Technical principle of front and rear end of live broadcast system

Mobile LVB system can be divided into collection, pre-processing, coding, transmission, decoding, rendering, these links, the following editor respectively explain:

1. LVB capture:

IOS is relatively simple, while Android needs to do some model adaptation work. PC is a little more troublesome, and all kinds of cameras need to be driven, so you need to do all kinds of adaptation and constantly optimize it.

2. Pre-LVB processing:

Now the live Beauty SDK is standard, and most anchors can't watch it without Beauty. The beauty algorithm needs to be programmed by GPU and someone who knows the image processing algorithm.

3. LVB code:

Be sure to use hard coding, soft coding 720p is completely hopeless, barely able to code will also cause the CPU to overheat the camera. Hard-coding compatibility is another big hole, and someone has to fill it out on android. Coding should find the best balance in the design of parameters such as resolution, frame rate, bit rate, GOP and so on.

4. Live transmission:

It is not realistic to do it yourself, give it to the CDN service provider, that is, it is a bit expensive, I believe that you are not short of money if you are interested in doing a live broadcast system to change the world. Assume that the monthly bandwidth cost of 2W PCU is about 100000, because the clear and smooth 720p is about 1.5mbps. CDN only provides bandwidth and transmission between servers, and the network connection jitter buffers of the sender and receiver still have to be written by themselves. If you don't want stutter, you have to increase the buffer, which will lead to high delay, high delay and interactivity.

5. LVB decoding:

It is also necessary to hard decode. At present, mobile phones generally support hard decoding, but there is still a big compatibility hole to be filled on android.

6. LVB rendering:

This difficulty does not lie in drawing, but in sound and picture synchronization. At present, only a few professional live broadcast system developers have done very well.

The one-stop live broadcast solution of Tuofang Technology includes all the functions of the front and back end, and a more comprehensive and professional mobile live broadcast system.