avcodec/nvenc: make number of slices per frame configurable

Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
Signed-off-by: Timo Rothenpieler <timo@rothenpieler.org>

libavcodec/nvenc.c

@@ -1074,7 +1074,7 @@ static av_cold int nvenc_setup_h264_config(AVCodecContext *avctx)
         || vui->videoFullRangeFlag != 0);
 
     h264->sliceMode = 3;
-    h264->sliceModeData = 1;
+    h264->sliceModeData = avctx->slices > 0 ? avctx->slices : 1;
 
     h264->disableSPSPPS = (avctx->flags & AV_CODEC_FLAG_GLOBAL_HEADER) ? 1 : 0;
     h264->repeatSPSPPS  = (avctx->flags & AV_CODEC_FLAG_GLOBAL_HEADER) ? 0 : 1;
@@ -1171,7 +1171,7 @@ static av_cold int nvenc_setup_hevc_config(AVCodecContext *avctx)
         || vui->videoFullRangeFlag != 0);
 
     hevc->sliceMode = 3;
-    hevc->sliceModeData = 1;
+    hevc->sliceModeData = avctx->slices > 0 ? avctx->slices : 1;
 
     hevc->disableSPSPPS = (avctx->flags & AV_CODEC_FLAG_GLOBAL_HEADER) ? 1 : 0;
     hevc->repeatSPSPPS  = (avctx->flags & AV_CODEC_FLAG_GLOBAL_HEADER) ? 0 : 1;