Optimized on-screen video composition for mobile device

摘要

A method for displaying continuous video content on a mobile phone LCD renders plural source video textures as consecutive surfaces on the display. A hardware scaler, rather than a general purpose graphical processing unit (GPU), is used to render a particular surface whenever possible, because it uses less battery power than the GPU. The method determines if the hardware scaler is capable of rendering a particular surface and if the particular surface is to be rendered with one or more additional images derived from a source other than a source video texture. The hardware scaler renders surfaces, including any additional images, if it is capable of doing so; otherwise the GPU renders the surface. The method is applied dynamically to each video texture in a video session, so that the manner of rendering each surface, whether by using the hardware scaler or the GPU, can change from surface to surface.

主权项

1. A method for displaying continuous video content in a video session by rendering plural source video textures as consecutive surfaces on a display, the method comprising:
(a) determining if a hardware scaler module is capable of rendering all of a particular surface, the hardware scaler module having a first rendering mode and a second rendering mode, the first rendering mode comprising a secondary-only-optimized mode and the second rendering mode comprising a secondary-only mode; (b) rendering the surface using a general purpose graphical processing unit (GPU) if the response to the determining step (a) is negative, the graphical processing unit requiring greater power than the hardware scaler unit to operate, the hardware scaler unit configured to perform only a subset of graphic operations performable by the graphical processing unit; (c) determining if the particular surface to be rendered comprises one or more additional images incapable of rendering by the hardware scaler by iterating through the one or more additional images; (d) when:
the determining step (a) is affirmative and the determining step (c) is not affirmative, and it is determined that the surface does not comprise letterboxing portions: using the hardware scaler module in the first rendering mode to render the surface,the determining step (a) is affirmative and determining step (c) is not affirmative, and it is determined that the surface comprises letterboxing portions, wherein the surface comprises only video data renderable by the hardware scaler and letterboxing portions, using the hardware scaler module in the second rendering mode to render the surface without using the GPU to render the surface, and whendetermining step (c) is affirmative using the GPU and the hardware scaler module in the second rendering mode to render the surface; and (e) repeating steps (a) through (d) for the next consecutive surface.