Patent Publication Number: US-2016241770-A1

Title: Ip camera and video playback method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from Taiwan Patent Application No. 104105569, filed on Feb. 17, 2015, in Taiwan Intellectual Property Office, the contents of which are hereby incorporated by reference in their entirety for all purposes. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The exemplary embodiment(s) of the present invention described hereinafter relates to an IP camera, more specifically, the exemplary embodiment(s) of the present invention relates to a video playback method thereof with automatically detecting the quality of the output image and accordingly performing improvements thereon. 
     2. Description of the Related Art 
     IP camera is an apparatus includes a camera, a video compression chip, and a computer, and the computer therein is a micro-computer designed for network application function. Each IP cameras has its own IP network address, and can be connected to the network as a network equipment. The IP camera also includes built-in software acting as web-servers, FTP servers, FTP clients, and E-mail clients. 
     While the captured video is transmitted by the IP camera through the network, network congestion usually happens under the environment of wired/wireless network, which is inconvenient for users who desire for real-time video. In prior arts, the reduction of the resolution of the video may be utilized to solve the problem, however, it may also cause the problem of blurring image. 
     Hence, it is a primary issue to give consideration to both the fluency and the clarity of the picture quality while the IP cameras are streaming videos via the network. 
     SUMMARY OF THE INVENTION 
     To solve the problems in the conventional arts, a primary objective of the present invention is to provide an IP camera and a video playback method thereof to solve the fluency problem happens while the IP camera is playing in real-time through the network. 
     To solve the problems in the conventional arts, it is a primary objective of the present invention to provide an IP camera and a video playback method thereof to solve the clarity problem that happens while the IP camera is playing in real-time through the network. 
     To achieve the above object, the present invention provides a video playback method applicable to an IP camera and a host interconnected through the network. The IP camera includes a processor, an image capturing unit and an input/output (I/O) buffer unit. The video playback method includes using the image capturing unit to capture an external video of an external environment, and the external video includes a plurality of frames; using the processor to determine an video output rate between the IP camera and the host; generating a processed video by using the processor to reduce a resolution of the external video and to remark a confirm flag in at least one first frame of the plurality of the frames according to a feature point in the at least one first frame while the video output rate is lower than a threshold value; and inputting the external video or the processed video to the I/O buffer unit as an output external video to be transferred to the host. 
     Preferably, the host may transmit a receiving confirm packet to the processor when the host receives the at least one first frame. 
     Preferably, the video playback method may further include a step of using the processor to merely transmit the at least one first frame among the plurality of the frames when the processor does not receive the receiving confirm packet beyond an expiration time. 
     Preferably, the processor may be configured to search the at least one first frame having the feature point by performing an image identification process, and the confirm flag is added to the at least one first frame. 
     Preferably, the feature point may include a face of person, a license plate, text, and an image of a vehicle, or any combination thereof. 
     To achieve another objective, the present invention further provides an IP camera connected to a host through the network. The IP camera includes an image capturing unit, a processor, and an input/output buffer unit. An external video of an external environment is captured by the image capturing unit and includes a plurality of frames, an video output rate between the IP camera and the host is determined by the processor. A processed video is generated by the processor by reducing a resolution of the external video and remarking a confirm flag in at least one first frame of the plurality of the frames according to a feature point in the at least one first frame while the video output rate is lower than a threshold value, and the external video or the processed video is inputted to the I/O buffer unit to generate an output external video to be transferred to the host. 
     Preferably, the host may transmit a receiving confirm packet to the processor when the host receives the at least one first frame. 
     Preferably, the processor may merely transmit the at least one first frame of the plurality of the frames when the processor does not receive the receiving confirm package beyond an expiration time. 
     Preferably, the processor may further search the at least one first frame having a feature point by performing an image identification process, and the confirm flag is added into the at least one first frame. 
     Preferably, the feature point may include a face of a person, a license plate, text, an image of a vehicle, or any combination thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The exemplary embodiment(s) of the present invention will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the invention, which, however, should not be taken to limit the invention to the specific embodiments, but are for explanation and understanding only. 
         FIG. 1  is a block diagram of an IP camera according to the present invention. 
         FIG. 2A  is a first schematic diagram according to the IP camera of the present invention. 
         FIG. 2B  is a second schematic diagram according to the IP camera of the present invention 
         FIG. 3  is a flow chart according to the video playback method for IP cameras of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments are shown. This invention may, however, be embodied in many different forms, and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference numerals refer to like elements throughout. 
     Advantages and features of the present invention and methods of accomplishing the same may be understood more readily by reference to the following detailed description of preferred embodiments and the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art, and the present invention will only be defined by the appended claims. 
     Please refer to  FIG. 1 , which illustrates a block diagram of an IP camera according to the present invention. The IP camera  20  of the present invention is connected to a host  10  through a cable network or a wireless network. The IP camera  20  includes an image capturing unit  22 , a processor  21 , and an input/output (I/O) buffer unit  23 . The host  10  may include a computer host, a server, or a notebook, the image capturing unit  22  includes a lens, the processor  21  includes a micro-processor or a central process unit, and the I/O buffer unit  23  includes a physical memory or a cache memory. 
     The image capturing unit  22  may be used for capturing an external video  31  of an external environment, and the external video  31  may include a plurality of frames  35 . The I/O buffer unit  23  may be used for inputting the external video  31  or a processed video  32  to generate an output external video  33 , such that the output external video  33  may be transmitted to the host  10 . 
     The processor  21  may be used for determining an video output rate  38  of the above-described I/O buffer unit  23 , when the video output rate  38  is lower than a threshold value, the processor  21  reduces a resolution of the external video  31  and remarking a confirm flag  36  in at least one first frame  34  of the plurality of frames  35  to generate the processed video  32 . Here, the video output rate  38  is the transmission speed of the output external video  33  from the IP camera  20  to the host  10 , and may be determined according to the network speed and the network bandwidth between the IP camera  20  and the host  10 . 
     Furthermore, the processor  21  may perform a video identification process on the at least one first frame  34  in order to confirm whether a feature point  39  is existed in the at least one first frame  34 , if “yes”, a confirm flag  36  is added into the at least one first frame  34  and the first frame  34  is inputted to the I/O buffer unit  23  by the processor  21 . 
     When the host  10  receives the first frame  34 , a receiving confirm packet  37  is transmitted back to the processor  21  to ensure the first frame  34  is transmitted to the host  10 . When the processor  21  does not receive the receiving confirm packet  27  beyond an expiration period, the processor  21  merely transmits the at least one first frame  34  of the plurality of the frames  35  again, and the feature point  39  in the first frame  34  may be more important or more interesting part of video regarded by the users, such as a face of a person, a license plate of a vehicle, texts, a figure, etc. By this way, after a period of time, a total file size of the processed video  32  inputted to the I/O buffer unit  23  by the processor  21  will be decreased gradually, and the output external video  33  received by the host  10  will be a continuous video with fluency and having the feature point  39 . 
     Please refer to  FIG. 2A  and  FIG. 2B , which illustrate a first and a second schematic drawing according to the IP camera of the present invention, respectively. In  FIG. 2A , an output external video  33  is transmitted to a host  10  by a IP camera  20  through a network. The IP camera  20  includes a processor  21 , an image capturing unit  22 , and an input/output (I/O) buffer unit  23 . In the embodiment, the captured external video  31  is continuously inputted to the I/O buffer unit  23  by the image capturing unit  22  of the IP camera  20 , and when the network is overloaded by an excessive number of packets, or the host  10  is busy, delays or stagnations of the video transmitted to the host  10  from the IP camera  20  will occur due to the network congestion. 
     When the video output rate  38  is determined to be lower than a threshold value by the processor  21 , the captured external video  31  may be divided into a first frame  34  and other frame  35  by the processor  21 , and the first frame may be an I-Frame, and the other frame  35  may be a P-Frame or a B-Frame. The first frame  34  includes at least one feature point  39 , such a face signature of a person, texts, numbers, or lines, etc., that is to say, the first frame  34  is a part of the video must be presented clearly on the host  10 , and the other frame  35  may be presented on the host  10  by using the way of image compensations or other image processing methods. 
     A confirm flag  36  may be added to the first frame  34  to generate a processed video by the processor  21 , and the processed video  32  is inputted into the I/O buffer unit  23 . The other frame  35  may be inputted into the I/O buffer unit  23  directly or be inputted after a resolution of the other frame  35  is reduced. Here, the video inputted into the I/O buffer unit  23  is denoted as an output external video  33  for clarity, and the output external video  33  is transmitted to the host  10  through the network. 
     As shown in  FIG. 2A , after the first frame  34  in the output external video  33  is received by the host  10 , a receiving confirm packet  37  is transmitted back to the processor  21 . If the receiving confirm packet  37  is not received by the processor  21  within a predetermined time period, the first frame  34  is transmitted to the host  10  again. Note that the previous transmitted other frame  35  will not be transmitted again along with the first frame in the later transmission. 
     Thus, the video content of the first frame  34  may be clearly received continuously by the host  10 , and the other frame  35  may be obtained compensatorily by using a decoding method of general image processing method, such that the problem of network congestion may be improved, that is, the real-time video transmitted from the IP camera  20  may be received fluently by the host  10 . 
     Please refer to  FIG. 3 , which illustrates a flow chart according to the video playback method for IP cameras of the present invention. The video playback method is applicable to an IP camera and a host interconnected through network. The IP camera includes a processor, an image capturing unit and an input/output (I/O) buffer unit, and the video playback method includes following steps. 
     Step S 1 : Using the image capturing unit to capture an external video of an external environment, and the external video comprising a plurality of frames. 
     Step S 2 : Using the processor to determine a video output rate. 
     Step S 3 : Generating a processed video by using the processor to reduce a resolution of the external video and remarking a confirm flag in at least one first frame of the plurality of the frames while the video output rate is lower than a threshold value. 
     Step S 4 : Inputting the external video or the processed video to the I/O buffer unit as an output external video. 
     From the above, the IP camera and the video playback method disclose a scheme for generating a processed video by utilizing the reduction of the resolution or addition of the confirm flag, and the method may be utilized to solve problems of the fluency and the clarity while the IP cameras are real-time broadcasting via the network during the network is suffering from network congestion. 
     In accordance with the embodiment(s) of the present invention, the components, process steps, and/or data structures described herein may be implemented using various types of operating systems, computing platforms, computer programs, and/or general purpose machines. In addition, those of ordinary skill in the art will recognize that devices of a less general purpose nature, such as hardwired devices, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), or the like, may also be used without departing from the scope and spirit of the inventive concepts disclosed herein. Where a method comprising a series of process steps is implemented by a computer or a machine and those process steps can be stored as a series of instructions readable by the machine, they may be stored on a tangible medium such as a computer memory device (e.g., ROM (Read Only Memory), PROM (Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), FLASH Memory, Jump Drive, and the like), magnetic storage medium (e.g., tape, magnetic disk drive, and the like), optical storage medium (e.g., CD-ROM, DVD-ROM, paper card and paper tape, and the like) and other known types of program memory. 
     While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from this invention and its broader aspects. Therefore, the appended claims are intended to encompass within their scope of all such changes and modifications as are within the true spirit and scope of the exemplary embodiment(s) of the present invention.