background

When 4K video was first proposed, most people thought it was unnecessary. The emergence of 4K means higher hardware specifications and transmission requirements. 1080P is very cool and clear to watch, which fully meets daily needs. With the increasing size of TVS, the original 1080P imaging can no longer meet people’s pursuit of the ultimate in detail. 4K video not only has more exquisite imaging, but also has obvious advantages in detail processing, brighter, fuller and lifelike colors, giving people an immersive feeling. 4K video has the advantages of high resolution, wide color gamut and high dynamic range. With the release of 5G technology and H.265(HEVC) coding standard, 4K video live broadcasting has ushered in the dawn.

One chart explains 4K VS 1080P

1080p

Often, 1080p is referred to as “Full HD.” In a 1080p television There are 1,920 columns multiplied by 1,080 rows for a total of 2,073,600 pixels — more than twice as many pixels as You’ll find a 720p screen. For a while now, 1080p has been the industry standard For high-definition displays, and most content (that is, television broadcasts, shows, and movies) is produced and distributed in 1080p.

4K Ultra HD

The next level of HD is 4K — often called “Ultra HD” or UHD. Demeaning, The name is a bit of a misnomer, Because there are 3,840 columns and 2,160 rows of pixels, Which is why you’ll occasionally see this resolution referred to as 2160p. That’s a total of 8,294,400 pixels, which is four times as many pixels as a Full HD 1080p display and nine times as many pixels as a 720p display.

 

Windows platform real time 4K live broadcast solution

First, let’s explain what is real-time video. Real-time video is the whole process of video image from generation to consumption without delay. As long as the video business meets this requirement, it can be called real-time video. The real-time performance of the video can be summarized into three levels:

  • Pseudo real-time: video consumption delay of more than 3 seconds, one-way real-time viewing;
  • Quasi real-time: video consumption delay 1-3 seconds, can be two-way interaction but interaction barriers;
  • Real time: video consumption delay < 1 second, average 500 ms.

RTMP, RTSP low delay technology solution based on NVIDIA NVENC hard coding

4K is equivalent to four 1080P, Windows platform soft coding is somewhat difficult, especially H265, let alone 4K soft coding, 4K soft solution in some general configuration of the machine is difficult, based on this, Daniu Live SDK (Github) to achieve Windows platform specific models hard coding, hard decoding low delay solution.

  • In terms of coding, we have implemented the RTMP and RTSP low-latency technology solution based on NVIDIA NVENC hard coding, which can be written in 4K and 30FPS regardless of H265 or H264 (the following test screenshot is based on GeForce RTX 2060).
  • For decoding playback, especially for Windows platform multi-channel playback, we implement Windows platform specific model hard decoding.

With the overall technical solution of hard coding and decoding for specific models, we control the overall delay of RTMP in 4K to 180-300 milliseconds, realizing the real time technical solution without picture or truth:

RTMP extension H265 live

The camera adopts “Hikvision surveillance camera 8 million 4K ultra hd USB live streaming camera network course remote video conference desktop computer camera 2CS54U0B-SD”.

RTMP push H265 4K hardcoded configuration (corresponding to SmartPublisherDemo.exe) :

RTMP Player H265 4K hard decoding effect (corresponding to SmartPlayer.exe) :

RTMP H265 4K encoding and decoding GPU, CPU usage:

 

RTMP H265 4K delay effect

You can see that the delay is just over 100 milliseconds.

RTMP H264 live

RTMP push H264 4K hard coding (corresponding to SmartPublisherDemo.exe) :

RTMP Player H264 4K hard decoding effect (corresponding to SmartPlayer.exe) :

RTMP H264 4K hard codec GPU, CPU usage:

RTMP H264 4K live low delay effect:

Conclusion:

Overall, Nvidia hard coding (NVENC) delivers the desired results, with low latency and high resolution at the millisecond level. NVENC also provides flexible bit rate control strategies to meet different coding requirements.