Whats going on with HEVC (h265)

At one time, the development of the H264 codec was a real breakthrough, because it turned out to put at one table people involved in television, IP cameras, conference calls and give birth to a standard that was generally enough for everyone.

I remind you that a codec is not a specific algorithm, but a description of video packaging formats so that you can get into the maximum compressed number of bits. The encoder is free to choose packaging methods according to the codec standard.

So H264 is a combination of a good codec, good encoders and a lot of decent decoders. But what happens with H265?

H265 is the standard that replaces the H264. His arrival was overshadowed by the dubious adventure of Google with their VP6, VP9, ​​VP10 and tales that VP codecs are better than any H264, etc.
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The main essence of H265 is that it is sold as a solution for screen sizes higher than FullHD. For what it is really good, we'll talk below, but the world is designed so that you first need to sell. Here for 4K it is for sale.

I want to talk a little about the current status of H265 support, because we are approached with this and we have to conduct an educational program every time.

Coding

To date, H265, also known as HEVC, is already supported on a large number of encoders: software, ordinary hardware (Nvidia NVENC, Intel QSV) and hardware iron.

Some noticeable use of H265 can be found on satellite TV (rare, but already encountered channels with a giant bitrate), IP cameras and all kinds of boxes for capturing and encoding HDMI (and a little SDI).

Why do you need to capture HDMI and publish to the site? Well, as if guess yourself, especially if the piece of iron promises to open HDCP. I will only tell you that it is very popular for streaming games, when you do not want to add any load on the computer.

Here you have to be very careful with what exactly the hardware or software will be able to do. For example, Hisilicon for a long time released the first H265-enabled chipset for IP cameras, but the software was almost a year and a half behind them. Today, it still sells full of cameras that have H265 written, and they cannot give it in real time - just export files through non-working Chinese software. What is the support of H265 here, the sellers cannot answer, but they nod persistently: yes, yes, we can h265.

A similar problem with RTMP encoders. One of the most common questions: “what, your software is not able to H265 via RTMP?”.

This is not our software "does not know how", and RTMP does not know how H265. In RTML, flv-like frame packaging is used, and H265 is not available in either standard or other standard. There are all sorts of clever hacks, allowing you to cram H265 into a protocol that is not designed for it, but calling it RTMP will already be overkill - it will be a proprietary, closed protocol. Such changes exist, they are made by the Chinese, and this usually means just a hysterical attitude to the proposals to share the protocol specification.

Those. iron may be able to H265, and the software running on it may lag behind in development and simply not be able to work with it and this is still full.

Broadcasting

Now in the wild, the H265 is easiest to find on IP cameras: it already exists there and is spreading slowly, thanks to HUAWEI. You can also find 30-megabit channels compressed in H265 on satellites.

In our experience, attempts are being made to implement it in various OTT services, where there is control over the device.

Regarding the broadcast, the situation is the following: H265 in the HLS protocol has been supported by everyone for a long time, and the Apple very much time came to their senses and fixed the obvious in the standard. But so far everyone does not care, because few iPhones can lose it.

Those. It is important to remember: MPEG-TS has long and reliably been able to transmit H265, which means that what is called UDP or HTTP is also likely to be able to.

H265 is also transmitted via RTSP: there is packaging in both SDP and RTP. There remains an old nuance with the transfer of bframes over the RTSP, but this is a separate headache.

If you meet H265 and RTMP, then most likely this is chatter, but if it really works, then people just stuffed a byte and use the patched server and client. In the standard RTMP H265 does not fit.

Playing

For now, forget it =)

From desktop browsers H265 now only Microsoft Edge can actually show, the rest do not.

There is playback on set-top boxes, SmartTV and in programs / applications, but browsers are still very far behind.

You also need to understand that on phones now h265 will most likely be played on the processor, i.e. If you have enough batteries to view ads, this is not a bad thing.

Competition

H265 is compared to h264: after all, the difference in bitrate should still be seen, but h264 support is now absolutely everywhere

H265 is compared to VP10, because so asked Google. In practice, the VP10 has problems with even less support from the side of hardware (which means it needs even more batteries and processing power) and bad playback protocols.

H265 began to be compared with AV1, but for the time being it is not possible to consider it at all - too new. Very interesting, wait a few years.

Summary

H265 is developing, spreading, but today, most likely, there will be nothing fatal if you are not considering it.

He already has competitors at the start, with whom he will have to fight, but there is also a good starting position in the form of a decent pedigree (from the same people as H264) and good support in transport and video delivery protocols.