How to compress video with minimal quality loss?

Question

Video

There are many terabytes of video from DVRs (cheap). As far as I understand, not a very fast processor is installed in the regs and it does not effectively compress the video. To save space, I want to compress the video (a slight loss of quality is allowed), but I have no experience with video and I'm not really aware of the effectiveness of various codecs and other details. I ask knowledgeable people to suggest which codec and with what settings to convert the video in order to reduce its size and not lose much in quality (which is not very special)))). And it will also be great if you share information about the software with which this can be done in batches.
Here is the mediainfo information from the file, this is what we have now:
General
Format: AVI
Format/Info : Audio Video Interleave
File size : 36.6 MB
Duration : 14 sec. 633 ms.
Total Stream : 21.0 Mbps

Video
ID : 0
Format : JPEG
Codec ID : MJPG
Duration : 14 sec. 633 ms.
Bitrate : 20.4Mbps
Width : 1280px
Height : 720px
Aspect Ratio : 16:9
Frame Rate : 30,000fps
Color Space : YUV
Saturation Subsampling : 4:2:0
Bit Depth : 8bit Compression
Method
: Lossy Bit/(Pixels*Frames) : 0.736 Stream
Size : 35.5MB (97%)

Audio
Identifier : 1
Format : PCM Format
Endianness Parameter : Little
Format Sign Parameter : Signed
Codec ID : 1
Duration : 14 sec. 0 ms.
Bitrate Type : Constant
Bitrate : 512Kbps
Channels : 1ch
Frequency : 32.0KHz
Bit Depth : 16 bits
Stream Size : 875KB (2%)
Equalization : Splicing Splicing Gap
Length : 1045ms. (31.36 video frames)

Answer 1

Download https://ffmpeg.org/
You may need to separately download www.videolan.org/developers/x264.html
Simple compression:
Compression with x264 codec and profile selection, -crf 0 means to compress video with minimal loss:
Fast, but compress badly
Slow but good squeeze

ffmpeg -i input -c:v libx264 -preset veryslow -crf 0 output.mkv