Video decoding apparatus, video decoding method, and digital audio/video playback system capable of controlling presentation of sub-pictures

摘要

A video decoding apparatus capable of controlling presentation of sub-pictures includes a first decoder, a second decoder, a first scaler, a second scaler and a combiner. The first decoder and the second decoder respectively decode a digital audio/video signal to generate a decoded video and a decoded sub-picture. In accordance with an output picture size, the decoded video size, the decoded sub-picture size and a sub-picture aspect ratio, the first scaler and the second scaler generate a first scaling factor and a second scaling factor. The combiner combines the decoded video and the decoded sub-picture according to the first scaling factor and the second scaling factor and outputs the combination thereof. A video decoding method and a digital audio/video playback system capable of controlling presentation of sub-pictures are also disclosed.

主权项

1. A video decoding apparatus capable of controlling presentation of sub-pictures, which is for decoding a digital audio/video signal and outputting an output picture through a video output device, wherein the digital audio/video signal includes a video bit stream and a sub-picture bit stream, the video decoding apparatus comprising:
a first decoder which receives the video bit stream and decodes the video bit stream to generate a decoded video; a second decoder which receives the sub-picture bit stream and decodes the sub-picture bit stream to generate at least one decoded sub-picture; a first scaler which captures the size of the decoded video and generates a first scaling factor according to the size of the output picture and the size of the decoded video; a second scaler which captures the size and the position of the decoded sub-picture and generates a second scaling factor according to the size of the output picture, the size of the decoded sub-picture, and a sub-picture aspect ratio; and a combiner which sets the size of the decoded video according to the first scaling factor, sets the size and the position of the decoded sub-picture according to the second scaling factor, combines the decoded video and the decoded sub-picture, and outputs the combined picture to the video output device.