Don't save frames into a single file if decoder reconfigure is detected for resolution changes - save into separate files for each resolution (#123)

utils/rocvideodecode/roc_video_dec.h

@@ -403,4 +403,6 @@ class RocVideoDecoder {
         FILE *fp_out_ = NULL;
         struct AVMD5 *md5_ctx_;
         uint8_t md5_digest_[16];
+        bool is_decoder_reconfigured_ = false;
+        std::string current_output_filename = "";
 };