Implement AV1 support

src/nvenc/nvenc_config.h

@@ -35,6 +35,9 @@ namespace nvenc {
     // Min QP value for HEVC when enable_min_qp is selected
     unsigned min_qp_hevc = 23;
 
+    // Min QP value for AV1 when enable_min_qp is selected
+    unsigned min_qp_av1 = 23;
+
     // Use CAVLC entropy coding in H.264 instead of CABAC, not relevant and here for historical reasons
     bool h264_cavlc = false;