This allows you to choose between the EVR, VMR9 and VMR7 renderers that are used to display video in the player. It is recommended that you leave EVR or VMR9 selected, but some older graphics cards (or buggy drivers) may play "blank" video using EVR or VMR9 - in such cases choosing VMR7 may solve this problem.
You can also choose between the windowless or windowed mode of the VMR9 or VMR7. Windowless mode is preferred, but the older windowed mode (also referred to as compatibility mode) is sometimes useful for supporting older graphics cards.
Note that windowed mode may be the only mode which works in virtual machines such as VirtualBox and VMWare Fusion due to the limited capabilities of the virtual graphics drivers. For this reason the use of DVMP Pro on virtual machines is not recommended.
We always recommend that video is shot in landscape orientation because most displays (e.g. TV and monitors) where it will be viewed are inherently landscape devices. If video is recorded on a smartphone this means that the smartphone should be held in landscape/sideways orientation. However, smartphone users sometimes record video by holding the camera "upright" in portrait orientation, which results in video files where the image is lying on its side when played back on a TV or computer monitor.
Although video is always recorded in landscape format, most smartphones do detect which way up the phone is being held and store a corresponding orientation flag in the recorded video file.
When video files are played in DVMP Pro, it would be great if the video renderer could check this orientation flag and if necessary rotate the video image so that it would be displayed in its original portrait orientation, instead of "on its side". Unfortunately all of the Microsoft renderers in the selectable list are not capable of rotating the video image. However, if you often need to play video files that have been shot in portrait orientation, you can check the tickbox Use rotation-capable renderer when video is rotated which tells DVMP Pro to override the selected renderer and use a third-party rotation-capable renderer whenever you play a file that is flagged as portrait oriented - the video image is then displayed rotated according to the file's orientation flag. If your computer does not have a rotation-capable renderer installed, the tickbox text will be suffixed with "(none detected, setting ignored)".
At present the only third-party rotation-capable renderer that is supported by DVMP Pro is MadVR which can be downloaded from its web site http://madvr.com - but it is slighty tricky to install. It downloads as a ZIP file which you must unzip into a new folder on your computer - the new folder will be its home so you must not subsequently delete or rename the folder otherwise MadVR will stop working. You then right-click the install.bat file and choose Run as administrator - this will register the MadVR renderer with Windows which allows it to be used by DVMP Pro and other video software on your computer. Then in DVMP Pro click the Tools > Options > Renderers menu and the "(none detected, setting ignored)" text should have disappeared - this confirms that MadVR was successfully installed. The first time you play a portrait video file you might see a warning message box saying "File Open - Security Warning Do you want to run this file madHcCtrl.exe" - this is just the madVR control panel, so UNtick "Always ask before opening this file" and click the Run button, then you won't see the warning again.
Please note that on some computers the Intel AVC/H.264 and MPEG-2 video decoders do not work well with madVR. If you are using madVR and the Intel video decoders, and you encounter errors, freezing or green-tinted video in the player window when playing portrait oriented files, then change the selected AVC/H.264 and MPEG-2 video decoders in Tools > Options > Video Decoders to the "LAV Video Decoder" which works much better with madVR. Further details of the LAV Video Decoder can be found in the Decoder Recommendations section.
For a more detailed explanation of video orientation see the Portrait Oriented Video section.
The Force Display Aspect Ratio option can be used to force the video to be displayed in the player as 16:9 or 4:3. You should find that nearly all of the supported video file formats play with the correct display aspect ratio, so we recommend that you leave this option un-checked.