Flussonic Media Server documentation


Processing Audio from IP Cameras

Most IP cameras are able to output sound only in PCMA/PCMU codecs (also known as G. 711a and G. 711u).

Flussonic can record this codec into the archive and send it to those protocols that can transmit this codec: RTMP and HDS. Other protocols do not imply transmitting the codec, so it is impossible to send such a sound via HLS or upload it to MP4 so that the client hears it.

To make the audio sound available to all client devices and players, you must enable transcoding of the audio received from an IP camera.

To do so, install the flussonic-transcoder package:

Note. The package flussonic-transcoder is necessary only if you plan to use the CPU to perform transcoding. If you use Nvidia NVENC, no extra packages are needed.

apt-get install -y flussonic-transcoder

Then enable sound transcoding for the stream from the camera:

stream cam1 {
  url rtsp2://....;


stream cam1 {
  url rtsp://.... aac=true;

In this configuration, Flussonic will transcode the audio to AAC, and send it to all clients on all protocols.