The worst thing about H.265 is the patent licensing situation. There are two separate patent pools and you need a license from both:

1. http://www.streamingmedia.com/Articles/Editorial/Featured-Ar...

2. http://www.mpegla.com/main/programs/HEVC/Pages/Intro.aspx

3. https://www.hevcadvance.com/

It's much simpler and easier to use formats which are licensed under royalty-free terms, which is what VP9 offers now and what AV1 will also offer in future:

1. https://en.wikipedia.org/wiki/VP9

2. https://en.wikipedia.org/wiki/AOMedia_Video_1

To me the important result from Netflix's test is that VP9 is better than H.264, almost as good as H.265, and absent the patent licensing problems. I think the simpler licensing makes VP9 the better choice today and AV1 the best choice in the future.

Realistically it will probably come down to what's implemented in hardware. Youtube's 4k video in chrome is really a terrible experience when you don't have hardware acceleration for vp8. It pegs your CPU at nearly 100% and god help you if you're viewing a 4k 60fps video.

Luckily it looks like most hardware manufacturers are getting on board with VP9 these days, but the current support for encoding at least is abysmal: https://en.wikipedia.org/wiki/VP9#Hardware_encoding.2Fdecodi...

Browser support is the most important factor for web video. H.265 currently has no browser support but VP9 is supported by Firefox, Chrome, Microsoft Edge, Opera, Vivaldi, etc.

Odds on Safari ever supporting VP9? Especially since Apple are already using HEVC/H.265?

I'd say there's a reasonable chance, and if not VP9 then definitely AV1. The next version of macOS and iOS supports WebP (a still image format based on VP8) so the VP8/VP9/AV1 family has a foot in the door:

1. http://www.cnet.com/news/apple-ios-macos-tests-googles-webp-...

2. https://developers.google.com/speed/webp/

What makes you think that 4k 60fps is even possible without hardware acceleration? That's 12.7 Gbps output bandwidth (assuming true color), barely possible even using just memcpy, let alone decoding.

Interesting point. However, just to be pedantic, if memory bandwidth were the only bottleneck, you'd expect video decoding to generate output faster than memcpy, since it wouldn't have to read as much :-)

My Intel NUC cost me £300 in January and is therefore a fairly low-end machine. It has 307 Gbps of memory bandwidth (2 slots of DDR4-2400). It's surprising how big that number is on a cheap machine today.

I'd love to see a profile of where the CPU time goes in a modern CPU-only video decoder. I guess I could get off my arse and do the profiling myself instead of posting this. Anyway, my guess is that the processor speed is the bottleneck, not the memory bandwidth.

That's mostly partial acceleration. Chips now support a lot of codecs. And aside H264/AVC chips makers cannot afford to use so much hardware surface for codecs that are not so popular.

You must be talking about either a wimpy laptop CPU, a cellphone or a tablet.

Old desktop Sandy Bridge does 4k 60 FPS decoding with no problems, as long as output can sustain it. And integrated GPU does not. You need quite a lot of bandwidth to sustain that much image data.

>You must be talking about either a wimpy laptop CPU, a cellphone or a tablet.

Surely margin-of-error-sized markets to ignore them that easily.

Unfortunately these codecs still have a few important issues (http://www.gpac-licensing.com/2016/07/12/vp9-av1-bitstream-f...). I wish AV1 can fix those but they want to go for such a tight timeline...

It's always weird to read codec commentary from broadcast people; their world and concerns are just so alien to me. I also rather wonder what he considers a raw bytestream that HEVC has and VP9 doesn't...

Anyway, I guess the only major concern from him is the DCT overflow? I mean, for the extra precision, even HEVC has increased from 16-bit intermediates in the newer profiles. I think Daala's transforms would solve his issues with VP9's, I'd imagine they're being considered.

You forgot to mention the skeleton in the closet on vp9's license terms.

It is patent encumbered, by Google owned patents, but they allow free use, so long as you promise to never sue them for patent infringement.

Given how many pies they have their fingers in, that seems like a pretty big catch.

It depends... the better the input and larger the resolution, the better x265 works for a given display. On the other side, I recently started re-ripping my DVDs of Babylon 5 for seasons 4-5 (had already watched seasons 1-3 on dvd) via Handbrake. I had to play a lot with the settings, and found that for DVD, a constant quality level 18 at medium seemed to work about best without losing too much quality. This resulted in a file size anywhere from around 290mb to 390mb, so some variance in size, for local data store this works fine, for online streams this wouldn't work as well, and would probably want a 2-pass for a consistent bitrate. This is compared to an average 850mb or so file size for the prior rip to x264. The time to encode (i7 4770k) seems to be about 13-16 minutes per episode. Again, this is at DVD source/output quality.

At 1080p, you can lower the quality to around 22-24, and get near blue-ray output... the flatter the input (animation is a great example) the bigger the difference. I'm seeing encodes at 40-60% of comparable blue-ray.

The down side, is it is significantly slower, and the quality of the x265 version of the codec is much better than say the nvidia x265 encoder, which is a shame as it's much slower too, so it becomes kind of a non-option for archives imho.

If you are encoding new media for your library, definitely go x265, it's worth the file size saving (so long as your playback devices support it well enough), but I wouldn't go back and re-encode it all, it's just too slow for now... maybe if x264 gets some CUDA support, that would be really nice (recently upgraded to a 1080 GTX).

The sizes you quote for B5; are those per episode or per disc?

Also, using a 3d denoiser on B5 will drop the bitrate a huge amount without trading off much quality. There is significant grain in those (though seasons 1-2 were worse than 3-5 IIRC).

Per episode... I used the 3d denoiser at low setting, which helped a lot. I know Seasons 1-2 are really bad in terms of quality, which is why I mentioned it.. suspecting that s1-2 will be closer to the larger sizes because of it.

How would I use a 3d denoiser with ffmpeg? Any tips?

The filter hqdn3d is what you want. Note that the defaults are for noisy video, so unless you have a really noisy source you'll want to use lower settings. I've seen hqdn3d=4:4:3:3 as a good place to start, and you can tune the numbers (lower is more noise, less blur, higher is less noise, more blur). In addition, the default values for each parameter is scaled based upon the previous value(s), so you can be lazy and just pass one or two values to get a coarse idea of the strength you want.

If the videos are to be played back on a player that supports video filters, you can add some noise back in on decode, which is particularly useful for non-HD sources as your eyes will often interpret noise as detail. Back in the h.263 days I used to do this as 1) h.263 was much worse than 264 or 265 and handling noise and 2) disk space was more expensive, so I couldn't just up the bitrate. I still have some vlc settings that can do that for playing old DVD rips. Today, unless you plan on streaming the video, I would recommend just upping the bitrate and using conservative enough denoise settings to not need it.

> near blue-ray output

I have those B5 DVDs as well and that's confusing - the source video quality is just not that great.

That particular comment was with respect to 1080p source material (as opposed to the B5 DVDs).

x265 is actually worse than x264 on high bitrate content, which is why its use is banned on private trackers where picture quality is totally paramount.

x265 tends to smooth out film grain that x264 preserves at high bitrates. That being said - Netflix has never offered x264 content at sufficiently high bitrates (visually indistinguishable to Blu-ray quality) anyway, so it's a moot point.

Sound like a very real concern. But I also remember the same complaints back in MPEG-2 vs h.264 times. We need some objective benchmark for this.

It doesn't need beefier hardware its just not implemented in most SOCs or GPUs so it uses software decoding. X264 was also a hog when it didn't had dedicated hardware decoders now everything even your microwave can probably decode it in hardware.

I think the patents covering x265 might be younger, too.