libx265: Enable 12-bit encoding

The configure detection is bumped to X265_BUILD >= 68,
since API version 68 corresponds with the x265 1.8
release tarball. The warnings inside x265 about
12-bit being experimental were removed prior to API
version 72 a short time later.  At this time of
writing, X265_BUILD is at version 80.

12-bit support in the HEVC standard was approved in
October 2014 as part of HEVC Version 2 and published
in January 2015:

http://www.itu.int/ITU-T/recommendations/rec.aspx?rec=12296
http://www.itu.int/rec/T-REC-H.265-201410-S
https://hevc.hhi.fraunhofer.de/rext

Reveiwed-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

configure

@@ -5556,8 +5556,8 @@ enabled libx264           && { use_pkg_config x264 "stdint.h x264.h" x264_encode
                              { check_cpp_condition x264.h "X264_MPEG2" &&
                                enable libx262; }
 enabled libx265           && require_pkg_config x265 x265.h x265_api_get &&
-                             { check_cpp_condition x265.h "X265_BUILD >= 57" ||
-                               die "ERROR: libx265 version must be >= 57."; }
+                             { check_cpp_condition x265.h "X265_BUILD >= 68" ||
+                               die "ERROR: libx265 version must be >= 68."; }
 enabled libxavs           && require libxavs xavs.h xavs_encoder_encode -lxavs
 enabled libxvid           && require libxvid xvid.h xvid_global -lxvidcore
 enabled libzimg           && require_pkg_config zimg zimg.h zimg_get_api_version

libavcodec/libx265.c

@@ -146,14 +146,17 @@ static av_cold int libx265_encode_init(AVCodecContext *avctx)
     switch (avctx->pix_fmt) {
     case AV_PIX_FMT_YUV420P:
     case AV_PIX_FMT_YUV420P10:
+    case AV_PIX_FMT_YUV420P12:
         ctx->params->internalCsp = X265_CSP_I420;
         break;
     case AV_PIX_FMT_YUV422P:
     case AV_PIX_FMT_YUV422P10:
+    case AV_PIX_FMT_YUV422P12:
         ctx->params->internalCsp = X265_CSP_I422;
         break;
     case AV_PIX_FMT_YUV444P:
     case AV_PIX_FMT_YUV444P10:
+    case AV_PIX_FMT_YUV444P12:
         ctx->params->internalCsp = X265_CSP_I444;
         break;
     }
@@ -318,6 +321,16 @@ static const enum AVPixelFormat x265_csp_eight[] = {
     AV_PIX_FMT_NONE
 };
 
+static const enum AVPixelFormat x265_csp_ten[] = {
+    AV_PIX_FMT_YUV420P,
+    AV_PIX_FMT_YUV422P,
+    AV_PIX_FMT_YUV444P,
+    AV_PIX_FMT_YUV420P10,
+    AV_PIX_FMT_YUV422P10,
+    AV_PIX_FMT_YUV444P10,
+    AV_PIX_FMT_NONE
+};
+
 static const enum AVPixelFormat x265_csp_twelve[] = {
     AV_PIX_FMT_YUV420P,
     AV_PIX_FMT_YUV422P,
@@ -325,13 +338,18 @@ static const enum AVPixelFormat x265_csp_twelve[] = {
     AV_PIX_FMT_YUV420P10,
     AV_PIX_FMT_YUV422P10,
     AV_PIX_FMT_YUV444P10,
+    AV_PIX_FMT_YUV420P12,
+    AV_PIX_FMT_YUV422P12,
+    AV_PIX_FMT_YUV444P12,
     AV_PIX_FMT_NONE
 };
 
 static av_cold void libx265_encode_init_csp(AVCodec *codec)
 {
-    if (x265_api_get(10))
+    if (x265_api_get(12))
         codec->pix_fmts = x265_csp_twelve;
+    else if (x265_api_get(10))
+        codec->pix_fmts = x265_csp_ten;
     else if (x265_api_get(8))
         codec->pix_fmts = x265_csp_eight;
 }