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Diffstat (limited to 'media/libwebp/dsp/alpha_processing.c')
| -rw-r--r-- | media/libwebp/dsp/alpha_processing.c | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/media/libwebp/dsp/alpha_processing.c b/media/libwebp/dsp/alpha_processing.c new file mode 100644 index 000000000..4b60e092b --- /dev/null +++ b/media/libwebp/dsp/alpha_processing.c @@ -0,0 +1,397 @@ +// Copyright 2013 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. +// ----------------------------------------------------------------------------- +// +// Utilities for processing transparent channel. +// +// Author: Skal (pascal.massimino@gmail.com) + +#include <assert.h> +#include "./dsp.h" + +// Tables can be faster on some platform but incur some extra binary size (~2k). +// #define USE_TABLES_FOR_ALPHA_MULT + +// ----------------------------------------------------------------------------- + +#define MFIX 24 // 24bit fixed-point arithmetic +#define HALF ((1u << MFIX) >> 1) +#define KINV_255 ((1u << MFIX) / 255u) + +static uint32_t Mult(uint8_t x, uint32_t mult) { + const uint32_t v = (x * mult + HALF) >> MFIX; + assert(v <= 255); // <- 24bit precision is enough to ensure that. + return v; +} + +#ifdef USE_TABLES_FOR_ALPHA_MULT + +static const uint32_t kMultTables[2][256] = { + { // (255u << MFIX) / alpha + 0x00000000, 0xff000000, 0x7f800000, 0x55000000, 0x3fc00000, 0x33000000, + 0x2a800000, 0x246db6db, 0x1fe00000, 0x1c555555, 0x19800000, 0x172e8ba2, + 0x15400000, 0x139d89d8, 0x1236db6d, 0x11000000, 0x0ff00000, 0x0f000000, + 0x0e2aaaaa, 0x0d6bca1a, 0x0cc00000, 0x0c249249, 0x0b9745d1, 0x0b1642c8, + 0x0aa00000, 0x0a333333, 0x09cec4ec, 0x0971c71c, 0x091b6db6, 0x08cb08d3, + 0x08800000, 0x0839ce73, 0x07f80000, 0x07ba2e8b, 0x07800000, 0x07492492, + 0x07155555, 0x06e45306, 0x06b5e50d, 0x0689d89d, 0x06600000, 0x063831f3, + 0x06124924, 0x05ee23b8, 0x05cba2e8, 0x05aaaaaa, 0x058b2164, 0x056cefa8, + 0x05500000, 0x05343eb1, 0x05199999, 0x05000000, 0x04e76276, 0x04cfb2b7, + 0x04b8e38e, 0x04a2e8ba, 0x048db6db, 0x0479435e, 0x04658469, 0x045270d0, + 0x04400000, 0x042e29f7, 0x041ce739, 0x040c30c3, 0x03fc0000, 0x03ec4ec4, + 0x03dd1745, 0x03ce540f, 0x03c00000, 0x03b21642, 0x03a49249, 0x03976fc6, + 0x038aaaaa, 0x037e3f1f, 0x03722983, 0x03666666, 0x035af286, 0x034fcace, + 0x0344ec4e, 0x033a5440, 0x03300000, 0x0325ed09, 0x031c18f9, 0x0312818a, + 0x03092492, 0x03000000, 0x02f711dc, 0x02ee5846, 0x02e5d174, 0x02dd7baf, + 0x02d55555, 0x02cd5cd5, 0x02c590b2, 0x02bdef7b, 0x02b677d4, 0x02af286b, + 0x02a80000, 0x02a0fd5c, 0x029a1f58, 0x029364d9, 0x028ccccc, 0x0286562d, + 0x02800000, 0x0279c952, 0x0273b13b, 0x026db6db, 0x0267d95b, 0x026217ec, + 0x025c71c7, 0x0256e62a, 0x0251745d, 0x024c1bac, 0x0246db6d, 0x0241b2f9, + 0x023ca1af, 0x0237a6f4, 0x0232c234, 0x022df2df, 0x02293868, 0x02249249, + 0x02200000, 0x021b810e, 0x021714fb, 0x0212bb51, 0x020e739c, 0x020a3d70, + 0x02061861, 0x02020408, 0x01fe0000, 0x01fa0be8, 0x01f62762, 0x01f25213, + 0x01ee8ba2, 0x01ead3ba, 0x01e72a07, 0x01e38e38, 0x01e00000, 0x01dc7f10, + 0x01d90b21, 0x01d5a3e9, 0x01d24924, 0x01cefa8d, 0x01cbb7e3, 0x01c880e5, + 0x01c55555, 0x01c234f7, 0x01bf1f8f, 0x01bc14e5, 0x01b914c1, 0x01b61eed, + 0x01b33333, 0x01b05160, 0x01ad7943, 0x01aaaaaa, 0x01a7e567, 0x01a5294a, + 0x01a27627, 0x019fcbd2, 0x019d2a20, 0x019a90e7, 0x01980000, 0x01957741, + 0x0192f684, 0x01907da4, 0x018e0c7c, 0x018ba2e8, 0x018940c5, 0x0186e5f0, + 0x01849249, 0x018245ae, 0x01800000, 0x017dc11f, 0x017b88ee, 0x0179574e, + 0x01772c23, 0x01750750, 0x0172e8ba, 0x0170d045, 0x016ebdd7, 0x016cb157, + 0x016aaaaa, 0x0168a9b9, 0x0166ae6a, 0x0164b8a7, 0x0162c859, 0x0160dd67, + 0x015ef7bd, 0x015d1745, 0x015b3bea, 0x01596596, 0x01579435, 0x0155c7b4, + 0x01540000, 0x01523d03, 0x01507eae, 0x014ec4ec, 0x014d0fac, 0x014b5edc, + 0x0149b26c, 0x01480a4a, 0x01466666, 0x0144c6af, 0x01432b16, 0x0141938b, + 0x01400000, 0x013e7063, 0x013ce4a9, 0x013b5cc0, 0x0139d89d, 0x01385830, + 0x0136db6d, 0x01356246, 0x0133ecad, 0x01327a97, 0x01310bf6, 0x012fa0be, + 0x012e38e3, 0x012cd459, 0x012b7315, 0x012a150a, 0x0128ba2e, 0x01276276, + 0x01260dd6, 0x0124bc44, 0x01236db6, 0x01222222, 0x0120d97c, 0x011f93bc, + 0x011e50d7, 0x011d10c4, 0x011bd37a, 0x011a98ef, 0x0119611a, 0x01182bf2, + 0x0116f96f, 0x0115c988, 0x01149c34, 0x0113716a, 0x01124924, 0x01112358, + 0x01100000, 0x010edf12, 0x010dc087, 0x010ca458, 0x010b8a7d, 0x010a72f0, + 0x01095da8, 0x01084a9f, 0x010739ce, 0x01062b2e, 0x01051eb8, 0x01041465, + 0x01030c30, 0x01020612, 0x01010204, 0x01000000 }, + { // alpha * KINV_255 + 0x00000000, 0x00010101, 0x00020202, 0x00030303, 0x00040404, 0x00050505, + 0x00060606, 0x00070707, 0x00080808, 0x00090909, 0x000a0a0a, 0x000b0b0b, + 0x000c0c0c, 0x000d0d0d, 0x000e0e0e, 0x000f0f0f, 0x00101010, 0x00111111, + 0x00121212, 0x00131313, 0x00141414, 0x00151515, 0x00161616, 0x00171717, + 0x00181818, 0x00191919, 0x001a1a1a, 0x001b1b1b, 0x001c1c1c, 0x001d1d1d, + 0x001e1e1e, 0x001f1f1f, 0x00202020, 0x00212121, 0x00222222, 0x00232323, + 0x00242424, 0x00252525, 0x00262626, 0x00272727, 0x00282828, 0x00292929, + 0x002a2a2a, 0x002b2b2b, 0x002c2c2c, 0x002d2d2d, 0x002e2e2e, 0x002f2f2f, + 0x00303030, 0x00313131, 0x00323232, 0x00333333, 0x00343434, 0x00353535, + 0x00363636, 0x00373737, 0x00383838, 0x00393939, 0x003a3a3a, 0x003b3b3b, + 0x003c3c3c, 0x003d3d3d, 0x003e3e3e, 0x003f3f3f, 0x00404040, 0x00414141, + 0x00424242, 0x00434343, 0x00444444, 0x00454545, 0x00464646, 0x00474747, + 0x00484848, 0x00494949, 0x004a4a4a, 0x004b4b4b, 0x004c4c4c, 0x004d4d4d, + 0x004e4e4e, 0x004f4f4f, 0x00505050, 0x00515151, 0x00525252, 0x00535353, + 0x00545454, 0x00555555, 0x00565656, 0x00575757, 0x00585858, 0x00595959, + 0x005a5a5a, 0x005b5b5b, 0x005c5c5c, 0x005d5d5d, 0x005e5e5e, 0x005f5f5f, + 0x00606060, 0x00616161, 0x00626262, 0x00636363, 0x00646464, 0x00656565, + 0x00666666, 0x00676767, 0x00686868, 0x00696969, 0x006a6a6a, 0x006b6b6b, + 0x006c6c6c, 0x006d6d6d, 0x006e6e6e, 0x006f6f6f, 0x00707070, 0x00717171, + 0x00727272, 0x00737373, 0x00747474, 0x00757575, 0x00767676, 0x00777777, + 0x00787878, 0x00797979, 0x007a7a7a, 0x007b7b7b, 0x007c7c7c, 0x007d7d7d, + 0x007e7e7e, 0x007f7f7f, 0x00808080, 0x00818181, 0x00828282, 0x00838383, + 0x00848484, 0x00858585, 0x00868686, 0x00878787, 0x00888888, 0x00898989, + 0x008a8a8a, 0x008b8b8b, 0x008c8c8c, 0x008d8d8d, 0x008e8e8e, 0x008f8f8f, + 0x00909090, 0x00919191, 0x00929292, 0x00939393, 0x00949494, 0x00959595, + 0x00969696, 0x00979797, 0x00989898, 0x00999999, 0x009a9a9a, 0x009b9b9b, + 0x009c9c9c, 0x009d9d9d, 0x009e9e9e, 0x009f9f9f, 0x00a0a0a0, 0x00a1a1a1, + 0x00a2a2a2, 0x00a3a3a3, 0x00a4a4a4, 0x00a5a5a5, 0x00a6a6a6, 0x00a7a7a7, + 0x00a8a8a8, 0x00a9a9a9, 0x00aaaaaa, 0x00ababab, 0x00acacac, 0x00adadad, + 0x00aeaeae, 0x00afafaf, 0x00b0b0b0, 0x00b1b1b1, 0x00b2b2b2, 0x00b3b3b3, + 0x00b4b4b4, 0x00b5b5b5, 0x00b6b6b6, 0x00b7b7b7, 0x00b8b8b8, 0x00b9b9b9, + 0x00bababa, 0x00bbbbbb, 0x00bcbcbc, 0x00bdbdbd, 0x00bebebe, 0x00bfbfbf, + 0x00c0c0c0, 0x00c1c1c1, 0x00c2c2c2, 0x00c3c3c3, 0x00c4c4c4, 0x00c5c5c5, + 0x00c6c6c6, 0x00c7c7c7, 0x00c8c8c8, 0x00c9c9c9, 0x00cacaca, 0x00cbcbcb, + 0x00cccccc, 0x00cdcdcd, 0x00cecece, 0x00cfcfcf, 0x00d0d0d0, 0x00d1d1d1, + 0x00d2d2d2, 0x00d3d3d3, 0x00d4d4d4, 0x00d5d5d5, 0x00d6d6d6, 0x00d7d7d7, + 0x00d8d8d8, 0x00d9d9d9, 0x00dadada, 0x00dbdbdb, 0x00dcdcdc, 0x00dddddd, + 0x00dedede, 0x00dfdfdf, 0x00e0e0e0, 0x00e1e1e1, 0x00e2e2e2, 0x00e3e3e3, + 0x00e4e4e4, 0x00e5e5e5, 0x00e6e6e6, 0x00e7e7e7, 0x00e8e8e8, 0x00e9e9e9, + 0x00eaeaea, 0x00ebebeb, 0x00ececec, 0x00ededed, 0x00eeeeee, 0x00efefef, + 0x00f0f0f0, 0x00f1f1f1, 0x00f2f2f2, 0x00f3f3f3, 0x00f4f4f4, 0x00f5f5f5, + 0x00f6f6f6, 0x00f7f7f7, 0x00f8f8f8, 0x00f9f9f9, 0x00fafafa, 0x00fbfbfb, + 0x00fcfcfc, 0x00fdfdfd, 0x00fefefe, 0x00ffffff } +}; + +static WEBP_INLINE uint32_t GetScale(uint32_t a, int inverse) { + return kMultTables[!inverse][a]; +} + +#else + +static WEBP_INLINE uint32_t GetScale(uint32_t a, int inverse) { + return inverse ? (255u << MFIX) / a : a * KINV_255; +} + +#endif // USE_TABLES_FOR_ALPHA_MULT + +void WebPMultARGBRowC(uint32_t* const ptr, int width, int inverse) { + int x; + for (x = 0; x < width; ++x) { + const uint32_t argb = ptr[x]; + if (argb < 0xff000000u) { // alpha < 255 + if (argb <= 0x00ffffffu) { // alpha == 0 + ptr[x] = 0; + } else { + const uint32_t alpha = (argb >> 24) & 0xff; + const uint32_t scale = GetScale(alpha, inverse); + uint32_t out = argb & 0xff000000u; + out |= Mult(argb >> 0, scale) << 0; + out |= Mult(argb >> 8, scale) << 8; + out |= Mult(argb >> 16, scale) << 16; + ptr[x] = out; + } + } + } +} + +void WebPMultRowC(uint8_t* const ptr, const uint8_t* const alpha, + int width, int inverse) { + int x; + for (x = 0; x < width; ++x) { + const uint32_t a = alpha[x]; + if (a != 255) { + if (a == 0) { + ptr[x] = 0; + } else { + const uint32_t scale = GetScale(a, inverse); + ptr[x] = Mult(ptr[x], scale); + } + } + } +} + +#undef KINV_255 +#undef HALF +#undef MFIX + +void (*WebPMultARGBRow)(uint32_t* const ptr, int width, int inverse); +void (*WebPMultRow)(uint8_t* const ptr, const uint8_t* const alpha, + int width, int inverse); + +//------------------------------------------------------------------------------ +// Generic per-plane calls + +void WebPMultARGBRows(uint8_t* ptr, int stride, int width, int num_rows, + int inverse) { + int n; + for (n = 0; n < num_rows; ++n) { + WebPMultARGBRow((uint32_t*)ptr, width, inverse); + ptr += stride; + } +} + +void WebPMultRows(uint8_t* ptr, int stride, + const uint8_t* alpha, int alpha_stride, + int width, int num_rows, int inverse) { + int n; + for (n = 0; n < num_rows; ++n) { + WebPMultRow(ptr, alpha, width, inverse); + ptr += stride; + alpha += alpha_stride; + } +} + +//------------------------------------------------------------------------------ +// Premultiplied modes + +// non dithered-modes + +// (x * a * 32897) >> 23 is bit-wise equivalent to (int)(x * a / 255.) +// for all 8bit x or a. For bit-wise equivalence to (int)(x * a / 255. + .5), +// one can use instead: (x * a * 65793 + (1 << 23)) >> 24 +#if 1 // (int)(x * a / 255.) +#define MULTIPLIER(a) ((a) * 32897U) +#define PREMULTIPLY(x, m) (((x) * (m)) >> 23) +#else // (int)(x * a / 255. + .5) +#define MULTIPLIER(a) ((a) * 65793U) +#define PREMULTIPLY(x, m) (((x) * (m) + (1U << 23)) >> 24) +#endif + +static void ApplyAlphaMultiply(uint8_t* rgba, int alpha_first, + int w, int h, int stride) { + while (h-- > 0) { + uint8_t* const rgb = rgba + (alpha_first ? 1 : 0); + const uint8_t* const alpha = rgba + (alpha_first ? 0 : 3); + int i; + for (i = 0; i < w; ++i) { + const uint32_t a = alpha[4 * i]; + if (a != 0xff) { + const uint32_t mult = MULTIPLIER(a); + rgb[4 * i + 0] = PREMULTIPLY(rgb[4 * i + 0], mult); + rgb[4 * i + 1] = PREMULTIPLY(rgb[4 * i + 1], mult); + rgb[4 * i + 2] = PREMULTIPLY(rgb[4 * i + 2], mult); + } + } + rgba += stride; + } +} +#undef MULTIPLIER +#undef PREMULTIPLY + +// rgbA4444 + +#define MULTIPLIER(a) ((a) * 0x1111) // 0x1111 ~= (1 << 16) / 15 + +static WEBP_INLINE uint8_t dither_hi(uint8_t x) { + return (x & 0xf0) | (x >> 4); +} + +static WEBP_INLINE uint8_t dither_lo(uint8_t x) { + return (x & 0x0f) | (x << 4); +} + +static WEBP_INLINE uint8_t multiply(uint8_t x, uint32_t m) { + return (x * m) >> 16; +} + +static WEBP_INLINE void ApplyAlphaMultiply4444(uint8_t* rgba4444, + int w, int h, int stride, + int rg_byte_pos /* 0 or 1 */) { + while (h-- > 0) { + int i; + for (i = 0; i < w; ++i) { + const uint32_t rg = rgba4444[2 * i + rg_byte_pos]; + const uint32_t ba = rgba4444[2 * i + (rg_byte_pos ^ 1)]; + const uint8_t a = ba & 0x0f; + const uint32_t mult = MULTIPLIER(a); + const uint8_t r = multiply(dither_hi(rg), mult); + const uint8_t g = multiply(dither_lo(rg), mult); + const uint8_t b = multiply(dither_hi(ba), mult); + rgba4444[2 * i + rg_byte_pos] = (r & 0xf0) | ((g >> 4) & 0x0f); + rgba4444[2 * i + (rg_byte_pos ^ 1)] = (b & 0xf0) | a; + } + rgba4444 += stride; + } +} +#undef MULTIPLIER + +static void ApplyAlphaMultiply_16b(uint8_t* rgba4444, + int w, int h, int stride) { +#ifdef WEBP_SWAP_16BIT_CSP + ApplyAlphaMultiply4444(rgba4444, w, h, stride, 1); +#else + ApplyAlphaMultiply4444(rgba4444, w, h, stride, 0); +#endif +} + +static int DispatchAlpha_C(const uint8_t* alpha, int alpha_stride, + int width, int height, + uint8_t* dst, int dst_stride) { + uint32_t alpha_mask = 0xff; + int i, j; + + for (j = 0; j < height; ++j) { + for (i = 0; i < width; ++i) { + const uint32_t alpha_value = alpha[i]; + dst[4 * i] = alpha_value; + alpha_mask &= alpha_value; + } + alpha += alpha_stride; + dst += dst_stride; + } + + return (alpha_mask != 0xff); +} + +static void DispatchAlphaToGreen_C(const uint8_t* alpha, int alpha_stride, + int width, int height, + uint32_t* dst, int dst_stride) { + int i, j; + for (j = 0; j < height; ++j) { + for (i = 0; i < width; ++i) { + dst[i] = alpha[i] << 8; // leave A/R/B channels zero'd. + } + alpha += alpha_stride; + dst += dst_stride; + } +} + +static int ExtractAlpha_C(const uint8_t* argb, int argb_stride, + int width, int height, + uint8_t* alpha, int alpha_stride) { + uint8_t alpha_mask = 0xff; + int i, j; + + for (j = 0; j < height; ++j) { + for (i = 0; i < width; ++i) { + const uint8_t alpha_value = argb[4 * i]; + alpha[i] = alpha_value; + alpha_mask &= alpha_value; + } + argb += argb_stride; + alpha += alpha_stride; + } + return (alpha_mask == 0xff); +} + +static void ExtractGreen_C(const uint32_t* argb, uint8_t* alpha, int size) { + int i; + for (i = 0; i < size; ++i) alpha[i] = argb[i] >> 8; +} + +void (*WebPApplyAlphaMultiply)(uint8_t*, int, int, int, int); +void (*WebPApplyAlphaMultiply4444)(uint8_t*, int, int, int); +int (*WebPDispatchAlpha)(const uint8_t*, int, int, int, uint8_t*, int); +void (*WebPDispatchAlphaToGreen)(const uint8_t*, int, int, int, uint32_t*, int); +int (*WebPExtractAlpha)(const uint8_t*, int, int, int, uint8_t*, int); +void (*WebPExtractGreen)(const uint32_t* argb, uint8_t* alpha, int size); + +//------------------------------------------------------------------------------ +// Init function + +extern void WebPInitAlphaProcessingMIPSdspR2(void); +extern void WebPInitAlphaProcessingSSE2(void); +extern void WebPInitAlphaProcessingSSE41(void); +extern void WebPInitAlphaProcessingNEON(void); + +static volatile VP8CPUInfo alpha_processing_last_cpuinfo_used = + (VP8CPUInfo)&alpha_processing_last_cpuinfo_used; + +WEBP_TSAN_IGNORE_FUNCTION void WebPInitAlphaProcessing(void) { + if (alpha_processing_last_cpuinfo_used == VP8GetCPUInfo) return; + + WebPMultARGBRow = WebPMultARGBRowC; + WebPMultRow = WebPMultRowC; + WebPApplyAlphaMultiply = ApplyAlphaMultiply; + WebPApplyAlphaMultiply4444 = ApplyAlphaMultiply_16b; + + WebPDispatchAlpha = DispatchAlpha_C; + WebPDispatchAlphaToGreen = DispatchAlphaToGreen_C; + WebPExtractAlpha = ExtractAlpha_C; + WebPExtractGreen = ExtractGreen_C; + + // If defined, use CPUInfo() to overwrite some pointers with faster versions. + if (VP8GetCPUInfo != NULL) { +#if defined(WEBP_USE_SSE2) + if (VP8GetCPUInfo(kSSE2)) { + WebPInitAlphaProcessingSSE2(); +#if defined(WEBP_USE_SSE41) + if (VP8GetCPUInfo(kSSE4_1)) { + WebPInitAlphaProcessingSSE41(); + } +#endif + } +#endif +#if defined(WEBP_USE_NEON) + if (VP8GetCPUInfo(kNEON)) { + WebPInitAlphaProcessingNEON(); + } +#endif +#if defined(WEBP_USE_MIPS_DSP_R2) + if (VP8GetCPUInfo(kMIPSdspR2)) { + WebPInitAlphaProcessingMIPSdspR2(); + } +#endif + } + alpha_processing_last_cpuinfo_used = VP8GetCPUInfo; +} |