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Diffstat (limited to 'src/3rdparty/libwebp/src/enc/picture.c')
| -rw-r--r-- | src/3rdparty/libwebp/src/enc/picture.c | 1324 |
1 files changed, 1324 insertions, 0 deletions
diff --git a/src/3rdparty/libwebp/src/enc/picture.c b/src/3rdparty/libwebp/src/enc/picture.c new file mode 100644 index 0000000..011690d --- /dev/null +++ b/src/3rdparty/libwebp/src/enc/picture.c @@ -0,0 +1,1324 @@ +// 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 + +//------------------------------------------------------------------------------ + |