Screen test

In spite of continuing speculation as to whether mobile video broadcast will ever get the take up needed to be regarded as a success, the demand for high quality mobile video on handheld devices is strong. The mobile gaming and media player market expects a vibrant, high resolution wide screen experience and the first mobile phone handsets with displays capable of supporting this are starting to appear on the market. Technology is defined by how people use it and the modern user’s expectation, set by home cinema screens and fantastic surround sound audio. PDAs, portable media players and mobile phones therefore have a tough job to impress when full motion video is offered in handheld guise. This obviously entails complexity not found in larger, mains powered devices and power consumption, which directly relates to play time, is the most limiting factor. It doesn’t matter how great the display is if the battery doesn’t last until the end of the movie. And any display designer will tell you that full frame rate displays are a lot tougher to get right than a static display. Whether the video stream originates from a 3G network or from a micro hard disk, there is dsp overhead for decompression and processing. This requires much more processing power than decompressing a static image. Then it has to be displayed. Driving the lcd in a portable device and providing the colour management required for quality video can increase power significantly too. Add to this the problems of backlight control to deal with temperature variations and ambient light correction and the power budget goes top of the list.