Next generation video coding for mobile applications : Industry requirements and technologies Handheld batteryoperated consumer electronics devices such as camera phones, digital still cameras, digital camcorders, and personal media players have become very popular in recent years. Video codecs are extensively used in these devices for video capture andor playback. The annual shipment of such devices already exceeds a hundred million units and is growing, which makes mobile batteryoperated video device requirements very important to focus in video coding research and development. This paper highlights the following unique set of requirements for video coding for these applications: low power consumption, high video quality at low complexity, and low cost, and motivates the need for a new video coding standard that enables better tradeoffs of power consumption, complexity, and coding efficiency to meet the challenging requirements of portable video devices. This paper also provides a brief overview of some of the video coding technologies being presented in the ITUT Video Coding Experts Group (VCEG) standardization body for computational complexity reduction and for coding efficiency improvement in a future video coding standard.

PowerEfficient Video Streaming on Mobile Devices Using Optimal Spatial Scaling This paper derives optimal spatial scaling and rate control parameters for powerefficient wireless video streaming on portable devices. A video streaming application is studied, which receives a highresolution and highquality video stream from a remote server and displays the content to the enduser. We show that the resolution of the input video can be adjusted such that the qualitypower tradeoff is optimized. Making use of a power model from the literature and subjective quality evaluation using a perceptual metric, we derive optimal combinations of the scaling factor and the ratecontrol parameter for encoding. For HD sequences, up to 10% of power can be saved at negligible quality losses and up to 15% of power can be saved at tolerable distortions. To show general validity, the method was tested for WiFi and a mobile network as well as for two different smartphones.