Scroll down. If you have an NVIDIA GPU, change the encoder from "x264" to "H.264 (NVEnc)." This will triple your speed but slightly increase file size for the same visual quality.
When selecting an MPEG-4 AVC converter, consider the following key features: mpeg-4 avc converter
On the right-hand "Summary" tab, ensure the format is set to "MP4 File." Scroll down