// Copyright 2011 Google Inc. All Rights Reserved. // // This code is licensed under the same terms as WebM: // Software License Agreement: http://www.webmproject.org/license/software/ // Additional IP Rights Grant: http://www.webmproject.org/license/additional/ // ----------------------------------------------------------------------------- // // WebPPicture utils: colorspace conversion, crop, ... // // Author: Skal (pascal.massimino@gmail.com) #include #include #include "./vp8enci.h" #if defined(__cplusplus) || defined(c_plusplus) extern "C" { #endif #define HALVE(x) (((x) + 1) >> 1) //------------------------------------------------------------------------------ // WebPPicture //------------------------------------------------------------------------------ int WebPPictureAlloc(WebPPicture* const picture) { if (picture) { 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; 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 || // check for luma/alpha param error uv_width < 0 || uv_height < 0 || // check for u/v param error y_size >= (1ULL << 40) || // check for reasonable global size (size_t)total_size != total_size) { // check for overflow on 32bit return 0; } picture->y_stride = y_stride; picture->uv_stride = uv_stride; picture->a_stride = a_stride; picture->uv0_stride = uv0_stride; WebPPictureFree(picture); // erase previous buffer mem = (uint8_t*)malloc((size_t)total_size); if (mem == NULL) return 0; 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; } } return 1; } // Grab the 'specs' (writer, *opaque, width, height...) from 'src' and copy them // into 'dst'. Mark 'dst' as not owning any memory. 'src' can be NULL. static void WebPPictureGrabSpecs(const WebPPicture* const src, WebPPicture* const dst) { if (src) *dst = *src; dst->y = dst->u = dst->v = NULL; dst->u0 = dst->v0 = NULL; dst->a = NULL; } // Release memory owned by 'picture'. void WebPPictureFree(WebPPicture* const picture) { if (picture) { free(picture->y); WebPPictureGrabSpecs(NULL, picture); } } //------------------------------------------------------------------------------ // Picture copying // TODO(skal): move to dsp/ ? 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; } } int WebPPictureCopy(const WebPPicture* const src, WebPPicture* const dst) { if (src == NULL || dst == NULL) return 0; if (src == dst) return 1; WebPPictureGrabSpecs(src, dst); if (!WebPPictureAlloc(dst)) return 0; 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 ((dst->colorspace & WEBP_CSP_UV_MASK) == 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 return 1; } //------------------------------------------------------------------------------ // Picture cropping int WebPPictureCrop(WebPPicture* const pic, int left, int top, int width, int height) { WebPPicture tmp; if (pic == NULL) return 0; if (width <= 0 || height <= 0) return 0; if (left < 0 || ((left + width + 1) & ~1) > pic->width) return 0; if (top < 0 || ((top + height + 1) & ~1) > pic->height) return 0; WebPPictureGrabSpecs(pic, &tmp); tmp.width = width; tmp.height = height; if (!WebPPictureAlloc(&tmp)) return 0; { 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) { 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) { int w = width; int l = left; if (tmp.colorspace == WEBP_YUV422) { w = HALVE(w); l = HALVE(l); } CopyPlane(pic->u0 + top * pic->uv0_stride + l, pic->uv0_stride, tmp.u0, tmp.uv0_stride, w, l); CopyPlane(pic->v0 + top * pic->uv0_stride + l, pic->uv0_stride, tmp.v0, tmp.uv0_stride, w, l); } #endif WebPPictureFree(pic); *pic = tmp; return 1; } //------------------------------------------------------------------------------ // Simple picture rescaler #define RFIX 30 #define MULT(x,y) (((int64_t)(x) * (y) + (1 << (RFIX - 1))) >> RFIX) static WEBP_INLINE void ImportRow(const uint8_t* src, int src_width, int32_t* frow, int32_t* irow, int dst_width) { const int x_expand = (src_width < dst_width); const int fx_scale = (1 << RFIX) / dst_width; int x_in = 0; int x_out; int x_accum = 0; if (!x_expand) { int sum = 0; for (x_out = 0; x_out < dst_width; ++x_out) { x_accum += src_width - dst_width; for (; x_accum > 0; x_accum -= dst_width) { sum += src[x_in++]; } { // Emit next horizontal pixel. const int32_t base = src[x_in++]; const int32_t frac = base * (-x_accum); frow[x_out] = (sum + base) * dst_width - frac; sum = MULT(frac, fx_scale); // fresh fractional start for next pixel } } } else { // simple bilinear interpolation int left = src[0], right = src[0]; for (x_out = 0; x_out < dst_width; ++x_out) { if (x_accum < 0) { left = right; right = src[++x_in]; x_accum += dst_width - 1; } frow[x_out] = right * (dst_width - 1) + (left - right) * x_accum; x_accum -= src_width - 1; } } // Accumulate the new row's contribution for (x_out = 0; x_out < dst_width; ++x_out) { irow[x_out] += frow[x_out]; } } static void ExportRow(int32_t* frow, int32_t* irow, uint8_t* dst, int dst_width, const int yscale, const int64_t fxy_scale) { int x_out; for (x_out = 0; x_out < dst_width; ++x_out) { const int frac = MULT(frow[x_out], yscale); const int v = (int)(MULT(irow[x_out] - frac, fxy_scale)); dst[x_out] = (!(v & ~0xff)) ? v : (v < 0) ? 0 : 255; irow[x_out] = frac; // new fractional start } } 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) { const int x_expand = (src_width < dst_width); const int fy_scale = (1 << RFIX) / dst_height; const int64_t fxy_scale = x_expand ? ((int64_t)dst_height << RFIX) / (dst_width * src_height) : ((int64_t)dst_height << RFIX) / (src_width * src_height); int y_accum = src_height; int y; int32_t* irow = work; // integral contribution int32_t* frow = work + dst_width; // fractional contribution memset(work, 0, 2 * dst_width * sizeof(*work)); for (y = 0; y < src_height; ++y) { // import new contribution of one source row. ImportRow(src, src_width, frow, irow, dst_width); src += src_stride; // emit output row(s) y_accum -= dst_height; for (; y_accum <= 0; y_accum += src_height) { const int yscale = fy_scale * (-y_accum); ExportRow(frow, irow, dst, dst_width, yscale, fxy_scale); dst += dst_stride; } } } #undef MULT #undef RFIX int WebPPictureRescale(WebPPicture* const 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; work = malloc(2 * width * sizeof(int32_t)); if (work == NULL) { WebPPictureFree(&tmp); return 0; } RescalePlane(pic->y, prev_width, prev_height, pic->y_stride, tmp.y, width, height, tmp.y_stride, work); RescalePlane(pic->u, HALVE(prev_width), HALVE(prev_height), pic->uv_stride, tmp.u, HALVE(width), HALVE(height), tmp.uv_stride, work); RescalePlane(pic->v, HALVE(prev_width), HALVE(prev_height), pic->uv_stride, tmp.v, HALVE(width), HALVE(height), tmp.uv_stride, work); if (tmp.a) { RescalePlane(pic->a, prev_width, prev_height, pic->a_stride, tmp.a, width, height, tmp.a_stride, work); } #ifdef WEBP_EXPERIMENTAL_FEATURES if (tmp.u0) { int s = 1; if ((tmp.colorspace & WEBP_CSP_UV_MASK) == WEBP_YUV422) { s = 2; } RescalePlane( pic->u0, (prev_width + s / 2) / s, prev_height, pic->uv0_stride, tmp.u0, (width + s / 2) / s, height, tmp.uv0_stride, work); RescalePlane( pic->v0, (prev_width + s / 2) / s, prev_height, pic->uv0_stride, tmp.v0, (width + s / 2) / s, height, tmp.uv0_stride, work); } #endif WebPPictureFree(pic); free(work); *pic = tmp; return 1; } //------------------------------------------------------------------------------ // Write-to-memory typedef struct { uint8_t** mem; size_t max_size; size_t* size; } WebPMemoryWriter; static void InitMemoryWriter(WebPMemoryWriter* const writer) { *writer->mem = NULL; *writer->size = 0; writer->max_size = 0; } static int WebPMemoryWrite(const uint8_t* data, size_t data_size, const WebPPicture* const picture) { WebPMemoryWriter* const w = (WebPMemoryWriter*)picture->custom_ptr; size_t next_size; if (w == NULL) { return 1; } next_size = (*w->size) + data_size; if (next_size > w->max_size) { uint8_t* new_mem; size_t next_max_size = w->max_size * 2; if (next_max_size < next_size) next_max_size = next_size; if (next_max_size < 8192) next_max_size = 8192; new_mem = (uint8_t*)malloc(next_max_size); if (new_mem == NULL) { return 0; } if ((*w->size) > 0) { memcpy(new_mem, *w->mem, *w->size); } free(*w->mem); *w->mem = new_mem; w->max_size = next_max_size; } if (data_size) { memcpy((*w->mem) + (*w->size), data, data_size); *w->size += data_size; } return 1; } //------------------------------------------------------------------------------ // RGB -> YUV conversion // The exact naming is Y'CbCr, following the ITU-R BT.601 standard. // More information at: http://en.wikipedia.org/wiki/YCbCr // Y = 0.2569 * R + 0.5044 * G + 0.0979 * B + 16 // U = -0.1483 * R - 0.2911 * G + 0.4394 * B + 128 // V = 0.4394 * R - 0.3679 * G - 0.0715 * B + 128 // We use 16bit fixed point operations. enum { YUV_FRAC = 16 }; static WEBP_INLINE int clip_uv(int v) { v = (v + (257 << (YUV_FRAC + 2 - 1))) >> (YUV_FRAC + 2); return ((v & ~0xff) == 0) ? v : (v < 0) ? 0 : 255; } static WEBP_INLINE int rgb_to_y(int r, int g, int b) { const int kRound = (1 << (YUV_FRAC - 1)) + (16 << YUV_FRAC); const int luma = 16839 * r + 33059 * g + 6420 * b; return (luma + kRound) >> YUV_FRAC; // no need to clip } static WEBP_INLINE int rgb_to_u(int r, int g, int b) { return clip_uv(-9719 * r - 19081 * g + 28800 * b); } static WEBP_INLINE int rgb_to_v(int r, int g, int b) { return clip_uv(+28800 * r - 24116 * g - 4684 * b); } // TODO: we can do better than simply 2x2 averaging on U/V samples. #define SUM4(ptr) ((ptr)[0] + (ptr)[step] + \ (ptr)[rgb_stride] + (ptr)[rgb_stride + step]) #define SUM2H(ptr) (2 * (ptr)[0] + 2 * (ptr)[step]) #define SUM2V(ptr) (2 * (ptr)[0] + 2 * (ptr)[rgb_stride]) #define SUM1(ptr) (4 * (ptr)[0]) #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] = rgb_to_u(r, g, b); \ picture->v[dst] = rgb_to_v(r, g, b); \ } #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] = rgb_to_u(r, g, b); \ picture->v0[dst] = rgb_to_v(r, g, b); \ } 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 Import(WebPPicture* const picture, const uint8_t* const rgb, int rgb_stride, int step, int swap_rb, int import_alpha) { const WebPEncCSP uv_csp = picture->colorspace & WEBP_CSP_UV_MASK; int x, y; 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 int width = picture->width; const int height = picture->height; // 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] = rgb_to_y(r_ptr[offset], g_ptr[offset], b_ptr[offset]); } } // 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 (picture->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 (import_alpha) { const uint8_t* const a_ptr = rgb + 3; assert(step >= 4); 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; } #undef SUM4 #undef SUM2V #undef SUM2H #undef SUM1 #undef RGB_TO_UV int WebPPictureImportRGB(WebPPicture* const picture, const uint8_t* const rgb, int rgb_stride) { picture->colorspace &= ~WEBP_CSP_ALPHA_BIT; if (!WebPPictureAlloc(picture)) return 0; return Import(picture, rgb, rgb_stride, 3, 0, 0); } int WebPPictureImportBGR(WebPPicture* const picture, const uint8_t* const rgb, int rgb_stride) { picture->colorspace &= ~WEBP_CSP_ALPHA_BIT; if (!WebPPictureAlloc(picture)) return 0; return Import(picture, rgb, rgb_stride, 3, 1, 0); } int WebPPictureImportRGBA(WebPPicture* const picture, const uint8_t* const rgba, int rgba_stride) { picture->colorspace |= WEBP_CSP_ALPHA_BIT; if (!WebPPictureAlloc(picture)) return 0; return Import(picture, rgba, rgba_stride, 4, 0, 1); } int WebPPictureImportBGRA(WebPPicture* const picture, const uint8_t* const rgba, int rgba_stride) { picture->colorspace |= WEBP_CSP_ALPHA_BIT; if (!WebPPictureAlloc(picture)) return 0; return Import(picture, rgba, rgba_stride, 4, 1, 1); } //------------------------------------------------------------------------------ // 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* const 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 //------------------------------------------------------------------------------ // Simplest call: 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, uint8_t** output) { size_t output_size = 0; 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 } pic.width = width; pic.height = height; pic.writer = WebPMemoryWrite; pic.custom_ptr = &wrt; wrt.mem = output; wrt.size = &output_size; InitMemoryWriter(&wrt); ok = import(&pic, rgba, stride) && WebPEncode(&config, &pic); WebPPictureFree(&pic); if (!ok) { free(*output); *output = NULL; return 0; } return output_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, out); \ } ENCODE_FUNC(WebPEncodeRGB, WebPPictureImportRGB); ENCODE_FUNC(WebPEncodeBGR, WebPPictureImportBGR); ENCODE_FUNC(WebPEncodeRGBA, WebPPictureImportRGBA); ENCODE_FUNC(WebPEncodeBGRA, WebPPictureImportBGRA); #undef ENCODE_FUNC //------------------------------------------------------------------------------ #if defined(__cplusplus) || defined(c_plusplus) } // extern "C" #endif