avcodec/nvenc: add b_as_ref support for HEVC

Signed-off-by: Timo Rothenpieler <timo@rothenpieler.org>

libavcodec/nvenc.c

@@ -1070,6 +1070,10 @@ static av_cold int nvenc_setup_hevc_config(AVCodecContext *avctx)
 
     hevc->tier = ctx->tier;
 
+#ifdef NVENC_HAVE_HEVC_BFRAME_REF_MODE
+    hevc->useBFramesAsRef = ctx->b_ref_mode;
+#endif
+
     return 0;
 }
 

libavcodec/nvenc.h

@@ -49,6 +49,11 @@ typedef void ID3D11Device;
 #define NVENC_HAVE_QP_MAP_MODE
 #endif
 
+// SDK 9.0 compile time feature checks
+#if NVENCAPI_CHECK_VERSION(9, 0)
+#define NVENC_HAVE_HEVC_BFRAME_REF_MODE
+#endif
+
 typedef struct NvencSurface
 {
     NV_ENC_INPUT_PTR input_surface;

libavcodec/nvenc_hevc.c

@@ -116,6 +116,17 @@ static const AVOption options[] = {
                                                             OFFSET(cqp),          AV_OPT_TYPE_INT,   { .i64 = -1 }, -1, 51, VE },
     { "weighted_pred","Set 1 to enable weighted prediction",
                                                             OFFSET(weighted_pred),AV_OPT_TYPE_INT,   { .i64 = 0 }, 0, 1, VE },
+#ifdef NVENC_HAVE_HEVC_BFRAME_REF_MODE
+    { "b_ref_mode",   "Use B frames as references",         OFFSET(b_ref_mode),   AV_OPT_TYPE_INT,   { .i64 = NV_ENC_BFRAME_REF_MODE_DISABLED }, NV_ENC_BFRAME_REF_MODE_DISABLED, NV_ENC_BFRAME_REF_MODE_MIDDLE, VE, "b_ref_mode" },
+    { "disabled",     "B frames will not be used for reference", 0,               AV_OPT_TYPE_CONST, { .i64 = NV_ENC_BFRAME_REF_MODE_DISABLED }, 0, 0, VE, "b_ref_mode" },
+    { "each",         "Each B frame will be used for reference", 0,               AV_OPT_TYPE_CONST, { .i64 = NV_ENC_BFRAME_REF_MODE_EACH }, 0, 0, VE, "b_ref_mode" },
+    { "middle",       "Only (number of B frames)/2 will be used for reference", 0,AV_OPT_TYPE_CONST, { .i64 = NV_ENC_BFRAME_REF_MODE_MIDDLE }, 0, 0, VE, "b_ref_mode" },
+#else
+    { "b_ref_mode",   "(not supported)",                    OFFSET(b_ref_mode),   AV_OPT_TYPE_INT,   { .i64 = 0 }, 0, INT_MAX, VE, "b_ref_mode" },
+    { "disabled",     "",                                   0,                    AV_OPT_TYPE_CONST, { .i64 = 0 }, 0, 0,       VE, "b_ref_mode" },
+    { "each",         "",                                   0,                    AV_OPT_TYPE_CONST, { .i64 = 1 }, 0, 0,       VE, "b_ref_mode" },
+    { "middle",       "",                                   0,                    AV_OPT_TYPE_CONST, { .i64 = 2 }, 0, 0,       VE, "b_ref_mode" },
+#endif
     { NULL }
 };
 

libavcodec/version.h

@@ -29,7 +29,7 @@
 
 #define LIBAVCODEC_VERSION_MAJOR  58
 #define LIBAVCODEC_VERSION_MINOR  47
-#define LIBAVCODEC_VERSION_MICRO 100
+#define LIBAVCODEC_VERSION_MICRO 101
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \