1080p60 Capture over USB2

I thought it would be quite interesting to see what kind of quality you could capture at data rates for USB 2. There are two main reasons I thought of this idea. Not everybody has the knowledge or confidence to install an internal hard drive. Additionally, some people may just have an external hard drive that only has a USB 2 connection.

The best codec for this has to be x264vfw. Not only does this give us the best compression ratio, it will also allow us to modify the CRF value in order to hit the data rates we need. USB 2 advertises 480 Mb/s but you will never get close to this. A more realistic target is 200 Mb/s. For the testing process, I was looking for a quantizer value that would never go above a peak bit rate of 200 Mb/s regardless of the scene. Like my lossless comparison, Super Street Fighter IV is the source material.

 After thorough testing, this is my configuration:

Click to enlarge

I settled on a CRF value of 16. I was able to set the CRF to 14 but I was getting ever so close to 200 Mb/s. You might be asking, why not just use 14 then? The problem is that the 1080p60 material I own is very limited. There might be material other people have where they do go over 200 Mb/s with the 14 value. Choosing a slightly higher value means that even if people do find a harder to compress scene, it is still likely going to be under 200 Mb/s. I should reinforce I am talking about peak bit rates here. It is very uncommon that you will even go near 160 Mb/s.

You may also see I have enabled extra command line use (--keyint 1). This is to improve frame seeking in Sony Vegas and similar editing programs. You can read about this here.

Happy 1080p60 capturing over USB 2!