SRT restreaming is supported on Ubuntu for Red5 Pro distributions. Please see Ubuntu setup document for requirements.

SRT Configuration

To configure Red5 Pro Server for SRT, the following steps are required:

• Enable SRT by modifying red5pro/conf/restreamer-plugin.properties, and setting enable.srtingest=true
• Enable the Restreamer servlet in your webapp by modifying red5pro/webapps/YOUR_APP_NAME/WEB-INF/red5-web.xml and adding or uncommenting the following:

<servlet>
    <servlet-name>Restreamer</servlet-name>
    <servlet-class>com.red5pro.server.plugin.restreamer.RestreamerServlet</servlet-class>   
</servlet>
<servlet-mapping>
    <servlet-name>Restreamer</servlet-name>
    <url-pattern>/restream</url-pattern>
</servlet-mapping>

• An optional step is to modify the socket.idle.timeout= value in red5pro/conf/srt-ingest-plugin.properties to set a longer timeout for socket idle, if the default of 2 minutes is not sufficient (time is configured in milliseconds)
• Other options may be configured in the redred5pro/conf/srt-ingest-plugin.properties as needed such as encryption key passphrase, length, etc.

API Calls

The Restreamer API documentation can be found in the development section.

Starting an endpoint for SRT streaming, requires a call to the API command prior to the start of your stream. By default, a timeout of 2 minutes is enforced while the endpoint listens for an SRT connection; this is the period during which the stream should be started. If the stream is not started within that time, the endpoint will be closed and the stream will need to be re-created.

An SRT stream requires a passphrase for encryption, which is set for each stream via the API call. The default encryption is set to a 16-byte key length (128-bit encryption), but this can be configured to use 24 or 32-length as well.

Test SRT Streaming with FFmpeg

How to test SRT with an MP4 file via FFmpeg.

1 – Create the SRT stream by running the API call (note: make sure the ports match between the API call and the FFmpeg command)

POST: https://(server)/live/restream

{
    "guid": "live/stream1",
    "context": "live",
    "name": "stream1",
    "level": 0,
    "parameters": {
        "type": "srt",
        "action": "create",
        "ip": "0.0.0.0",
        "port": 8000,
        "frameType": 0,
        "latency": 100,
        "reorder": 16, 
        "overhead": 100,
        "keyLength": 16,
        "passphrase": "Red5ProRules2024"
    }
}

2 – Start the stream via FFmpeg:

ffmpeg -re -stream_loop -1 -i TESTFILE.mp4 -c:v libx264 -b:v 5000k -bsf:v h264_mp4toannexb -profile:v baseline -level:v 3.2 -x264-params keyint=120:scenecut=0 -c:a aac -b:a 128k -ar 44100 -f mpegts "srt://YOUR-SERVER-IP:8000?pkt_size=1316&mode=caller&minversion=0x010300&latency=100000&oheadbw=100&transtype=live&pbkeylen=16&passphrase=Red5ProRules2024"

3 – Go to the subscribe page and refresh, the stream will be listed.