The WTV file format is recorded at a very high bitrate, which provides excellent video quality. To get a good conversion, I suggest using the Mpeg4 output with the h.264 compressor (codec). Also, keep the aspect ratio and dimensions of the video the same as the source to avoid distortion. You will need to experiment a little with the bitrate to balance the file size with the quality of output you are looking for. Try starting at 3000kbps and adjust downwards to see if the output quality is acceptable. See this page for a visual guide to the settings: https://www.deskshare.com/help/dmcpro/MP4Settings.aspx