The UMSIW_Portable object provides support for the G10 Graphics with Motion Video Adapter. This object inherits or overrides all methods from the UMSImageWindow base class and does not add new methods.
This object supports the YUV422 and YUV422_UYVY image formats.
A YUV422 image is composed of 32 bits per pair of pixels. The pixels are in order from left to right, top to bottom. For each pair of pixels in memory, the first 8 bits are Y1. The next 8 bits are U. The next 8 bits are Y2. The last 8 bits are V.
A YUV422_UYVY image is composed of 32 bits per pair of pixels. The pixels are in order from left to right, top to bottom. For each pair of pixels in memory, the first 8 bits are U. The next 8 bits are Y1. The next 8 bits are V. The last 8 bits are Y2.
Because of the format of the YUV422 and YUV422_UYVY images, the width must be an even number.
The maximum image size is 640x480 pixels.
There is one default that can be set in the .UMS_config file for this object. The stanza begins with the text "UMSIW_Portable:". The setting default_color_key can be set to the name of any color that the X11 function XAllocNamedColor accepts.
This object uses color keying to clip the video to the window boundary. The method is similar to, but not the same as, chroma-keying. The color used for keying is specified in the .UMS_config file in the default_color_key setting. There is no way to prevent other applications from using the same color. The video might show through into other windows. You can change the color in the configuration file to reduce the interference.
The UMSVideoInPortable and UMSIW_Portable objects talk to the same hardware. There can be only one of these objects active at a time. The objects also cannot use the hardware if it is being used by another application. An example would be a video conferencing application that talks directly to the device. The objects cannot open the device when the NTSC output is turned on (with the command "ntsc on").
These objects cannot open the device if the XVideo extension is not present in the server. The command line arguments -x xv are usually added to the /usr/lpp/X11/defaults/xserverrc file. This extension might not be present if the X server is started in a way that does not use the xserverrc file.
For introductory information, see Programming with Image Window Objects.