There are dozens of codecs out there, and each has their strengths and weaknesses. In this guide, you’ve learned about bit depth, bit rate, chroma subsampling, long-GOP compression, and all of the other important factors when choosing codecs.
But we’re artists. We care about how our images look, and it’s impossible to capture the look of an image with a few statistics.
That’s why we built this codec comparison project – so that you can compare codecs visually.
First, we filmed several different shots with extremely high-resolution RED cameras (at 8K or 6K), and then we downsampled those to 4K uncompressed DPX files, to ensure that we were starting with perfect pixel quality.
Then, we transcoded each of those clips to 46 different codec variations and uploaded them to the project.
Then, one by one, we overlaid the compressed files on top of the original uncompressed DPX files and used the Difference blend mode. The resulting images highlight any areas where the codec is losing information. In areas where the image is black, the codec has done a great job. In areas where the image is light, the codec has lost information. In order to make the differences easier to see, we increased the brightness slightly.
We uploaded all 552 resulting video clips to the Codec Comparison Project, and we used Frame.io’s Version Stack feature to combine all of the different codecs for each clip into a single asset.
With the clips in a version stack, you can use the side-by-side comparison view to look at two different codecs side by side, including their Difference videos.
We’ve uploaded all of the media so that you can download them and replicate our tests, or do your own. We uploaded the original RED R3D files as well.
We used Adobe Media Encoder to produce the rendered files (we used a plugin in order to add VP8 and VP9 exporting capabilities), and we used After Effects to produce the Difference clips, with the Curves effect to increase brightness/contrast.
It’s impossible to view a ProRes file or a DNxHR file right in the browser (you’re viewing an H.264 version in the browser), so if you want to examine them in their native format, you can download the original files untouched from the Frame.io project.