Portsdown Webcams

Introduction

Webcams have proved difficult to support on the Portsdown as manufacturers spend a lot of effort in developing Windows drivers (for their major market), but very little effort in developing Linux drivers as it does not bring them much revenue.

The recommended WebCam is the Logitech C920, but this has 3 versions with identical external hardware, but with different elctronics and drivers. Only the oldest version is supported by the Portsdown 2020, but all 3 versions are supported by the Portsdown 4.

Logitech C920

The Logitech C920 has 3 versions:

• The original version, marketed from first introduction until early 2019, included a hardware H264 encoder, and is supported for DATV transmissions by both the Portsdown 2020 and the Portsdown 4. This version responds the the Linux lsusb command with

Bus 001 Device 00x: ID 046d:082d Logitech, Inc. HD Pro Webcam C920

• The second version used electronics manufactured by Orbicam and is only supported by the Portsdown 4. It was marketed from 2019 through to the end of 2020. It does not include a hardware H264 encoder, and responds to the lsusb command with:

Bus 001 Device 00x: ID 046d:0892 Logitech, Inc. OrbiCam

• The latest version does not include a hardware H264 encoder and is only supported by the Portsdown 4. It responds to the lsusb command with:

Bus 001 Device 00x: ID 046d:08e5 Logitech, Inc.

Logitech C170

The Logitech C170 is a cheaper, standard definition, mono sound webcam and is supported by the Portsdown 4.

Logitech C525

The Logitech C525 is supported by the Portsdown 4 for transmission with the Pluto. HOWEVER, after ceasing transmission the touchscreen is unresponsive for 5 seconds while the webcam drivers are reloaded.

Logitech C930e

The Logitech C930e is partially supported by the Portsdown 4 for transmission with the LimeSDR; some users have reported that the audio does not work. It works in a simialr fashion with the Pluto for DVB-T transmission, but not at all for DVB-S or DVB-S2.

Testing WebCams

The Info Screen (accessible from Menu 2) on the Portsdown 4 will report the variant of C920 that is connected to the Portsdown.

The C920 monitor (again from Menu 2) will show the image from many connected WebCams. However, the fact that an image is shown does not mean that Portsdown supports that WebCam. The Monitor display uses different drivers from the transmitting software.

Streaming from WebCams

The Portsdown 4 will stream vision and audio from a connected C920 (all versions) or a C170.

Providing WebCam Support

It is very difficult to configure Portsdown to work with a particular webcam. Usually, physical testing and incremental development is required with the actual webcam. Hence good support will always be provided for the original C920 and the C170, as these are available to the Portsdown developer. Support for other webcams relies on loan of examples and then maintenance of capability cannot be guaranteed as changes to the software may have adverse effects that cannot be tested before release.