Abstract:
A video recorder includes a sound occurrence detection system to detect a sound occurrence in an area. A detection method can detect the sound occurrence by using the video recorder. The detection method establishes relationships between rotation angles of the video recorder and sound output orientations of a sound source in the area. Furthermore, the detection method determines a rotation angle according to the relationships once the sound occurrence occurs, and rotates the video recorder according to the rotation angle, to record videos and sounds of a sound source that causes the sound occurrence.

Description:
BACKGROUND 
     1. Technical Field 
     Embodiments of the present disclosure generally relate to video systems, and more particularly to a video recorder and a method for detecting a sound occurrence in an area where the video recorder is used. 
     2. Description of Related Art 
     A video recorder, in normal use, refers to a device that records videos and sounds in a digital format to a disk drive or other memory medium. Video recorders often will be used to monitor an area by recording videos and sounds in the area. 
     However, a conventional video recorder can only record videos and sounds of objects that are located in a immovable working area of the video recorder. It cannot automatically record videos and sounds of objects that are not located in the immovable working area. Such kind of video recorder is thus less functional than otherwise desired, leading to failure to obtain some recordings for some videos and sounds occurrences in a monitored area. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of one embodiment of a video recorder for detecting a sound occurrence in an area. 
         FIG. 2  is a flowchart illustrating one embodiment of a method for establishing a relationship list used by a video recorder. 
         FIG. 3  illustrates one embodiment of determining a sound output orientation of a sound occurrence. 
         FIG. 4  illustrates one embodiment of dividing an area into a plurality of subareas to detect a sound occurrence. 
         FIG. 5  is a flowchart illustrating one embodiment of a method for detecting a sound occurrence in an area through the relationship list of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
     The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one. 
     In general, each “step” described below, is operative under the controlling of a corresponding “module.” The word “module,” as described herein, refers to logic embodied in hardware or firmware, or to a collection of software instructions, written in a programming language, such as, for example, Java, C, or Assembly. One or more software instructions in the modules may be embedded in firmware, such as an EPROM. It will be appreciated that modules may comprised connected logic units, such as gates and flip-flops, and may comprise programmable units, such as programmable gate arrays or processors. The modules described herein may be implemented as either software and/or hardware modules and may be stored in any type of computer-readable medium or other computer storage device. 
       FIG. 1  is a block diagram of one embodiment of a video recorder  1 . The video recorder  1  may include a sound occurrence detection system  12 , a sound classifier  13 , and a drive motor  15 . The sound occurrence detection system  12  may be used to monitor an area by detecting a sound occurrence in the area. In the embodiment, at least three sound receivers  5  are set around the video recorder to receive the sound occurrence. 
     In the embodiment, the sound classifier  13  includes a plurality of sound classes. Sound representative characters of one of the sound classes can be determined by a prerecorded sound class. The classification accuracy of the sound classifier  13  mostly depends on sound sample data used during the prerecorded sound class. If the sound sample data of each sound class can be collected completely, the sound classifier  13  has better classification accuracy. The sound classifier  13  can classify a sound received from the three sound receivers  5  if the sound belongs to one of the plurality of sound classes. 
     In the embodiment, the drive motor  15  is controlled by the sound occurrence detection system  12  to rotate the video recorder  1 , to record videos and sounds of a sound source. 
     In the embodiment, the sound occurrence detection system  12  includes a relationship establishing module  120  and a sound detection module  121 . The relationship establishing module  120  establishes a relationship between a rotation angle of the video recorder  1  and a sound output orientation of each sound source in the area. 
     The sound detection module  121  determines a current sound output orientation of a sound occurrence in the area. Furthermore, the sound detection module  121  determines a current rotation angle of the video recorder  1  according to an established relationship related to the current sound output orientation. In addition, the sound detection module  121  controls the drive motor  15  to rotate the video recorder  1  according to the current rotation angle, to record videos and sounds of a sound source that causes the sound occurrence. 
     In the embodiment, the video recorder  1  may include a memory system  16 , such as a random access memory (RAM) for temporary storage of information and/or a read only memory (ROM) for permanent storage of information, and/or a mass storage device  11 , such as a hard drive, or optical media storage device. The mass storage device  11  may comprise one or more hard disk drives, optical drive, networked drive, or some combination of various digital storage systems. In the embodiment, the mass storage device  11  may store the sound occurrence detection system  12 , sound data, and needed data generated by the sound occurrence detection system  12 . The video recorder  1  also includes at least one processor  10  for computation during the process of detecting sound occurrences in the area. The memory system  16  or the mass storage device  11  may include one or more function modules to implement the sound occurrence detection system  12 . The above mentioned components may be coupled by one or more communication buses or signal lines. It should be apparent that  FIG. 1  is only one example of an architecture for the video recorder  1  that can be included with more or fewer components than shown, or a different configuration of the various components. 
     The video recorder  1  is generally controlled and coordinated by an operating system, such as the UNIX, Linux, Windows 95, 98, NT, 2000, XP, Vista, Mac OS X, an embedded operating system, or any other compatible operating systems. In other embodiments, the video recorder  1  may be controlled by a proprietary operating system. 
       FIG. 2  is a flowchart illustrating one embodiment of a method for detecting a sound occurrence in an area through the video recorder  1 . In the embodiment, the sound occurrence detection system  12  comprises one or more computerized codes that are stored in the sound occurrence detection system  12  and executable by the at least one processor  10  of the video recorder  1  to perform the method. 
     In block S 10 , the video recorder  1  is set in an area to be monitored, and the three sound receivers  5  are set around the video recorder  1 . For example, as shown in  FIG. 3 , locations of three sound receivers  5  forms a triangle, and the sound output orientation of a sound generator  2  is determined according to a sequence and time differences that the three sound receivers  5  receive a sound of the sound generator  2 . 
     In block S 11 , the relationship establishing module  120  divides the area into a plurality of subareas, and selects a subarea as a normally monitored area of the video recorder  1 . Furthermore, the relationship establishing module  120  controls the video recorder  1  to focus on the center of the selected subarea. For example, as shown in  FIG. 4 , the area  3  is divided into a plurality of subareas  4 . 
     In block S 12 , the relationship establishing module  120  places the sound generator  2  at the center of the selected subarea, obtains a first sound output from the sound generator  2 , and analyzes the first sound to get a standard sound output orientation. 
     In block S 13 , the relationship establishing module  120  controls the video recorder  1  to focus on the sound generator  2  when the sound generator  2  is placed at the center of another subarea. Furthermore, the relationship establishing module  120  obtains a second sound output from the sound generator  2 , and analyzes the second sound to get a current sound output orientation. 
     In block S 15 , the relationship establishing module  120  calculates a rotation angle of the video recorder  1  according to the standard sound output orientation and the current sound output orientation. Furthermore, the relationship establishing module  120  establishes a relationship between the rotation angle and the current sound output orientation, and controls the video recorder  1  to refocus on the center of the selected subarea. 
     In block S 16 , the relationship establishing module  120  analyzes whether relationships of all the subareas have been established. 
     If the relationships of all the subareas have been established, block S 17  is implemented. If a relationship of a subarea has not been established, block S 13  is repeated. 
     In block S 17 , the relationship establishing module  120  generates a relationship list according to established relationships. 
       FIG. 5  is a flowchart illustrating one embodiment of a method for detecting a sound occurrence in the area through the relationship list. 
     In block S 20 , the sound detection module  121  detects a sound of the sound occurrence in the area by the at least three sound receivers  5 . 
     In block S 21 , the sound detection module  121  analyzes whether the detected sound is acceptable by the sound classifier  13  of the video recorder  1 . In the embodiment, the sound detection module  121  analyzes that the detected sound is acceptable, by analyzing if the detected sound belongs to a sound class of the sound classifier  13 . Otherwise, the sound detection module  121  analyzes that the detected sound is unacceptable, by analyzing if the detected sound does not belong to a sound class of the sound classifier  13 . 
     If the detected sound is acceptable, block S 22  is implemented. If the detected sound is unacceptable, block S 20  is repeated. 
     In block S 22 , the sound detection module  121  analyzes the detected sound to get the current sound output orientation. 
     In block S 23 , the sound detection module  121  determines a current rotation angle of the video recorder  1 , by searching a established relationship related to the current sound output orientation from the relationship list. 
     In block S 25 , the sound detection module  121  controls the drive motor  15  to rotate the video recorder  1  according to the current rotation angle. 
     In block S 26 , the sound detection module  121  controls the video recorder  1  to record videos of a sound source that causes the sound occurrence. 
     In block S 27 , the sound detection module  121  controls the video recorder  1  to record the sound of the sound source. 
     Although certain inventive embodiments of the present disclosure have been specifically described, the present disclosure is not to be construed as being limited thereto. Various changes or modifications may be made to the present disclosure without departing from the scope and spirit of the present disclosure.