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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef HW_EMULATOR_CAMERA_CONVERTERS_H
     18 #define HW_EMULATOR_CAMERA_CONVERTERS_H
     19 
     20 #include <endian.h>
     21 
     22 #ifndef __BYTE_ORDER
     23 #error "could not determine byte order"
     24 #endif
     25 
     26 /*
     27  * Contains declaration of framebuffer conversion routines.
     28  *
     29  * NOTE: RGB and big/little endian considerations. Wherewer in this code RGB
     30  * pixels are represented as WORD, or DWORD, the color order inside the
     31  * WORD / DWORD matches the one that would occur if that WORD / DWORD would have
     32  * been read from the typecasted framebuffer:
     33  *
     34  *      const uint32_t rgb = *reinterpret_cast<const uint32_t*>(framebuffer);
     35  *
     36  * So, if this code runs on the little endian CPU, red color in 'rgb' would be
     37  * masked as 0x000000ff, and blue color would be masked as 0x00ff0000, while if
     38  * the code runs on a big endian CPU, the red color in 'rgb' would be masked as
     39  * 0xff000000, and blue color would be masked as 0x0000ff00,
     40  */
     41 
     42 namespace android {
     43 
     44 /*
     45  * RGB565 color masks
     46  */
     47 
     48 #if __BYTE_ORDER == __LITTLE_ENDIAN
     49 static const uint16_t kRed5     = 0x001f;
     50 static const uint16_t kGreen6   = 0x07e0;
     51 static const uint16_t kBlue5    = 0xf800;
     52 #else   // __BYTE_ORDER
     53 static const uint16_t kRed5     = 0xf800;
     54 static const uint16_t kGreen6   = 0x07e0;
     55 static const uint16_t kBlue5    = 0x001f;
     56 #endif  // __BYTE_ORDER
     57 static const uint32_t kBlack16  = 0x0000;
     58 static const uint32_t kWhite16  = kRed5 | kGreen6 | kBlue5;
     59 
     60 /*
     61  * RGB32 color masks
     62  */
     63 
     64 #if __BYTE_ORDER == __LITTLE_ENDIAN
     65 static const uint32_t kRed8     = 0x000000ff;
     66 static const uint32_t kGreen8   = 0x0000ff00;
     67 static const uint32_t kBlue8    = 0x00ff0000;
     68 #else   // __BYTE_ORDER
     69 static const uint32_t kRed8     = 0x00ff0000;
     70 static const uint32_t kGreen8   = 0x0000ff00;
     71 static const uint32_t kBlue8    = 0x000000ff;
     72 #endif  // __BYTE_ORDER
     73 static const uint32_t kBlack32  = 0x00000000;
     74 static const uint32_t kWhite32  = kRed8 | kGreen8 | kBlue8;
     75 
     76 /*
     77  * Extracting, and saving color bytes from / to WORD / DWORD RGB.
     78  */
     79 
     80 #if __BYTE_ORDER == __LITTLE_ENDIAN
     81 /* Extract red, green, and blue bytes from RGB565 word. */
     82 #define R16(rgb)    static_cast<uint8_t>(rgb & kRed5)
     83 #define G16(rgb)    static_cast<uint8_t>((rgb & kGreen6) >> 5)
     84 #define B16(rgb)    static_cast<uint8_t>((rgb & kBlue5) >> 11)
     85 /* Make 8 bits red, green, and blue, extracted from RGB565 word. */
     86 #define R16_32(rgb) static_cast<uint8_t>(((rgb & kRed5) << 3) | ((rgb & kRed5) >> 2))
     87 #define G16_32(rgb) static_cast<uint8_t>(((rgb & kGreen6) >> 3) | ((rgb & kGreen6) >> 9))
     88 #define B16_32(rgb) static_cast<uint8_t>(((rgb & kBlue5) >> 8) | ((rgb & kBlue5) >> 14))
     89 /* Extract red, green, and blue bytes from RGB32 dword. */
     90 #define R32(rgb)    static_cast<uint8_t>(rgb & kRed8)
     91 #define G32(rgb)    static_cast<uint8_t>(((rgb & kGreen8) >> 8) & 0xff)
     92 #define B32(rgb)    static_cast<uint8_t>(((rgb & kBlue8) >> 16) & 0xff)
     93 /* Build RGB565 word from red, green, and blue bytes. */
     94 #define RGB565(r, g, b) static_cast<uint16_t>((((static_cast<uint16_t>(b) << 6) | g) << 5) | r)
     95 /* Build RGB32 dword from red, green, and blue bytes. */
     96 #define RGB32(r, g, b) static_cast<uint32_t>((((static_cast<uint32_t>(b) << 8) | g) << 8) | r)
     97 #else   // __BYTE_ORDER
     98 /* Extract red, green, and blue bytes from RGB565 word. */
     99 #define R16(rgb)    static_cast<uint8_t>((rgb & kRed5) >> 11)
    100 #define G16(rgb)    static_cast<uint8_t>((rgb & kGreen6) >> 5)
    101 #define B16(rgb)    static_cast<uint8_t>(rgb & kBlue5)
    102 /* Make 8 bits red, green, and blue, extracted from RGB565 word. */
    103 #define R16_32(rgb) static_cast<uint8_t>(((rgb & kRed5) >> 8) | ((rgb & kRed5) >> 14))
    104 #define G16_32(rgb) static_cast<uint8_t>(((rgb & kGreen6) >> 3) | ((rgb & kGreen6) >> 9))
    105 #define B16_32(rgb) static_cast<uint8_t>(((rgb & kBlue5) << 3) | ((rgb & kBlue5) >> 2))
    106 /* Extract red, green, and blue bytes from RGB32 dword. */
    107 #define R32(rgb)    static_cast<uint8_t>((rgb & kRed8) >> 16)
    108 #define G32(rgb)    static_cast<uint8_t>((rgb & kGreen8) >> 8)
    109 #define B32(rgb)    static_cast<uint8_t>(rgb & kBlue8)
    110 /* Build RGB565 word from red, green, and blue bytes. */
    111 #define RGB565(r, g, b) static_cast<uint16_t>((((static_cast<uint16_t>(r) << 6) | g) << 5) | b)
    112 /* Build RGB32 dword from red, green, and blue bytes. */
    113 #define RGB32(r, g, b) static_cast<uint32_t>((((static_cast<uint32_t>(r) << 8) | g) << 8) | b)
    114 #endif  // __BYTE_ORDER
    115 
    116 /* An union that simplifies breaking 32 bit RGB into separate R, G, and B colors.
    117  */
    118 typedef union RGB32_t {
    119     uint32_t    color;
    120     struct {
    121 #if __BYTE_ORDER == __LITTLE_ENDIAN
    122         uint8_t r; uint8_t g; uint8_t b; uint8_t a;
    123 #else   // __BYTE_ORDER
    124         uint8_t a; uint8_t b; uint8_t g; uint8_t r;
    125 #endif  // __BYTE_ORDER
    126     };
    127 } RGB32_t;
    128 
    129 
    130 /* Clips a value to the unsigned 0-255 range, treating negative values as zero.
    131  */
    132 static __inline__ int
    133 clamp(int x)
    134 {
    135     if (x > 255) return 255;
    136     if (x < 0)   return 0;
    137     return x;
    138 }
    139 
    140 /********************************************************************************
    141  * Basics of RGB -> YUV conversion
    142  *******************************************************************************/
    143 
    144 /*
    145  * RGB -> YUV conversion macros
    146  */
    147 #define RGB2Y(r, g, b) (uint8_t)(((66 * (r) + 129 * (g) +  25 * (b) + 128) >> 8) +  16)
    148 #define RGB2U(r, g, b) (uint8_t)(((-38 * (r) - 74 * (g) + 112 * (b) + 128) >> 8) + 128)
    149 #define RGB2V(r, g, b) (uint8_t)(((112 * (r) - 94 * (g) -  18 * (b) + 128) >> 8) + 128)
    150 
    151 /* Converts R8 G8 B8 color to YUV. */
    152 static __inline__ void
    153 R8G8B8ToYUV(uint8_t r, uint8_t g, uint8_t b, uint8_t* y, uint8_t* u, uint8_t* v)
    154 {
    155     *y = RGB2Y((int)r, (int)g, (int)b);
    156     *u = RGB2U((int)r, (int)g, (int)b);
    157     *v = RGB2V((int)r, (int)g, (int)b);
    158 }
    159 
    160 /* Converts RGB565 color to YUV. */
    161 static __inline__ void
    162 RGB565ToYUV(uint16_t rgb, uint8_t* y, uint8_t* u, uint8_t* v)
    163 {
    164     R8G8B8ToYUV(R16_32(rgb), G16_32(rgb), B16_32(rgb), y, u, v);
    165 }
    166 
    167 /* Converts RGB32 color to YUV. */
    168 static __inline__ void
    169 RGB32ToYUV(uint32_t rgb, uint8_t* y, uint8_t* u, uint8_t* v)
    170 {
    171     RGB32_t rgb_c;
    172     rgb_c.color = rgb;
    173     R8G8B8ToYUV(rgb_c.r, rgb_c.g, rgb_c.b, y, u, v);
    174 }
    175 
    176 /********************************************************************************
    177  * Basics of YUV -> RGB conversion.
    178  * Note that due to the fact that guest uses RGB only on preview window, and the
    179  * RGB format that is used is RGB565, we can limit YUV -> RGB conversions to
    180  * RGB565 only.
    181  *******************************************************************************/
    182 
    183 /*
    184  * YUV -> RGB conversion macros
    185  */
    186 
    187 /* "Optimized" macros that take specialy prepared Y, U, and V values:
    188  *  C = Y - 16
    189  *  D = U - 128
    190  *  E = V - 128
    191  */
    192 #define YUV2RO(C, D, E) clamp((298 * (C) + 409 * (E) + 128) >> 8)
    193 #define YUV2GO(C, D, E) clamp((298 * (C) - 100 * (D) - 208 * (E) + 128) >> 8)
    194 #define YUV2BO(C, D, E) clamp((298 * (C) + 516 * (D) + 128) >> 8)
    195 
    196 /*
    197  *  Main macros that take the original Y, U, and V values
    198  */
    199 #define YUV2R(y, u, v) clamp((298 * ((y)-16) + 409 * ((v)-128) + 128) >> 8)
    200 #define YUV2G(y, u, v) clamp((298 * ((y)-16) - 100 * ((u)-128) - 208 * ((v)-128) + 128) >> 8)
    201 #define YUV2B(y, u, v) clamp((298 * ((y)-16) + 516 * ((u)-128) + 128) >> 8)
    202 
    203 
    204 /* Converts YUV color to RGB565. */
    205 static __inline__ uint16_t
    206 YUVToRGB565(int y, int u, int v)
    207 {
    208     /* Calculate C, D, and E values for the optimized macro. */
    209     y -= 16; u -= 128; v -= 128;
    210     const uint16_t r = (YUV2RO(y,u,v) >> 3) & 0x1f;
    211     const uint16_t g = (YUV2GO(y,u,v) >> 2) & 0x3f;
    212     const uint16_t b = (YUV2BO(y,u,v) >> 3) & 0x1f;
    213     return RGB565(r, g, b);
    214 }
    215 
    216 /* Converts YUV color to RGB32. */
    217 static __inline__ uint32_t
    218 YUVToRGB32(int y, int u, int v)
    219 {
    220     /* Calculate C, D, and E values for the optimized macro. */
    221     y -= 16; u -= 128; v -= 128;
    222     RGB32_t rgb;
    223     rgb.r = YUV2RO(y,u,v) & 0xff;
    224     rgb.g = YUV2GO(y,u,v) & 0xff;
    225     rgb.b = YUV2BO(y,u,v) & 0xff;
    226     return rgb.color;
    227 }
    228 
    229 /* YUV pixel descriptor. */
    230 struct YUVPixel {
    231     uint8_t     Y;
    232     uint8_t     U;
    233     uint8_t     V;
    234 
    235     inline YUVPixel()
    236         : Y(0), U(0), V(0)
    237     {
    238     }
    239 
    240     inline explicit YUVPixel(uint16_t rgb565)
    241     {
    242         RGB565ToYUV(rgb565, &Y, &U, &V);
    243     }
    244 
    245     inline explicit YUVPixel(uint32_t rgb32)
    246     {
    247         RGB32ToYUV(rgb32, &Y, &U, &V);
    248     }
    249 
    250     inline void get(uint8_t* pY, uint8_t* pU, uint8_t* pV) const
    251     {
    252         *pY = Y; *pU = U; *pV = V;
    253     }
    254 };
    255 
    256 /* Converts an YV12 framebuffer to RGB565 framebuffer.
    257  * Param:
    258  *  yv12 - YV12 framebuffer.
    259  *  rgb - RGB565 framebuffer.
    260  *  width, height - Dimensions for both framebuffers.
    261  */
    262 void YV12ToRGB565(const void* yv12, void* rgb, int width, int height);
    263 
    264 /* Converts an YV12 framebuffer to RGB32 framebuffer.
    265  * Param:
    266  *  yv12 - YV12 framebuffer.
    267  *  rgb - RGB32 framebuffer.
    268  *  width, height - Dimensions for both framebuffers.
    269  */
    270 void YV12ToRGB32(const void* yv12, void* rgb, int width, int height);
    271 
    272 /* Converts an YU12 framebuffer to RGB32 framebuffer.
    273  * Param:
    274  *  yu12 - YU12 framebuffer.
    275  *  rgb - RGB32 framebuffer.
    276  *  width, height - Dimensions for both framebuffers.
    277  */
    278 void YU12ToRGB32(const void* yu12, void* rgb, int width, int height);
    279 
    280 /* Converts an NV12 framebuffer to RGB565 framebuffer.
    281  * Param:
    282  *  nv12 - NV12 framebuffer.
    283  *  rgb - RGB565 framebuffer.
    284  *  width, height - Dimensions for both framebuffers.
    285  */
    286 void NV12ToRGB565(const void* nv12, void* rgb, int width, int height);
    287 
    288 /* Converts an NV12 framebuffer to RGB32 framebuffer.
    289  * Param:
    290  *  nv12 - NV12 framebuffer.
    291  *  rgb - RGB32 framebuffer.
    292  *  width, height - Dimensions for both framebuffers.
    293  */
    294 void NV12ToRGB32(const void* nv12, void* rgb, int width, int height);
    295 
    296 /* Converts an NV21 framebuffer to RGB565 framebuffer.
    297  * Param:
    298  *  nv21 - NV21 framebuffer.
    299  *  rgb - RGB565 framebuffer.
    300  *  width, height - Dimensions for both framebuffers.
    301  */
    302 void NV21ToRGB565(const void* nv21, void* rgb, int width, int height);
    303 
    304 /* Converts an NV21 framebuffer to RGB32 framebuffer.
    305  * Param:
    306  *  nv21 - NV21 framebuffer.
    307  *  rgb - RGB32 framebuffer.
    308  *  width, height - Dimensions for both framebuffers.
    309  */
    310 void NV21ToRGB32(const void* nv21, void* rgb, int width, int height);
    311 
    312 }; /* namespace android */
    313 
    314 #endif  /* HW_EMULATOR_CAMERA_CONVERTERS_H */
    315