AV1 — Why It Matters To Streaming Services
Netflix, Disney+, Amazon Prime and Hulu are just a few of the available streaming services that deliver entertainment to millions of homes around the world. Originally called VOD (Video-On-Demand) service, streaming delivers content OTT (Over-The-Top) via the Internet. This requires billions and billions of bytes of data sent each day to users who watch streaming video on their devices (e.g. smartphones, tablets, computers, smart TVs).
Streaming requires the use of CODECs, which compresses transmitted data across the network. The content is first compressed from the content delivery provider’s site and then transmitted or streamed to its destination. When it reaches a user’s device for playback, the content is then decompressed and viewed from a web browser or app. This process is what makes video streaming possible.
Without CODECs it would take much longer to transmit content, making streaming services unlikely to perform well. A typical movie on platforms like Netflix require Gigabytes of data which can clog networks when you have millions of users streaming at the same time. Compressing the data from the source and then caching copies of it on the edge of the network helps to speed streaming delivery.
AV1 (AOMedia Video 1) is a CODEC that helps to improve compression for streaming content. Currently, streaming providers use either H.264, HEVC, VP9 or a combination of those CODECs. A new format like AV1 can help to not only improve content delivery, but allow providers to encode higher quality streaming content. The higher quality content deliver faster frame rates, better details in color and contrast and supports true high resolution imaging (e.g. 4K and 8K format).
The AV1 CODEC
AV1 is a CODEC that is open source and royalty-free. It is a video standard that improves data compression, which increases efficiency without reducing the quality of the video. This allows providers to deliver higher frame rates in 4K and other high resolution formats. The AV1 format performs data processing at 10 or 12 bits per sample. This improves the compression due to smaller rounding errors in imaging.
AV1 partitions data into “Superblocks”, which are 128 x 128 or 64 x 64 pixels. These partitions are further partitioned into different patterns that can be 4×4 (recursive), horizontal split (4:1), vertical split (1:4), or T-shaped patterns. The partitions are then quantized and then coded into a bit stream. AV1 then uses different profiles and levels that support different video resolution formats.
Quality and bit rate are the metrics to look for when analyzing CODEC performance. The best algorithm produces a high compression rate that delivers the best quality. When bit rate is also reduced (lower bandwidth requirements), it means better performance when it comes to streaming content. According to Facebook research, when tested the AV1 CODEC had a 50.3% higher data compression than H.264 formats. Overall, based on other tests AV1 is 50%, 30% and 25% better than AVC (H.264), HEVC (H.265) and VP9.
When compressing data, you do lose some quality as part of a trade off. This is important to note because with AV1s higher compression ratios, it is still able to preserve the quality of the content when delivered to the device. It is not perfect since many content use a lossy compression technique, but AV1 also supports lossless compression. It depends on how the content was encoded for streaming.
AV1 is being touted as a successor to Google’s VP9 standard video coding format. AV1 is also based on VP9, but adds features that allow developers to adapt the coding to different types of input. The group behind AV1, the Alliance for Open Media or AOMedia, is a non-profit organization that aim to develop open interoperable technology solutions in the media industry. This has wide support from tech companies, which include the likes of Netflix, Google, Facebook, Amazon, Microsoft and Intel (to name a few).
The Takeaways of AV1
Despite the advantages of AV1, there are some reasons why it is not yet widely used by streaming providers in 2021. One of the key takeaway against wider AV1 adoption is that it takes much more time to encode AV1 when compared to H.264 or HEVC. It can take double or more time to export video content encoded in AV1. There is another main reason why it is not widely used yet.
AV1 CODECs will require hardware encoding for the best performance. There are only a few processors or chips in 2021 that have native support for hardware-based AV1 encoding. This gives the advantage to HEVC or H.264, which has wider support from existing hardware-based encoding that reduces processing times. While that means less AV1 content is available, it still has support from some of the latest mobile devices. This is due to AV1s integration with ARM-based SoC that have built-in support for the CODEC.
There is a software-based decoder called dav1d that is supported on x86 CPUs (e.g. Intel and AMD processors) for laptops and desktop computers. The decoder dav1d is cross-platform (operating systems) and is used by the VLC player. It supports all AV1 features and provides the highest speed possible in a software-based decoder. Users can view AV1 encoded video that does not have an AV1 hardware CODEC that has software-based CODECs like dav1d. It favors newer hardware (CPUs and displays) because the processing can be demanding for high resolution content.
Use Cases For AV1
Netflix has started using AV1 on a few of its titles. Some devices also support the CODEC, according to an article from The Verge. For streaming providers like Netflix, it is a way to keep costs down for mobile users. With the Netflix ‘Save Data’ feature on Android devices, users can use less bandwidth for AV1 streams where it is possible.
Here is a list of some devices that support AV1:
- Samsung Galaxy S21 series (Exynos 2100)
- Dimensity 1000
- Roku Ultra
- LG 8K TVs
- Samsung 8K TVs
- Nvidia RTX 30 series GPU
- Amazon FireTV
- Sony PlayStation 4 PRO (PS4 Pro)
The following are some streaming providers that support AV1:
- Netflix
- YouTube
- Twitch (expected in 2022/23)
- Vimeo
Here are a few video players that support AV1:
- VLC
- MPV
- PotPlayer
- Google Duo (for video calls)
It will not only be Netflix, but its competitors will begin encoding some of their titles into AV1. It seems inevitable due to the market trending toward mobile and ARM-based devices.
The demand for more speed from the Internet cannot always be satisfied, as streaming content become more bandwidth hungry. Even with fiber-optic backbones, edge devices, faster WiFi6 and 5G data transmission, quality content requires fatter pipes to transmit data. Compression algorithms like that used in AV1 can help deliver quality content with less bandwidth consumed.
More users are watching streaming content from their mobile devices (e.g. smartphones), so AV1 is ideal for delivery. This allows users to save costs on their data plan since they are streaming less data due to the efficiency of AV1 encoding. Mobile services that offer 5G provide more bandwidth as well, and adding AV1 encoding further helps with streaming content.
AV1 Content Samples
You can find sample AV1 encoded content on YouTube. There is a beta launch playlist of some videos in various resolutions, from 720p to 4K.
Checkout the Dua Lipa music video “New Rules”. I had it set to 1080p Full HD streaming on a MacBook Pro (late 2017), and noticed no jitter or delays. It streamed smoothly over a 16.1 Mbps connection.
For nature lovers check out “Blackmagic Pocket Cinema Camera 4K Nature”. I set the resolution all the way up to 4K UHD (2160p) and viewed from a Samsung 4K OLED TV.
Select Right-Click on a PC or two-finger “force click” on a Mac to bring up the ‘Stat For Nerds’ option to see the encoder used. I noticed that on a different machine I don’t get the AV1, but instead get a VP9 encoding of the same content. I will not elaborate on this, but it seems to be device dependent. YouTube will determine if your device can stream the AV1 encoded content.
Overall, the AV1 content had great quality at their highest resolution format. There were no delays or skipping of frames, and flowed smoothly like it was playing on a DVD player. The audio was excellent as well and maintained in synch with the frame rate.
Synopsis
AV1 provides lower bit rate requirements with efficient data compression to deliver content, allowing less bandwidth usage that can save on costs and battery power consumption for mobile users. It can also provide higher quality content streams for higher end displays like 4K and 8K TVs.
It is also royalty-free, meaning it does not require expensive licensing agreements to the inventor of the technology. Other competing technologies have patents that require a royalty payment. AV1 specifications are also open source, so many developers can integrate it with their products or services. This is because the inventors of AV1 are a non-profit organization that consist of industry leaders who want to promote more open technologies that can also benefit their business.
What is holding further AV1 adoption is the support from vendors and apps. More devices will need to incorporate AV1 support (in their chipsets on devices) in the next generation of gadgets while streaming providers will need to encode more of their content using the AV1 CODEC. It can also be implemented with apps that use a software based decoder , but its performance may not be the same as a hardware-based CODEC (it will depend on the hardware running the software).
The AV1 standard has only been around since 2015, so there is more room for growth. As more demand for quality streaming content increases, along with further usage from mobile devices, AV1 is the likely choice to deliver on those needs.
