avcodec/nvenc: add multiple reference frames support

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

libavcodec/nvenc.c

@@ -403,6 +403,19 @@ static int nvenc_check_capabilities(AVCodecContext *avctx)
     }
 #endif
 
+#ifdef NVENC_HAVE_MULTIPLE_REF_FRAMES
+    ret = nvenc_check_cap(avctx, NV_ENC_CAPS_SUPPORT_MULTIPLE_REF_FRAMES);
+    if(avctx->refs != NV_ENC_NUM_REF_FRAMES_AUTOSELECT && ret <= 0) {
+        av_log(avctx, AV_LOG_VERBOSE, "Multiple reference frames are not supported\n");
+        return AVERROR(ENOSYS);
+    }
+#else
+    if(avctx->refs != 0) {
+        av_log(avctx, AV_LOG_VERBOSE, "Multiple reference frames need SDK 9.1 at build time\n");
+        return AVERROR(ENOSYS);
+    }
+#endif
+
     ctx->support_dyn_bitrate = nvenc_check_cap(avctx, NV_ENC_CAPS_SUPPORT_DYN_BITRATE_CHANGE);
 
     return 0;
@@ -1010,6 +1023,11 @@ static av_cold int nvenc_setup_h264_config(AVCodecContext *avctx)
     h264->useBFramesAsRef = ctx->b_ref_mode;
 #endif
 
+#ifdef NVENC_HAVE_MULTIPLE_REF_FRAMES
+    h264->numRefL0 = avctx->refs;
+    h264->numRefL1 = avctx->refs;
+#endif
+
     return 0;
 }
 
@@ -1094,6 +1112,11 @@ static av_cold int nvenc_setup_hevc_config(AVCodecContext *avctx)
     hevc->useBFramesAsRef = ctx->b_ref_mode;
 #endif
 
+#ifdef NVENC_HAVE_MULTIPLE_REF_FRAMES
+    hevc->numRefL0 = avctx->refs;
+    hevc->numRefL1 = avctx->refs;
+#endif
+
     return 0;
 }
 

libavcodec/nvenc.h

@@ -54,6 +54,11 @@ typedef void ID3D11Device;
 #define NVENC_HAVE_HEVC_BFRAME_REF_MODE
 #endif
 
+// SDK 9.1 compile time feature checks
+#if NVENCAPI_CHECK_VERSION(9, 1)
+#define NVENC_HAVE_MULTIPLE_REF_FRAMES
+#endif
+
 typedef struct NvencSurface
 {
     NV_ENC_INPUT_PTR input_surface;

libavcodec/version.h

@@ -29,7 +29,7 @@
 
 #define LIBAVCODEC_VERSION_MAJOR  58
 #define LIBAVCODEC_VERSION_MINOR  59
-#define LIBAVCODEC_VERSION_MICRO 100
+#define LIBAVCODEC_VERSION_MICRO 101
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \