These tests were run with an sinput file (input.bvr) file size of 6703K (6.7M) and with ffmpeg using the x264 codec (included). 

The factors that influence the output file size the most are the codec, the output size (scaled or unscaled), and the CRF (Constant Rate Factor) parameter. In general, a higher CRF produces a smaller file. Note that a lower CRF *may* produce a larger file under some circumstances. For x264, sane values are between 18 and 28. 

CRF can be used in a constrained/capped mode to prevent bitrate spikes.

0 <---- 18 <---- 23 ----> 28 ----> 51
(Lossless, better, worse, worst)

More information on CRF can be found here: https://slhck.info/video/2017/02/24/crf-guide.html


Standard compression with CRF of 30 
ffmpeg -i input.bvr -vcodec libx264 -crf 30  output.mp4
Converted size: 4626K 

Standard compression with CRF of 25  
ffmpeg -i input.bvr -vcodec libx264 -crf 25 output.mp4
Converted size: 8037K  

Compress and reduce size to 1/2, CRF of 30
ffmpeg -i input.bvr -vcodec libx264 -crf 30 -vf "scale=iw/2:ih/2" output.mp4
Converted size: 854K  

Compress and reduce size to 1/2, CRF of 25
ffmpeg -i input.bvr -vcodec libx264 -crf 20 -vf "scale=iw/2:ih/2" output.mp4
Converted size: 3524K  

ffmpeg -n -loglevel error -i input.bvr -vcodec libx264 -crf 28 -preset faster -tune film output.mp4
Converted size: 5379K  

ffmpeg -n -loglevel error -i input.bvr -vcodec libx264 -crf 28 -preset faster -tune film -vf "scale=iw/2:ih/2" output.mp4
Converted size: 979K  



