Your output file is rarely the same size as your original video. There are many variables involved. I don't know how long your original video is or what device recorded it, but it could be using any number of compression systems.
770 mb is not terribly large for a movie. A HD MP4 at 25 fps is perfect for loading to YouTube. YouTube will re-encode it to make it a more efficient streaming file, as it does anything you upload to it.
I ran media info and got this below. But window size is too small and quality of render is very poor
My selections on the render were: Any suggestions greatly appreciated, thanks
General Complete name : C:\Users\Andrew\Documents\Movie Studio 16.0 Platinum Projects\sat2-video1.mp4 Format : MPEG-4 Format profile : Base Media / Version 2 Codec ID : mp42 (isom/mp42) File size : 24.4 MiB Duration : 8 min 52 s Overall bit rate mode : Variable Overall bit rate : 384 kb/s Encoded date : UTC 2019-07-13 16:50:30 Tagged date : UTC 2019-07-13 16:50:30
Video ID : 2 Format : AVC Format/Info : Advanced Video Codec Format profile : Main@L3.2 Format settings : CABAC / 3 Ref Frames Format settings, CABAC : Yes Format settings, Reference frames : 3 frames Format settings, GOP : M=4, N=15 Codec ID : avc1 Codec ID/Info : Advanced Video Coding Duration : 8 min 52 s Bit rate mode : Constant Bit rate : 192 kb/s Width : 1 280 pixels Height : 720 pixels Display aspect ratio : 16:9 Frame rate mode : Constant Frame rate : 25.000 FPS Standard : PAL Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.008 Stream size : 12.1 MiB (50%) Language : English Encoded date : UTC 2019-07-13 16:50:31 Tagged date : UTC 2019-07-13 16:50:31 Color range : Limited Codec configuration box : avcC
Audio ID : 1 Format : AAC LC Format/Info : Advanced Audio Codec Low Complexity Codec ID : mp4a-40-2 Duration : 8 min 52 s Bit rate mode : Variable Bit rate : 192 kb/s Maximum bit rate : 342 kb/s Channel(s) : 2 channels Channel layout : L R Sampling rate : 48.0 kHz Frame rate : 46.875 FPS (1024 SPF) Compression mode : Lossy Stream size : 12.0 MiB (49%) Language : English Encoded date : UTC 2019-07-13 16:50:31 Tagged date : UTC 2019-07-13 16:50:31
Like @Musicvid said your projectfile has a very low bitrate and that means no quality for that kind of file with 1280x720 pixels For seeing your preview in total your projectsettings have to be as follows For rendering you should choose the following screen with the customized template to get the same quality and possible filesize in VMS 16, but maybe better is for this case of a bad sourcefile is to choose half bitrate of that default ( not customized) template: