Encoding UHD for devices with tiny buffers

[Blue_MiSfit]

Hello!

I'm working on encoding VOD for certain 4k smart TVs with very limited buffer capacity. I want to send it 2160p Main10 HEVC.

If you run a very high data rate like 25 Mbps it will stream okay if the network connection is perfect, but any jitter or latency and it falls apart and stutters all over the place because there's very little buffer.

20 or 15 Mbps are better, but still not very good. 12 is fine.

I'm already encoding using CBR - e.g. bitrate=maxrate=bufsize and enabling strict CBR.

Any other suggestions to improve smooth playback?

[qyot27]

--tune zerolatency?

[MGarret]

If 12 Mbps is fine then set bufsize=12000. For CBR only bitrate and maxrate should be the same, bufsize can be lower or even higher. At least that's how it is for x264. The only difference is that with bufsize under one second, bitrate peaks will be lower and even more constrained. So if you set bitrate and maxrate to 24000 and bufsize to 12000, you'll have constant bitrate with half a second buffer.