yuv.c 5.5 KB

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  1. // Copyright 2010 Google Inc. All Rights Reserved.
  2. //
  3. // Use of this source code is governed by a BSD-style license
  4. // that can be found in the COPYING file in the root of the source
  5. // tree. An additional intellectual property rights grant can be found
  6. // in the file PATENTS. All contributing project authors may
  7. // be found in the AUTHORS file in the root of the source tree.
  8. // -----------------------------------------------------------------------------
  9. //
  10. // YUV->RGB conversion functions
  11. //
  12. // Author: Skal (pascal.massimino@gmail.com)
  13. #include "./yuv.h"
  14. #if defined(WEBP_YUV_USE_TABLE)
  15. static int done = 0;
  16. static WEBP_INLINE uint8_t clip(int v, int max_value) {
  17. return v < 0 ? 0 : v > max_value ? max_value : v;
  18. }
  19. int16_t VP8kVToR[256], VP8kUToB[256];
  20. int32_t VP8kVToG[256], VP8kUToG[256];
  21. uint8_t VP8kClip[YUV_RANGE_MAX - YUV_RANGE_MIN];
  22. uint8_t VP8kClip4Bits[YUV_RANGE_MAX - YUV_RANGE_MIN];
  23. void VP8YUVInit(void) {
  24. int i;
  25. if (done) {
  26. return;
  27. }
  28. #ifndef USE_YUVj
  29. for (i = 0; i < 256; ++i) {
  30. VP8kVToR[i] = (89858 * (i - 128) + YUV_HALF) >> YUV_FIX;
  31. VP8kUToG[i] = -22014 * (i - 128) + YUV_HALF;
  32. VP8kVToG[i] = -45773 * (i - 128);
  33. VP8kUToB[i] = (113618 * (i - 128) + YUV_HALF) >> YUV_FIX;
  34. }
  35. for (i = YUV_RANGE_MIN; i < YUV_RANGE_MAX; ++i) {
  36. const int k = ((i - 16) * 76283 + YUV_HALF) >> YUV_FIX;
  37. VP8kClip[i - YUV_RANGE_MIN] = clip(k, 255);
  38. VP8kClip4Bits[i - YUV_RANGE_MIN] = clip((k + 8) >> 4, 15);
  39. }
  40. #else
  41. for (i = 0; i < 256; ++i) {
  42. VP8kVToR[i] = (91881 * (i - 128) + YUV_HALF) >> YUV_FIX;
  43. VP8kUToG[i] = -22554 * (i - 128) + YUV_HALF;
  44. VP8kVToG[i] = -46802 * (i - 128);
  45. VP8kUToB[i] = (116130 * (i - 128) + YUV_HALF) >> YUV_FIX;
  46. }
  47. for (i = YUV_RANGE_MIN; i < YUV_RANGE_MAX; ++i) {
  48. const int k = i;
  49. VP8kClip[i - YUV_RANGE_MIN] = clip(k, 255);
  50. VP8kClip4Bits[i - YUV_RANGE_MIN] = clip((k + 8) >> 4, 15);
  51. }
  52. #endif
  53. done = 1;
  54. }
  55. #else
  56. void VP8YUVInit(void) {}
  57. #endif // WEBP_YUV_USE_TABLE
  58. //-----------------------------------------------------------------------------
  59. // Plain-C version
  60. #define ROW_FUNC(FUNC_NAME, FUNC, XSTEP) \
  61. static void FUNC_NAME(const uint8_t* y, \
  62. const uint8_t* u, const uint8_t* v, \
  63. uint8_t* dst, int len) { \
  64. const uint8_t* const end = dst + (len & ~1) * XSTEP; \
  65. while (dst != end) { \
  66. FUNC(y[0], u[0], v[0], dst); \
  67. FUNC(y[1], u[0], v[0], dst + XSTEP); \
  68. y += 2; \
  69. ++u; \
  70. ++v; \
  71. dst += 2 * XSTEP; \
  72. } \
  73. if (len & 1) { \
  74. FUNC(y[0], u[0], v[0], dst); \
  75. } \
  76. } \
  77. // All variants implemented.
  78. ROW_FUNC(YuvToRgbRow, VP8YuvToRgb, 3)
  79. ROW_FUNC(YuvToBgrRow, VP8YuvToBgr, 3)
  80. ROW_FUNC(YuvToRgbaRow, VP8YuvToRgba, 4)
  81. ROW_FUNC(YuvToBgraRow, VP8YuvToBgra, 4)
  82. ROW_FUNC(YuvToArgbRow, VP8YuvToArgb, 4)
  83. ROW_FUNC(YuvToRgba4444Row, VP8YuvToRgba4444, 2)
  84. ROW_FUNC(YuvToRgb565Row, VP8YuvToRgb565, 2)
  85. #undef ROW_FUNC
  86. // Main call for processing a plane with a WebPSamplerRowFunc function:
  87. void WebPSamplerProcessPlane(const uint8_t* y, int y_stride,
  88. const uint8_t* u, const uint8_t* v, int uv_stride,
  89. uint8_t* dst, int dst_stride,
  90. int width, int height, WebPSamplerRowFunc func) {
  91. int j;
  92. for (j = 0; j < height; ++j) {
  93. func(y, u, v, dst, width);
  94. y += y_stride;
  95. if (j & 1) {
  96. u += uv_stride;
  97. v += uv_stride;
  98. }
  99. dst += dst_stride;
  100. }
  101. }
  102. //-----------------------------------------------------------------------------
  103. // Main call
  104. WebPSamplerRowFunc WebPSamplers[MODE_LAST];
  105. extern void WebPInitSamplersSSE2(void);
  106. extern void WebPInitSamplersMIPS32(void);
  107. void WebPInitSamplers(void) {
  108. WebPSamplers[MODE_RGB] = YuvToRgbRow;
  109. WebPSamplers[MODE_RGBA] = YuvToRgbaRow;
  110. WebPSamplers[MODE_BGR] = YuvToBgrRow;
  111. WebPSamplers[MODE_BGRA] = YuvToBgraRow;
  112. WebPSamplers[MODE_ARGB] = YuvToArgbRow;
  113. WebPSamplers[MODE_RGBA_4444] = YuvToRgba4444Row;
  114. WebPSamplers[MODE_RGB_565] = YuvToRgb565Row;
  115. WebPSamplers[MODE_rgbA] = YuvToRgbaRow;
  116. WebPSamplers[MODE_bgrA] = YuvToBgraRow;
  117. WebPSamplers[MODE_Argb] = YuvToArgbRow;
  118. WebPSamplers[MODE_rgbA_4444] = YuvToRgba4444Row;
  119. // If defined, use CPUInfo() to overwrite some pointers with faster versions.
  120. if (VP8GetCPUInfo != NULL) {
  121. #if defined(WEBP_USE_SSE2)
  122. if (VP8GetCPUInfo(kSSE2)) {
  123. WebPInitSamplersSSE2();
  124. }
  125. #endif // WEBP_USE_SSE2
  126. #if defined(WEBP_USE_MIPS32)
  127. if (VP8GetCPUInfo(kMIPS32)) {
  128. WebPInitSamplersMIPS32();
  129. }
  130. #endif // WEBP_USE_MIPS32
  131. }
  132. }
  133. //-----------------------------------------------------------------------------