Overview

A watermark can be applied to stream captured while translating it to subscribers. To do this, the following parameter should be added to flashphoner.properties file to specify watermark PNG file name:

...

Stream watermarking will increase the server load approximately 0.5-1 core for each incoming video stream depending on video transcoded resolution. For example, 16 incoming streams handling may require 8-16 core server. In this regard, it is recommended to apply watermark on stream publisher source if possible.

Watermark picture mixing with alpha channels support

Some watermark picture colors may be distorted or invisible (transparent) when applying this picture as watermark. It depends on alpha channel values of the picture applied. Since build 5.2.1064 the following parameter is added to enable watermark picture mixing with alpha channels support

custom_watermark_mix=true

Note that alpha channels support implementation today executes a many subsequental operations. This can lead to CPU load inscreasing and low quality of the resulting image. In the future, it is planned to be implemented using parallel mixing on GPU.

Known issues

1. Default watermark (black picture) will be used if watermark file is damaged or absent

Symptoms: black picture in output stream when watermark is added, there is a message in server log 

Wrong watermark file format. Should be PNG.

Solution: use only correct PNG file to add watermark