Streaming via LiveU encoders

[SebastianReg]

Hello, 

 

 

I have a technical question. We broadcast very often using hardware encoders such as LiveU LU300 or LU600. In these devices, the encoder profile can be selected from Main and High, so when I send a signal to the Ant Media Server to  WebRTC apllication  (main or high profile), the image is not smooth. However, when I send signal, for example, via vMix, with the baseline encoder profile, everything works very smoothly. What to do to send a WebRTC signal through the hardware encoder, so with the codecs LiveU uses, the image was smooth and 500  milliseconds delay(WebRTC).

[Burak]

Hi @Sebastian Reg,

Thank you for your entry. This is a chance for us to tell why WebRTC has issue with Main or High profiles RTMP streams. 

In Main and High profiles, H264 encoder generates B frames (which requires upcoming frames to decode) to compress more. Since WebRTC is a real time streaming protocol it doesn't accept B frames and drops them. Otherwise it would waits for the future frames and so requires buffering. But it doesn't do it. So eliminating B frames is important for RTMP to WebRTC streaming.

If you can't change encoder profile to Baseline you may prevent B frames (if your encoder settings let you do it). Also adding an adaptive bitrate setting in Ant Media Server is another solution to solve this.