lavc video: do not set interlaced DCT for libx265

Interlacing is not honored by libx265, anyways, and this saves the
eventual HWacc warning.

It is still passed to QSV even for HEVC, anyways. Not sure how the API
handles that but FFmpeg seems to pass it.

src/video_compress/libavcodec.cpp

@@ -1648,7 +1648,9 @@ configure_x264_x265(AVCodecContext *codec_ctx, struct setparam_param *param)
         //codec_ctx->rc_qsquish = 0;
         //codec_ctx->scenechange_threshold = 100;
 
-        if (param->desc.interlacing == INTERLACED_MERGED && param->interlaced_dct != 0) {
+        if (param->desc.interlacing == INTERLACED_MERGED &&
+            param->interlaced_dct != 0 &&
+            codec_ctx->codec_id == AV_CODEC_ID_H264) {
                 incomp_feature_warn(INCOMP_INTERLACED_DCT, param->interlaced_dct);
                 codec_ctx->flags |= AV_CODEC_FLAG_INTERLACED_DCT;
         }