Google announced today that YouTube users have already watched over 25 billion hours of VP9-encoded videos during the past 12 months. VP9 is Google's own open source video codec and alternative to HEVC. It's also the successor to VP8, the codec Google received by acquiring On2 Technologies (and later made open source).
The VP8 codec didn't manage to become particularly popular in part because it arrived late, and its main competitor, the AVC/h.264 codec, was already becoming entrenched on the video market. The VP8 also wasn't competitive enough performance-wise.
Likewise, the VP9 codec arrived slightly later than HEVC, but this time Google pushed it much more aggressively to its hardware partners and via its own products and services. Although Google promised to give up on h.264 and go all-in with VP9 in Chrome back in 2011, that never happened.
Now, Google is using VP9 as its main codec for YouTube videos. According to the company, a significant portion of those 25 billion hours of videos played in the last year couldn't have been watched in HD quality without the VP9 codec.
“This new format bumps everybody one notch closer to our goal of instant, high-quality, buffer-free videos. That means that if your Internet connection used to only play up to 480p without buffering on YouTube, it can now play silky smooth 720p with VP9," said Google in a blog post.
Mobile users, or those who live in countries where data plans are expensive, can also save money or bandwidth by watching VP9-encoded videos instead of h.264-encoded ones. At the same image quality level, VP9 videos usually have a bitrate of roughly half that of h.264 videos, which gives significant bandwidth savings.
VP9 was also designed from the beginning with high resolution video content in mind. At larger video sizes, the VP9 codec becomes even more efficient compared to h.264. Therefore, thanks to VP9, YouTube is serving uninterrupted 4K streaming to a growing audience as even lower-speed connections can now play 4K videos. In the past year, the number of 4K videos being uploaded to YouTube have tripled.
While Google and the MPEG-LA (HEVC's creator) are both currently pushing their own video codecs, Xiph, Mozilla, and the IETF are working on the next-generation NETVC (former Daala) codec. NETVC is supposed to go beyond the performance that the VP9 and HEVC codecs have today (roughly half the bandwidth of h.264), while at the same time not being patent-encumbered.