KR20100010605A - A transfer device of encoded data of analog camera signals on networks and a method for composing images therefor - Google Patents

Abstract

PURPOSE: A transfer device transmitting encoded analog image signal data of analog camera signals on networks and a composing method therefore are provided to transmit the image data with the analog camera to digital data output device by using the analog camera. CONSTITUTION: An ADC(Analog-Digital Converter)(10) changes an analog image signal inputted from analog movie photographic means(60) into the digital signal. A codec(20) encodes the analog image signal transformed to digital. A DSP(Digital Signal Processor)(80) calculates an I-Frame, B-Frame, and P-Frame and P'-Frame value from an encoded video signal. A storage means(50) stores video signal from the I-Frame, B-Frame, P-Frame and P'-Frame value. A network interface card(30) transmits the encoded video signal saved in the storage means to an external output device connected to network.

Description

A transfer device of encoded data of analog camera signals on networks and a method for composing images therefor}

The present invention relates to an apparatus for transmitting data obtained by encoding an image signal taken by an analog camera into digital data on a network, and a method of constructing an image for the apparatus. In particular, the present invention relates to a network transmission apparatus of encoded analog video signal data separated from a conventional analog camera and a video composition method using I-Frame, P-Frame, P'-Frame and B-Frame.

In the prior art, there is a known device for transmitting a digital image by a digital camera to a network. Previously, it was known about a device that converts an analog image into an digital signal when it is obtained by an analog camera and transmits it to a network. However, these conventional devices were bulky and expensive because they were digital devices from the beginning, or were composed of analog cameras and digital signal converters, and users with existing analog cameras could network their analog video footage. It was not possible to transmit to a digital output device connected to the network through the network. Therefore, there has been a need for the emergence of a technology that allows analog camera holders to transmit to digital output devices without discarding their own analog cameras and without purchasing expensive analog / digital camera integrated digital data transmission devices.

In the conventional method of configuring an image, a large amount of time is required to transmit a large amount of image data to an external output device using only I-Frame, P-Frame, and B-Frame. Therefore, in order to solve these problems, it was necessary to find a way to generate these frames more efficiently.

An object of the present invention is to provide an apparatus capable of transmitting image data taken by an analog camera to a network using a conventional analog camera and a method of constructing an image for the apparatus.

Other objects and advantages of the present invention will become more apparent from the following detailed description of the invention and the accompanying drawings.

The network transmission apparatus of the encoded analog video signal data according to the present invention is connected to a network, and converts the analog signal received from an external analog video recording means into a digital signal, and then connects the TCP / IP, RTP to an external digital output device connected to the network. A device for transmitting through a known communication method including UDP,

An analog / digital converter for converting an analog video signal input from the analog video photographing means into a digital signal;

A codec for encoding an analog image signal digitally converted by the analog / digital converter;

A DSP for calculating I-Frame, B-Frame, P-Frame, and P'-Frame values from the video signal encoded by the above codec;

Storage means for storing an image signal obtained from I-Frame, B-Frame, P-Frame, and P'-Frame values calculated by the DSP;

A network interface unit for transmitting the encoded video signal stored in the storage unit to an external output device connected to a network; And

It characterized in that it comprises a central processing unit for controlling the above components as a whole.

In this embodiment, the analog video signal input to the above device is preferably a composite video in signal, S-video in signal and component video in signal.

In this embodiment, the external output devices connected to the network are required to install a predetermined video signal receiving program in order to receive the video signal from the transmission device.

In this embodiment, the video signal receiving program is preferably a codec for decoding the video signal provided by the network transmission device.

In this embodiment, the external output devices connected to the network are all output devices including a PC, a digital TV, a mobile phone, a PMP, and having a data transmission / reception function through a known communication method including TCP / IP, RTP, and UDP. It is preferable.

In this embodiment, the codec preferably includes indio, MPEG1, MPEG2, MPEG4, MOV, DivX, AVI, and H.264.

Image construction method using I-Frame, P-Frame, B-Frame and P'-Frame according to the present invention, the network transmission device of the video signal data connected to the network receives the analog signal received from the external analog video recording means A video composition method for transmitting video signal data through a known communication method including TCP / IP, RTP, and UDP to an external digital output device connected to a network after converting it into a digital signal.

Generating, by the network transmission device, an I-Frame after converting an analog signal received from the analog video photographing means into a digital signal;

Calculating the motion vector and the difference vector when the I-Frame is generated;

Generating a P-Frame when the motion vector and the car vector are obtained from the above;

Calculating a predicted motion vector indicating a moving position by comparing the I-Frame and the P-Frame when the P-Frame is generated, and calculating a predictive difference vector indicating the changed position by comparing the I-Frame and the P-Frame;

Determining whether each of the predicted motion vector and the predicted difference vector value calculated above is 3 or more;

Generating a P'-Frame if the predicted motion vector and the predicted difference vector value calculated as the above result are 3 or more, respectively, otherwise generating a B-Frame;

Storing the generated P'-Frame and B-Frame in the internal storage means; And

And an external output device having a TCP / IP communication function receives and outputs the P'-Frame and the B-Frame stored in the storage means.

The criterion of P-Frame is always the latest I-Frame, the criterion of P'-Frame is always the latest P-Frame, and the criterion of B-Frame is always the latest I-Frame and P-Frame. .

In this embodiment, it is preferable to generate a P'-Frame by setting the size of the macro block to 32 x 32 so as to accurately search the motion vector and reduce the amount of computation when encoding data with the codec.

In this embodiment, to reduce the bit rate, shorten the generation time of P'-Frame and B-Frame, reduce the size of P'-Frame and B-Frame, and adjust the Bit Rate with B-Frame according to the network speed. It is desirable to.

In this embodiment, the calculation of the above I-Frame, P-Frame, B-Frame and P'-Frame is preferably performed by the DSP.

Due to the implementation of the present invention, analog image data taken using existing analog cameras, which have been widely used, is transmitted to a newly distributed digital data output device through a network, thereby allowing a user to set up an expensive digital camera integrated set-top box. It is economical because you can view the image data taken by the existing analog camera without purchasing the box. In other words, by implementing the present invention, economical efficiency can be ensured, and the conventional analog camera can be used without disposal, which can prevent enormous resource waste, thus contributing to preservation of a clean global environment.

With reference to FIG. 1, the structure and operation principle of this invention are demonstrated. 1 is a block diagram of an apparatus for encoding analog image data into digital image data according to the present invention and transmitting it over a network. The configuration of the A transfer device of encoded data of analog camera signals on networks 100 of the present invention is an analog video signal input to the device from an external analog camera 60. Analog-to-digital converter 10 for converting the signal into a digital signal, a codec 20 for encoding a digitally converted signal, and I-Frame, B-Frame, P from the image signal encoded by the above codec. DSP 80 for calculating Frame, P'-Frame values, and storing image signals obtained from I-Frame, B-Frame, P-Frame, P'-Frame values calculated by DSP 80 above Storage means 50 for transmitting the network interface unit 30 for transmitting the encoded video signal stored in the storage means to the network, and the components 10, 20, 30, 50, and ( And a central processing unit 40 to control the entirety.

At this time, various well-known codecs can be used as a codec. For example, Intel suggests and uses the most popular indios, MPEG developed by Microsoft for use in video editors (MPEG1, MPEG2, MPEG4 versions, etc.), Apple's MOV, and MPEG4. Various codecs such as .264 can be used.

The encoded signals output from the network transmission apparatus 100 of the encoded analog image signal data of the present invention are transmitted to a network (for example, the Internet network), and digital output devices 70 (for example, PCs) connected to the network. , Digital TV, mobile phone, PMP, etc.) can be played. In this case, a method of transmitting an encoded signal to a network is performed by using a known IP access technology such as TCP / IP, RTP, and UDP. Therefore, in this invention, these well-known techniques are not described separately.

That is, if the encoded signal is stored in the storage means 50 in the network transmission apparatus 100, the PC 70 connected to the Internet connects to the network interface unit 30 through the normal IP connection and then the storage means. The encoded video signal stored in 50 is taken, decoded by a codec in the PC 70, and output to the monitor to reproduce the original video. Any device having a general TCP / IP communication interface can utilize the network transmission device 100 of the present invention. In the same way, the image taken by the analog camera 60 can be viewed in a mobile phone, PMP and digital TV.

Meanwhile, the analog video signal captured by the analog camera 60 input to the network transmission apparatus 100 according to the present invention includes a composite video in signal (signal 10), an S-video in signal (signal 20), and a component video in signal. (signal 30) is included. These three signals are simultaneously input to the network transmission apparatus 100 according to the present invention.

The composite video in signal (signal 10) is a signal mixed with a video signal and an audio signal, and the S-video in signal (signal 20) is different from the composite video in signal (signal 10) and a codec method, and the component video in signal (signal). 30 is an RGB signal.

The flowchart of FIG. 4 shows a method for constructing an image suitable for the device of FIG. 1 according to the invention, and FIG. 5 illustrates the relationship of I-Frame, P-Frame and P'-Frame. 6 shows a flow of a method for encoding analog image data into digital image data according to the present invention and transmitting it over a network. Before we explain this method, let's define some terms.

1. Definition of terms

<Definition 1> GOP (Group of Pictures)

GOP is the most basic element in encoding. It is a collection of frames from a key frame to the next key frame. There are three frame types constituting an image: I-Frame (hereinafter simply referred to as I), P-Frame (hereinafter simply referred to as P), and B-Frame (hereinafter simply referred to as B). The order of these frames is between I-Frames in the same way as I, B, B, P, B, B, P, B, B, P, B, B, I, B, B, P, ... P-Frames are constructed in such a way that a B frame is inserted between an I-Frame and a P-Frame. And from I-Frame to the next I-Frame, one GOP is grouped and the GOP size is the number of frames, so the GOP size becomes 12 in the above case. Since the number of P-Frames is the number of P-Frames in the GOP, and the number of B frames is the number of B-Frames between I / P frames, the number of P-Frames is 3 and B-Frame. The number of will be two.

<Definition 2> Frame

In this invention, a frame means one screen. The size of the frame can be specified in pixels and the percentage of the entire screen can be specified in%.

<Definition 3> Full Frame

The full screen refers to a screen having an aspect ratio (AR) in which a ratio of width (width) to height (height) is 4: 3 in the full screen of an analog television. 4: 3 aspect ratio is also referred to as 1.33: 1 aspect ratio or simply 1.33 aspect ratio. Screens having such aspect ratios are also called full screens. Thus, a video signal with this aspect ratio fills the entire screen of an analog television. And in order to properly view widescreen video on a 4: 3 television, it must be compressed vertically, so only part of the screen is used for video.

<Definition 4> In-coded Frames

I-Frame is data that represents the coordinate information of all pixels obtained by compressing the entire image taken by the camera and is also called a key frame. Therefore, I-Frame has the best image quality but the largest capacity compared to other frames. I-Frames have full frame information and do not need any other information from the screen before or after the video has been played properly. In other words, I-Frame is an independent frame and a random access frame. I-Frame is the most basic frame and can be encoded and decoded regardless of front and rear frame. In other words, compression is performed only with information in the current image. Due to the nature of compression, I-Frame is often used to realize random access or fast playback for FF / REW.

<Definition 5> Inline Frame

The internal screen is another small screen created in one screen, and creating an internal screen means dividing the screen as a whole. There may be a plurality of internal screens in one screen.

<Definition 6> P-Frame (Predictive Frame)

The P-Frame is a frame obtained by finding commonalities by referring to previously-coded I-Frames or P-Frames, and coding only for portions that are not common. In other words, P-Frame is a frame composed based on the information of the previous key frame, and the quality and capacity are intermediate between I-Frame and B-Frame. As such, the P-Frame does not represent information on the entire screen, but only changed information of the preceding I-Frame following the I-Frame. The P-Frame is also called a delta frame, and the P-Frame uses a motion compensation technique. The P-Frame calculates the error between the previous frame and the current frame and performs DCT when the error of the corresponding block of the previous frame is larger than the threshold, and compresses only the direction direction vector information of similar blocks when the error is smaller than the threshold. use. The equation for the P-Frame is:

P-Frame = Previous Frame-Current Frame + Motion Vector (MV)

The P-Frame only transmits the motion vector value from the I-Frame, and the reference is always the latest I-Frame. In the example of FIG. 5, a vector (denoted by arrow P) moving from one point 20, 21 to another point 18, 25 is P-Frame. In the present invention, the P-Frame is a frame obtained by searching for the common point only by referring to only the I-Frame that was previously coded, and coding only the non-common part.

<Definition 7> Motion Estimation

Motion Estimation is a process of searching for a similar block by searching a predetermined area around a corresponding block of a previous frame on the basis of 16 × 16 or 8 × 8 block units, which are Macro Block units of the current frame, during encoding. In this case, the search area is referred to as a searching area and may be appropriately controlled according to H / W performance. 2 is a conceptual diagram of a video vector search method according to the prior art, and FIG. 3 illustrates a concept of a video vector search method according to the present invention. In the present invention, it is based on a macroblock unit of 32x32. And many methods are used to find similarity between each block, but in most commercial codecs, SAD (sum of absolute differences), which is the average value of absolute coefficients of all coefficients, is found to be similar when it comes within a certain range. If the calculated SAD is larger than the threshold, it is recognized that there is no similar block and the corresponding block is encoded like I-Frame.

<Definition 8> P'-Frame

The P'-Frame is a frame obtained by searching for the common point only by referring to the latest P-Frame and coding only the non-common part. It is essentially a P-Frame. Since only the movement vector value from the P-Frame is transmitted, the reference is always the latest P-Frame. In the example of FIG. 5, the vector (denoted by arrow P ′) moving from one point 18, 25 to another point 18, 27 is P′-Frame.

<Definition 9> Bi-directionally Predictive Frame (B-Frame)

B-Frame is a frame composed based on the information of I-Frame before and after P-Frame. In other words, B-Frame is a frame predicted from two directions and is made by referring to I-Frame and P-Frame. A B-Frame is a frame having only information except for overlapping parts by searching for a common part by examining the previous I-Frame or P-Frame and the next I-Frame or P-Frame. Therefore, B-Frame refers to a lot of references, so the overlapping parts are excluded and only the changed parts are displayed. Therefore, when the B-Frame increases, the compression ratio is improved. Instead, the compression takes a long time because the prediction time of the reference frame is long. B-Frame has the lowest quality and capacity compared to I-Frame and P-Frame, and does not represent full screen information, but screen information predicted by both previous frames and next frames. Indicates. The equation for the B-Frame is:

B-Frame = Previous Frame-Next Frame + Bidirectional MV

Deleting a B-Frame does not become a standard for creating other frames, so it helps to adjust the speed of the network.

<Definition 10> Vector

A vector represents a point on the screen and can be called a dynamic array. If you use the general array, you have to decide how much screen size to use beforehand.However, since the vector is a dynamic array, unlike the general array, the screen is deleted or reduced in size depending on the situation. , Increase.

<Definition 11> motion vector

The movement vector is an array of coordinate values when a point moves from one position to another on the screen.

<Definition 12> Difference vector

The difference vector is an array that shows how a point has changed on the screen.

In general, when a video plays, I first reference the I-Frame. This information is then passed to the B-Frame and P-Frame closest to the I-Frame. The P-Frame then references this information, creates new information, and sends them to the front B-Frame. It also sends information to other P-Frames and B-Frames that come after the P-Frame. That is, the P-Frame becomes like a second I-Frame while a video is played.

At this time, the information sent from the I-Frame to the P-Frame is the position vector of the object. That is, when the object sends information that the object has moved, the P-Frame shows the object in the corresponding position.

2. Description of the composition and operation of the invention

Now, the method of generating a P-Frame and a B-Frame according to the present invention using the terms defined above will be described in detail.

When executing this method, I-Frame is first generated (S20). To generate an I-Frame Since the method is a known technique, a description thereof will be omitted here.

After the I-Frame is created, the motion vector and the difference vector are calculated (S40). Since a method of calculating the motion vector and the difference vector is also known, a description thereof will be omitted.

When the motion vector and the car vector are obtained, a P-Frame is generated (S60). Since the method of generating the P-Frame is also known technology, a description thereof will be omitted.

When the P-Frame is generated, the prediction motion vector and the prediction difference vector are calculated (S80). The predicted motion vector indicates the moving position by comparing the I-Frame and the P-Frame, and the predictive difference vector indicates the changed position by comparing the I-Frame and the P-Frame.

It is determined whether the calculated predicted motion vector and the predicted difference vector are 3 or more, respectively (S100).

As a result of the determination, if the predicted motion vector and the predicted difference vector value are each 3 or more, a P'-Frame is generated (S120), otherwise, the B-Frame is generated and terminated (S140). A method for generating a B-Frame is also a known technique.

In the present invention, it is possible to generate a P'-Frame by precisely searching for a motion vector by setting a macro block from an existing 16 × 16 to 32 × 32. And since the P-Frame needs to track the motion vector of every pixel of the I-Frame The frame generation time is long, but the P'-Frame and B-Frame are also short. The reason is that the P'-Frame tracks the motion vector based on the P-Frame, and the B-Frame does not actually calculate the motion vector but applies the prediction vector to apply the motion vector of the P-Frame to the I-Frame. This is because the amount is reduced by 70-95% depending on the situation.

And as we saw in the previous terminology definition, the size of P'-Frame and B-Frame is also smaller than I-Frame and P-Frame, and the bit rate reduction effect is big. It is also possible to adjust.

As such, the present invention may be variously modified and may take various forms, and only the specific embodiments thereof are described in the detailed description of the present invention. It is to be understood, however, that the invention is not limited to the particular forms mentioned in the detailed description of the invention, but rather includes all modifications, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. It should be understood to do.

When connected to an existing analog camera, still images or videos taken by the analog camera are encoded into digital data by the device of the present invention, and can be connected to digital output devices such as PCs, digital TVs, mobile phones, and PMPs, which are capable of TCP / IP interface over a network. Industrial output is very high because it can be printed.

1 is a block diagram of an apparatus for encoding analog image data into digital image data according to the present invention and transmitting it over a network.

2 is a conceptual diagram illustrating a video vector search method according to the prior art.

3 is a conceptual diagram illustrating a video vector search method according to the present invention;

4 is a flowchart showing a video composition method according to the present invention;

5 is an exemplary diagram illustrating a relationship between an I-Frame, a P-Frame, and a P'-Frame.

6 is a flow chart of a method for encoding analog video data into digital video data and transmitting it over a network in accordance with the present invention.

<Description of drawing reference number of main part of drawing>

10: Analog / Digital converter

20: codec engine

30: network interface unit

40: CPU

50: storage means

60: analog camera

70: output device (PC, mobile phone, PMP, digital TV, etc.)

80: DSP

100: Encoding Data Network Transfer Device from Analog Camera Signal (EDNTD) for analog cameras

200: macro block

210: navigation area of previous frame

signal 10: Composite Video In Signal

signal 20: S-Video In Signal

signal 30: Component Video In Signal

Claims (10)

Encoded analog video, which is connected to the network and converts the analog signal received from an external analog video recording means into a digital signal, and then transmits it to an external digital output device connected to the network through a known communication method including TCP / IP, RTP, and UDP. In the network transmission device of the signal data, An analog / digital converter for converting an analog video signal input from the analog video photographing means into a digital signal; A codec for encoding an analog image signal digitally converted by the analog / digital converter; A DSP for calculating I-Frame, B-Frame, P-Frame, and P'-Frame values from the video signal encoded by the above codec; Storage means for storing an image signal obtained from I-Frame, B-Frame, P-Frame, and P'-Frame values calculated by the DSP; A network interface unit for transmitting the encoded video signal stored in the storage unit to an external output device connected to a network; And Network processing apparatus for encoded analog video signal data, characterized in that it comprises a central processing unit for controlling the above components as a whole. The apparatus of claim 1, wherein the analog video signal input to the device is a composite video in signal, an S-video in signal, and a component video in signal. The apparatus of claim 1, wherein external output devices connected to the network must install a predetermined video signal receiving program in order to receive a video signal from the transmitting device. The apparatus of claim 3, wherein the video signal receiving program is a codec for decoding a video signal provided by a network transmission device. According to claim 1, wherein the external output device connected to the network is a PC, digital TV, mobile phone, PMP including all output devices having a data transmission and reception function through a known communication method including TCP / IP, RTP, UDP A network transmission device for encoded analog video signal data, characterized in that. The apparatus of claim 1, wherein the codec includes indio, MPEG1, MPEG2, MPEG4, MOV, DivX, AVI, and H.264. A network transmission device for video signal data connected to a network converts an analog signal input from an external analog video recording means into a digital signal, and then uses a known communication method including TCP / IP, RTP, and UDP to an external digital output device connected to the network. In the method for configuring the image using I-Frame, P-Frame, B-Frame and P'-Frame to transmit the video signal data through Generating, by the network transmission device, an I-Frame after converting an analog signal received from the analog video photographing means into a digital signal; Calculating the motion vector and the difference vector when the I-Frame is generated; Generating a P-Frame when the motion vector and the car vector are obtained from the above; Calculating a predicted motion vector indicating a moving position by comparing the I-Frame and the P-Frame when the P-Frame is generated, and calculating a predictive difference vector indicating the changed position by comparing the I-Frame and the P-Frame; Determining whether each of the predicted motion vector and the predicted difference vector value calculated above is 3 or more; Generating a P'-Frame if the predicted motion vector and the predicted difference vector value calculated as the above result are 3 or more, respectively, otherwise generating a B-Frame; Storing the generated P'-Frame and B-Frame in the internal storage means; And And an external output device having a TCP / IP communication function receives and outputs the P'-Frame and the B-Frame stored in the storage means. The criterion of P-Frame is always the latest I-Frame, the criterion of P'-Frame is always the latest P-Frame, and the criterion of B-Frame is always the latest I-Frame and P-Frame. How to configure video using, I-Frame, P-Frame, B-Frame, and P'-Frame. 8. The I-Frame method according to claim 7, characterized in that a P'-Frame is generated by setting a macro block size of 32 × 32 to accurately perform a motion vector search and reduce a computation amount when encoding data with a codec. How to configure video using P-Frame, B-Frame and P'-Frame. The method according to claim 7 or 8, wherein the generation time of the P'-Frame and the B-Frame is shortened to reduce the bit rate, the size of the P'-Frame and the B-Frame is reduced, and the B-Frame is reduced according to the network speed. Image composition using I-Frame, P-Frame, B-Frame and P'-Frame, characterized in that the bit rate is adjusted. 8. The method of claim 7, wherein the calculation of the I-Frame, P-Frame, B-Frame and P'-Frame is performed by the DSP, I-Frame, P-Frame, B-Frame and P'-Frame How to configure the image using.

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