[FFmpeg-user] formula for transcoding to ogv, shrinking an mkv

[James Miller]

On Fri, 18 Jan 2013, Tom Evans wrote:

> If all your videos are roughly of similar lengths and content, you
> should be able to choose a CRF that produces good results, and  always
> under the size limit, where as by calculating and using a target
> bitrate, the file size will always be your maximum/target file size,
> and quality will vary depending upon length of the video.

Thank you for your further helpful input, Tom. My screencasts do vary in 
terms of length, though the content is pretty similar. They could be as 
short as 30 minutes or as long as 75 minutes. I've determined that a good 
size to aim for in the final, transcoded file, is about 1.5 MB per minute. 
I think I will continue trying to achieve that, though your suggestion 
about specifying a final output file size is also an interesting 
consideration.

James