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Diffstat (limited to 'files/docs/formats.md')
| -rw-r--r-- | files/docs/formats.md | 55 |
1 files changed, 50 insertions, 5 deletions
diff --git a/files/docs/formats.md b/files/docs/formats.md index 97e8ce05..12ea9465 100644 --- a/files/docs/formats.md +++ b/files/docs/formats.md @@ -4,7 +4,9 @@ Formats (FOURCC) supported by libyuv are detailed here. # Core Formats -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. +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. Filtering functions such as scaling and planar functions work on I420 and/or ARGB. @@ -36,7 +38,7 @@ This is how OSX formats map to libyuv The following is extracted from video_common.h as a complete list of formats supported by libyuv. enum FourCC { - // 9 Primary YUV formats: 5 planar, 2 biplanar, 2 packed. + // 10 Primary YUV formats: 5 planar, 2 biplanar, 2 packed. FOURCC_I420 = FOURCC('I', '4', '2', '0'), FOURCC_I422 = FOURCC('I', '4', '2', '2'), FOURCC_I444 = FOURCC('I', '4', '4', '4'), @@ -46,16 +48,20 @@ The following is extracted from video_common.h as a complete list of formats sup FOURCC_YUY2 = FOURCC('Y', 'U', 'Y', '2'), FOURCC_UYVY = FOURCC('U', 'Y', 'V', 'Y'), FOURCC_H010 = FOURCC('H', '0', '1', '0'), // unofficial fourcc. 10 bit lsb + FOURCC_U010 = FOURCC('U', '0', '1', '0'), // bt.2020, unofficial fourcc. + // 10 bit lsb // 1 Secondary YUV format: row biplanar. - FOURCC_M420 = FOURCC('M', '4', '2', '0'), + FOURCC_M420 = FOURCC('M', '4', '2', '0'), // deprecated. - // 11 Primary RGB formats: 4 32 bpp, 2 24 bpp, 3 16 bpp, 1 10 bpc + // 13 Primary RGB formats: 4 32 bpp, 2 24 bpp, 3 16 bpp, 1 10 bpc, 2 64 bpp FOURCC_ARGB = FOURCC('A', 'R', 'G', 'B'), FOURCC_BGRA = FOURCC('B', 'G', 'R', 'A'), FOURCC_ABGR = FOURCC('A', 'B', 'G', 'R'), FOURCC_AR30 = FOURCC('A', 'R', '3', '0'), // 10 bit per channel. 2101010. FOURCC_AB30 = FOURCC('A', 'B', '3', '0'), // ABGR version of 10 bit + FOURCC_AR64 = FOURCC('A', 'R', '6', '4'), // 16 bit per channel. + FOURCC_AB64 = FOURCC('A', 'B', '6', '4'), // ABGR version of 16 bit FOURCC_24BG = FOURCC('2', '4', 'B', 'G'), FOURCC_RAW = FOURCC('r', 'a', 'w', ' '), FOURCC_RGBA = FOURCC('R', 'G', 'B', 'A'), @@ -66,7 +72,7 @@ The following is extracted from video_common.h as a complete list of formats sup // 1 Primary Compressed YUV format. FOURCC_MJPG = FOURCC('M', 'J', 'P', 'G'), - // 8 Auxiliary YUV variations: 3 with U and V planes are swapped, 1 Alias. + // 11 Auxiliary YUV variations: 3 with U and V planes are swapped, 1 Alias. FOURCC_YV12 = FOURCC('Y', 'V', '1', '2'), FOURCC_YV16 = FOURCC('Y', 'V', '1', '6'), FOURCC_YV24 = FOURCC('Y', 'V', '2', '4'), @@ -75,6 +81,9 @@ The following is extracted from video_common.h as a complete list of formats sup FOURCC_J400 = FOURCC('J', '4', '0', '0'), // unofficial fourcc FOURCC_H420 = FOURCC('H', '4', '2', '0'), // unofficial fourcc FOURCC_H422 = FOURCC('H', '4', '2', '2'), // unofficial fourcc + FOURCC_U420 = FOURCC('U', '4', '2', '0'), // bt.2020, unofficial fourcc + FOURCC_U422 = FOURCC('U', '4', '2', '2'), // bt.2020, unofficial fourcc + FOURCC_U444 = FOURCC('U', '4', '4', '4'), // bt.2020, unofficial fourcc // 14 Auxiliary aliases. CanonicalFourCC() maps these to canonical fourcc. FOURCC_IYUV = FOURCC('I', 'Y', 'U', 'V'), // Alias for I420. @@ -104,6 +113,27 @@ The following is extracted from video_common.h as a complete list of formats sup I444, NV24 and NV42 are full width, full height I400 and J400 have no chroma channel. +# Color space + The YUV formats start with a letter to specify the color space. e.g. I420 + I = BT.601 limited range + J = BT.601 full range (J = JPEG that uses this) + H = BT.709 limited range (H for HD) + F = BT.709 full range (F for Full range) + U = BT.2020 limited range (U for UHD) + V = BT.2020 full range + For YUV to RGB conversions, a matrix can be passed. See also convert_argh.h + +# HDR formats + Planar formats with 10 or 12 bits use the following fourcc: + I010, I012, P010, P012 are half width, half height + I210, I212, P210, P212 are half width, full height + I410, I412, P410, P412 are full width, full height + where + I is the color space (see above) and 3 planes: Y, U and V. + P is a biplanar format, similar to NV12 but 16 bits, with the valid bits in the high bits. There is a Y plane and a UV plane. + 0, 2 or 4 is the last digit of subsampling: 4:2:0, 4:2:2, or 4:4:4 + 10 or 12 is the bits per channel. The bits are in the low bits of a 16 bit channel. + # The ARGB FOURCC There are 4 ARGB layouts - ARGB, BGRA, ABGR and RGBA. ARGB is most common by far, used for screen formats, and windows webcam drivers. @@ -152,6 +182,13 @@ The 2 bit alpha has 4 values. Here are the comparable 8 bit alpha values. The 10 bit RGB values range from 0 to 1023. XR30 is the same as AR30 but with no alpha channel. +# AB64 and AR64 + +AB64 is similar to ABGR, with 16 bit (2 bytes) per channel. Each channel stores an unsigned short. +In memory R is the lowest and A is the highest. +Each channel has value ranges from 0 to 65535. +AR64 is similar to ARGB. + # NV12 and NV21 NV12 is a biplanar format with a full sized Y plane followed by a single @@ -161,3 +198,11 @@ The 12 in NV12 refers to 12 bits per pixel. NV12 has a half width and half height chroma channel, and therefore is a 420 subsampling. NV16 is 16 bits per pixel, with half width and full height. aka 422. NV24 is 24 bits per pixel with full sized chroma channel. aka 444. +Most NV12 functions allow the destination Y pointer to be NULL. + +# YUY2 and UYVY + +YUY2 is a packed YUV format with half width, full height. + +YUY2 is YUYV in memory +UYVY is UYVY in memory |