HARDWARE ACCELERATED ENCODING
IF YOU’RE LOOKING FOR ABSOLUTE maximum quality for archiving videos that you might want to look back on decades in the future, nothing beats higher bitrates. Storage is relatively cheap these days, with hard drives now starting at around 1.5 cents per GB. What does that mean in practical terms? You can store excellent quality videos for less than 15 cents per hour of content. Depending on your codec of choice, you could even cut the cost requirements in half without sacrificing much in the way of quality.
There’s also the tradeoff of encoding time versus quality, so if you want to minimize file size and are willing to spend more processing time, you can do that. There are limits to how far this can take you, however. Even with the best current video codecs, if you try to squeeze 4K content into 2Mbp, you won’t get a great result, you’d be better off targeting a lower resolution with the same bitrate. There’s still the matter of how to best use that bitrate, and that’s where software encoders can excel, doing two passes with the first focused on figuring out which areas of each frame benefit most from more bitrate, and which areas need less.
The problem with software encoding is that it can be slow, especially on older processors. The Ryzen 9 7950X and Core i913900K can generally handle 4K encoding in real-time at more than 60fps, but they use a lot of their number-crunching power on the task. Playing a demanding game while dedicating half of your CPU cores to video encoding can result in stutters and other undesirable behavior. There’s also the matter of H.264 encoding being quite complex back when it was first introduced.
The solution is hardware-accelerated video encoding, which has been around since 2011. Nvidia Kepler GPUs added NVENC (Nvidia Encoder) for H.264 with the GTX 600-series in 2012. AMD
added video encoding support with its HD 7000 line of cards, via its VCE (Video Code Engine). Intel’s integrated graphics solutions have also included video encoding support via QuickSync Video (QSV) with the first Sand Bridge (2nd Gen Core) processors.
The benefit of these video encoders is that they offload most of the complex work to dedicated hardware, leaving your CPU and most of your GPU free to do other work. The drawback is that they’re generally not as flexible as software encoders, but for real-time encoding, they can be a great solution. This brings us to the heart of the matter—how good are the AMD, Intel, and Nvidia encoders, with H.264, HEVC, and now AV1? We tested multiple generations of hardware, but the focus here will be on the latest solutions that have all added AV1 support.