Slashdot Mirror

← Back to Stories (view on slashdot.org)

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

Posted by msmash on from the magic-sauce dept.

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%.

15 of 76 comments (clear)

  1. what about h.265? by anthony_greer · · Score: 3, Informative

    I hear it does great things for 4k, so it seems that it would be really great for HD, and even older 720 or 480 content too.

    1. Re:what about h.265? by Dwedit · · Score: 4, Informative

      Nobody wants to pay the licensing fees for it, so it's dead in the water.

    2. Re:what about h.265? by Anonymous Coward · · Score: 3, Informative

      The H.265 licensing is expensive (both in terms of each download, in terms of there not being per-organization caps, like with H.264) and complex (there are two patent pools you need to negotiate with separately).

    3. Re:what about h.265? by Tx · · Score: 4, Informative

      Most modern mid-to-high end phones and tablets have hardware h.265 already. See the SnapDragon video specs.

      --
      Oh no... it's the future.
    4. Re:what about h.265? by nadaou · · Score: 3, Interesting

      > 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.

      --
      ~.~
      I'm a peripheral visionary.
    5. Re:what about h.265? by pavon · · Score: 5, Informative

      It's not just about money, either. The licensing situation for H.265 a cluster-fuck, with patent holders having split into 2 licensing pools and several other patent holders that aren't participating in either pool. So even if companies were content with paying the licensing fees (which are significantly higher than H.264), they don't have any easy way of doing so that will cover all the patent holders. Most big players would prefer to pay and use H.265, but the patent holders have gotten too greedy and too splintered.

      Most of the major players have gotten fed up with this shit, and committed to pool their patents and expertise create a royalty free format AV1, in place of H.265. Alliance for Open Media includes: Microsoft, Google, Mozilla, Netfix, Amazon, BBC, ARM, Intel, AMD, nVidia, Broadcom, Cisco, Polycom, and more. The only companies that haven't signed on yet and are big enough to prevent wide adoption are Apple and Qualcomm, and Qualcomm has previously supported VP9, so I don't know why they wouldn't support AV1 once it is ready.

    6. Re:what about h.265? by Kjella · · Score: 2

      I hear it does great things for 4k, so it seems that it would be really great for HD, and even older 720 or 480 content too.

      The main reason it does great on 4k/UHD is that the fixed 16x16 macroblocks in H.264 are too small, HEVC brings flexible coding tree units (CTUs) that vary from 64x64 to 16x16 which obviously has the most effect for the highest resolutions. If you restrict it to 16x16 CTUs you get a ~37% penalty on 2160p, ~19% on 1080p and ~9% penalty on 480p. So not as big a deal for older content as you might think.

      --
      Live today, because you never know what tomorrow brings
    7. Re: what about h.265? by KingMotley · · Score: 2

      For Nvidia (Support for 10-bit and up to 8k video):
      https://developer.nvidia.com/n...

      For Intel:
      https://software.intel.com/en-...

      "4th Generation Intel Core processors (Haswell CPU 2- 3.5GHz, 4 Cores): Includes an HEVC Software Decoder capable of real time decode of HEVC 4K streams.
      5th Generation Intel Core processors (Broadwell): Supports HEVC 8-bit software/hybrid encode.
      6th Generation Intel Core processors (Skylake) Supports hardware accelerated HEVC 8-bit decode and encode."

    8. Re:what about h.265? by Anonymous Coward · · Score: 2, Insightful

      Bullshit. H.265 is a superior encoding method, what it has though is a clusterfuck for licensing, if it wasn't for licensing bullshit they created then H.265 would have easily dominated the market already.

    9. Re:what about h.265? by Anonymous Coward · · Score: 4, Interesting

      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.

  2. Banding by edxwelch · · Score: 2

    Bad luck if you're watching a film that has a sand storm or fog in it. The banding artifacts caused by compression make those scenes nearly unwatchable

  3. Also nothing supports it by Sycraft-fu · · Score: 4, Interesting

    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.

  4. Welcome to 2008! by BenJeremy · · Score: 2

    h.265 is where it's at, excerpt a lot of devices don't support it yet.

    Still, at a quarter the bandwidth for the same quality, it should be the target, if supported.

    As for savings using h.264... what the hell were they using as a codec before?

  5. What compression efficiency means by TheSync · · Score: 5, Interesting

    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.

    1. Re:What compression efficiency means by Anonymous Coward · · Score: 2, Informative

      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.

      Don't worry. Netflix has and YouTube has