y + RADIUS + 1;
for (x = 0; x < w; ++x) {
const int x_0 = (x - RADIUS < 0) ? 0 : x - RADIUS;
const int x_1 = (x + RADIUS + 1 >= w) ? w : x + RADIUS + 1;
double best_sse = 255. * 255.;
const double value = (double)ref[y * ref_stride + x];
int i, j;
for (j = y_0; j < y_1; ++j) {
const uint8_t* s = src + j * src_stride;
for (i = x_0; i < x_1; ++i) {
const double sse = (double)(s[i] - value) * (s[i] - value);
if (sse < best_sse) best_sse = sse;
}
}
total_sse += best_sse;
}
}
return (float)total_sse;
}
#undef RADIUS
//------------------------------------------------------------------------------
// Distortion
// Max value returned in case of exact similarity.
static const double kMinDistortion_dB = 99.;
static float GetPSNR(const double v) {
return (float)((v > 0.) ? -4.3429448 * log(v / (255 * 255.))
: kMinDistortion_dB);
}
int WebPPictureDistortion(const WebPPicture* src, const WebPPicture* ref,
int type, float result[5]) {
DistoStats stats[5];
int has_alpha;
int uv_w, uv_h;
if (src == NULL || ref == NULL ||
src->width != ref->width || src->height != ref->height ||
src->y == NULL || ref->y == NULL ||
src->u == NULL || ref->u == NULL ||
src->v == NULL || ref->v == NULL ||
result == NULL) {
return 0;
}
// TODO(skal): provide distortion for ARGB too.
if (src->use_argb == 1 || src->use_argb != ref->use_argb) {
return 0;
}
has_alpha = !!(src->colorspace & WEBP_CSP_ALPHA_BIT);
if (has_alpha != !!(ref->colorspace & WEBP_CSP_ALPHA_BIT) ||
(has_alpha && (src->a == NULL || ref->a == NULL))) {
return 0;
}
memset(stats, 0, sizeof(stats));
uv_w = HALVE(src->width);
uv_h = HALVE(src->height);
if (type >= 2) {
float sse[4];
sse[0] = AccumulateLSIM(src->y, src->y_stride,
ref->y, ref->y_stride, src->width, src->height);
sse[1] = AccumulateLSIM(src->u, src->uv_stride,
ref->u, ref->uv_stride, uv_w, uv_h);
sse[2] = AccumulateLSIM(src->v, src->uv_stride,
ref->v, ref->uv_stride, uv_w, uv_h);
sse[3] = has_alpha ? AccumulateLSIM(src->a, src->a_stride,
ref->a, ref->a_stride,
src->width, src->height)
: 0.f;
result[0] = GetPSNR(sse[0] / (src->width * src->height));
result[1] = GetPSNR(sse[1] / (uv_w * uv_h));
result[2] = GetPSNR(sse[2] / (uv_w * uv_h));
result[3] = GetPSNR(sse[3] / (src->width * src->height));
{
double total_sse = sse[0] + sse[1] + sse[2];
int total_pixels = src->width * src->height + 2 * uv_w * uv_h;
if (has_alpha) {
total_pixels += src->width * src->height;
total_sse += sse[3];
}
result[4] = GetPSNR(total_sse / total_pixels);
}
} else {
int c;
VP8SSIMAccumulatePlane(src->y, src->y_stride,
ref->y, ref->y_stride,
src->width, src->height, &stats[0]);
VP8SSIMAccumulatePlane(src->u, src->uv_stride,
ref->u, ref->uv_stride,
uv_w, uv_h, &stats[1]);
VP8SSIMAccumulatePlane(src->v, src->uv_stride,
ref->v, ref->uv_stride,
uv_w, uv_h, &stats[2]);
if (has_alpha) {
VP8SSIMAccumulatePlane(src->a, src->a_stride,
ref->a, ref->a_stride,
src->width, src->height, &stats[3]);
}
for (c = 0; c <= 4; ++c) {
if (type == 1) {
const double v = VP8SSIMGet(&stats[c]);
result[c] = (float)((v < 1.) ? -10.0 * log10(1. - v)
: kMinDistortion_dB);
} else {
const double v = VP8SSIMGetSquaredError(&stats[c]);
result[c] = GetPSNR(v);
}
// Accumulate forward
if (c < 4) VP8SSIMAddStats(&stats[c], &stats[4]);
}
}
return 1;
}
//------------------------------------------------------------------------------
// Simplest high-level calls:
typedef int (*Importer)(WebPPicture* const, const uint8_t* const, int);
static size_t Encode(const uint8_t* rgba, int width, int height, int stride,
Importer import, float quality_factor, int lossless,
uint8_t** output) {
WebPPicture pic;
WebPConfig config;
WebPMemoryWriter wrt;
int ok;
if (!WebPConfigPreset(&config, WEBP_PRESET_DEFAULT, quality_factor) ||
!WebPPictureInit(&pic)) {
return 0; // shouldn't happen, except if system installation is broken
}
config.lossless = !!lossless;
pic.use_argb = !!lossless;
pic.width = width;
pic.height = height;
pic.writer = WebPMemoryWrite;
pic.custom_ptr = &wrt;
WebPMemoryWriterInit(&wrt);
ok = import(&pic, rgba, stride) && WebPEncode(&config, &pic);
WebPPictureFree(&pic);
if (!ok) {
free(wrt.mem);
*output = NULL;
return 0;
}
*output = wrt.mem;
return wrt.size;
}
#define ENCODE_FUNC(NAME, IMPORTER) \
size_t NAME(const uint8_t* in, int w, int h, int bps, float q, \
uint8_t** out) { \
return Encode(in, w, h, bps, IMPORTER, q, 0, out); \
}
ENCODE_FUNC(WebPEncodeRGB, WebPPictureImportRGB)
ENCODE_FUNC(WebPEncodeBGR, WebPPictureImportBGR)
ENCODE_FUNC(WebPEncodeRGBA, WebPPictureImportRGBA)
ENCODE_FUNC(WebPEncodeBGRA, WebPPictureImportBGRA)
#undef ENCODE_FUNC
#define LOSSLESS_DEFAULT_QUALITY 70.
#define LOSSLESS_ENCODE_FUNC(NAME, IMPORTER) \
size_t NAME(const uint8_t* in, int w, int h, int bps, uint8_t** out) { \
return Encode(in, w, h, bps, IMPORTER, LOSSLESS_DEFAULT_QUALITY, 1, out); \
}
LOSSLESS_ENCODE_FUNC(WebPEncodeLosslessRGB, WebPPictureImportRGB)
LOSSLESS_ENCODE_FUNC(WebPEncodeLosslessBGR, WebPPictureImportBGR)
LOSSLESS_ENCODE_FUNC(WebPEncodeLosslessRGBA, WebPPictureImportRGBA)
LOSSLESS_ENCODE_FUNC(WebPEncodeLosslessBGRA, WebPPictureImportBGRA)
#undef LOSSLESS_ENCODE_FUNC
//------------------------------------------------------------------------------