OLD | NEW |
(Empty) | |
| 1 // Copyright 2012 Google Inc. All Rights Reserved. |
| 2 // |
| 3 // This code is licensed under the same terms as WebM: |
| 4 // Software License Agreement: http://www.webmproject.org/license/software/ |
| 5 // Additional IP Rights Grant: http://www.webmproject.org/license/additional/ |
| 6 // ----------------------------------------------------------------------------- |
| 7 // |
| 8 // Image transforms and color space conversion methods for lossless decoder. |
| 9 // |
| 10 // Authors: Vikas Arora (vikaas.arora@gmail.com) |
| 11 // Jyrki Alakuijala (jyrki@google.com) |
| 12 |
| 13 #ifndef WEBP_DSP_LOSSLESS_H_ |
| 14 #define WEBP_DSP_LOSSLESS_H_ |
| 15 |
| 16 #include "../webp/types.h" |
| 17 #include "../webp/decode.h" |
| 18 |
| 19 #if defined(__cplusplus) || defined(c_plusplus) |
| 20 extern "C" { |
| 21 #endif |
| 22 |
| 23 //------------------------------------------------------------------------------ |
| 24 // Image transforms. |
| 25 |
| 26 struct VP8LTransform; // Defined in dec/vp8li.h. |
| 27 |
| 28 // Performs inverse transform of data given transform information, start and end |
| 29 // rows. Transform will be applied to rows [row_start, row_end[. |
| 30 // The *in and *out pointers refer to source and destination data respectively |
| 31 // corresponding to the intermediate row (row_start). |
| 32 void VP8LInverseTransform(const struct VP8LTransform* const transform, |
| 33 int row_start, int row_end, |
| 34 const uint32_t* const in, uint32_t* const out); |
| 35 |
| 36 // Subtracts green from blue and red channels. |
| 37 void VP8LSubtractGreenFromBlueAndRed(uint32_t* argb_data, int num_pixs); |
| 38 |
| 39 void VP8LResidualImage(int width, int height, int bits, |
| 40 uint32_t* const argb, uint32_t* const argb_scratch, |
| 41 uint32_t* const image); |
| 42 |
| 43 void VP8LColorSpaceTransform(int width, int height, int bits, int step, |
| 44 uint32_t* const argb, uint32_t* image); |
| 45 |
| 46 //------------------------------------------------------------------------------ |
| 47 // Color space conversion. |
| 48 |
| 49 // Converts from BGRA to other color spaces. |
| 50 void VP8LConvertFromBGRA(const uint32_t* const in_data, int num_pixels, |
| 51 WEBP_CSP_MODE out_colorspace, uint8_t* const rgba); |
| 52 |
| 53 //------------------------------------------------------------------------------ |
| 54 // Misc methods. |
| 55 |
| 56 // Computes sampled size of 'size' when sampling using 'sampling bits'. |
| 57 static WEBP_INLINE uint32_t VP8LSubSampleSize(uint32_t size, |
| 58 uint32_t sampling_bits) { |
| 59 return (size + (1 << sampling_bits) - 1) >> sampling_bits; |
| 60 } |
| 61 |
| 62 // Faster logarithm for integers, with the property of log2(0) == 0. |
| 63 float VP8LFastLog2(int v); |
| 64 // Fast calculation of v * log2(v) for integer input. |
| 65 static WEBP_INLINE float VP8LFastSLog2(int v) { return VP8LFastLog2(v) * v; } |
| 66 |
| 67 // In-place difference of each component with mod 256. |
| 68 static WEBP_INLINE uint32_t VP8LSubPixels(uint32_t a, uint32_t b) { |
| 69 const uint32_t alpha_and_green = |
| 70 0x00ff00ffu + (a & 0xff00ff00u) - (b & 0xff00ff00u); |
| 71 const uint32_t red_and_blue = |
| 72 0xff00ff00u + (a & 0x00ff00ffu) - (b & 0x00ff00ffu); |
| 73 return (alpha_and_green & 0xff00ff00u) | (red_and_blue & 0x00ff00ffu); |
| 74 } |
| 75 |
| 76 //------------------------------------------------------------------------------ |
| 77 |
| 78 #if defined(__cplusplus) || defined(c_plusplus) |
| 79 } // extern "C" |
| 80 #endif |
| 81 |
| 82 #endif // WEBP_DSP_LOSSLESS_H_ |
OLD | NEW |