IPTS Input to Portsdown with the LimeSDR

You can feed pictures to your Portsdown from a PC-based video application such as vMix or OBS. For vMix the workflow is:

1. Start vMix and enable the external output. The settings are described in detail here Feeding_Video_to_Portsdown_from_vMix.
2. Use ffmpeg running on the PC (started by a batch file) to capture the "DirectShow" output from vMix and encode it into a transport stream to be sent to the Portsdown
3. Set IPTS input (from the "Encoding" menu) on the Portsdown and select transmit.

The complex part of this process is the encoding on the PC.

Use of a Batch File For Video Encoding on a PC

First, make sure that you have ffmpeg installed on your PC as detailed here: Feeding_Video_to_Portsdown_from_vMix#ffmpeg

The notes here are based on this batch file File:vMix2PortsdownH264DVB-S2.zip, which you should download, unzip and store in a sensible place on your PC. You will need to run it every time you set up transmissions from vMix or OBS. You will also need to edit it before using it for the first time.

One-time Editing

Before first use, you need to edit the batch file and enter your Portsdown's IP address and your callsign. So right-click the file and select Edit.

• Change the line "set ip=192.168.2.214" to the IP address of your Portsdown. You can look this up on Menu 2, Info on the touchscreen.
• Change the line "set callsign=G8GKQ" with your callsign.
• Near the end of the script, make sure that the line "C:\ffmpeg\bin\ffmpeg ^" actually points to where the ffmpeg program is. Don't forget to leave the ^ at the end of the line.