I'm not sure if this will help but change the downscale filter to lanczos (I know you're not downscaling but just set it to that to see if it makes a difference) but more importantly don't use CBR for recording with H.264, it will produce fine quality (as the video you posted demonstrates, I feel like the quality looks pretty good) but using the CQP rate control with a value of anywhere between 12-17 makes for some really high quality recordings with (IMO) much better edge retention. Try using 17 to start and then decrease downwards until you find a point where you like it, however don't go below 12 unless you have massive hard drive reserves for your files to sit until you are done with them. Hope that helps! +)