In order to compare latency achievements of the HESP protocol, we designed a test scenario where HESP is compared with CMAF-CTE, using the same encoding settings, and a selected set of chunk and segment sizes for the CMAF setup (meaning a changing GOP size).

Both encoded signals are sent over RTMP to a packager on AWS. Both signals are delivered into players running on Chrome version 73. The camera was pointed towards a millisecond accurate clock, for which the latency was compared with the video displayed in the player.

Following test setup/settings were compared:

  1. HESP
  2. CMAF-CTE with 1s segments and 1 frame chunks
  3. CMAF-CTE with 2s segments and 5 frame chunks
  4. CMAF-CTE with 6s segments and 5 frame chunks

The following results were measured.

Screenshot 2019-09-03 at 10.37.31

As the results of this test indicate, end-to-end latency for the HESP protocol is significantly lower compared to all CMAF-CTE configurations which were tested. The latency measured of 330ms is low enough to enable new interactive formats, where for example viewers can directly interact with the TV broadcaster.

Reference Infrastructure