Both Axis and Pelco depend on OpenGL for dewarping. If dewarping is not working for a Windows client because of GPU driver issues you can use the following open source Mesa3D software OpenGL drivers as a work around. This will basically use a software implementation of OpenGL to do the dewarping which is really no worse than 90% of the other dewarping libraries anyway. It will not perform as well as if it were using the GPU OpenGL drivers, but it seems reasonable. CPU usage went from 6% using GPU drivers to 12% using these drivers.
The process of decompressing and displaying hundreds of video images per second is processor-intensive. It is possible to use the capabilities of modern display adapters to offload the main workstation processor from some of this work.<br>
The ExacqVision Desktop Client tries to automatically determine the best operational mode and colorspace for the available display hardware. Because various display adapter vendors have different levels of support or tests for the various modes and colorspaces, occasionally situations arise where the automatically detected mode does not work properly. The Client settings page allows the user to control the selection of the mode and colorspace of the display acceleration.<br>
The following modes are available:
In Auto mode, the Client will attempt to detect the correct GPU decoded path for your operating system. The Client will revert to None automatically if it detects that the display adapter does not support that mode.
In Direct3D mode, additional options are available for selecting specific colorspaces. Direct3D is a decoding method developed by Microsoft for Windows only GPU decoding. Direct3D enables applications to interact with display hardware from any vendor that provides a Direct3D driver and provides a method for applications to determine the modes of hardware acceleration that are available in the display hardware.
In OpenGL mode, additional options are available for selecting specific colorspaces. OpenGL is a cross-platform GPU decoding method, meaning it can be used on non-Windows operating systems as well. When selecting OpenGL, the processor decompresses the frame and provides it to the display adapter in a supported colorspace. The display hardware scales the image and copies it to the overlay buffer. Each time the monitor retraces, the display adapter combines the frame buffer with the overlay buffer to produce an output. This mode offers the best performance because the workstation processor does not have to scale images or convert colorspace. It also reduces flicker because any onscreen graphics are in the frame buffer, which is independent of the images that are updated in the overlay buffer.
In None mode, the workstation processor does all the work and makes no use of display adapter acceleration. The None setting for VGA acceleration is the most conservative setting in terms of minimizing potential issues with VGA drivers. However, selecting None requires more CPU horsepower to decompress and display images in the Client.
NOTE: While the None mode is reliable, because it does not depend on a driver from the display adapter manufacturer, this mode could result in a reduced displayable frame rate if the workstation processor is 100% in use. You can assess this setting in a Windows Client by running Task Manager and monitoring CPU usage while running in Live Mode. Remember that a single instance of the Client cannot run on multiple cores, so if you have a two-core processor, it might display 50% CPU usage when fully loaded by a single Client.
