Balluff - BVS CA-GT Technical Documentation
VLC Media Player Issues

Wrong Colors in the VLC Media Player

When using the DirectShow_Acquire capture source with VLC Media Player 3, wrong colors can be seen in the camera images.

This is a known bug in VLC Media Player 3, which will apparently be fixed in version 4.x, but probably not in version 3.x. The effect results from VLC interpreting the normal 24-bit video format delivered by all DirectShow Video Capture sources (=RV24, MEDIASUBTYPE_RGB24) as a different pixel layout and consequently swapping the red and the blue channels.

As a workaround, the image format of the DirectShow_Acquire capture source can be changed before starting streaming. To do this, follow the steps according to Changing Camera Properties and change the ImageDestination/PixelFormat from "RGB888Packed" to "BGR888Packed".

After clicking "OK" in the property dialog, choose your desired activity, and the camera will show correct colors.

Note
The PixelFormat used for streaming can only be changed manually for a recording/playback session, but not permanently.

Background

Changing the device's property ImageDestination/PixelFormat from "RGB888Packed" to "BGR888Packed" might seem odd if you are used to the PixelFormatNamingConvention or have already delved into details about in-memory image format storage.

The 24-bit Windows RGB format defines pixels of blue, green and red color in this order, so logically, this is a "BGR" format. Due to historical reasons, the Impact Acquire image format "RGB888Packed" corresponds to this standard Windows bitmap format.

The PixelFormat property of the camera, on the other hand, conforms to the GenICam™ Pixel Format Naming Convention, and would be described there as "BGR8".