Why does the Veo Web Camera generate timeout errors when using Image Acquisition Toolbox 1.7 (R14SP1)?

I am using the Image Acquisition Toolbox with a device named "Veo Web Camera (VFW Mapper for Messenger)". However, when I try using GETSNAPSHOT or GETDATA, a Timeout error is thrown. For example, I might execute:

vid = videoinput('winvideo'); 

data = getsnapshot(vid);

This code generates the following error:

 ??? A timeout occurred during GETSNAPSHOT.

If I try using PREVIEW, the preview window does not update or display any data.

Answer 1

[MathWorks Support Team]

This enhancement has been incorporated in Release 14 Service Pack 3 (R14SP3). For previous product releases, read below for any possible workarounds:

There is an issue when using the Image Acquisition Toolbox with the Veo Mobile Connect Web Camera. When using the Image Acquisition Toolbox, this device is typically exposed as 2 separate devices named "Veo Mobile/Advanced Web Camera" and "Veo Web Camera (VFW Mapper for Messenger)".

When the "Veo Web Camera (VFW Mapper for Messenger)" device is accessed, the low-level driver provided by the vendor is a Video For Windows (VFW) driver, which is based on VFW, an obsolete Microsoft technology. To make this device compatible with Microsoft's newer DirectX technology, DirectX uses a VFW driver wrapper that emulates the functionality of a Windows Driver Model (WDM) driver. However, these driver wrappers are often limited in their functionality since they are ultimately using a VFW driver.

In this specific case, the vendor's VFW driver only supports DirectX "previewing", which is used by programs such as AMCAP. However, the toolbox requires DirectX "capture" support, which the vendor's VFW driver does not support.

To work around this problem, use the device named "Veo Mobile/Advanced Web Camera" instead. This device uses a true WDM driver, and is compatible with the Image Acquisition Toolbox.