Render parameters

I try Blender as video editor. My footages is 1920x1080 50fps. I have question about render parameters for my videos.
In Windows I use Magix video editor and when export footages to MP4 I not worry about export parameters except container format, the program select it automaticaly. Final video bitrate is aboute 30000-35000 kb/s different from video to video. What parameters I must select in Blender to get Hi quality video? I set H.264 + AAC and set lossless output, but my video have only sound and black screen.
Thank you!

What was the source format
What exact output settings
Have you tried using the presets
Did you select an audio codec ?

Please make a demo file with a very small video clip and supply download link for review

The source format is MTS 1920x1080 50fps.
Output is 1920x1080 50fps. See settings on image.

With low bitrate output video more pixelate.
I dont understand how I can calculate bitrate for my video?

P.S. I cant upload sample video now.

I have only basic experience on Blender video encoding, but it is good to know that it uses ffmpeg.

Before studying more (you can google alot of things about ffmpeg), I would try at least to increase the Rate:minimun, because at default ffmped is known to be very aggressive to make the file size very small. So the 0 minimum gives ffmpeg all the rights to make pixelate video.

Thank you!