Abstract:
A computer executable digital video rendering restoration method is disclosed. Through setting a saving interval, data of states during the rendering process of digital videos are recorded periodically. When the rendering process is abnormally interrupted, the state data in the record file can be immediately used to restore the digital video before the last recording so that the user can continue the digital video rendering.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The invention pertains to a computer-based digital video rendering method and, in particular, to a method that records state data periodically during the rendering process of a digital video so that the video can be immediately restored once the process is abnormally interrupted. 
     2. Related Art 
     Making digital video using computers is always a time-consuming job. Althrough with the help of computers the editing task is much easier and faster than traditional manual processing, it still takes hours or even days to render videos because of the varieties of materials used during filming and in order to produce special effects. 
     During the long video rendering process, the users often worry that it may be interrupted because of abnormal conditions happened to the computer. Such abnormal conditions may be caused by irregular power supply, system breakdown, etc. These problems usually result in re-doing the video rendering because the work is not saved. This would be a disaster for those who spend a lot of time rendering digital videos. 
     Therefore, for film companies that are devoted to developing computer-based digital video rendering software, it is among the top priorities to be able to restoring digital videos back to their original states within the shortest possible time if an abnormal interruption happens to the rendering process. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, the invention provides a computer-based digital video rendering restoration method. A primary objective of the invention is to periodically record the stata data during the digital video rendering process. If anything abnormal or interruption occurs to the rendering process, the previously stored state data can be used to return to the original rendering process. 
     Another objective of the invention is to temporarily record digital videos in memory in a periodic way. A flushing process is performed only after each small section of the digital video is completed. Therefore, the invention also achieves the goal for a fast and efficient digital video rendering process. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will become more fully understood from the detailed description given hereinbelow illustration only, and thus are not limitative of the present invention, and wherein: 
       FIG.  1 - a  is a flowchart of the disclosed computer-based digital video rendering restoration method for video rendering; and 
       FIG.  1 - b  is a flowchart of restoring a render digital video according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention discloses a computer-based digital video rendering restoration method. Set by the user, the computer can automatically record state data during the digital video rendering process. If anything abnormal happens, the saved file can be immediately used to restore the state of the video rendering before the last recording. In the traditional video rendering process, only a single project file is employed to record the paths of required materials, item names of materials, length of the film, time-ordering of the film, and special effects. It does not contain any information about the state of the rendering process. Once the process is abnormally interrupted, there is no way to restore the unfinished part as long as it is not saved. The user therefore has to spend more time to re-rendering the lost video. 
     In the following paragraphs, we use FIG.  1 - a  and FIG.  1 - b  to explain the procedure of the disclosed method. 
     First, the system reads a project file (step  100 ). This file stores the paths of rendering materials, item names of materials, length of the film, time-ordering of the film, and special effects. These data are set by the user before rendering the video. The main purpose of this file is to perform the film making process according to the user            settings. Step  110  extracts the value of recording interval and counts the number of recording times. The recording interval can be set by the user in advance or predetermined using the program          default. The number of recording times is determined by the length of the film divided by the recording interval. For example, if the length of the film is 100 minutes and the recording interval is 10 minutes, then the number of recording times is 100/10=10. Step  120  starts the video rendering process and time-counting. The video contents are temporarily stored in memory. To reduce direct access to disk drive and increase the video rendering efficiency, the temporarily finished video is stored in the memory, which is usually random access memory (RAM). The system then determines whether the rendering process reaches the recording interval (step  130 ). If not yet, step  120  continues; otherwise, the video contents in the memory is flushed to the end of the temporary file in the disk drive (step  140 ). Afterwards, the system updates the rendering state of a restoration file (step  150 ). The system further determines whether the number of recording times is reached or not (step  160 ). If not, then the system keeps updating the rendering and time states (step  180 ). Otherwise, the temporary video file is closed and the rendering state recording is stopped (step  170 ). This concludes the whole video rendering process.
     At the same time, if there is no abnormal interruption during the video rendering, the whole digital video can be smoothly completed. However, if there is any interruption (step  190 ), e.g. if power supply is out of order or the computer system breaks down during steps  120 ,  140 ,  150 , or  170 , the system enters step A to restore the video. This part is illustrated in FIG.  1 - b.    
     After restarting the system automatically by the computer itself or manually (step  200 ), the disclosed method directly retrieves the last video project file and reads out the rendering state (step  210 ). The rendering state is stored in the restoration file. The file contains: paths of rendering materials, item names of materials, length of the film, the path of the project file, closing state tag, recording interval, the number of recording times, and rendering time. The system determines whether there is a closing state tag in the restoration file (step  220 ). If there is, it means that the previous video rendering is completed and no restoration is needed. If there is no closing state tag, then the system further extracts the recording interval, the number of recording times, and the rendering time (step  230 ). The rendering time records the last time point of the previous video rendering. It is compared with the number of recording times in order to determine a correct time for the video restoration. Once it is determined, the system reads the project file (step  240 ) and obtains the paths of rendering materials, the item names of materials, the length of the video, the time-ordering of the video, and special effects. The system extracts the rendering materials (step  250 ) to see if they are complete (step  260 ). If they are not complete, namely, the paths of rendering materials or rendering materials are destroyed such that they cannot be used, the system prompts a window for the user to input new locations of the rendering materials (step  280 ). After the input, the procedure goes to step  250  and starts to extract rendering materials. If the rendering materials are complete (step  260 ), then the video rendering process starts (step  270 ). After the restoration, the video rendering process enters step  120 . The system starts time-counting and temporarily stores video contents in the memory. The rest of the procedure is exactly the same as that after step  120  described in FIG.  1 - a.    
     Certain variations would be apparent to those skilled in the art, which variations are considered within the spirit and scope of the claimed invention.