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Diffstat (limited to 'src/3rdparty/libwebp/src/dsp/lossless.h')
| -rw-r--r-- | src/3rdparty/libwebp/src/dsp/lossless.h | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/src/3rdparty/libwebp/src/dsp/lossless.h b/src/3rdparty/libwebp/src/dsp/lossless.h new file mode 100644 index 0000000..0f1d442 --- /dev/null +++ b/src/3rdparty/libwebp/src/dsp/lossless.h @@ -0,0 +1,220 @@ +// Copyright 2012 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. +// ----------------------------------------------------------------------------- +// +// Image transforms and color space conversion methods for lossless decoder. +// +// Authors: Vikas Arora (vikaas.arora@gmail.com) +// Jyrki Alakuijala (jyrki@google.com) + +#ifndef WEBP_DSP_LOSSLESS_H_ +#define WEBP_DSP_LOSSLESS_H_ + +#include "../webp/types.h" +#include "../webp/decode.h" + +#ifdef __cplusplus +extern "C" { +#endif + +//------------------------------------------------------------------------------ +// + +typedef uint32_t (*VP8LPredClampedAddSubFunc)(uint32_t c0, uint32_t c1, + uint32_t c2); +typedef uint32_t (*VP8LPredSelectFunc)(uint32_t c0, uint32_t c1, uint32_t c2); +typedef void (*VP8LSubtractGreenFromBlueAndRedFunc)(uint32_t* argb_data, + int num_pixs); +typedef void (*VP8LAddGreenToBlueAndRedFunc)(uint32_t* data_start, + const uint32_t* data_end); + +extern VP8LPredClampedAddSubFunc VP8LClampedAddSubtractFull; +extern VP8LPredClampedAddSubFunc VP8LClampedAddSubtractHalf; +extern VP8LPredSelectFunc VP8LSelect; +extern VP8LSubtractGreenFromBlueAndRedFunc VP8LSubtractGreenFromBlueAndRed; +extern VP8LAddGreenToBlueAndRedFunc VP8LAddGreenToBlueAndRed; + +// Must be called before calling any of the above methods. +void VP8LDspInit(void); + +//------------------------------------------------------------------------------ +// Image transforms. + +struct VP8LTransform; // Defined in dec/vp8li.h. + +// Performs inverse transform of data given transform information, start and end +// rows. Transform will be applied to rows [row_start, row_end[. +// The *in and *out pointers refer to source and destination data respectively +// corresponding to the intermediate row (row_start). +void VP8LInverseTransform(const struct VP8LTransform* const transform, + int row_start, int row_end, + const uint32_t* const in, uint32_t* const out); + +// Similar to the static method ColorIndexInverseTransform() that is part of +// lossless.c, but used only for alpha decoding. It takes uint8_t (rather than +// uint32_t) arguments for 'src' and 'dst'. +void VP8LColorIndexInverseTransformAlpha( + const struct VP8LTransform* const transform, int y_start, int y_end, + const uint8_t* src, uint8_t* dst); + +void VP8LResidualImage(int width, int height, int bits, + uint32_t* const argb, uint32_t* const argb_scratch, + uint32_t* const image); + +void VP8LColorSpaceTransform(int width, int height, int bits, int step, + uint32_t* const argb, uint32_t* image); + +//------------------------------------------------------------------------------ +// Color space conversion. + +// Converts from BGRA to other color spaces. +void VP8LConvertFromBGRA(const uint32_t* const in_data, int num_pixels, + WEBP_CSP_MODE out_colorspace, uint8_t* const rgba); + +//------------------------------------------------------------------------------ +// Misc methods. + +// Computes sampled size of 'size' when sampling using 'sampling bits'. +static WEBP_INLINE uint32_t VP8LSubSampleSize(uint32_t size, + uint32_t sampling_bits) { + return (size + (1 << sampling_bits) - 1) >> sampling_bits; +} + +// Faster logarithm for integers. Small values use a look-up table. +#define LOG_LOOKUP_IDX_MAX 256 +extern const float kLog2Table[LOG_LOOKUP_IDX_MAX]; +extern const float kSLog2Table[LOG_LOOKUP_IDX_MAX]; +float VP8LFastLog2Slow(int v); +float VP8LFastSLog2Slow(int v); +static WEBP_INLINE float VP8LFastLog2(int v) { + return (v < LOG_LOOKUP_IDX_MAX) ? kLog2Table[v] : VP8LFastLog2Slow(v); +} +// Fast calculation of v * log2(v) for integer input. +static WEBP_INLINE float VP8LFastSLog2(int v) { + return (v < LOG_LOOKUP_IDX_MAX) ? kSLog2Table[v] : VP8LFastSLog2Slow(v); +} + +// ----------------------------------------------------------------------------- +// PrefixEncode() + +// use GNU builtins where available. +#if defined(__GNUC__) && \ + ((__GNUC__ == 3 && __GNUC_MINOR__ >= 4) || __GNUC__ >= 4) +static WEBP_INLINE int BitsLog2Floor(uint32_t n) { + return 31 ^ __builtin_clz(n); +} +#elif defined(_MSC_VER) && _MSC_VER > 1310 && \ + (defined(_M_X64) || defined(_M_IX86)) +#include <intrin.h> +#pragma intrinsic(_BitScanReverse) + +static WEBP_INLINE int BitsLog2Floor(uint32_t n) { + unsigned long first_set_bit; + _BitScanReverse(&first_set_bit, n); + return first_set_bit; +} +#else +// Returns (int)floor(log2(n)). n must be > 0. +static WEBP_INLINE int BitsLog2Floor(uint32_t n) { + int log = 0; + uint32_t value = n; + int i; + + for (i = 4; i >= 0; --i) { + const int shift = (1 << i); + const uint32_t x = value >> shift; + if (x != 0) { + value = x; + log += shift; + } + } + return log; +} +#endif + +static WEBP_INLINE int VP8LBitsLog2Ceiling(uint32_t n) { + const int log_floor = BitsLog2Floor(n); + if (n == (n & ~(n - 1))) // zero or a power of two. + return log_floor; + else + return log_floor + 1; +} + +// Splitting of distance and length codes into prefixes and +// extra bits. The prefixes are encoded with an entropy code +// while the extra bits are stored just as normal bits. +static WEBP_INLINE void VP8LPrefixEncodeBitsNoLUT(int distance, int* const code, + int* const extra_bits) { + const int highest_bit = BitsLog2Floor(--distance); + const int second_highest_bit = (distance >> (highest_bit - 1)) & 1; + *extra_bits = highest_bit - 1; + *code = 2 * highest_bit + second_highest_bit; +} + +static WEBP_INLINE void VP8LPrefixEncodeNoLUT(int distance, int* const code, + int* const extra_bits, + int* const extra_bits_value) { + const int highest_bit = BitsLog2Floor(--distance); + const int second_highest_bit = (distance >> (highest_bit - 1)) & 1; + *extra_bits = highest_bit - 1; + *extra_bits_value = distance & ((1 << *extra_bits) - 1); + *code = 2 * highest_bit + second_highest_bit; +} + +#define PREFIX_LOOKUP_IDX_MAX 512 +typedef struct { + int8_t code_; + int8_t extra_bits_; +} VP8LPrefixCode; + +// These tables are derived using VP8LPrefixEncodeNoLUT. +extern const VP8LPrefixCode kPrefixEncodeCode[PREFIX_LOOKUP_IDX_MAX]; +extern const uint8_t kPrefixEncodeExtraBitsValue[PREFIX_LOOKUP_IDX_MAX]; +static WEBP_INLINE void VP8LPrefixEncodeBits(int distance, int* const code, + int* const extra_bits) { + if (distance < PREFIX_LOOKUP_IDX_MAX) { + const VP8LPrefixCode prefix_code = kPrefixEncodeCode[distance]; + *code = prefix_code.code_; + *extra_bits = prefix_code.extra_bits_; + } else { + VP8LPrefixEncodeBitsNoLUT(distance, code, extra_bits); + } +} + +static WEBP_INLINE void VP8LPrefixEncode(int distance, int* const code, + int* const extra_bits, + int* const extra_bits_value) { + if (distance < PREFIX_LOOKUP_IDX_MAX) { + const VP8LPrefixCode prefix_code = kPrefixEncodeCode[distance]; + *code = prefix_code.code_; + *extra_bits = prefix_code.extra_bits_; + *extra_bits_value = kPrefixEncodeExtraBitsValue[distance]; + } else { + VP8LPrefixEncodeNoLUT(distance, code, extra_bits, extra_bits_value); + } +} + +// In-place difference of each component with mod 256. +static WEBP_INLINE uint32_t VP8LSubPixels(uint32_t a, uint32_t b) { + const uint32_t alpha_and_green = + 0x00ff00ffu + (a & 0xff00ff00u) - (b & 0xff00ff00u); + const uint32_t red_and_blue = + 0xff00ff00u + (a & 0x00ff00ffu) - (b & 0x00ff00ffu); + return (alpha_and_green & 0xff00ff00u) | (red_and_blue & 0x00ff00ffu); +} + +void VP8LBundleColorMap(const uint8_t* const row, int width, + int xbits, uint32_t* const dst); + +//------------------------------------------------------------------------------ + +#ifdef __cplusplus +} // extern "C" +#endif + +#endif // WEBP_DSP_LOSSLESS_H_ |