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Diffstat (limited to 'thirdparty/libwebp/src/dsp/dsp.h')
| -rw-r--r-- | thirdparty/libwebp/src/dsp/dsp.h | 632 |
1 files changed, 632 insertions, 0 deletions
diff --git a/thirdparty/libwebp/src/dsp/dsp.h b/thirdparty/libwebp/src/dsp/dsp.h new file mode 100644 index 0000000000..99eefe092f --- /dev/null +++ b/thirdparty/libwebp/src/dsp/dsp.h @@ -0,0 +1,632 @@ +// 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. +// ----------------------------------------------------------------------------- +// +// Speed-critical functions. +// +// Author: Skal (pascal.massimino@gmail.com) + +#ifndef WEBP_DSP_DSP_H_ +#define WEBP_DSP_DSP_H_ + +#ifdef HAVE_CONFIG_H +#include "src/webp/config.h" +#endif + +#include "src/webp/types.h" + +#ifdef __cplusplus +extern "C" { +#endif + +#define BPS 32 // this is the common stride for enc/dec + +//------------------------------------------------------------------------------ +// CPU detection + +#if defined(__GNUC__) +# define LOCAL_GCC_VERSION ((__GNUC__ << 8) | __GNUC_MINOR__) +# define LOCAL_GCC_PREREQ(maj, min) \ + (LOCAL_GCC_VERSION >= (((maj) << 8) | (min))) +#else +# define LOCAL_GCC_VERSION 0 +# define LOCAL_GCC_PREREQ(maj, min) 0 +#endif + +#if defined(__clang__) +# define LOCAL_CLANG_VERSION ((__clang_major__ << 8) | __clang_minor__) +# define LOCAL_CLANG_PREREQ(maj, min) \ + (LOCAL_CLANG_VERSION >= (((maj) << 8) | (min))) +#else +# define LOCAL_CLANG_VERSION 0 +# define LOCAL_CLANG_PREREQ(maj, min) 0 +#endif + +#ifndef __has_builtin +# define __has_builtin(x) 0 +#endif + +// for now, none of the optimizations below are available in emscripten +#if !defined(EMSCRIPTEN) + +#if defined(_MSC_VER) && _MSC_VER > 1310 && \ + (defined(_M_X64) || defined(_M_IX86)) +#define WEBP_MSC_SSE2 // Visual C++ SSE2 targets +#endif + +#if defined(_MSC_VER) && _MSC_VER >= 1500 && \ + (defined(_M_X64) || defined(_M_IX86)) +#define WEBP_MSC_SSE41 // Visual C++ SSE4.1 targets +#endif + +// WEBP_HAVE_* are used to indicate the presence of the instruction set in dsp +// files without intrinsics, allowing the corresponding Init() to be called. +// Files containing intrinsics will need to be built targeting the instruction +// set so should succeed on one of the earlier tests. +#if defined(__SSE2__) || defined(WEBP_MSC_SSE2) || defined(WEBP_HAVE_SSE2) +#define WEBP_USE_SSE2 +#endif + +#if defined(__SSE4_1__) || defined(WEBP_MSC_SSE41) || defined(WEBP_HAVE_SSE41) +#define WEBP_USE_SSE41 +#endif + +#if defined(__AVX2__) || defined(WEBP_HAVE_AVX2) +#define WEBP_USE_AVX2 +#endif + +// The intrinsics currently cause compiler errors with arm-nacl-gcc and the +// inline assembly would need to be modified for use with Native Client. +#if (defined(__ARM_NEON__) || \ + defined(__aarch64__) || defined(WEBP_HAVE_NEON)) && \ + !defined(__native_client__) +#define WEBP_USE_NEON +#endif + +#if !defined(WEBP_USE_NEON) && defined(__ANDROID__) && \ + defined(__ARM_ARCH_7A__) && defined(HAVE_CPU_FEATURES_H) +#define WEBP_ANDROID_NEON // Android targets that may have NEON +#define WEBP_USE_NEON +#endif + +#if defined(_MSC_VER) && _MSC_VER >= 1700 && defined(_M_ARM) +#define WEBP_USE_NEON +#define WEBP_USE_INTRINSICS +#endif + +#if defined(__mips__) && !defined(__mips64) && \ + defined(__mips_isa_rev) && (__mips_isa_rev >= 1) && (__mips_isa_rev < 6) +#define WEBP_USE_MIPS32 +#if (__mips_isa_rev >= 2) +#define WEBP_USE_MIPS32_R2 +#if defined(__mips_dspr2) || (defined(__mips_dsp_rev) && __mips_dsp_rev >= 2) +#define WEBP_USE_MIPS_DSP_R2 +#endif +#endif +#endif + +#if defined(__mips_msa) && defined(__mips_isa_rev) && (__mips_isa_rev >= 5) +#define WEBP_USE_MSA +#endif + +#endif /* EMSCRIPTEN */ + +#ifndef WEBP_DSP_OMIT_C_CODE +#define WEBP_DSP_OMIT_C_CODE 1 +#endif + +#if (defined(__aarch64__) || defined(__ARM_NEON__)) && WEBP_DSP_OMIT_C_CODE +#define WEBP_NEON_OMIT_C_CODE 1 +#else +#define WEBP_NEON_OMIT_C_CODE 0 +#endif + +#if !(LOCAL_CLANG_PREREQ(3,8) || LOCAL_GCC_PREREQ(4,8) || defined(__aarch64__)) +#define WEBP_NEON_WORK_AROUND_GCC 1 +#else +#define WEBP_NEON_WORK_AROUND_GCC 0 +#endif + +// This macro prevents thread_sanitizer from reporting known concurrent writes. +#define WEBP_TSAN_IGNORE_FUNCTION +#if defined(__has_feature) +#if __has_feature(thread_sanitizer) +#undef WEBP_TSAN_IGNORE_FUNCTION +#define WEBP_TSAN_IGNORE_FUNCTION __attribute__((no_sanitize_thread)) +#endif +#endif + +#define WEBP_UBSAN_IGNORE_UNDEF +#define WEBP_UBSAN_IGNORE_UNSIGNED_OVERFLOW +#if defined(__clang__) && defined(__has_attribute) +#if __has_attribute(no_sanitize) +// This macro prevents the undefined behavior sanitizer from reporting +// failures. This is only meant to silence unaligned loads on platforms that +// are known to support them. +#undef WEBP_UBSAN_IGNORE_UNDEF +#define WEBP_UBSAN_IGNORE_UNDEF \ + __attribute__((no_sanitize("undefined"))) + +// This macro prevents the undefined behavior sanitizer from reporting +// failures related to unsigned integer overflows. This is only meant to +// silence cases where this well defined behavior is expected. +#undef WEBP_UBSAN_IGNORE_UNSIGNED_OVERFLOW +#define WEBP_UBSAN_IGNORE_UNSIGNED_OVERFLOW \ + __attribute__((no_sanitize("unsigned-integer-overflow"))) +#endif +#endif + +// Regularize the definition of WEBP_SWAP_16BIT_CSP (backward compatibility) +#if !defined(WEBP_SWAP_16BIT_CSP) +#define WEBP_SWAP_16BIT_CSP 0 +#endif + +typedef enum { + kSSE2, + kSSE3, + kSlowSSSE3, // special feature for slow SSSE3 architectures + kSSE4_1, + kAVX, + kAVX2, + kNEON, + kMIPS32, + kMIPSdspR2, + kMSA +} CPUFeature; +// returns true if the CPU supports the feature. +typedef int (*VP8CPUInfo)(CPUFeature feature); +WEBP_EXTERN VP8CPUInfo VP8GetCPUInfo; + +//------------------------------------------------------------------------------ +// Init stub generator + +// Defines an init function stub to ensure each module exposes a symbol, +// avoiding a compiler warning. +#define WEBP_DSP_INIT_STUB(func) \ + extern void func(void); \ + WEBP_TSAN_IGNORE_FUNCTION void func(void) {} + +//------------------------------------------------------------------------------ +// Encoding + +// Transforms +// VP8Idct: Does one of two inverse transforms. If do_two is set, the transforms +// will be done for (ref, in, dst) and (ref + 4, in + 16, dst + 4). +typedef void (*VP8Idct)(const uint8_t* ref, const int16_t* in, uint8_t* dst, + int do_two); +typedef void (*VP8Fdct)(const uint8_t* src, const uint8_t* ref, int16_t* out); +typedef void (*VP8WHT)(const int16_t* in, int16_t* out); +extern VP8Idct VP8ITransform; +extern VP8Fdct VP8FTransform; +extern VP8Fdct VP8FTransform2; // performs two transforms at a time +extern VP8WHT VP8FTransformWHT; +// Predictions +// *dst is the destination block. *top and *left can be NULL. +typedef void (*VP8IntraPreds)(uint8_t *dst, const uint8_t* left, + const uint8_t* top); +typedef void (*VP8Intra4Preds)(uint8_t *dst, const uint8_t* top); +extern VP8Intra4Preds VP8EncPredLuma4; +extern VP8IntraPreds VP8EncPredLuma16; +extern VP8IntraPreds VP8EncPredChroma8; + +typedef int (*VP8Metric)(const uint8_t* pix, const uint8_t* ref); +extern VP8Metric VP8SSE16x16, VP8SSE16x8, VP8SSE8x8, VP8SSE4x4; +typedef int (*VP8WMetric)(const uint8_t* pix, const uint8_t* ref, + const uint16_t* const weights); +// The weights for VP8TDisto4x4 and VP8TDisto16x16 contain a row-major +// 4 by 4 symmetric matrix. +extern VP8WMetric VP8TDisto4x4, VP8TDisto16x16; + +// Compute the average (DC) of four 4x4 blocks. +// Each sub-4x4 block #i sum is stored in dc[i]. +typedef void (*VP8MeanMetric)(const uint8_t* ref, uint32_t dc[4]); +extern VP8MeanMetric VP8Mean16x4; + +typedef void (*VP8BlockCopy)(const uint8_t* src, uint8_t* dst); +extern VP8BlockCopy VP8Copy4x4; +extern VP8BlockCopy VP8Copy16x8; +// Quantization +struct VP8Matrix; // forward declaration +typedef int (*VP8QuantizeBlock)(int16_t in[16], int16_t out[16], + const struct VP8Matrix* const mtx); +// Same as VP8QuantizeBlock, but quantizes two consecutive blocks. +typedef int (*VP8Quantize2Blocks)(int16_t in[32], int16_t out[32], + const struct VP8Matrix* const mtx); + +extern VP8QuantizeBlock VP8EncQuantizeBlock; +extern VP8Quantize2Blocks VP8EncQuantize2Blocks; + +// specific to 2nd transform: +typedef int (*VP8QuantizeBlockWHT)(int16_t in[16], int16_t out[16], + const struct VP8Matrix* const mtx); +extern VP8QuantizeBlockWHT VP8EncQuantizeBlockWHT; + +extern const int VP8DspScan[16 + 4 + 4]; + +// Collect histogram for susceptibility calculation. +#define MAX_COEFF_THRESH 31 // size of histogram used by CollectHistogram. +typedef struct { + // We only need to store max_value and last_non_zero, not the distribution. + int max_value; + int last_non_zero; +} VP8Histogram; +typedef void (*VP8CHisto)(const uint8_t* ref, const uint8_t* pred, + int start_block, int end_block, + VP8Histogram* const histo); +extern VP8CHisto VP8CollectHistogram; +// General-purpose util function to help VP8CollectHistogram(). +void VP8SetHistogramData(const int distribution[MAX_COEFF_THRESH + 1], + VP8Histogram* const histo); + +// must be called before using any of the above +void VP8EncDspInit(void); + +//------------------------------------------------------------------------------ +// cost functions (encoding) + +extern const uint16_t VP8EntropyCost[256]; // 8bit fixed-point log(p) +// approximate cost per level: +extern const uint16_t VP8LevelFixedCosts[2047 /*MAX_LEVEL*/ + 1]; +extern const uint8_t VP8EncBands[16 + 1]; + +struct VP8Residual; +typedef void (*VP8SetResidualCoeffsFunc)(const int16_t* const coeffs, + struct VP8Residual* const res); +extern VP8SetResidualCoeffsFunc VP8SetResidualCoeffs; + +// Cost calculation function. +typedef int (*VP8GetResidualCostFunc)(int ctx0, + const struct VP8Residual* const res); +extern VP8GetResidualCostFunc VP8GetResidualCost; + +// must be called before anything using the above +void VP8EncDspCostInit(void); + +//------------------------------------------------------------------------------ +// SSIM / PSNR utils + +// struct for accumulating statistical moments +typedef struct { + uint32_t w; // sum(w_i) : sum of weights + uint32_t xm, ym; // sum(w_i * x_i), sum(w_i * y_i) + uint32_t xxm, xym, yym; // sum(w_i * x_i * x_i), etc. +} VP8DistoStats; + +// Compute the final SSIM value +// The non-clipped version assumes stats->w = (2 * VP8_SSIM_KERNEL + 1)^2. +double VP8SSIMFromStats(const VP8DistoStats* const stats); +double VP8SSIMFromStatsClipped(const VP8DistoStats* const stats); + +#define VP8_SSIM_KERNEL 3 // total size of the kernel: 2 * VP8_SSIM_KERNEL + 1 +typedef double (*VP8SSIMGetClippedFunc)(const uint8_t* src1, int stride1, + const uint8_t* src2, int stride2, + int xo, int yo, // center position + int W, int H); // plane dimension + +#if !defined(WEBP_REDUCE_SIZE) +// This version is called with the guarantee that you can load 8 bytes and +// 8 rows at offset src1 and src2 +typedef double (*VP8SSIMGetFunc)(const uint8_t* src1, int stride1, + const uint8_t* src2, int stride2); + +extern VP8SSIMGetFunc VP8SSIMGet; // unclipped / unchecked +extern VP8SSIMGetClippedFunc VP8SSIMGetClipped; // with clipping +#endif + +#if !defined(WEBP_DISABLE_STATS) +typedef uint32_t (*VP8AccumulateSSEFunc)(const uint8_t* src1, + const uint8_t* src2, int len); +extern VP8AccumulateSSEFunc VP8AccumulateSSE; +#endif + +// must be called before using any of the above directly +void VP8SSIMDspInit(void); + +//------------------------------------------------------------------------------ +// Decoding + +typedef void (*VP8DecIdct)(const int16_t* coeffs, uint8_t* dst); +// when doing two transforms, coeffs is actually int16_t[2][16]. +typedef void (*VP8DecIdct2)(const int16_t* coeffs, uint8_t* dst, int do_two); +extern VP8DecIdct2 VP8Transform; +extern VP8DecIdct VP8TransformAC3; +extern VP8DecIdct VP8TransformUV; +extern VP8DecIdct VP8TransformDC; +extern VP8DecIdct VP8TransformDCUV; +extern VP8WHT VP8TransformWHT; + +// *dst is the destination block, with stride BPS. Boundary samples are +// assumed accessible when needed. +typedef void (*VP8PredFunc)(uint8_t* dst); +extern VP8PredFunc VP8PredLuma16[/* NUM_B_DC_MODES */]; +extern VP8PredFunc VP8PredChroma8[/* NUM_B_DC_MODES */]; +extern VP8PredFunc VP8PredLuma4[/* NUM_BMODES */]; + +// clipping tables (for filtering) +extern const int8_t* const VP8ksclip1; // clips [-1020, 1020] to [-128, 127] +extern const int8_t* const VP8ksclip2; // clips [-112, 112] to [-16, 15] +extern const uint8_t* const VP8kclip1; // clips [-255,511] to [0,255] +extern const uint8_t* const VP8kabs0; // abs(x) for x in [-255,255] +// must be called first +void VP8InitClipTables(void); + +// simple filter (only for luma) +typedef void (*VP8SimpleFilterFunc)(uint8_t* p, int stride, int thresh); +extern VP8SimpleFilterFunc VP8SimpleVFilter16; +extern VP8SimpleFilterFunc VP8SimpleHFilter16; +extern VP8SimpleFilterFunc VP8SimpleVFilter16i; // filter 3 inner edges +extern VP8SimpleFilterFunc VP8SimpleHFilter16i; + +// regular filter (on both macroblock edges and inner edges) +typedef void (*VP8LumaFilterFunc)(uint8_t* luma, int stride, + int thresh, int ithresh, int hev_t); +typedef void (*VP8ChromaFilterFunc)(uint8_t* u, uint8_t* v, int stride, + int thresh, int ithresh, int hev_t); +// on outer edge +extern VP8LumaFilterFunc VP8VFilter16; +extern VP8LumaFilterFunc VP8HFilter16; +extern VP8ChromaFilterFunc VP8VFilter8; +extern VP8ChromaFilterFunc VP8HFilter8; + +// on inner edge +extern VP8LumaFilterFunc VP8VFilter16i; // filtering 3 inner edges altogether +extern VP8LumaFilterFunc VP8HFilter16i; +extern VP8ChromaFilterFunc VP8VFilter8i; // filtering u and v altogether +extern VP8ChromaFilterFunc VP8HFilter8i; + +// Dithering. Combines dithering values (centered around 128) with dst[], +// according to: dst[] = clip(dst[] + (((dither[]-128) + 8) >> 4) +#define VP8_DITHER_DESCALE 4 +#define VP8_DITHER_DESCALE_ROUNDER (1 << (VP8_DITHER_DESCALE - 1)) +#define VP8_DITHER_AMP_BITS 7 +#define VP8_DITHER_AMP_CENTER (1 << VP8_DITHER_AMP_BITS) +extern void (*VP8DitherCombine8x8)(const uint8_t* dither, uint8_t* dst, + int dst_stride); + +// must be called before anything using the above +void VP8DspInit(void); + +//------------------------------------------------------------------------------ +// WebP I/O + +#define FANCY_UPSAMPLING // undefined to remove fancy upsampling support + +// Convert a pair of y/u/v lines together to the output rgb/a colorspace. +// bottom_y can be NULL if only one line of output is needed (at top/bottom). +typedef void (*WebPUpsampleLinePairFunc)( + const uint8_t* top_y, const uint8_t* bottom_y, + const uint8_t* top_u, const uint8_t* top_v, + const uint8_t* cur_u, const uint8_t* cur_v, + uint8_t* top_dst, uint8_t* bottom_dst, int len); + +#ifdef FANCY_UPSAMPLING + +// Fancy upsampling functions to convert YUV to RGB(A) modes +extern WebPUpsampleLinePairFunc WebPUpsamplers[/* MODE_LAST */]; + +#endif // FANCY_UPSAMPLING + +// Per-row point-sampling methods. +typedef void (*WebPSamplerRowFunc)(const uint8_t* y, + const uint8_t* u, const uint8_t* v, + uint8_t* dst, int len); +// Generic function to apply 'WebPSamplerRowFunc' to the whole plane: +void WebPSamplerProcessPlane(const uint8_t* y, int y_stride, + const uint8_t* u, const uint8_t* v, int uv_stride, + uint8_t* dst, int dst_stride, + int width, int height, WebPSamplerRowFunc func); + +// Sampling functions to convert rows of YUV to RGB(A) +extern WebPSamplerRowFunc WebPSamplers[/* MODE_LAST */]; + +// General function for converting two lines of ARGB or RGBA. +// 'alpha_is_last' should be true if 0xff000000 is stored in memory as +// as 0x00, 0x00, 0x00, 0xff (little endian). +WebPUpsampleLinePairFunc WebPGetLinePairConverter(int alpha_is_last); + +// YUV444->RGB converters +typedef void (*WebPYUV444Converter)(const uint8_t* y, + const uint8_t* u, const uint8_t* v, + uint8_t* dst, int len); + +extern WebPYUV444Converter WebPYUV444Converters[/* MODE_LAST */]; + +// Must be called before using the WebPUpsamplers[] (and for premultiplied +// colorspaces like rgbA, rgbA4444, etc) +void WebPInitUpsamplers(void); +// Must be called before using WebPSamplers[] +void WebPInitSamplers(void); +// Must be called before using WebPYUV444Converters[] +void WebPInitYUV444Converters(void); + +//------------------------------------------------------------------------------ +// ARGB -> YUV converters + +// Convert ARGB samples to luma Y. +extern void (*WebPConvertARGBToY)(const uint32_t* argb, uint8_t* y, int width); +// Convert ARGB samples to U/V with downsampling. do_store should be '1' for +// even lines and '0' for odd ones. 'src_width' is the original width, not +// the U/V one. +extern void (*WebPConvertARGBToUV)(const uint32_t* argb, uint8_t* u, uint8_t* v, + int src_width, int do_store); + +// Convert a row of accumulated (four-values) of rgba32 toward U/V +extern void (*WebPConvertRGBA32ToUV)(const uint16_t* rgb, + uint8_t* u, uint8_t* v, int width); + +// Convert RGB or BGR to Y +extern void (*WebPConvertRGB24ToY)(const uint8_t* rgb, uint8_t* y, int width); +extern void (*WebPConvertBGR24ToY)(const uint8_t* bgr, uint8_t* y, int width); + +// used for plain-C fallback. +extern void WebPConvertARGBToUV_C(const uint32_t* argb, uint8_t* u, uint8_t* v, + int src_width, int do_store); +extern void WebPConvertRGBA32ToUV_C(const uint16_t* rgb, + uint8_t* u, uint8_t* v, int width); + +// utilities for accurate RGB->YUV conversion +extern uint64_t (*WebPSharpYUVUpdateY)(const uint16_t* src, const uint16_t* ref, + uint16_t* dst, int len); +extern void (*WebPSharpYUVUpdateRGB)(const int16_t* src, const int16_t* ref, + int16_t* dst, int len); +extern void (*WebPSharpYUVFilterRow)(const int16_t* A, const int16_t* B, + int len, + const uint16_t* best_y, uint16_t* out); + +// Must be called before using the above. +void WebPInitConvertARGBToYUV(void); + +//------------------------------------------------------------------------------ +// Rescaler + +struct WebPRescaler; + +// Import a row of data and save its contribution in the rescaler. +// 'channel' denotes the channel number to be imported. 'Expand' corresponds to +// the wrk->x_expand case. Otherwise, 'Shrink' is to be used. +typedef void (*WebPRescalerImportRowFunc)(struct WebPRescaler* const wrk, + const uint8_t* src); + +extern WebPRescalerImportRowFunc WebPRescalerImportRowExpand; +extern WebPRescalerImportRowFunc WebPRescalerImportRowShrink; + +// Export one row (starting at x_out position) from rescaler. +// 'Expand' corresponds to the wrk->y_expand case. +// Otherwise 'Shrink' is to be used +typedef void (*WebPRescalerExportRowFunc)(struct WebPRescaler* const wrk); +extern WebPRescalerExportRowFunc WebPRescalerExportRowExpand; +extern WebPRescalerExportRowFunc WebPRescalerExportRowShrink; + +// Plain-C implementation, as fall-back. +extern void WebPRescalerImportRowExpand_C(struct WebPRescaler* const wrk, + const uint8_t* src); +extern void WebPRescalerImportRowShrink_C(struct WebPRescaler* const wrk, + const uint8_t* src); +extern void WebPRescalerExportRowExpand_C(struct WebPRescaler* const wrk); +extern void WebPRescalerExportRowShrink_C(struct WebPRescaler* const wrk); + +// Main entry calls: +extern void WebPRescalerImportRow(struct WebPRescaler* const wrk, + const uint8_t* src); +// Export one row (starting at x_out position) from rescaler. +extern void WebPRescalerExportRow(struct WebPRescaler* const wrk); + +// Must be called first before using the above. +void WebPRescalerDspInit(void); + +//------------------------------------------------------------------------------ +// Utilities for processing transparent channel. + +// Apply alpha pre-multiply on an rgba, bgra or argb plane of size w * h. +// alpha_first should be 0 for argb, 1 for rgba or bgra (where alpha is last). +extern void (*WebPApplyAlphaMultiply)( + uint8_t* rgba, int alpha_first, int w, int h, int stride); + +// Same, buf specifically for RGBA4444 format +extern void (*WebPApplyAlphaMultiply4444)( + uint8_t* rgba4444, int w, int h, int stride); + +// Dispatch the values from alpha[] plane to the ARGB destination 'dst'. +// Returns true if alpha[] plane has non-trivial values different from 0xff. +extern int (*WebPDispatchAlpha)(const uint8_t* alpha, int alpha_stride, + int width, int height, + uint8_t* dst, int dst_stride); + +// Transfer packed 8b alpha[] values to green channel in dst[], zero'ing the +// A/R/B values. 'dst_stride' is the stride for dst[] in uint32_t units. +extern void (*WebPDispatchAlphaToGreen)(const uint8_t* alpha, int alpha_stride, + int width, int height, + uint32_t* dst, int dst_stride); + +// Extract the alpha values from 32b values in argb[] and pack them into alpha[] +// (this is the opposite of WebPDispatchAlpha). +// Returns true if there's only trivial 0xff alpha values. +extern int (*WebPExtractAlpha)(const uint8_t* argb, int argb_stride, + int width, int height, + uint8_t* alpha, int alpha_stride); + +// Extract the green values from 32b values in argb[] and pack them into alpha[] +// (this is the opposite of WebPDispatchAlphaToGreen). +extern void (*WebPExtractGreen)(const uint32_t* argb, uint8_t* alpha, int size); + +// Pre-Multiply operation transforms x into x * A / 255 (where x=Y,R,G or B). +// Un-Multiply operation transforms x into x * 255 / A. + +// Pre-Multiply or Un-Multiply (if 'inverse' is true) argb values in a row. +extern void (*WebPMultARGBRow)(uint32_t* const ptr, int width, int inverse); + +// Same a WebPMultARGBRow(), but for several rows. +void WebPMultARGBRows(uint8_t* ptr, int stride, int width, int num_rows, + int inverse); + +// Same for a row of single values, with side alpha values. +extern void (*WebPMultRow)(uint8_t* const ptr, const uint8_t* const alpha, + int width, int inverse); + +// Same a WebPMultRow(), but for several 'num_rows' rows. +void WebPMultRows(uint8_t* ptr, int stride, + const uint8_t* alpha, int alpha_stride, + int width, int num_rows, int inverse); + +// Plain-C versions, used as fallback by some implementations. +void WebPMultRow_C(uint8_t* const ptr, const uint8_t* const alpha, + int width, int inverse); +void WebPMultARGBRow_C(uint32_t* const ptr, int width, int inverse); + +// RGB packing function. 'step' can be 3 or 4. r/g/b input is rgb or bgr order. +extern void (*WebPPackRGB)(const uint8_t* r, const uint8_t* g, const uint8_t* b, + int len, int step, uint32_t* out); + +// This function returns true if src[i] contains a value different from 0xff. +extern int (*WebPHasAlpha8b)(const uint8_t* src, int length); +// This function returns true if src[4*i] contains a value different from 0xff. +extern int (*WebPHasAlpha32b)(const uint8_t* src, int length); + +// To be called first before using the above. +void WebPInitAlphaProcessing(void); + +//------------------------------------------------------------------------------ +// Filter functions + +typedef enum { // Filter types. + WEBP_FILTER_NONE = 0, + WEBP_FILTER_HORIZONTAL, + WEBP_FILTER_VERTICAL, + WEBP_FILTER_GRADIENT, + WEBP_FILTER_LAST = WEBP_FILTER_GRADIENT + 1, // end marker + WEBP_FILTER_BEST, // meta-types + WEBP_FILTER_FAST +} WEBP_FILTER_TYPE; + +typedef void (*WebPFilterFunc)(const uint8_t* in, int width, int height, + int stride, uint8_t* out); +// In-place un-filtering. +// Warning! 'prev_line' pointer can be equal to 'cur_line' or 'preds'. +typedef void (*WebPUnfilterFunc)(const uint8_t* prev_line, const uint8_t* preds, + uint8_t* cur_line, int width); + +// Filter the given data using the given predictor. +// 'in' corresponds to a 2-dimensional pixel array of size (stride * height) +// in raster order. +// 'stride' is number of bytes per scan line (with possible padding). +// 'out' should be pre-allocated. +extern WebPFilterFunc WebPFilters[WEBP_FILTER_LAST]; + +// In-place reconstruct the original data from the given filtered data. +// The reconstruction will be done for 'num_rows' rows starting from 'row' +// (assuming rows upto 'row - 1' are already reconstructed). +extern WebPUnfilterFunc WebPUnfilters[WEBP_FILTER_LAST]; + +// To be called first before using the above. +void VP8FiltersInit(void); + +#ifdef __cplusplus +} // extern "C" +#endif + +#endif /* WEBP_DSP_DSP_H_ */ |