// 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 #include #include #include "./vp8enci.h" #include "../utils/random.h" #include "../utils/utils.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) 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 a_width, a_stride; uint64_t y_size, uv_size, a_size, total_size; uint8_t* mem; // U/V switch (uv_csp) { case WEBP_YUV420: break; default: return 0; } // 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; // 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; // 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 > 0) { picture->a = mem; mem += a_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->y_stride = picture->uv_stride = 0; picture->a_stride = 0; } // Grab the 'specs' (writer, *opaque, width, height...) from 'src' and copy them // into 'dst'. Mark 'dst' as not owning any memory. 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; WebPSafeFree(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) { WebPSafeFree(picture->memory_); WebPSafeFree(picture->memory_argb_); PictureResetYUVA(picture); PictureResetARGB(picture); } } //------------------------------------------------------------------------------ // 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); } WebPSafeFree(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; } void WebPMemoryWriterClear(WebPMemoryWriter* writer) { if (writer != NULL) { WebPSafeFree(writer->mem); writer->mem = NULL; writer->size = 0; writer->max_size = 0; } } //------------------------------------------------------------------------------ // 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) { return (int)(base_value << shift); } #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); \ } 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 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); } } 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); } //------------------------------------------------------------------------------ // 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) { WebPMemoryWriterClear(&wrt); *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 //------------------------------------------------------------------------------