Need help with FFmpeg video conversion tool

nIGHTmAYOR said:

I am trying to do a format conversion to some VR files I captured with my VR camera . While it took me days to finally figure that my options are very limited to a couple of expensive video editors or rather the free FFmpeg and more days to acquire the right command line syntax to do it I am still faced by this ambiguous result ....

See the original bite rate is 30 MB/s , however the result file becomes only 4 MB/s now this makes the result video of lower quality than supposed to and it shows , now I am not an expert with FFmpeg and so far I cant find an answer to this dilemma .

So for those who came across this before , what are the correct parameters to make the output video of same bite rate as the input one or even get to set it manually to 30 MB/s ?

What you want to achieve is to control the quality, not necessarily the bitrate. You can do this by specifying a Constant Rate Factor (CRF) value in the command line. You can also chose a preset for the speed of encoding, the slower it is, the better the resulting quality for any given CRF value.

The range of the CRF scale is 0–51, where 0 is lossless ... 23 is the default, and 51 is worst quality possible. A lower value generally leads to higher quality, and a subjectively sane range is 17–28. Consider 17 or 18 to be visually lossless or nearly so; it should look the same or nearly the same as the input but it isn't technically lossless.

The range is exponential, so increasing the CRF value +6 results in roughly half the bitrate / file size, while -6 leads to roughly twice the bitrate....

....A preset is a collection of options that will provide a certain encoding speed to compression ratio. A slower preset will provide better compression (compression is quality per filesize). This means that, for example, if you target a certain file size or constant bit rate, you will achieve better quality with a slower preset...

See here for a lot more details: Encode/H.264 – FFmpeg

If you don't specify anything the defaults are CRF 23 and Medium for the preset.
For high quality try: ffmpeg -i input.mp4 -crf 16 -preset veryslow output.mp4