Method for using memory in time of decoding sub image frame of DVD

Abstract

In time of decoding sub image frame, only under condition that there is at least more than one pixel with contrast value of pixel other than zero in pixels of X coordinate and with Y coordinate equal to n, color value and contrast value of all pixels in X coordinate related to Y coordinate are stored in memory. Then, values of Y coordinate, where contrast value is not equal to zero, in original sub image frame are stored so as to accomplish decoding for sub image frame. Using stored values of Y coordinate in original sub image frame update value of SET_DAREA. Not storing color values and contrast values of decoded sub image frame in background pixel area, which users are unable to watch, into OSD memory reaches to effects of reducing use of OSD memory space, and raising efficiency of hardware.

Description

technical field [0001] The present invention relates to a sub-picture decoding device for DVD video, and more specifically, is an invention of a method for efficiently using memory by utilizing bitmap characteristics of pixel data during sub-picture decoding. Background technique [0002] DVD (Digital Video Disc) is an optical disc device, which has a single-layer (for example, DVD5) 4.7GB, double-layer (for example, DVD9) 8.5GB large-capacity, high-quality video and high-quality sound multimedia storage device. [0003] Such DVDs are played by DVD players or PCs with DVD-ROM drives, etc., through hardware and software decoding devices and display processing devices, the images and audio signals are restored for users to watch. [0004] In addition to the subtitles of ordinary DVDs, the latest DVD players also have CD-R, CD-RW, and CDDA playback functions. Some DVD players also have support for DVD-Audio, SACD, VCD, SVCD, DVD-R, DVD±RW , HDCD, MP3 functions. [0005] In a...

AI Technical Summary

Problems solved by technology

However, the user cannot see the background pixel area with a contrast value of 0

[0049] Therefore, if Image 6 As shown, when all encoded sub-picture data including the pixel data of all background pixel regions is decoded in the sub-picture decoder 150 and stored in the OSD memory 160, the problem of occupying a large amount of storage space of the OSD memory 160 occurs.

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