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Comment by clouddrover | Hacker News Reader

I don't think time efficiency is the primary concern for the big encoders like Netflix and YouTube. They're more interested in lowering the bitrate while maintaining image quality and are willing to throw compute resources at slower encoders which achieve that. Netflix, for example, does multiple encodes per scene in multiple formats to get the best possible quality for each format for each scene.

VP9 outperforms H.264 (libvpx versus x264) for Netflix's use case. Here are some articles from the Netflix TechBlog on their experiences with VP9 and their encoding approach in general:

https://medium.com/netflix-techblog/optimized-shot-based-enc...

https://medium.com/netflix-techblog/more-efficient-mobile-en...

https://medium.com/netflix-techblog/netflix-downloads-on-and...

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You're right, time efficiency certainly isn't as big of a concern for companies with effectively infinite resources to throw at encoding, but the rest of us probably want to finish our encodes within this decade :) (the reference AV1 encoder is extremely slow)

It is a concern even for Netflix. The number only starts to make sense assuming a 30% bitrate reduction and 5x speed encoding time. This means the current encoder needs to speed up anywhere from 50x to 500x to get to that point.

Imagine if Netflix spends 1M on encoding, even 5x is 4M more, and the current encoder is anywhere from 250M to 2.5B more. This is not a small sum of money.

I think before they talk about speed up, they just need to iron out all the bugs and bitstream freeze before we speak.

Netflix have said they'll roll it out once it's below 5x slower.

But they can start with only the most popular videos to get the most bang per buck, they'll also likely target geographic areas with low bandwidth but decent spec desktops, which means they're getting a return on investment by increasing reach, not just saving bandwidth.

So basically, there's plenty of niches where it makes sense almost as soon as the spec is frozen and they can expand the roll out as it proves itself and speeds up.

Time efficiency is still important for live streaming. Last time I checked (OK that was one year ago) x265 was way too slow for live, even at not so high resolution.

Bitmovin produced an AV1 live stream a year ago using 200 cores: https://bitmovin.com/bitmovin-supports-av1-encoding-vod-live...

And six months ago they had improved on that to do live streaming with 32 cores: https://bitmovin.com/constantly-evolving-video-landscape-dis...

So I'll be interested to read about any live streaming demos they do at NAB in the next couple of weeks.

It's impressive that AV1 allows so much parallelism. That's great news.

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