Latency settings

ApsaraVideo Live provides latency settings for three protocols. For each protocol, you can select a Low, Medium, or High latency level. The actual latency depends on the latency setting and the group of pictures (GOP) of the stream ingest. See the following table for details.

We recommend a stream ingest GOP of 1 to 2 seconds to balance latency and smoothness. The GOP affects the HLS segment duration, as each Transport Stream (TS) segment must contain at least one GOP. For example, if the GOP is 2 seconds, the latency is calculated as follows: High is 2 seconds × 6 segments, Medium is 2 seconds × 4 segments, and Low is 2 seconds × 3 segments.

The delay configuration takes effect only for RTMP, FLV, and HLS protocol playback. When the ARTC protocol is used for stream pushing and the above three protocols are used for playback, the delay is also determined according to the following table. If the HLS playback delay is too high, first check whether the HLS delay is set to high and whether the push GOP is too large. For sub-second delay, please use ARTC protocol to play, please refer Get started with Real-Time Streaming (RTS).

For more information, see live streaming latency.