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BBC Confirms 50% Bitrate Savings For H.265/HEVC Vs H.264/AVC (bbc.co.uk)
An anonymous reader writes: A research team from the BBC has done a series of tests to confirm earlier computations showing a ~50% savings in bit rate for H.265/HEVC compared to video using H.264/AVC at comparable quality. "The subjective tests used a carefully selected set of coded video sequences at four different picture sizes: UHD (3840x2160 and 4096x2048), 1080p (1920x1080), 720p (1280x720) and 480p (832x480), at frame rates of 30Hz, 50Hz, or 60Hz. The video content was chosen to represent diverse spatial and temporal characteristics, and then coded using HEVC and AVC standards at a wide span of bit rates producing a variety of quality levels." Here is the full published analysis. "The tests confirmed the significant compression efficiency improvements achieved in HEVC, verifying the results previously reported using objective quality metrics (PSNR based methods)." The team did not test against VP9, which is shaping up to be an impressive standard as well.
What is it's Weissman Score?
I've played in this space in a former position. Interesting lessons learned:
- PSNR is nearly worthless: An image with almost the same score can look terrible. Not all the time, but enough of the time.
- The only quantitative test I found that worked reliably was an old analog Tektronix PQA500 (lots of work to use for digital CODEC.)
- Management didn't like the PQA data (it said our product was terrible), decided to use PSNR data (product is great!)
- Customers fixed this discrepancy and product line failed spectacularly (due to video quality, surprise!)
- I never could find any published information sufficient to recreate the Tek PQA algorithm.
Now you can consume 4k video on your 3" screen (assuming anyone's mobile device has the grunt to decode it). :)
Name another media company that went out of their way to develop a patent-free media codec that was independent and competitive with other codecs of the time? (Google Dirac)
The BBC are publicly-funded, and under immense pressure to justify their funding at the moment - there's talk of scrapping the TV licence, and with it the BBC. They receive no advertising revenue in the UK at all. They only get some foreign revenue from sale of media (not even their own codecs or patents), and that goes to their commercial arm which isn't funding stuff like this.
There's no profit in them evaluating codecs, only if they then go out and build their own hardware that uses it. They didn't manage to do that with Dirac either, so why they would with this I have no idea.
All they want to know is what's best to push through iPlayer and store in their archive.
Not-for-profit does not mean not-with-costs.
There are two types of people in the world: Those who crave closure
50% bitrate reduction vs H.264 sure, but not vs x264 which is the current gold standard for HQ video compression.
It's like comparing a new audio codec to the original fraunhofer MP3 encoder. LAME on the other hand is a significantly better MP3 encoder like x264 is a better H.264 encoder.
My own compression testing between HEVC and x264 show that at verty low bitrates, yes HEVC is better, but only at bitrates below what I would normally use and what I would consider "quality" encodes.
When you compare say a 10GB x264 encode of a full-length BluRay film, even 8GB for the HEVC does not provide an equal or superior copy.
That means it'll take half the time to bittorrent Doctor Who episodes. :-)
The benefit for them is that they can reduce costs by reducing the bitrate, and claim not to have reduced picture quality. They have done it before - when HD broadcasts started they were around 18Mb/sec IIRC, but were later reduced to less than half that (average per channel, they actually balance about 18Mb/sec between two channels in a kind of VBR system). They claimed that the picture didn't suffer but it very clearly did, and it's now rather poor.
They are under immense financial pressure, and reducing bitrate (and picture quality) allows them to save something else, someone else's job.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
Mobile devices typically contain physical hardware decoders built in to the SoC so that they don't have to use their CPU cores, which would be much less efficient or practically impossible in the days of slow, single core mobile devices.
I recall from several years ago when Apple released iMovie for their iDevices, that they could encode videos more quickly than their high-end, vastly more expensive Intel-based computers simply because the dedicated hardware encoder in the SoC could beat the Intel CPUs.
Erm you do realise that this isn't actually a quality reduction?
If you read up on HEVC, you'll notice it's a completely separate codec to AVC that was designed specifically to hit 50% better (higher quality same bitrate or same quality at half bitrate). AVC was the benchmark codec that it was being compared to.
So the BBC is just confirming that they hit that mark.
https://en.wikipedia.org/wiki/...
Name another media company that went out of their way to develop a patent-free media codec that was independent and competitive with other codecs of the time? (Google Dirac)
There is nothing royalty-free about HEVC.
"Somebody has to do something. It's just incredibly pathetic it has to be us."
--- Jerry Garcia
Pirates will be eager to adopt though. Patents are no issue for them, but bitrate is.
Umm, all the employees and in particular the leaders who draw multiple million dollar salaries?
Troll is not a replacement for I disagree.
I have done my own comparisons of AVC (using x264, single-thread, veryslow preset) and HEVC (using x265, disabling wavefront processing because it slightly reduces quality, veryslow preset). All 1080p video, significant because HEVC is supposed to scale to 4K better than AVC.
My conclusions:
1) x265 takes FAR longer to encode, but we knew that. Understandable.
2) When "low in bits", x265 blurs images rather than making them look blocky. This sometimes looks better but to me often looks worse.
3) x265 seems to force a denoise filter. Video is far easier to encode efficiently when denoised, so I figure this is part of the data savings. It's a bit of a cheat, however, because I can get far smaller file sizes by running a denoise filter myself for x264-encoded video.
I looked closely, for example, at Captain America the Blu-ray. Much of the detail of, e.g. car leather and grass and tree leaves is lost in an x265 encode, even at about the same overall data rate as x265/
x265 supports "--tune grain", roughly analogous to "--tune film" for x264, but it makes the video vastly larger -- often larger than x264's version, and it often looks worse. It does a better job of keeping grain, however.
My experience is very similar to many others' in forums. I had committed to switching my encoding to HEVC, but the results of my tests showed it is not ready for prime time. Some may not mind blurry ("soft" is probably a better word) video, or video that looks like it has been through a denoise filter, but I do.
This is not to say that x265 is junk. I am sure it will mature over time just like x264 had to over time. x264 started out as being not all that much better than divx, the previous generation.
Computer Science is no more about computers than astronomy is about telescopes. --E. W. Dijkstra
It plays fine on all tablets I have tried it on, and it plays on some of the little 40 dollar pcs they make now.
Troll is not a replacement for I disagree.
They contain hardware AVC decoders, not HEVC decoders. This is why YouTube now plays like crap on old netbooks unless you install a plugin that forces MP4 instead of VP9.
Peter predicted that you would "deliberately forget" creation 2000 years ago...
But not on any 2013 or earlier machine at all.
Peter predicted that you would "deliberately forget" creation 2000 years ago...
But if no quality reduction it is also a benefit to the user. Why stick to a patent encumbered standard when there's an alternative, just because someone is making money (which will happen with either standard)?
The problem is, HEVC is expensive. While the MPEG-LA made h.264 the way it is by making streaming free (if the viewer doesn't pay) and offering caps to the maximum license fees, thereby encouraging big users (Cisco, Apple, Microsoft, Netflix, etc) to switch to h.264 and merely pay the cap every year
Of course, MPEG-LA wanted to encourage the switch to HEVC by offering the same terms, and several patentholders balked which is why they pulled out of the MPEG-LA pool and created the HEVC Alliance which licenses without a cap, without free streaming (they want some money per HEVC stream), meaning the money you save in bandwidth might go straight to licensing fees.
And I'm sure the BBC streams under h.264 were basically cost-free since the streams were available at no charge (granted, you paid with your TV license, but the MPEG-LA doesn't count that), so switching will create costs.
I've read many many posts indicating that for low bitrate stuff, 265 is doing very well but for the higher end stuff, it's only marginally better than 265 (more like 25%)
That's an approximation, I don't recall the exact figure, but I do recall it being significantly less than 50%
This is pretty disappointing, perhaps other tweaks and improvements will be eeked out over time, but as it stands, I can't see a 3TB movies folder being recompressed to 1.5TB with the same quality at this point in time.
(I know that would be lossy to lossy and stupid, that's not the intention of the post)
There seems to be this misconception that because the bbc is publicly funded it seeks to do everything "in the public interest " and generally doesn't behave like any other large corporation.
The truth as I see it at least is that there are a lot of highly paid media types with one eye on their careers who justify every decision using exactly the same metrics as the rest of the industry. The bbc news website is turning into a clickbait riddled buzz feed clone exactly because they judge success in terms of uniques and audience retention as if they were selling ads. TV programs are similarly judged on audience share rather than quality. This led to a major climb down a few months ago when someone sufficiently senior pointed out that spending 10's of millions trying to compete directly with ITVs Saturday evening prime time offering was probably not an effective use of what is essentially public money.
Similarly the website has come under fire for having a huge and poorly defined scope, along with costing a fortune to run. Being able to point at these figures and saying "but look what we saved on bandwidth!" Is either going to justify someone's continued employment or allow them to push through their 8k@120hz resume padding vanity project.
Right. This is why I think VP9 actually could win and become the new standard (replacing H.264).
H.265 and VP9 seem like they are definitely in the same ballpark on quality. And H.265 is heavily encumbered with patents; you have to pay royalties, and you never know what the royalties might cost in five years. VP9, on the other hand, is simply free: no royalties, no restrictions on what you may do with the video.
Even if VP9 takes a lot more CPU time to encode, and even if H.265 is slightly better than VP9, not having to pay royalties (not even having to keep track of what you do with the video!) is such a huge benefit. It seems like a no-brainer.
And Google will be making sure that all the Android phones at least will have good hardware support for VP9 decoding. VP8 never had a chance against H.264 because the hardware support wasn't there, and large companies were content to pay the capped fees as you noted.
All that's left is possible legal FUD around VP9, but even that seems pretty cut-and-dried to me. MPEG-LA tried for something like a year to find patents to put into their patent pool to extract royalties from VP8, and in the end Google gave them a one-time payment of (to Google) a relatively small amount of money. Thanks to that one-time payment we know MPEG-LA won't ever come after anyone for using a VP8-derived codec, and I have no reason to think anyone would be able to prevail in court if they try it.
Given all of the above, it seems to me that VP9 is the obvious choice for the new video standard, and I kind of wonder why anyone is still interested in using H.265 and paying the royalties.
lf(1): it's like ls(1) but sorts filenames by extension, tersely
Lawyer up.
"Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
Do you think that is how normal for profit enterprises work????
Troll is not a replacement for I disagree.
Because the set of subsisting patents is so large that you can't prove a negative. It costs a substantial chunk of change to deploy set-top decoder hardware for a new data format. Once hardware implementing a decoder for an allegedly royalty-free format has been shipped out, patent holders can come out of the woodwork and claim that their patents apply to the new format. With a patented format, on the other hand, it's more efficient for a patent holder to just join the existing patent pool.
There's also Daala in the pipline, which uses entirely new compression techniques that are not patent encumbered.
I don't see any mention of how motion compensation and other "smart" features of the display devices influenced the perceived quality. Software in these devices may work in both positive and negative ways.
Is there something intrinsic with all these codecs that Intel Quick Sync can do in hardware (CPU instruction set)? Or does the actual CODEC have to be baked in hardware?
Wikipedia did mention something that I wasn't aware of, but makes sense in hindsight: "Quick Sync, like other hardware accelerated video encoding technologies, gives lower quality results than with CPU only encoders. Speed is prioritized over quality.[6]".
I'm guessing people looking for the best quality won't be using Quick Sync after all, or rather haven't. This must be for the average person whom takes video with a cell phone, edits it on a computer, and posts to FB or YouTube.
Life is not for the lazy.
You are aware the current DG is a Director of HSBC, a Tory party doner and a personal friend of David Cameron. I don't trust the BBC to tell me the time anymore
Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.
The answer is yes you can consume 4K video. And if you do and its encoded with HEVC, you take half the whack on your bandwidth cap. Of course I expect most people would be viewing videos encoded at lower resolutions and bitrates but the savings apply their too - if 4MBs HEVC can show an image subjectively the same as 7MBs AVC then it's a benefit. Not only do they use less bandwidth but they're less likely to suffer buffering issues, or step downs to lower bitrates.
Switching from MPEG-2 to H.264 really is about a 50% savings. If your video looks bad at 18Mbps MPEG-2, you need better hardware. It won't look great, it's almost as much as the ATSC standard. It's not as bad as satellite TV that allocates less than 5Mbps H.264 to HD channels.
None of it's anything compared to the 20Mbps+ H.264 used on Blu-Ray.
If I recall correctly Google also held some important media-related patents from its Motorola purchase that allowed Google to just basically cross-license the H264 patents, the small fee being for the much greater number of patents held by the MPEG-LA. These patents are besides the cellphone-related patents that Google wasn't able to enforce because they fell into the FRAND category of essential industry patents.
It went to Eton and then it was eaten?
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
I haven't read the HDCP agreement myself, but I wouldn't be surprised if it forbade modification of the video signal.
Even if this is not forbidden, a DRM scheme operates on the principle that implementations are assumed noncompliant until proven compliant. The fixed costs of an equipment producer joining a DRM scheme include the cost of an audit (possibly probabilistic) of the compliance of the equipment producer's product on behalf of the scheme's maintainer. So even if it were compliant, whether a device is compliant or not does not matter if the prospective manufacturer cannot draw enough investors to make the device exist in the first place.
I haven't read the HDCP agreement myself, but I wouldn't be surprised if it forbade modification of the video signal.
You can definitely modify the video signal - http://support.xbox.com/en-US/...
Looks like there are HDCP certification services that will test your device for under $5000 (Simplay Labs). I assume they would be liable if the device was actually non-compliant.
My 2 year old phone will play 4k, with HEVC. Running bottom of the line hardware for 10 years gets you lots of things that won't work right by the time you finally get rid of it.
Learn to love Alaska
My 2 year old phone will play 4k, with HEVC. So yes, most higher-end new phones should be able to play 4k on their screen (5.5 in my case, your screen may vary).
Learn to love Alaska
The truth as I see it at least is that there are a lot of highly paid media types with one eye on their careers who justify every decision using exactly the same metrics as the rest of the industry.
Two eyes.
When all you have is a hammer, every problem starts to look like a thumb.
the money you save in bandwidth might go straight to licensing fees
+1 Nailed it. And since bandwidth always increases while license fees usually do not decease, the deal gets worse the longer you play this game.
When all you have is a hammer, every problem starts to look like a thumb.
What does that have to do with Dirac?