Patent Publication Number: US-2006005223-A1

Title: Method of recording and playing video at optimized resolution

Description:
BACKGROUND OF THE INVENTION  
      1. Field of Invention  
      The invention relates to a video recording and playing method implemented in computer software. In particular, the invention relates to a method of recording and playing video at an optimized resolution automatically according to the resolutions of a display device and an original video.  
      2. Related Art  
      As the burning technology becomes mature and there are increasing demands for multimedia applications, the conventional analog video recording technique is no longer satisfactory for many video players. Instead, the DVD video recording technology of the digital versatile disc or digital video disc (DVD) has become popular.  
      However, the digital video playing is often limited by the insufficient playing and display functions of many commercial products on the market. Therefore, the high resoluton digital video cannot be fully appreciated by such products. As a result, common users may consider lower resolutions in recording video in order to match the playing and display quality of normal commercial products. However, this may cause the information loss in the original video. Once the user has a device with better playing and display functions, it is still impossible to play the video at a better quality because the resolution has been sacrificed.  
      Consequently, it is highly desirable to use the currently prosperous computer software technology to develop a method that can intelligently record video data with different resolutions in the recording medium in order to satisfy playing and displaying devices at various levels. The users can therefore enjoy video contents at an optimized resolution. This is believed to be the mainstream in the field of digital audio-video (AV) recording technology in the near future.  
     SUMMARY OF THE INVENTION  
      In view of the foregoing, the invention provides a method of recording and playing video at an optimized resolution. Its primary objective is to achieve resolution optimization when recording video data through intelligent determination of the resolutions of a display device and an original video. At the same time of copying the stream file with the standard resolution, another stream file with an optimized resolution is recorded, too. When playing the video stored in the recording medium, the stream file with the most appropriate resolution is extracted for display. Therefore, the invention can satisfy different display devices and different needs of users.  
      To achieve the above objective, the system implemented with the disclosed method includes: an operating module, an extracting module, a playing module, and a recording module.  
      The disclosed method includes the steps of: selecting a source video file to start a recording procedure, extracting the maximum resolution of a display device, detecting the maximu resolution of the source video file, determining a final recording resolution, starting the recording procedure on a recording medium.  
      In a preferred embodiment of the invention, the disclosed method further includes the steps of: selecting a recording medium to start a playing procedure, reading the resolution data of the video data, extracting the maximum display resolution of the display device, comparing the maximum display resolution with the resolution data, and playing the stream file after the comparison. 
    
    
     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  shows the operation of the disclosed method of recording and playing video at an optimized resolution;  
       FIG. 2   a  is a flowchart of video recording according to the disclosed method;  
       FIG. 2   b  is another flowchart of video recording according to the disclosed method; and  
       FIG. 3  is a flowchart of video playing according to the disclosed method. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      The specification discloses a video recording and playing method with an optimized resolution. Through intelligent determination of the resolutions of a display device and an original video, an optimized recording resolution is found. In addition to copying the stream file with the standard resolution, the invention also records the stream file with the optimized resolution. When playing the video on the recording medium, the invention compares the identification data in each of the stream files and finds a most appropriate stream file that has the best quality on the display device. Therefore, the invention can satisfy all display devices and different playing needs of users.  
      In the following, we use  FIG. 1  to explain the system structure of the invention. The disclosed system  200  is between a computer executable platform  50  and a recording medium  100 . It is used to automatically find an optimized resolution when recording and playing video. Its basic structure contains: an operating module  210 , an extracting module  220 , a playing module  230 , and a recording module  240 .  
      (1) The operating module  210  is used to generate a user interface (UI) that provides a menu of various functions for the user to perform operations during video recording and playing. Such operations include: selecting a source video file, setting parameters for recording, executing the recording procedure, setting parameters for playing, and executing the playing procedure.  
      (2) The extracting module  220  extracts a source video file for recording from the computer executable platform  50 . During the playing procedure, the extracting module  220  extracts a stream file to be played from the recording medium  100 .  
      (3) The playing module  230  checks the identification data (e.g. title and resolution) in each of the stream files according to the user&#39;s operations. According to the display power of the display device on the computer executable platform  50 , the playing module  230  selects a stream file with the optimized quality to play.  
      (4) The recording module  240  performs the recording procedure with the optimized quality according to the display power of the display device on the computer executable platform  50  and the resolution of the source video file that the user wants to copy. In fact, in addition to performing optimized recording, the recording module  240  further has the function of recording using the standard resolution (usually 720*480 pixels) in order to ensure that the recorded video can be played on all display devices.  
      Moreover, the disclosed video recording and playing system  200  allows the user to assign a recording resolution through the UI. Therefore, in addition to the standard resolution recording, the optimized resolution recording, the user also has the choice of the customized resolution recording.  
      We use  FIGS. 2   a  and  2   b  to explain the procedure of video recording in accord with the invention. First, a user selects a source video file from a computer executable platform  50  to start a recording procedure (step  300 ). The system reads out the maximum display resolution of the display device on the computer executable platform  50  (step  310 ). Afterwards, the system detects the maximum video resolution in the source video file selected by the user (step  320 ). After obtaining the values in steps  310  and  320 , the system makes a comparison to see if the maximum display resolution is greater than the maximum video resolution (step  330 ). If the former is larger, the display power is better than the quality of the source video file. The system then takes the maximum video resolution of the source video file as the recording resolution (step  340 ). Otherwise, the display power of the display device is worse, and the system uses the maximum display resolution of the display device as the recording resolution (step  350 ). Once the recording resolution is determined, the system executes a recording procedure (step  360 ), whose detailed steps are shown in  FIG. 2   b  to be explained later. During the recording process, the system keeps checking if the recording is done (step  370 ). If not, then the system keeps executing step  360 . Otherwise, the recording procedure is completed (step  380 ).  
      When executing the recording procedure (see  FIG. 2   b ), the system first reads out the recording resolution (step  361 ) and then determines whether the recording resolution is the same as the predetermined standard resolution of the system (step  362 ). If they are different, the system has to perform the optimized resolution recording and the standard resolution recording at the same time. The system copies a stream file to the stream using the recording resolution (i.e. the optimized resolution) (step  363 ) and checks whether the recording is complete (step  364 ). If not, the procedure stays at step  363 ; otherwise, the completed stream file is appended with playing identification data (step  365 ). Afterwards, another stream file is recorded to another stream according to the standard resolution (step  366 ). Likewise, step  366  is repeated until the recording is completed and goes to step  380 . If the recording resolution is the same as the standard resolution in step  362 , there is no need for the optimized resolution recording and the system continues to step  366  directly for standard resolution recording.  
      Finally, we use  FIG. 3  to explain the video playing procedure. First, a user selects a recording medium in a storage medium device  100  to start a playing procedure (step  400 ). The system determines whether all the stream files in the storage medium device have playing identification data (step  410 ). If there are, the system further extracts the resolution data stored therein (step  420 ). The resolution data mainly contains the optimized playing resolution of the stream file. The system then reads the maximum display resolution of a display device (step  430 ). After the two resolution data are obtained, the system compares them (step  440 ). If the maximum display resolution is greater than the resolution data in the stream file, the display device has the ability to display the stream file and the system plays the stream file (step  450 ). Otherwise, the display device does not have sufficient display power, and the system plays the stream file with the standard recording resolution (step  460 ) and ends the video playing procedure. Likewise, if the system cannot fina any stream file with playing identification data in step  410 , it jumps to step  460  to play the stream file with the standard resolution.  
     EFFECTS OF THE INVENTION  
      The disclosed video recording and playing method with an optimized resolution can automatically find an optimized resolution between a display device and a source video. It generates an optimized stream file with a resolution higher than the standard one on a storage medium. Therefore, the source video will not be over-compressed to have distortion.  
      When playing the storage medium, the playing identification data in the stream file helps optimizing the playing effects according to the specification of the display device. The user can enjoy the best video quality available.  
      Certain variations would be apparent to those skilled in the art, which variations are considered within the spirit and scope of the claimed invention.