1 # Introduction 2 3 Formats (FOURCC) supported by libyuv are detailed here. 4 5 # Core Formats 6 7 There are 2 core formats supported by libyuv - I420 and ARGB. All YUV formats can be converted to/from I420. All RGB formats can be converted to/from ARGB. 8 9 Filtering functions such as scaling and planar functions work on I420 and/or ARGB. 10 11 # OSX Core Media Pixel Formats 12 13 This is how OSX formats map to libyuv 14 15 enum { 16 kCMPixelFormat_32ARGB = 32, FOURCC_BGRA 17 kCMPixelFormat_32BGRA = 'BGRA', FOURCC_ARGB 18 kCMPixelFormat_24RGB = 24, FOURCC_RAW 19 kCMPixelFormat_16BE555 = 16, Not supported. 20 kCMPixelFormat_16BE565 = 'B565', Not supported. 21 kCMPixelFormat_16LE555 = 'L555', FOURCC_RGBO 22 kCMPixelFormat_16LE565 = 'L565', FOURCC_RGBP 23 kCMPixelFormat_16LE5551 = '5551', FOURCC_RGBO 24 kCMPixelFormat_422YpCbCr8 = '2vuy', FOURCC_UYVY 25 kCMPixelFormat_422YpCbCr8_yuvs = 'yuvs', FOURCC_YUY2 26 kCMPixelFormat_444YpCbCr8 = 'v308', FOURCC_I444 ? 27 kCMPixelFormat_4444YpCbCrA8 = 'v408', Not supported. 28 kCMPixelFormat_422YpCbCr16 = 'v216', Not supported. 29 kCMPixelFormat_422YpCbCr10 = 'v210', FOURCC_V210 previously. Removed now. 30 kCMPixelFormat_444YpCbCr10 = 'v410', Not supported. 31 kCMPixelFormat_8IndexedGray_WhiteIsZero = 0x00000028, Not supported. 32 }; 33 34 35 # FOURCC (Four Charactacter Code) List 36 37 The following is extracted from video_common.h as a complete list of formats supported by libyuv. 38 39 enum FourCC { 40 // 8 Primary YUV formats: 5 planar, 2 biplanar, 2 packed. 41 FOURCC_I420 = FOURCC('I', '4', '2', '0'), 42 FOURCC_I422 = FOURCC('I', '4', '2', '2'), 43 FOURCC_I444 = FOURCC('I', '4', '4', '4'), 44 FOURCC_I400 = FOURCC('I', '4', '0', '0'), 45 FOURCC_NV21 = FOURCC('N', 'V', '2', '1'), 46 FOURCC_NV12 = FOURCC('N', 'V', '1', '2'), 47 FOURCC_YUY2 = FOURCC('Y', 'U', 'Y', '2'), 48 FOURCC_UYVY = FOURCC('U', 'Y', 'V', 'Y'), 49 50 // 1 Secondary YUV formats: row biplanar. 51 FOURCC_M420 = FOURCC('M', '4', '2', '0'), 52 53 // 9 Primary RGB formats: 4 32 bpp, 2 24 bpp, 3 16 bpp. 54 FOURCC_ARGB = FOURCC('A', 'R', 'G', 'B'), 55 FOURCC_BGRA = FOURCC('B', 'G', 'R', 'A'), 56 FOURCC_ABGR = FOURCC('A', 'B', 'G', 'R'), 57 FOURCC_24BG = FOURCC('2', '4', 'B', 'G'), 58 FOURCC_RAW = FOURCC('r', 'a', 'w', ' '), 59 FOURCC_RGBA = FOURCC('R', 'G', 'B', 'A'), 60 FOURCC_RGBP = FOURCC('R', 'G', 'B', 'P'), // rgb565 LE. 61 FOURCC_RGBO = FOURCC('R', 'G', 'B', 'O'), // argb1555 LE. 62 FOURCC_R444 = FOURCC('R', '4', '4', '4'), // argb4444 LE. 63 64 // 4 Secondary RGB formats: 4 Bayer Patterns. 65 FOURCC_RGGB = FOURCC('R', 'G', 'G', 'B'), 66 FOURCC_BGGR = FOURCC('B', 'G', 'G', 'R'), 67 FOURCC_GRBG = FOURCC('G', 'R', 'B', 'G'), 68 FOURCC_GBRG = FOURCC('G', 'B', 'R', 'G'), 69 70 // 1 Primary Compressed YUV format. 71 FOURCC_MJPG = FOURCC('M', 'J', 'P', 'G'), 72 73 // 5 Auxiliary YUV variations: 3 with U and V planes are swapped, 1 Alias. 74 FOURCC_YV12 = FOURCC('Y', 'V', '1', '2'), 75 FOURCC_YV16 = FOURCC('Y', 'V', '1', '6'), 76 FOURCC_YV24 = FOURCC('Y', 'V', '2', '4'), 77 FOURCC_YU12 = FOURCC('Y', 'U', '1', '2'), // Linux version of I420. 78 FOURCC_J420 = FOURCC('J', '4', '2', '0'), 79 FOURCC_J400 = FOURCC('J', '4', '0', '0'), 80 81 // 14 Auxiliary aliases. CanonicalFourCC() maps these to canonical fourcc. 82 FOURCC_IYUV = FOURCC('I', 'Y', 'U', 'V'), // Alias for I420. 83 FOURCC_YU16 = FOURCC('Y', 'U', '1', '6'), // Alias for I422. 84 FOURCC_YU24 = FOURCC('Y', 'U', '2', '4'), // Alias for I444. 85 FOURCC_YUYV = FOURCC('Y', 'U', 'Y', 'V'), // Alias for YUY2. 86 FOURCC_YUVS = FOURCC('y', 'u', 'v', 's'), // Alias for YUY2 on Mac. 87 FOURCC_HDYC = FOURCC('H', 'D', 'Y', 'C'), // Alias for UYVY. 88 FOURCC_2VUY = FOURCC('2', 'v', 'u', 'y'), // Alias for UYVY on Mac. 89 FOURCC_JPEG = FOURCC('J', 'P', 'E', 'G'), // Alias for MJPG. 90 FOURCC_DMB1 = FOURCC('d', 'm', 'b', '1'), // Alias for MJPG on Mac. 91 FOURCC_BA81 = FOURCC('B', 'A', '8', '1'), // Alias for BGGR. 92 FOURCC_RGB3 = FOURCC('R', 'G', 'B', '3'), // Alias for RAW. 93 FOURCC_BGR3 = FOURCC('B', 'G', 'R', '3'), // Alias for 24BG. 94 FOURCC_CM32 = FOURCC(0, 0, 0, 32), // Alias for BGRA kCMPixelFormat_32ARGB 95 FOURCC_CM24 = FOURCC(0, 0, 0, 24), // Alias for RAW kCMPixelFormat_24RGB 96 FOURCC_L555 = FOURCC('L', '5', '5', '5'), // Alias for RGBO. 97 FOURCC_L565 = FOURCC('L', '5', '6', '5'), // Alias for RGBP. 98 FOURCC_5551 = FOURCC('5', '5', '5', '1'), // Alias for RGBO. 99 100 // 1 Auxiliary compressed YUV format set aside for capturer. 101 FOURCC_H264 = FOURCC('H', '2', '6', '4'), 102 103 # Planar YUV 104 The following formats contains a full size Y plane followed by 1 or 2 105 planes for UV: I420, I422, I444, I400, NV21, NV12, I400 106 The size (subsampling) of the UV varies. 107 I420, NV12 and NV21 are half width, half height 108 I422, NV16 and NV61 are half width, full height 109 I444, NV24 and NV42 are full width, full height 110 I400 and J400 have no chroma channel. 111 112 # The ARGB FOURCC 113 114 There are 4 ARGB layouts - ARGB, BGRA, ABGR and RGBA. ARGB is most common by far, used for screen formats, and windows webcam drivers. 115 116 The fourcc describes the order of channels in a ***register***. 117 118 A fourcc provided by capturer, can be thought of string, e.g. "ARGB". 119 120 On little endian machines, as an int, this would have 'A' in the lowest byte. The FOURCC macro reverses the order: 121 122 #define FOURCC(a, b, c, d) (((uint32)(a)) | ((uint32)(b) << 8) | ((uint32)(c) << 16) | ((uint32)(d) << 24)) 123 124 So the "ARGB" string, read as an uint32, is 125 126 FOURCC_ARGB = FOURCC('A', 'R', 'G', 'B') 127 128 If you were to read ARGB pixels as uint32's, the alpha would be in the high byte, and the blue in the lowest byte. In memory, these are stored little endian, so 'B' is first, then 'G', 'R' and 'A' last. 129 130 When calling conversion functions, the names match the FOURCC, so in this case it would be I420ToARGB(). 131 132 All formats can be converted to/from ARGB. 133 134 Most 'planar_functions' work on ARGB (e.g. ARGBBlend). 135 136 Some are channel order agnostic (e.g. ARGBScale). 137 138 Some functions are symmetric (e.g. ARGBToBGRA is the same as BGRAToARGB, so its a macro). 139 140 ARGBBlend expects preattenuated ARGB. The R,G,B are premultiplied by alpha. Other functions don't care. 141
