pixfmt: Add ARIB STD-B76 color transfer characteristic

Adding hybrid log-gamma (https://en.wikipedia.org/wiki/Hybrid_Log-Gamma)
based on the standardization in ARIB STD-B67:
http://www.arib.or.jp/english/html/overview/doc/2-STD-B67v1_0.pdf

The choice of enum value of 18 is consistent with HEVC:
http://phenix.it-sudparis.eu/jct/doc_end_user/current_document.php?id=10481

And also with latest proposal for color format in mkv:
https://mailarchive.ietf.org/arch/search/?email_list=cellar&gbt=1&q=Colour+Format+proposalSigned-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

libavcodec/options_table.h

@@ -453,6 +453,7 @@ static const AVOption avcodec_options[] = {
 {"bt2020_12bit", "BT.2020 - 12 bit", 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_TRC_BT2020_12 },    INT_MIN, INT_MAX, V|E|D, "color_trc_type"},
 {"smptest2084",  "SMPTE ST 2084",    0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_TRC_SMPTEST2084 },  INT_MIN, INT_MAX, V|E|D, "color_trc_type"},
 {"smptest428_1", "SMPTE ST 428-1",   0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_TRC_SMPTEST428_1 }, INT_MIN, INT_MAX, V|E|D, "color_trc_type"},
+{"arib-std-b67", "ARIB STD-B67",     0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_TRC_ARIB_STD_B67 }, INT_MIN, INT_MAX, V|E|D, "color_trc_type"},
 {"colorspace", "color space", OFFSET(colorspace), AV_OPT_TYPE_INT, {.i64 = AVCOL_SPC_UNSPECIFIED }, 0, AVCOL_SPC_NB-1, V|E|D, "colorspace_type"},
 {"rgb",         "RGB",         0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_SPC_RGB },         INT_MIN, INT_MAX, V|E|D, "colorspace_type"},
 {"bt709",       "BT.709",      0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_SPC_BT709 },       INT_MIN, INT_MAX, V|E|D, "colorspace_type"},

libavcodec/version.h

@@ -29,7 +29,7 @@
 
 #define LIBAVCODEC_VERSION_MAJOR 57
 #define LIBAVCODEC_VERSION_MINOR 22
-#define LIBAVCODEC_VERSION_MICRO  0
+#define LIBAVCODEC_VERSION_MICRO  1
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \

libavutil/pixdesc.c

@@ -1634,6 +1634,7 @@ static const char *color_transfer_names[] = {
     [AVCOL_TRC_BT2020_12] = "bt2020-20",
     [AVCOL_TRC_SMPTEST2084] = "smptest2084",
     [AVCOL_TRC_SMPTEST428_1] = "smptest428-1",
+    [AVCOL_TRC_ARIB_STD_B67] = "arib-std-b67",
 };
 
 static const char *color_space_names[] = {

libavutil/pixfmt.h

@@ -324,6 +324,7 @@ enum AVColorTransferCharacteristic {
     AVCOL_TRC_BT2020_12    = 15, ///< ITU-R BT2020 for 12-bit system
     AVCOL_TRC_SMPTEST2084  = 16, ///< SMPTE ST 2084 for 10-, 12-, 14- and 16-bit systems
     AVCOL_TRC_SMPTEST428_1 = 17, ///< SMPTE ST 428-1
+    AVCOL_TRC_ARIB_STD_B67 = 18, ///< ARIB STD-B67, known as "Hybrid log-gamma"
     AVCOL_TRC_NB,                ///< Not part of ABI
 };
 

libavutil/version.h

@@ -54,7 +54,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR 55
-#define LIBAVUTIL_VERSION_MINOR 13
+#define LIBAVUTIL_VERSION_MINOR 14
 #define LIBAVUTIL_VERSION_MICRO  0
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \