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Netflix Finds x265 20% More Efficient Than VP9 (streamingmedia.com)

Reader StreamingEagle writes (edited): Netflix conducted a large-scale study comparing x264, x265 and libvpx (Google-owned VP9), under real-world conditions, and found that x265 encodes used 35.4% to 53.3% fewer bits than x264, and between 21.8% fewer bits than libvpx, when measured with Netflix's advanced VMAF assessment tool. This was the first large-scale study to use real-world encoder implementations, and a large sample size of high quality, professional content.A Netflix spokesperson explained why they did the test in the first place; "We wanted to understand the current state of the x265 and libvpx codec implementations when used to generate non-realtime encodes optimized for OTT use case. It was important to see how the codecs performed when testing on a diverse set of premium content from our catalog. This test can help us find areas of improvement for the different codecs."

6 of 178 comments (clear)

  1. Re:Mostly... by Black.Shuck · · Score: 5, Insightful

    x265 is not very important except for 4K content and mobile phones

    I think a 20% overall reduction in bandwidth for an in-demand and still-growing medium is *very* significant no matter what the resolution or device is.

  2. Re:Mostly... by geek · · Score: 5, Informative

    x265 is not very important except for 4K content and mobile phones

    I think a 20% overall reduction in bandwidth for an in-demand and still-growing medium is *very* significant no matter what the resolution or device is.

    The real number is 34-53%. The 20% is just over VP9. The 34-53% is over their current streaming codec.

  3. Re:Mostly... by Luthair · · Score: 5, Funny

    Clearly though, the image produced by mpeg2 is much superior to h265 much like records sound better than CDs.

  4. Re:Another Google Project Not Worth The Hype by TigerTime · · Score: 5, Informative

    You realize we're comparing a FREE option vs a PAID option. As a business trying to save money here/there, I'd rather go with the free one to be honest.

    Additionally, the title of this post is a bit misleading for what Netflix actually found. h.265 was better than VP9 in 4K content, but when it came down to 1080p and lower resolutions, VP9 did just as good or better than h.265. 1080p will STILL rule the streaming market for the foreseeable future, so VP9 is definitely relevant here.

    Quote from Netflix on their blog regarding this:

    Here’s a snapshot: x265 and libvpx demonstrate superior compression performance compared to x264, with bitrate savings reaching up to 50% especially at the higher resolutions. x265 outperforms libvpx for almost all resolutions and quality metrics, but the performance gap narrows (or even reverses) at 1080p.

    http://techblog.netflix.com/20...

  5. Re:Also significant is CPU burden by squiggleslash · · Score: 5, Informative

    Your slightly aged laptop probably has a built-in H.264 decoder, which will skew the results somewhat. Most graphic chipsets for the last eight years have included the functionality.

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  6. HTML5 - Video by DrYak · · Score: 5, Informative

    Speaking of which (HTML5 Video and Netflix):

    The IETF has a working group to produce a new gen video codec "NetVC" (Designed to be easy for wide adoptions, as the previous efforts of the IETF like Opus for audio).

    The main candidate is by a group called "AOMedia" (association for openmedia), working on AV1 (AOMedia's Video codec 1).

    The association includes:
    - Google (of Youtube fame) : They are using their current development as a base for AV1 (what would have become VP10 if there wasn't this whole NetVC story).
    - Xiph (of Vorbis and Opus fame, with also contributions toward Flac, Speex, etc.) : They are developing a very interesting project called Daala, and they ended up also contributing the innovation done for Daala into AV1.
    - Cisco : They gave what they have developed for their Thor codec also into AV1.

    Netflix has also joined the AOMedia and they are investing resources into it.
    Same with several browser makers (including Mozilla).

    With all the people involved:
    - you know there's some interesting performance coming (given the brains involved here, given past successes like Opus, and given the promising results of research projects like Daala).
    - given that 2 top content providers like Google (Youtube) and Netflix are on board, there's a high chance of seeing deployment of the new codec.
    - given that browser makers like Google (chrome), Mozilla, and Microsoft (Edge) are on board, there's a high chance of seeing browser support for the new codec.
    - given that hardware chip maker like ARM, Intel, AMD, Nvidia, etc. are on board there's going to be hardware decoding support.

    (Adobe is on board too, so browser support is guaranteed for the Widevine DRM plug-in required by Netflix' licensors. Not that it matters that much, because that part of HTML5 Video is already defined and deployed everywhere, except maybe with Firefox on Linux which is a bit delayed)

    But you know that this looks promision,
    and maybe same time next year, we'd be reading summaries along the lines of "Netflix and Google find AV1 20% more efficient than HEVC/H.265" "And also cheaper, royalty-free and widely supported"

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