This paper derives optimal spatial scaling and rate control parameters for power-efficient wireless video streaming on portable devices. A video streaming application is studied, which receives a high-resolution and high-quality video stream from a remote server and displays the content to the end-user.We show that the resolution of the input video can be adjusted such that the quality-power trade-off 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 rate-control 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 Wi-Fi and a mobile network as well as for two different smartphones.

翻译：本文推导了便携式设备上节能无线视频流的最优空间缩放与码率控制参数。研究了一种从远程服务器接收高分辨率高质量视频流并向终端用户显示内容的视频流应用。我们证明可通过调整输入视频的分辨率来优化质量与功耗之间的权衡。利用文献中的功耗模型及基于感知度量的主观质量评估，推导出了编码中缩放因子与码率控制参数的最优组合。对于高清序列，在可忽略的质量损失下可节省高达10%的功耗，在可容忍的失真下可节省高达15%的功耗。为验证普适性，该方法在Wi-Fi及移动网络环境下，并针对两款不同智能手机进行了测试。