TWI442771B - Method for processing multi-media stream and multi-media stream device with time-shift function - Google Patents

Description

Data processing method applied to multimedia stream device and multimedia stream device supporting time shift function

The present invention relates to a data processing method applied to a multimedia streaming device, and more particularly to a data processing method applied to a multimedia streaming device and a multimedia streaming device supporting the time shift function using the same method, so that the application The monitoring system of such a streaming device can continuously record and store data continuously.

With the development of multimedia technology and the popularity of broadband networks, multimedia streaming technology has become more and more widely used, such as entertainment, news, business applications, etc. on the Internet. In short, by means of multimedia streaming technology, users The terminal does not need to wait for a huge file to complete the download before viewing the image or listening to the sound.

On the other hand, the traditional monitoring device plus multimedia streaming technology produces another remote real-time monitoring system, taking the network camera as an example, through the network camera, multimedia streaming technology and simultaneous support network supporting the Internet application. The portable electronic device of the road access, remote monitoring and multimedia streaming technology allows the user to monitor the latest images captured by the network camera anytime and anywhere through the portable electronic device.

Whether in traditional surveillance devices or modern remote monitoring systems, in order to ensure that no important data is lost, continuous recording and storage of data is very important, but in modern remote monitoring systems, in order to continuously record and store data. It will require high transmission bandwidth transmission data and a large amount of memory space to store data.

In order to solve this problem, in some current monitoring systems, image analysis is used to record data and store data only when an event occurs, although this can greatly reduce the stored data space, but because of this event After that, the monitoring system begins to record, so important information is often missed.

Therefore, it is necessary to provide a data processing method applied to a multimedia streaming device and a multimedia streaming device supporting the time shift function using the method, so that the monitoring system using the streaming device can continuously record and store continuously. Information to address the above issues.

In view of the above needs, an object of the present invention is to provide a data processing method applied to a multimedia streaming device and a multimedia streaming device supporting the time shift function using the method, so that a monitoring system using the streaming device can Record and store data continuously and continuously.

The present invention provides a data processing method applied to a multimedia streaming device, which includes the steps of: encoding a multimedia data into a first data stream; temporarily storing the first data stream using a storage unit; and temporarily storing the data stream; The first data stream in the storage unit is selected to be output at a first starting point or a second starting point.

The present invention further provides a multimedia streaming device supporting a time shift function, comprising: an encoding unit for encoding a multimedia data into a first data stream and copying the first data stream into a second data stream a storage unit for temporarily storing the second data stream; and a stream processing unit electrically connected to the coding unit and the storage unit, and configured to output the first data stream sent by the coding unit Or outputting a second data stream that is temporarily stored in the storage unit and delayed for a period of time.

In another aspect, the present invention further provides a multimedia network monitoring system, including: an image sensor for converting an optical signal into a digital signal; a network interface; a detecting component; and a multimedia streaming device The method includes: a coding unit, configured to encode the digital signal into a first data stream, and copy the first data stream into a second data stream; and a storage unit for temporarily storing the second data And a stream processing unit electrically connected to the coding unit and the storage unit for outputting the first data stream sent by the coding unit through the network interface, or through the network interface a second data stream output that is temporarily stored in the storage unit and delayed to be sent for a period of time; and a data stream recording device that stores the output of the multimedia stream device according to a trigger command sent by the detecting component The first data stream and the second data stream.

The present invention provides another multimedia streaming device that supports a time shift function, comprising: an encoding unit for encoding a multimedia data into a first data stream; and a storage unit for temporarily storing the encoding unit The first data stream; and a stream processing unit electrically coupled to the encoding unit and the storage unit for selecting the first data stream temporarily stored in the storage unit to be selected from a first starting point or A second starting point begins to output, which in turn produces different degrees of time shifting effects.

In another aspect, the present invention further provides a multimedia network monitoring system, including: an image sensor for converting an optical signal into a digital signal; a network interface; a detecting component; and a multimedia streaming device The method includes: a coding unit for encoding the digital signal into a first data stream; a storage unit for storing the first data stream sent by the coding unit for a period of time; and a stream processing The unit is electrically connected to the storage unit for outputting the first data stream of the storage unit at a first time and a second time respectively through the network interface; and a data stream recording device according to the detection The measuring component sends a trigger command to store the first data stream output by the multimedia stream device.

The detailed description of the present invention and the accompanying drawings are to be understood by the accompanying claims

The invention discloses a data processing method applied to a multimedia stream device and a multimedia stream device supporting the time shift function using the method. The monitoring system using the stream device can continuously record and store data continuously. In order to make the description of the present invention more detailed and complete, reference is made to the following description and the related drawings.

1 is a flow chart of a data processing method applied to a multimedia stream device of the present invention. As shown in FIG. 1, first, a multimedia material is encoded into a data stream (step S102). Next, the data stream is temporarily stored by the storage unit (step S104). Finally, the request for the remote command can be received, and the first starting point or the second starting point can be selected to start outputting the temporarily stored data stream (step S106). In order to make the description of the present invention more detailed and complete, the following two embodiments are described to illustrate a multimedia streaming device that supports the time shift function using this method.

FIG. 2A is a schematic diagram of a multimedia stream device supporting a time-shift function according to the first embodiment of the present invention. As shown, the multimedia streaming device 200 supporting the time shift function includes an encoding unit 202, a first in first out buffer 204, a stream processing unit 206, and an interface unit 208. The encoding unit 202 is configured to encode the multimedia data into the real-time data stream S _D1 , and copy the real-time data stream S _D1 into the data stream S _DC , and the encoding unit 202 sends the real-time data stream S _D1 to the stream processing unit. 206, and the data stream S _{DC is} sent to the FIFO buffer 204. The data stream S _DC sent to the FIFO buffer 204, after a period of time _{T_d} , the FIFO buffer 204 sequentially pushes the time-shifted data stream ST _D1 . In the present invention, the stream processing unit 206 can simultaneously output the real-time data stream S _D1 , and after the period of time T _{_d} , output the time-shifted data stream ST _D1 . In addition, the time T _{_d} can be input and set by the external user through the interface unit 208, and the user can also input a demand command through the interface unit 208, and request the stream processing unit 206 to be at the first starting point or the second starting point. Output time-shifted data stream.

Assuming that the user sets the period of time _{T_d} to 20 seconds, the stream processing unit 206 can simultaneously output the instant data stream S _D1 and output the time-shifted data stream ST _D1 after 20 seconds. From another point of view, if the user sets the time T _{_d} to 20 seconds, then at this point in time, the stream processing unit 206 simultaneously outputs the instant data stream S _D1 and the previously existing FIFO. A time-shifted data stream ST _D-20 (not shown) of 20 seconds is reached in the buffer 204. In addition, since the FIFO buffer 204 stores the data stream from the first 20 seconds to the present, the user may additionally input the demand command through the interface unit 208 if the data stream of the first 15 seconds or the first 10 seconds is required. The stream processing unit 206 is required to output.

Since the data stream that can be stored by the FIFO buffer 204 is limited, it is determined whether the FIFO buffer 204 is full before the data stream is stored in the FIFO buffer 204, when the first in first out buffer When the buffer 204 is full, the first stored data is discarded, and the data stream is stored, so that the image data stream of the first 20 seconds can be continuously maintained. In other words, since the buffer capacity of the supports of the period of time T_ _d it is limited, for example, the buffer capacity to support up to 20 seconds streamed data, even outside the time period set by the user T_ _d 30 seconds, or Only the image screen 20 seconds ago can be seen.

In addition, the present invention can temporarily store data streams by using a storage device having similar functions such as random access memory, flash memory or hard disk. If the storage device can store more space, then the support can be supported. period of time will be longer T_ _d.

FIG. 2B is a flowchart of a data processing method applied to a multimedia stream device according to the first embodiment of the present invention. Please refer to FIG. 2A for understanding. The data processing method applied to the multimedia stream device 200 of the present invention includes the following steps: First, the encoding unit 202 encodes the multimedia material into the real-time data stream S _D1 (step S250). Next, the encoding unit 202 copies the real-time data stream S _D1 into the data stream S _DC (step S252). The real-time data stream S _{D1 is} sent to the stream processing unit 206, and is directly output by the stream processing unit 206 (step S254). The data stream S _{DC is} sent to the FIFO buffer 204 for temporary storage (step S256). Finally, after the period of time, the stream processing unit outputs the time-shifted data stream ST _D1 temporarily stored in the FIFO buffer (step S258).

The multimedia streaming device of the first embodiment of the present invention can be applied to a plurality of multimedia network monitoring systems. The following will be described by taking the multimedia streaming device of the first embodiment of the present invention as a network camera. 3 is a schematic diagram of a network camera according to a first embodiment of the present invention. As shown, the network camera 300 includes an encoding unit 302, a first in first out buffer 304, a stream processing unit 306, and a regional network interface 308. And a detecting component (not shown), an image sensor 310, and a lens 312. The lens 312 and the image sensor 310 are configured to convert the optical signal into a digital image signal, and the encoding unit 302 encodes the digital image signal into the real-time data stream S _D1 , and the real-time data stream S _D1 is adapted to be processed by the stream processing unit 306 . The area network interface 308 is transmitted to the format on the network, so the network camera 300 of the present invention has the function of providing digital motion picture transmission.

In addition to encoding the digital video signal into the real-time data stream S _D1 , the encoding unit 302 copies the real-time data stream S _D1 into the data stream S _DC , and the encoding unit 302 directly sends the real-time data stream S _D1 into the stream processing. Unit 306 sends the data stream S _{DC to the} FIFO buffer 304. The data stream S _{DC is} sent to the FIFO buffer 304. After the period of time _{T_d} , the FIFO buffer 304 _successively pushes the time-shifted data stream ST _D1 . In the present invention, the stream processing unit 306 can simultaneously output the real-time data stream S _D1 through the area network interface 308, and output the time-shifted data stream ST _D1 after the period of time _{T_d} .

In addition, the network camera can be connected to the personal computer 320 with the video software installed through the router 330, the network disk drive (hereinafter referred to as NAS) 322 supporting the network camera or the network video recording host (Network Video Recorder, hereinafter referred to as NVR). The electronic device such as 324 realizes the function of near-end monitoring through video recording via these electronic devices arranged in the same regional network. In addition, the network camera can connect to the Internet 340 through the router 330, and communicate with remote electronic devices such as the remote personal computer 350, the mobile phone 352, the personal digital assistant 354 or the receiving box 356. The end electronic device turns on the webcam 300 for remote monitoring and uses these remote electronic devices to record.

In the present invention, the time _{T_d} can be set by the user through the electronic device. For example, if the user sets the time _{T_d} to 20 seconds, the stream processing unit 306 can simultaneously output the instant data stream S _D1. And after 20 seconds, the time shift data stream ST _{D1 is} output. From another point of view, if the user sets the time T _{_d} to 20 seconds, then at this point in time, the stream processing unit 306 simultaneously outputs the instant data stream S _D1 and the previously existing first in first out. A time-shifted data stream ST _{D_20} of 20 seconds is reached in the buffer 304. In addition, since the FIFO buffer 304 stores the data stream from the first 20 seconds to the present, if the user needs the data stream of the first 15 seconds or the first 10 seconds, the input demand command can also be set through the above electronic device. The stream processing unit 306 is required to output the time-shifted data stream in advance.

In addition, the detecting component in the network camera 300 of the present invention may be a built-in event detector (not shown) to detect camera damage caused by special events and special needs, such as a vandal-proof detector. (painting, occlusion, etc.), the motion detector can detect abnormal turbulence in the designated restricted area, the passive infrared detector can detect nearby creatures close, and even intelligent analysis can do sophisticated and complex image processing to filter out Things that the human eye can't distinguish or require a lot of manpower to do, such as the calculation of the number of entrances and exits of buildings, the violation of traffic rules, the stay of suspicious people in the restricted area, and so on. In addition, the detecting component in the network camera 300 of the present invention may be an external sensor (not shown), such as a thermal sensor that can detect a fire, and an electromagnetic sensor that can detect a door or a window. Some intrusive behavior. Through these various built-in or external detection components. By detecting the component, the network camera 300 of the present invention can instantly detect the triggering of various events, and utilizes the personal computer 320, the NAS 322, the NVR 324, the personal computer 350, the mobile phone 352, and the personal digital assistant 354 equipped with the video software. Or the electronic device such as the receiving box 356 is recorded for effective monitoring.

4A is a schematic diagram of a multimedia stream device supporting a time-shift function according to a second embodiment of the present invention. As shown, the multimedia streaming device 400 supporting the time shift function includes an encoding unit 402, a first in first out buffer 404, a stream processing unit 406, and an interface unit 408. The encoding unit 402 is configured to encode the multimedia data into the data stream S _DC , and the encoding unit 402 sends the data stream S _{DC to the} first in first out buffer 404 . The stream processing unit 406 can immediately read the data stream S _DC sent to the FIFO buffer 404 to the instant data stream S _D1 in the figure, and the stream processing unit 406 can also be in the time T_. After _d , the data stream S _DC sent to the FIFO buffer 404 sequentially reads out the time-shifted data stream ST _D1 as shown in the figure. In the present invention, the stream processing unit 406 can simultaneously output the instant data stream S _D1 , and can also receive the request of the remote command through the interface unit 408 , and select to read the segment temporarily stored in the first in first out buffer 404 . when deposited before _d time T_ shift data stream ST _D1. That is, the period of time T_ _d may be input outside a user set 408 via the interface unit, so that users can enter through the interface unit 408 demands a command, required shift change stream data processing unit 406 is read out The point in time of the stream.

Assuming that the user sets the period of time _{T_d} to 20 seconds, the stream processing unit 406 can simultaneously output the instant data stream S _D1 and output the time-shifted data stream ST _D1 after 20 seconds. From another point of view, if the user sets the time T _{_d} to 20 seconds, then at this point in time, the stream processing unit 406 processes the instant data stream S _D1 and the previously existing FIFO. A time-shifted data stream ST _D-20 (not shown) of up to 20 seconds in the buffer 404. In addition, since the FIFO buffer 404 stores the data stream from the first 20 seconds to the present, the user may additionally input the demand command through the interface unit 408 if the data stream of the first 15 seconds or the first 10 seconds is required. The stream processing unit 406 is required to read from the first in first out buffer 404.

In addition, in another embodiment of the present invention, it is assumed that the data stream that can be stored by the FIFO buffer 404 is limited. Therefore, before the data stream is stored in the FIFO buffer 404, the first in first out is judged. Whether the buffer 404 is full or not, when the FIFO buffer 404 is full, the first stored data is discarded, and the data stream is stored, so that the image data stream of the first 20 seconds can be continuously maintained. In other words, since the buffer capacity can support the period of time T _{_d} is also limited, for example, the buffer capacity can support up to 20 seconds of data stream traffic, even if the external user sets the time T _{_d} to 30 seconds, Only the image screen 20 seconds ago can be seen.

In addition, the data stream can be temporarily stored by a storage device having a similar function such as a random access memory, a flash memory or a hard disk. If the storage device can store more space, the time T can be supported. _{_d} will be longer.

FIG. 4B is a flowchart of a data processing method applied to a multimedia stream device according to a second embodiment of the present invention. Referring to FIG. 4A, the data processing method applied to the multimedia stream device 400 of the present invention includes the following steps: First, the encoding unit 402 encodes the multimedia material into the data stream S _DC (step S450). The data stream S _{DC is} sent to the FIFO buffer 404 and temporarily stored in the FIFO buffer 404 (step S452). Next, the stream processing unit 406 outputs the data stream temporarily stored by the FIFO buffer 404 immediately after the period of time _{T_d} (step S454).

In the present invention, the output time of the data stream temporarily stored by the stream processing unit 406 for controlling the FIFO buffer 404 can be set by the user. In this embodiment, it is assumed that the output time of the two data streams set by the user is difference value, i.e., the period of time T_ _d is 20 seconds, the streaming processing unit 406 can output data stream S _D1 and immediate shift in the output data stream ST _D1 after 20 seconds. From another point of view, if the user sets the time T _{_d} to 20 seconds, then at this point in time, the stream processing unit 406 simultaneously outputs the instant data stream S _D1 and the previously existing first in first out. A time-shifted data stream ST _D-20 (not shown) of up to 20 seconds in the buffer 404. In addition, since the FIFO buffer 404 stores the data stream from the first 20 seconds to the present, the user may additionally input the demand command through the interface unit 408 if the data stream of the first 15 seconds or the first 10 seconds is required. The stream processing unit 406 is required to output.

In addition, the multimedia stream device of the second embodiment of the present invention can be applied to a plurality of multimedia network monitoring systems. Hereinafter, the multimedia stream device of the second embodiment of the present invention will be applied to a network camera as an example. 5 is a schematic diagram of a network camera according to a second embodiment of the present invention. As shown, the network camera 500 includes an encoding unit 502, a first in first out buffer 504, a stream processing unit 506, and a regional network interface 508. And a detecting component (not shown), an image sensor 510, and a lens 512. The lens 512 and the image sensor 510 are configured to convert the optical signal into a digital image signal, and the encoding unit 502 encodes the digital image signal into the data stream S _DC , and the data stream S _DC is suitable for being streamed by the stream processing unit 506 via the area network. The interface 508 is transmitted to the format on the network, so the network camera 500 of the present invention has the function of providing digital video transmission.

The encoding unit 502 encodes the digital video signal into the data stream S _DC and directly feeds the data stream S _DC into the FIFO buffer 504. The stream processing unit 506 can immediately read the data stream S _DC sent to the FIFO buffer 504 to sequentially read the real-time data stream S _D1 in the figure and simultaneously feed the data stream into the FIFO buffer 504. S _DC , after the period of time T _{_d} , the FIFO buffer 504 will continue to push the time-shifted data stream ST _D1 . In the present invention, the stream processing unit 506 can simultaneously output the real-time data stream S _D1 through the area network interface 508, and after the period of time _{T_d} , output the time-shifted data stream ST _D1 .

In addition, the network camera can be connected to the personal computer 520 with the video software installed through the router 530, the network disk drive (hereinafter referred to as NAS) 522 supporting the network camera or the network video recording host (Network Video Recorder, hereinafter referred to as NVR). The electronic device such as 524 realizes the function of near-end monitoring through video recording via these electronic devices arranged in the same regional network. In addition, the network camera can connect to the Internet 540 through the router 530, and communicate with remote electronic devices such as the remote personal computer 550, the mobile phone 552, the personal digital assistant 554 or the receiving box 556. The end electronic device turns on the webcam 500 for remote monitoring and uses these remote electronic devices to record.

In the present invention, the time _{T_d} can be set by the user through the electronic device. For example, if the user sets the time _{T_d} to 20 seconds, the stream processing unit 506 can simultaneously output the instant data stream S _D1. And after 20 seconds, the time shift data stream ST _{D1 is} output. From another point of view, if the user sets the time T _{_d} to 20 seconds, then at this point in time, the stream processing unit 506 simultaneously outputs the instant data stream S _D1 and the previously existing FIFO. A time-shifted data stream ST _D-20 of 20 seconds is reached in the buffer 504. In addition, since the FIFO buffer 504 stores the data stream from the first 20 seconds to the present, if the user needs the data stream of the first 15 seconds or the first 10 seconds, the input demand command can also be set through the above electronic device. The stream processing unit 506 is required to output the time-shifted data stream in advance.

In addition, the detecting component in the network camera 500 of the present invention may be a built-in event detector (not shown) to detect camera damage caused by special events and special needs, such as a vandal-proof detector. (painting, occlusion, etc.), the motion detector can detect abnormal turbulence in the designated restricted area, the passive infrared detector can detect nearby creatures close, and even intelligent analysis can do sophisticated and complex image processing to filter out Things that the human eye can't distinguish or require a lot of manpower to do, such as the calculation of the number of entrances and exits of buildings, the violation of traffic rules, the stay of suspicious people in the restricted area, and so on. In addition, the detecting component in the network camera 500 of the present invention may be an external sensor (not shown), such as a thermal sensor capable of detecting a fire, and an electromagnetic sensor capable of detecting a door and a window. Some intrusive behavior. Through these various built-in or external detection components. By detecting the component, the network camera 500 of the present invention can instantly detect the triggering of various events, and utilizes the personal computer 520, the NAS 522, the NVR 524, the personal computer 550, the mobile phone 552, and the personal digital assistant 554 equipped with the video software. Or the electronic device such as the receiving box 556 is recorded for effective monitoring.

In summary, the multimedia streaming device supporting the time shift function of the present invention and the data processing method applied thereto can enable the monitoring system using the streaming device to continuously record and store data continuously. The object of the invention is achieved.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

The components included in the diagram of this case are listed as follows:

200,400‧‧‧Multimedia streaming device

202, 302, 402, 502‧‧ ‧ coding unit

204, 304, 404, 504‧‧‧ FIFO buffer

206, 306, 406, 506‧‧‧ stream processing unit

300, 500‧‧‧ webcams

308, 508‧‧‧Local Network Interface

310, 510‧‧‧ image sensor

312, 512‧‧‧ lens

320, 520‧‧‧ PC

322, 522‧‧‧ network drive

324, 524‧‧‧ network video recording host

330, 530‧‧‧ router

340, 540‧‧‧ Internet

350, 550‧ ‧ personal computer

352, 552‧‧‧ mobile phones

354, 554‧ ‧ personal digital assistant

356, 556‧‧‧ receiving box

208, 408‧‧ interface unit

S _DC , S _D1 , ST _D1 ‧‧‧ data stream

The present invention can be further understood by the following figures and descriptions: FIG. 1 is a flow chart of a data processing method applied to a multimedia stream device according to the present invention.

FIG. 2A is a schematic diagram of a multimedia streaming device supporting a time shift function according to a first embodiment of the present invention.

FIG. 2B is a flowchart of a data processing method applied to a multimedia stream device according to the first embodiment of the present invention.

Fig. 3 is a schematic view showing a network camera of the first embodiment of the present invention.

4A is a schematic diagram of a multimedia streaming device supporting a time shift function according to a second embodiment of the present invention.

FIG. 4B is a flowchart of a data processing method applied to a multimedia stream device according to a second embodiment of the present invention.

Fig. 5 is a schematic view showing a network camera of a second embodiment of the present invention.

Claims (32)

A data processing method applied to a multimedia stream device, comprising the steps of: encoding a multimedia data into a first data stream; temporarily storing the first data stream in a preset time by using a storage unit; Receiving the first data stream in real time and the first data stream previously stored in the storage unit to simultaneously output the first data stream and the first data previously stored in the storage unit Data stream. The data processing method of claim 1, wherein the step of temporarily storing the first data stream by using the storage unit comprises the following sub-steps: determining whether the storage unit is full; when the storage unit is full At the time, discard the first data stored; and deposit the first data stream. The data processing method of claim 1, further comprising the substep of: receiving an input setting of the preset time by using an interface unit. The data processing method of claim 3, wherein the interface unit is configured to receive a demand command, and a stream processing unit is configured according to the demand command, before the preset time is reached. The first data stream is output. The data processing method of claim 1, wherein the storage unit is a first in first out buffer. The data processing method of claim 1, wherein the storage unit is a random access memory, a flash memory or a hard disk. A multimedia streaming device supporting a time shift function, comprising: an encoding unit, configured to encode a multimedia data into a first data stream, and copy the first data stream into a second data stream; a unit for temporarily storing the second data stream in a predetermined time; and a stream processing unit electrically connected to the encoding unit and the storage unit for simultaneously receiving the first data stream And the second data stream previously stored in the storage unit to simultaneously output the immediate first data stream and the second data stream previously stored in the storage unit. The multimedia streaming device of claim 7, further comprising an interface unit electrically connected to the streaming processing unit for receiving the input setting of the preset time from the outside to be transmitted to the streaming processing unit . The multimedia streaming device of claim 8, wherein the interface unit is configured to receive a demand command from the outside to be transmitted to the stream processing unit, and the stream processing unit is configured according to the demand command. The second data stream in the storage unit is outputted before the time is reached. The multimedia streaming device of claim 7, wherein the storage unit determines whether the storage unit is full before temporarily storing the second data stream, and discards the most when the storage unit is full. The pre-existing data is stored in the second data stream. The multimedia streaming device of claim 7, wherein the storage unit is a first in first out buffer. The multimedia streaming device of claim 7, wherein the storage unit is a random access memory, a flash memory or a hard dish. A multimedia network monitoring system includes: an image sensor for converting an optical signal into a digital signal; a network interface; a detecting component; and a multimedia streaming device comprising: a coding unit For encoding the digital signal into a first data stream, and copying the first data stream into a second data stream; a storage unit for temporarily storing the second data in a preset time And a stream processing unit electrically connected to the coding unit, the storage unit and the network interface for simultaneously receiving the instant first data stream and the previously stored in the storage unit The second data stream is outputted simultaneously with the first data stream that is sent by the coding unit through the network interface and the second data stream that has been previously stored in the storage unit. The multimedia network monitoring system of claim 13, wherein the multimedia network monitoring system further comprises a data stream recording device, wherein the data stream recording device sends a trigger command according to the detecting component. And storing the first data stream and the second data stream output by the multimedia stream device. The multimedia network monitoring system of claim 13, wherein the streaming processing unit receives the input setting of the preset time through the network interface. For example, the multimedia network monitoring system described in claim 13 of the patent scope, The network interface is configured to receive a demand command from the external network and transmit the request to the stream processing unit, where the stream processing unit selects the second one of the storage units before the preset time is reached according to the demand command. Data stream output. The multimedia network monitoring system of claim 13, wherein the storage unit determines whether the storage unit is full before temporarily storing the second data stream, and discards when the storage unit is full. The first stored data is stored in the second data stream. The multimedia network monitoring system of claim 13, wherein the storage unit is a first in first out buffer. The multimedia network monitoring system of claim 13, wherein the storage unit is a random access memory, a flash memory or a hard disk. A multimedia streaming device supporting a time shifting function, comprising: an encoding unit for encoding a multimedia data into a first data stream; and a storage unit for temporarily storing the encoding unit for a preset time And the first data stream; and a stream processing unit electrically connected to the storage unit for simultaneously receiving the first data stream and the first data previously stored in the storage unit Streaming to simultaneously output the first data stream in real time and the first data stream previously stored in the storage unit. The multimedia streaming device of claim 20, further comprising an interface unit for receiving the input setting of the preset time from the outside to be transmitted to the streaming processing unit. The multimedia streaming device of claim 21, wherein the interface unit is configured to receive a demand command and transmit to the stream processing unit, and the stream processing unit reaches the preset time according to the demand command. The first data stream in the storage unit is previously outputted. The multimedia streaming device of claim 20, wherein the storage unit determines whether the storage unit is full before temporarily storing the first data stream, and discards the most when the storage unit is full. The pre-existing data is stored in the first data stream. The multimedia streaming device of claim 20, wherein the storage unit is a first in first out buffer. The multimedia streaming device of claim 20, wherein the storage unit is a random access memory, a flash memory or a hard disk. A multimedia network monitoring system includes: an image sensor for converting an optical signal into a digital signal; a network interface; a detecting component; and a multimedia streaming device comprising: a coding unit For encoding the digital signal into a first data stream; a storage unit for storing the first data stream sent by the coding unit within a preset time; and a stream processing unit Electrically connected to the storage unit for simultaneously receiving the first data stream and the first data stream previously stored in the storage unit to be transmitted through the network interface The first data stream at the same time is output simultaneously with the first data stream previously stored in the storage unit. The multimedia network monitoring system of claim 26, wherein the multimedia network monitoring system further comprises a data stream recording device, wherein the data stream recording device sends a trigger command according to the detecting component. And storing the first data stream output by the multimedia stream device. The multimedia network monitoring system of claim 26, wherein the streaming processing unit receives the input setting of the preset time from the external network through the network interface. The multimedia network monitoring system of claim 28, wherein the network interface is configured to receive a demand command from an external network and transmit the request to the stream processing unit, the stream processing unit according to the demand command. The first data stream in the storage unit is outputted before the preset time is reached. The multimedia network monitoring system of claim 26, wherein the storage unit determines whether the storage unit is full before temporarily storing the first data stream, and discards when the storage unit is full. The first stored data is stored in the first data stream. The multimedia network monitoring system of claim 26, wherein the storage unit is a first in first out buffer. The multimedia network monitoring system of claim 26, wherein the storage unit is a random access memory, a flash memory or a hard disk.