Netflix Keeping Bandwidth Usage Low By Encoding Its Video With VP9 and H.264/AVC Codecs (slashgear.com)

Netflix announced last week that it is getting offline video downloads support. The company has since shared that it is using VP9 video compression codec to ensure that the file sizes don't weigh a lot. An anonymous reader shares an article on Slashgear (edited): For streaming content, Netflix largely relies on H.264/AVC to reduce the bandwidth, but for downloading content, it uses VP9 encoding. VP9 can allow better quality videos for the same amount of data needed to download. The challenge is that VP9 isn't supported by all streaming providers -- it is supported on Android devices and via the Chrome browser. So to get around that lack of support on iOS, Netflix is offering downloads in H.264/AVC High whereas streams are encoded in H.264/AVC Main on such devices. Netflix chooses the optimal encoding format for each title on its service after finding, for instance, that animated films are easier to encode than live-action. Netflix says that H.264 High encoding saves 19% bandwidth compared to other encoding standards while VP9 saves 36%.

Comments

Also nothing supports it

[Sycraft-fu]

I mean the newest devices support it in hardware, but it has to be a very new chip to have H.265 support. The vast majority of devices in use don't. For computers you could do it in software but that isn't ideal, since H.265 decoding is rather heavy so you'd hit the CPU pretty hard, whereas hardware accelerated H.264 would hit it almost not at all. For mobile/embedded devices though it just won't work. Too CPU intensive to do in software, so people need a new device.

Re:what about h.265?

[nadaou]

> I hear it does great things

Only because it has a well funded marketing campaign and VP9 doesn't. At this point VP9 is ahead but perhaps only because they had a bit of a head start as H.265 was delayed due to the member companies squabbling over who's patent protected tech got premier submarine status.

We'll have to wait for H.265 to be properly tuned before we can make a real comparison between it and VP9. VP9 has already won on the licensing front. H.265 might be faster at the initial encode but as mentioned it isn't entirely finished yet and new features could easily make the final product bloatier.

You do not want to use either of these codecs without dedicated hardware support. They aren't too different from H.264 and VP8, the primary change is trading disk space now for CPU cycles later. Think gzip vs. bzip2 - each has their place but different compromises are made.

What compression efficiency means

[TheSync]

Codecs (such as H.264 or VP9) describe a bit stream, and how to decode the bit stream. They basically provide a kit of tools that can be be used by encoders.

The quality of video encoding is mainly due to the technical knowledge and artistry of the encoder manufacturer and how the use that took kit. I can show you great H.264 encoders and horrible H.264 encoders, but they both emit valid H.264 bit streams.

In particular, the biggest challenge is rate control. If you don't care about the details of a variable bit rate, almost anyone can write a great H.264 or VP9 encoder, with the bit rate jumping up and down all over the place. However if you expect a bit rate to be held within say +/- 100 kbps, only a few vendors have the expertise to make a more constant bit rate look good.

I'll also add that I've seen no good data that shows that VP9 encoders perform better over a wide range of content than H.264.

Re:what about h.265?

[Anonymous Coward]

H.265 would have easily dominated the market already

But it hasn't and it won't. H.265 has no future in web video. AV1 from the Alliance for Open Media is the future of web video. Netflix will use VP9 for now and transition to AV1 when it's ready.