JP2013034152A - Video stationary determination method, video stationary determination device and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep stationary determination accuracy and reduce an operation amount concerning the stationary determination.SOLUTION: A video stationary determination device initializes stationary start time information using time information of an initial frame. Subsequently, a stationary time period is found from a difference absolute value between the stationary start time information corresponding to a coordinate of the relevant macroblock and the time information of a current frame. On the basis of a result of comparing the stationary time period and a predetermined threshold, it is determined whether or not the relevant macroblock is stationary for a certain time period or more. A pixel value change amount is calculated using any of SAD in which a calculation target pixel is limited, a difference absolute value between respective total pixel values of two blocks adjacent before and after, and a difference absolute value between respective sums of pixel values of target pixels included as a part in these two before and after blocks. The stationary determination is performed based on the calculated pixel value change amount and a threshold of the relevant macroblock.

Description

  The present invention relates to a video stillness determination method, a video stillness determination device, and a program that are used for speeding up inter-picture encoding of video encoding.

  H.264 is the latest video coding that efficiently compresses video data with vast amounts of information. H.264 / AVC is known. H. In H.264 / AVC, a large amount of computation is required for predictive coding between screens. Therefore, inter-screen coding using still information of video frames, that is, 1) First, each macroblock in a screen is “still”. Widely used is a method of determining whether it is “non-stationary” (stationary determination), and 2) predicting a macroblock that is stationary at the same coordinate one frame before Has been.

  This method is effective because it can reduce the amount of computation associated with P / B picture encoding while suppressing a decrease in encoding efficiency. Patent Document 1 is given as a representative example of inter-picture coding using still information. For example, in Patent Document 1, a sum of absolute differences (SAD: Sum of Absolute Difference) between a macroblock to be encoded and a macroblock at the same position one frame before is calculated. Therefore, the amount of calculation for the inter-picture encoding process is reduced by copying the reference macroblock.

  The stillness determination by SAD is not a problem in an environment where the calculation load is allowed. However, when real-time encoding such as video conferencing is executed by a PC (Personal Computer) having low calculation performance, in particular, the resolution / frame of video When the rate is high, the computation load becomes a problem. Therefore, an algorithm with a lower calculation amount is also required for the stillness determination method.

  With respect to the simple still region determination technique for solving the above problem, as a method that can be easily analogized, 1) a method for limiting the calculation target pixel of SAD to a part rather than the entire macroblock (for example, refer to Patent Document 2), or 2) A method of summing all or some of the pixel values of the encoding target block and the reference block and using the absolute value of the difference between the values is conceivable (see Patent Document 3, for example).

JP 2002-199408 A JP-A-10-229558 Japanese Patent No. 3968774

  However, in the conventional techniques described in Patent Documents 1 and 2 described above, since all changes in each pixel of the macroblock cannot be detected, it may be determined that the macroblock is stationary even though it is not stationary. As a result of prediction with a block at the same position in the immediately preceding frame, there is a problem that the encoding efficiency deteriorates.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a still image determination method and a still image determination method that can reduce the amount of computation associated with still determination while maintaining still determination accuracy. An apparatus and a program are provided.

  In order to solve the above-described problem, the present invention determines whether or not a macroblock in a video frame is stationary with respect to a macroblock located at the same coordinate of the immediately preceding frame in video encoding preprocessing. A method of initializing still image start time information given to spatial coordinates of each macro block by time information of an initial frame, and a still image of the same block in the frame immediately before the macro block If the determination result is non-still, the absolute value of the difference between the step of setting the still start time information of the macroblock in the current frame time information and the still start time information corresponding to the coordinates of the macroblock and the current frame time information Determining the stationary time from the step, comparing the stationary time with a predetermined threshold, and based on the comparison result. A step of determining whether or not the macroblock is stationary for a certain period of time, a SAD (Sum of Absolute Difference) in which the calculation target pixel is limited based on the determination result, and the respective pixels of the preceding and following two blocks Calculating a pixel value change amount using either a difference absolute value of a sum of values or a difference absolute value of values obtained by summing pixel values of a part of target pixels of each of the preceding and following two blocks; A still image determination method including a step of determining stillness based on a calculated pixel value change amount and a threshold value of the macroblock.

  In order to solve the above-described problem, the present invention determines whether or not a macroblock having a video frame is stationary with respect to a macroblock located at the same coordinate of the immediately preceding frame in the preprocessing of video encoding. A method of initializing still image start time information given to the spatial coordinates of each macro block with time information of an initial frame, and the same block of the frame immediately before the macro block If the stillness determination result is non-still, the step of setting the still start time information of the macroblock to the current frame time information and the difference between the still start time information corresponding to the coordinates of the macroblock and the time information of the current frame If the macro block is located at the edge of the screen, the size is different from the step of obtaining the stationary time from the absolute value. Of the two threshold values, the smaller first threshold value is compared with the stationary time, and if the macroblock is located at the center of the screen, the larger second value of the two threshold values having different sizes is selected. Comparing the threshold with the stationary time; determining whether the macroblock is stationary for a predetermined time or more based on the comparison result; and calculating the calculation target pixel based on the determination result. Limited SAD (Sum of Absolute Difference), absolute difference of the sum of the pixel values of the two previous and subsequent blocks, or absolute difference between the values of the sum of the pixel values of some target pixels of the two previous and subsequent blocks Calculating a pixel value change amount using any of the values, and performing a stillness determination based on the calculated pixel value change amount and a threshold value of the macroblock. A still image determination method characterized by the following.

  According to the present invention, in the above invention, when inter prediction prediction coding is performed using the still determination result, and when the prediction residual error is larger than a predetermined third threshold, the still start time of the macroblock The method further includes the step of correcting the information to time information of the current frame.

  In the present invention, in addition to the comparison result between the calculated pixel value change amount and the threshold value of the macroblock, in the above invention, the stationary time of the neighboring macroblock, the inter / intra mode information of the neighboring macroblock, It uses a motion vector of a neighboring macroblock.

  In order to solve the above-described problem, the present invention determines whether or not a macroblock having a video frame is stationary with respect to a macroblock located at the same coordinate of the immediately preceding frame in the preprocessing of video encoding. A still image start determination device for initializing still image start time information given to spatial coordinates of each macro block by time information of an initial frame, and a frame immediately preceding the macro block. If the stillness determination result of the block is non-still, setting means for setting the still start time information of the macroblock to the current frame time information, the still start time information corresponding to the coordinates of the macroblock and the current frame time information A stationary time calculating means for calculating a stationary time from a difference absolute value between the first and second comparators, and a comparing means for comparing the stationary time with a predetermined threshold value. Based on a comparison result by the comparison unit, a determination unit that determines whether or not the macroblock is stationary for a predetermined time or more, and a SAD (Sum of Sum) that limits a calculation target pixel based on the determination result by the determination unit Absolute Difference), the absolute value of the difference between the pixel values of the preceding and following two blocks, or the absolute value of the difference between the sum of the pixel values of some target pixels of the preceding and following two blocks A pixel value change amount calculating means for calculating a pixel value change amount, and a stillness determining means for performing stillness determination based on the pixel value change amount calculated by the pixel value change amount calculating means and a threshold value of the macroblock. It is an image stillness judging device characterized by comprising.

  In order to solve the above-described problem, the present invention determines whether or not a macroblock having a video frame is stationary with respect to a macroblock located at the same coordinate of the immediately preceding frame in the preprocessing of video encoding. A still image start determination device for initializing still image start time information given to spatial coordinates of each macro block by time information of an initial frame, and a frame immediately preceding the macro block. If the stillness determination result of the block is non-still, setting means for setting the still start time information of the macroblock to the current frame time information, the still start time information corresponding to the coordinates of the macroblock and the current frame time information If the macro block is located at the edge of the screen, the static time calculation means for calculating the static time from the absolute difference between Of the two different threshold values, the smaller first threshold value is compared with the stationary time, and if the macroblock is located at the center of the screen, the larger one of the two different threshold values. A comparing means for comparing the second threshold value with the stationary time, a determining means for determining whether or not the macroblock is stationary for a predetermined time or more based on a comparison result by the comparing means, and the determining means Based on the determination result by SAD (Sum of Absolute Difference) that limits the calculation target pixel, the difference absolute value of the sum of the pixel values of the preceding and following two blocks, or a part of each of the preceding and following two blocks Pixel value change amount calculating means for calculating a pixel value change amount using any one of absolute differences between values obtained by summing pixel values of pixels, and a pixel calculated by the pixel value change amount calculating means A video stillness determination apparatus comprising stillness determination means for determining stillness based on a value change amount and a threshold value of the macroblock.

  According to the present invention, in the above invention, when inter prediction prediction coding is performed using the still determination result, and when the prediction residual error is larger than a predetermined third threshold, the still start time of the macroblock The information processing apparatus further includes a correcting unit that corrects the information to time information of the current frame.

  According to the present invention, in the above invention, the stillness determining unit includes a comparison result between the pixel value change amount calculated by the pixel value change amount calculating unit and the macroblock threshold value, and a still time of neighboring macroblocks. And inter / intra mode information of neighboring macroblocks and motion vectors of neighboring macroblocks.

  In order to solve the above-described problem, the present invention determines whether or not a macroblock having a video frame is stationary with respect to a macroblock located at the same coordinate of the immediately preceding frame in the preprocessing of video encoding. An initialization function for initializing still image start time information given to the spatial coordinates of each macro block with time information of the initial frame to the computer of the video still image determination device for determining the same as the frame immediately before the macro block If the block stillness determination result is non-still, the setting function for setting the still start time information of the macroblock to the current frame time information, the still start time information corresponding to the coordinates of the macroblock and the time information of the current frame A stationary time calculation function for calculating a stationary time from a difference absolute value, a comparison function for comparing the stationary time with a predetermined threshold value A determination function that determines whether or not the macroblock is stationary for a predetermined time or more based on the comparison result by the comparison function, and a SAD (Sum of Absolute) that limits the calculation target pixel based on the determination result by the determination function Difference), the absolute difference value of the sum of the pixel values of the two preceding and following blocks, or the absolute difference value of the values obtained by summing the pixel values of some target pixels of the two preceding and succeeding blocks In order to realize a pixel value change amount calculation function for calculating a pixel value change amount, and a stillness determination function for performing stillness determination based on the pixel value change amount calculated by the pixel value change amount calculation function and a threshold value of the macroblock It is a program.

  In order to solve the above-described problem, the present invention determines whether or not a macroblock having a video frame is stationary with respect to a macroblock located at the same coordinate of the immediately preceding frame in the preprocessing of video encoding. An initialization function for initializing still image start time information given to the spatial coordinates of each macro block with time information of the initial frame to the computer of the video still image determination device for determining the same as the frame immediately before the macro block If the block stillness determination result is non-still, the setting function for setting the still start time information of the macroblock to the current frame time information, the still start time information corresponding to the coordinates of the macroblock and the time information of the current frame Static time calculation function that calculates static time from the difference absolute value, if the macroblock is located at the edge of the screen, Of the two thresholds having different sizes, the smaller first threshold is compared with the stationary time, and if the macroblock is located at the center of the screen, the larger of the two thresholds having different sizes is larger. A comparison function for comparing the second threshold value of the other and the stationary time, a determination function for determining whether the macroblock is stationary for a predetermined time or more based on a comparison result by the comparison function, and the determination function Based on the determination result, the SAD (Sum of Absolute Difference) in which the calculation target pixel is limited, the difference absolute value of the sum of the pixel values of the preceding and following two blocks, or a part of the target pixels of the preceding and following two blocks A pixel value change amount calculation function for calculating a pixel value change amount using any one of absolute differences between values obtained by summing the pixel values, and a pixel value change calculated by the pixel value change amount calculation function. This is a program for realizing a stillness determination function for performing stillness determination based on the conversion amount and the threshold value of the macroblock.

  According to the present invention, it is possible to reduce the amount of calculation associated with stillness determination while maintaining stillness determination accuracy.

It is a flowchart for demonstrating operation | movement of the stillness determination method by this 1st Embodiment. It is a flowchart for demonstrating the stationary stationary determination process by this 1st Embodiment. It is a flowchart for demonstrating the stationary determination process using the stationary stationary determination result by this 1st Embodiment. It is a conceptual diagram which shows the example in the case of (DELTA) DC = 0 and non-stationary. It is a conceptual diagram which shows the object range at the time of summing up a pixel value. It is a block diagram which shows the structure of the stillness determination processing apparatus by this 1st Embodiment. It is a block diagram which shows the structure of the stillness determination part 1 by this 1st Embodiment. It is a block diagram which shows the structure of the stationary time process part 11 by this 1st Embodiment. It is a flowchart for demonstrating the operation | movement of the stationary stationary determination process by this 2nd Embodiment. It is a flowchart for demonstrating operation | movement of the stillness determination method by this 3rd Embodiment. It is a flowchart for demonstrating operation | movement of the stationary start time information control process after an encoding by this 3rd Embodiment. It is a block diagram which shows the structure of the stillness determination processing apparatus by this 3rd Embodiment. It is a block diagram which shows the structure of the stationary determination part 1a by this 3rd Embodiment. It is a block diagram which shows the structure of the stationary time process part 11a by this 3rd Embodiment. It is a flowchart for demonstrating the operation | movement of the still determination process by this 4th Embodiment. It is a conceptual diagram which shows the neighborhood macroblock which refers to stationary start time information. When calculating the N _z, it is a conceptual diagram showing a macro block that references in response to each picture pattern. It is a conceptual diagram which shows the mode at the time of arranging the macroblock of a certain spatial coordinate in time series, and omitting evaluation of the pixel value variation | change_quantity with respect to the said macroblock. It is a block diagram which shows the structure of the still determination processing apparatus which implement | achieves the still determination method by this 4th Embodiment. It is a block diagram which shows the structure of the stationary determination part 1b by this 4th Embodiment. It is a block diagram which shows the structure of the stationary time process part 11b by this 4th Embodiment. It is a flowchart for demonstrating the operation | movement of the still determination process by this 4th Embodiment. It is a block diagram which shows the structure of the stationary determination part 1c by this 4th Embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, as the time information, the system time is used in all of the first to fourth embodiments. Hereinafter, the algorithm of the embodiment of the present invention is described as H.264. An example of H.264 / AVC will be described with reference to the drawings.

A. First Embodiment FIG. 1 is a flowchart for explaining the operation of a stillness determination method according to the first embodiment. First, all the still start time information corresponding to each macroblock is initialized to the system time P of the initial frame (step S1). Next, the encoding target frames are input one by one (step S2), and the encoding target macroblocks are input one by one in the raster scan order in units of macroblocks (step S3). Next, stationary stationary determination processing is performed (step S4), and stationary determination processing is performed (step S5).

  Next, for the encoding target macroblock, H. H.264 / AVC as a general encoder, encoding processing such as intra prediction / inter prediction, orthogonal transform / inverse orthogonal transform, quantization, entropy coding (CAVLC / CABAC) is performed. Output as binary data (step S6).

  In the encoding process of step S6, when performing inter-screen prediction encoding, the result of stillness determination is used. For example, in a block determined to be stationary, prediction is performed using a motion vector (0, 0), that is, a macroblock having the same coordinates in the immediately preceding frame. If the stillness determination is correctly performed, the prediction residual error can be sufficiently reduced by the prediction using the motion vector (0, 0).

  Next, it is determined whether or not the processing of all macroblocks in the frame has been completed (step S7). If not completed (false in step S7), the process returns to step S3 to return to the next macroblock. Process. On the other hand, if the processing of all the macroblocks in the frame has been completed (true in step S7), it is determined whether or not the processing of all frames has been completed (step S8). If not completed (false in step S8), the process returns to step S2 to process the next frame. If completed (true in step S8), the entire algorithm is terminated.

  Next, a specific algorithm for stationary determination (steady stationary determination processing in step S4 and stationary determination processing in step S5) in the first embodiment will be described in detail.

  FIG. 2 is a flowchart for explaining steady stationary determination processing according to the first embodiment. In the stationary stillness determination processing, first, the same coordinate macroblock of the immediately preceding frame of the (m, n) th macroblock (m and n are spatially the mth in the y direction and the nth in the x direction) to be determined. It is determined whether or not is stationary (step S11). If it is determined that the same coordinate macroblock of the immediately preceding frame is non-still (NO in step S11), the still start time information CNT (m, n) corresponding to the coordinate number of the still determination target macroblock is It updates like Formula (1) (step S12).

However, P is the system time of the frame. On the other hand, when it is determined to be stationary (YES in step S11), the stationary start time information is not changed, and the case classification of whether the (m, n) -th macroblock is stationary stationary or non-stationary stationary, Using the rest time (| CNT (m, n) −P |) and the threshold value TH _CNT , the following equation (2) is performed (step S13).

  FIG. 3 is a flowchart for explaining stillness determination processing using a stationary stillness determination result according to the first embodiment. In the stationary determination process, first, it is determined whether or not the stationary stationary determination is true (step S21). In the stationary stationary determination process (step S4 in FIG. 1), when it is determined that the stationary stationary is not performed, it is determined to be false in step S21. In this case, the pixel value change amount between the still determination target macroblock (see Equation (3)) and the same coordinate macroblock one frame before (see Equation (4)) is calculated using the SAD calculation equation (5). Evaluate (step S22).

  In the first embodiment, SAD is used. However, the pixel value change amount evaluation method used here may be sufficient if it can evaluate the change amount for each pixel. It may be a sum.

Then, using the threshold TH _SAD given from the outside, the state of the macroblock (see Equation (3)) is determined by the stationary determination condition of the following Equation (7). If so, false is output (step S23).

  This stillness determination result is applied to inter-picture prediction encoding in the encoding process of step S6 shown in FIG.

  On the other hand, if the stationary stationary determination process (step S4 in FIG. 1) determines that it is stationary stationary, it is determined to be true in step S21, and is identical to the stationary determination target macroblock (Equation (3)) one frame before. The pixel value change amount with respect to the coordinate macroblock (Formula (4)) is calculated using ΔDC defined by the following Formula (8) (Step S24).

  ΔDC is a difference between the total values of the macroblocks, and an approximate change amount of the entire block, not a change amount for each pixel, can be calculated with a calculation amount lower than that of SAD. In fact, in SAD, for a macroblock of 16 × 16 pixel size,

However, in ΔDC, if the total value (refer to Expression (10)) of the immediately preceding identical coordinate macroblock (Expression (4)) is stored, Expression (11) is obtained.

When the following equation (12) is true, ΔST is used to output the stillness determination result as true (stationary), and if it is false, the stillness determination result is output as false (non-stationary). S25). Here, TH _ΔDC is a threshold value for ΔDC.

  It should be noted here that when the pixel value change amount ΔDC is sufficiently small, the macro block for stationary determination is highly likely to be stationary with reference to the same coordinate macro block one frame before, but the pixel in SAD Unlike the case where the value change amount is calculated, the value change amount is not necessarily stationary. The specific example is shown below.

  For example, FIG. 4A shows the stillness determination target block (Formula (4)), and FIG. 4B shows the luminance value of the macroblock one frame before the stillness determination target block. Assume that white has a luminance value of 255 and gray has a luminance value of 0. In this case, ΔDC is 0, and it is considered that there is no change in the pixel value, but actually the texture is different.

  When stillness determination is performed based on the result of ΔDC = 0 in this situation, it is determined that the macroblock is stationary, and the macroblock is predicted by the immediately preceding macroblock by inter-frame prediction encoding. However, the prediction residual error energy becomes large, and the coding efficiency is significantly reduced.

  In the prior art, calculation that is lower in calculation than SAD such as ΔDC is directly used. However, according to the present invention, the simple evaluation of the change in luminance value by ΔDC is performed by the strict evaluation of the change in pixel value by SAD. Therefore, the above exception case can be excluded because it is applied only to a macroblock that is considered to be stationary at a sufficient time.

  In addition, the calculation method of ΔDC in the first embodiment is a range in which the pixels of the entire macroblock are added as shown in FIG. 5A, but in FIG. 5B and FIG. As described above, by limiting the pixel range calculated by ΔDC in the macroblock, it is possible to reduce the amount of calculation associated with the evaluation of the pixel value change amount. Further, not only for ΔDC but also for SAD, even if the target pixel range of the sum of absolute differences is limited to FIG. 5B and FIG.

  FIG. 6 is a block diagram showing the configuration of the stillness determination processing apparatus according to the first embodiment. As shown in FIG. 6, the stillness determination processing apparatus includes a stillness determination unit 1 and an encoding processing unit 2. The stillness determination unit 1 receives a macroblock of each frame as an input, and supplies the stillness determination result to the encoding processing unit 2. The encoding processing unit 2 encodes the macroblock to be encoded according to the stillness determination result, and outputs it as binary data.

  FIG. 7 is a block diagram illustrating a configuration of the stillness determination unit 1 according to the first embodiment. First, the stillness determination unit 1 includes a stationary time processing unit 11, a stationary stillness determination unit 12, a pixel value change evaluation method switching unit 13, a normal pixel value change evaluation unit 14, a normal stillness determination unit 15, and a simple pixel value change evaluation unit 16. And a simple stillness determination unit 17. The stationary time processing unit 11 receives the spatial coordinate position information of the macroblock and the system time.

  FIG. 8 is a block diagram showing a configuration of the stationary time processing unit 11 according to the first embodiment. As shown in FIG. 8, the stationary time processing unit 11 includes a stationary time control unit 111, a stationary start time information storage unit 112, and a stationary time calculation unit 113. The stationary time control unit 111 receives the spatial coordinates, the system time, and the stationary determination result in the previous frame, and sends them to the stationary time calculation unit 113. The stationary time calculation unit 113 updates the stationary start time information stored in the stationary start time information storage unit 112 to the system time of the current frame if it is non-still based on the previous stationary determination result, writes the value, The difference absolute value between the system time of the current frame and the still start time information is sent to the still time control unit 111 as a still time. Finally, the stationary time control unit 111 sends the stationary time to the stationary stationary determination unit 12 shown in FIG.

  The stationary stationary determination unit 12 determines whether the macroblock is stationary stationary according to the stationary time, and sends the result (true or false) to the pixel value change evaluation method switching unit 13. The pixel value change evaluation method switching unit 13 selects a stillness determination method according to the received stationary stillness determination result. If the stationary stationary determination result is false, the macroblock is regarded as non-stationary stationary, the SAD calculation is performed in the normal pixel value change evaluating unit 14, and the calculated SAD value is used as the normal stationary determining unit 15. To send. The normal stillness determination unit 15 determines whether or not the macroblock is still according to the received SAD value and a predetermined threshold value, and sends the stillness determination result to the encoding processing unit 2 shown in FIG. The encoding processing unit 2 simplifies inter-screen encoding according to the stillness determination result.

  If the stationary stationary determination result is true, it is regarded as stationary stationary, and the pixel value change evaluation method switching unit 13 selects the simple pixel value change evaluating unit 16. The simple pixel value change evaluation unit 16 calculates ΔDC of the pixel value change between the macroblock and the immediately preceding macroblock, and sends ΔDC to the simple stillness determination unit 17. The simple stillness determination unit 17 performs stillness determination based on the received ΔDC, and sends true to the encoding processing unit 2 shown in FIG. 6 if true, and false if false.

B. Second Embodiment The second embodiment provides a method that takes macroblock position information into consideration in stationary stationary determination (the flowchart of FIG. 2) in the algorithm of the first embodiment. In a video with little motion such as a video conference video, the video screen edge is more likely to be a background region without motion than the center. In the second embodiment, the stationary stationary is determined in consideration of such an image. The stationary determination processing apparatus that implements the algorithm of the second embodiment has the same configuration as that of FIGS. 6, 7, and 8 of the first embodiment, and a description thereof will be omitted.

  FIG. 9 is a flowchart for explaining the operation of the stationary stationary determination process according to the second embodiment. In the stationary still determination process, first, the (m, n) -th macroblock (m, n) to be determined is the same coordinate macro of the immediately preceding frame of the mth in the y direction and the nth in the x direction. It is determined whether or not the block is stationary (step S31). Then, when it is determined that the same coordinate macroblock of the immediately preceding frame is non-still (NO in step S31), the still start time information CNT (m, n) corresponding to the coordinate number of the still determination target macroblock is expressed as Update as in (1) (step S32).

  Next, when it is determined that the same-coordinate macroblock of the immediately preceding frame is stationary (YES in step S31), or after the process of step S32 is completed, it is determined whether the macroblock is located at the center of the screen (step). S33). If it is located at the center of the screen (YES in step S33), the stationary stationary is determined as in the following equation (13) (step S34), and if it is located at the edge of the screen (step S33). NO), and stationary stationary is determined as in equation (14) (step S35).

  However, P is the system time of the current frame, and the first threshold> the second threshold. For a video with many background areas, such as a video conference video, the still time becomes higher than the threshold at an earlier timing in the image edge area by properly using the threshold according to this area. That is, since a simple pixel value change evaluation method can be selected, the amount of calculation can be further reduced and effective compared to the first embodiment.

C. Third Embodiment The third embodiment provides a method that takes into account control of still start time information after encoding. Normally, if it is determined that the frame is still according to the result of the still determination, the macro block is generally predicted by the macro block at the same position in the immediately preceding frame. However, if an error occurs in the result of stillness determination (when it is determined that it is still, but the pixel value has actually changed and it is not still), the prediction residual is the result of prediction with the macroblock of the previous frame. The absolute value sum of the signals takes a very large value, which causes a decrease in coding efficiency.

  Furthermore, when the stationary time is sufficiently long, it is possible that the simple means for calculating the pixel value change amount cannot detect the motion and the erroneous determination of several frames continues. In view of this problem, it is desirable to immediately update the value of the still start time information to the current frame and return to the correct still determination by SAD.

  FIG. 10 is a flowchart for explaining the operation of the stillness determination method in which control of stillness start time information after encoding is introduced according to the third embodiment. The difference from the first embodiment and the second embodiment is that a process of controlling the static start time information in step S47 is added. Steps S41 to S46 correspond to Steps S1 to S6 in FIG. In step 47, control of the still-start time information after encoding is performed for the macroblock that is determined to be still in the stillness determination.

FIG. 11 is a flowchart for explaining the operation of the post-coding still start time information control process according to the third embodiment. In the post-coding still start time information control process, first, the prediction residual error (ΔE) after inter-frame coding is referred to, and the threshold TH _ΔE is compared with the magnitude relationship (step S51). If the prediction residual error (ΔE) is equal to or smaller than the threshold TH _ΔE (YES in step S51), the process returns to the main routine shown in FIG. 10 without doing anything. On the other hand, if the prediction residual error (ΔE) is larger than the threshold TH _ΔE (NO in step S51), the value of the still start time information is updated to the system time of the current frame as shown in equation (15) (step S52). ).

  Where P is the system time of the current frame.

  FIG. 12 is a block diagram illustrating a configuration of a stillness determination processing apparatus that introduces the still start time information control after encoding according to the third embodiment. As shown in FIG. 12, the stillness determination processing apparatus according to the third embodiment includes a stillness determination unit 1a and an encoding processing unit 2a. The stillness determination unit 1a receives a macroblock of each frame as an input, refers to the inter-screen prediction residual error, and supplies the stillness determination result to the encoding processing unit 2a. The encoding processing unit 2a supplies the inter-screen prediction residual error to the stillness determination unit 1a, encodes the encoding target macroblock according to the stillness determination result, and outputs the encoded macroblock as binary data.

  FIG. 13 is a block diagram illustrating a configuration of the stillness determination unit 1a according to the third embodiment. It should be noted that portions corresponding to those in FIG. In FIG. 13, the still time processing unit 11 a receives the spatial coordinate position information of the macroblock and the system time, and inputs information on the inter-screen prediction residual error as the encoding result from the encoding processing unit 2 a. And the value of the still start time information is updated to the system time of the current frame with reference to the inter-screen prediction residual error.

  FIG. 14 is a block diagram showing a configuration of the stationary time processing unit 11a according to the third embodiment. The parts corresponding to those in FIG. The stationary time processing unit 11a includes a stationary time control unit 111a, a stationary start time information storage unit 112, and a stationary time calculation unit 113. The still time control unit 111a receives the inter-screen prediction residual error as the encoding result from the encoding processing unit 2a in addition to the spatial coordinates, the system time, and the stillness determination result in the immediately preceding frame. To send.

D. Fourth Embodiment In the fourth embodiment, in addition to the stationary determination conditions of the first embodiment or the second embodiment described above, stationary time / coding information (inter / intra information, motion vector information) of neighboring macroblocks. ) Is provided.

  According to the present invention, the simple evaluation of the luminance value change amount based on the pixel value change amount ΔDC is limited to a macroblock that is considered to be stationary at a sufficient time by strict evaluation of the pixel value change amount based on the SAD. In order to apply, it is considered that the erroneous determination as described in the first embodiment hardly occurs. However, the possibility of sudden movement is sufficiently conceivable, and at the boundary between the actual moving area and the stationary area, there is a possibility that the object is not stationary due to a sudden intrusion of the object.

  At this time, it is conceivable that the simple calculation of the pixel value change amount cannot detect the motion and erroneously determines the stillness. In order to configure a more robust stillness determination method, in the fourth embodiment, in addition to the simply calculated pixel value change ΔDC between blocks, in addition to the static time of a macroblock near the stillness determination target macroblock, intra / intermediate Use mode information and motion vector information.

FIG. 15 is a flowchart for explaining the operation of stillness determination processing according to the fourth embodiment. In the stationary determination process, first, it is determined whether or not the stationary stationary determination is true (step S61). If it is determined to be non-stationary still (false in step S61), the stationary determination target macroblock (see Equation (3)) and the same coordinate macroblock one frame before (see Equation (4)) Is evaluated using the SAD calculation formula (5) (step S62). Then, using the threshold TH _SAD given from the outside, the state of the macroblock (see Equation (3)) is determined by the stillness determination condition of Equation (7). If false, it outputs false (step S63).

On the other hand, when it is determined that it is stationary still (true in step S61), the pixel value change amount between the still determination target macroblock (Equation (4)) and the same coordinate macroblock (Equation (4)) one frame before Is calculated using ΔDC defined by Equation (8) (step S64). Next, using ΔDC, the number of blocks N _c , and the number of blocks N _z , the stationary determination result is output as true (stationary) according to the truth of three conditions described later, and if it is false, the stationary determination result is output. False (non-stationary) is output (step S65).

Number of blocks N _c that are stationary stationary neighboring macroblocks and blocks coded with 16 × 16 size motion vectors (0, 0) in the neighboring macroblocks of the current frame and the immediately preceding frame, which are used in the processing of step S65 The number N _z is calculated as follows.

First, the calculation of _Nc will be described with reference to FIGS. 16 (a) and 16 (b). X represents a still determination target block. For the calculation of _Nc , each still time is calculated from the still start time information (FIG. 16 (b)) corresponding to the coordinates of the eight neighboring macroblocks adjacent to the still determination target macroblock, and the following equation (16) is obtained. The number of blocks is calculated as _Nc . When Nc is large, it can be determined that the vicinity of the stillness determination target macroblock is sufficiently stationary, so that the possibility that the stillness determination target macroblock is still is also high.

Will now be described with reference to FIGS. 17 (a) ~ (c) Calculation of _{N z.}
Figure 17 (a) ~ (c) is when calculating the N _z, it is a conceptual diagram showing a macro block that references in response to each picture pattern. In any of FIGS. 17A to 17C, X indicates a still determination target block. First, when the frame including the still determination target block is a P / B picture and the immediately preceding frame is also a P / B picture, as shown in FIG. 17A, nine neighboring macroblocks A1 to A1 of the current frame and the immediately preceding frame are displayed. A4 and B1 to B5 are referred to, and among them, the number of pixels that are encoded in inter mode, the inter-picture prediction pixel unit is 16 × 16, and the motion vector is (0, 0) is N _z . .

Next, when the frame including the still determination target block is an I picture and the immediately preceding frame is a P / B picture, the nine neighboring macroblocks B1 to B9 of the immediately preceding frame are referred to as shown in FIG. , in which, in inter-picture prediction pixel units 16 × 16, and a motion vector the number of those which are (0, 0) and _{N z.}

Lastly, when the frame including the still determination target block is a P / B picture and the immediately preceding frame is an I picture, as shown in FIG. to A4) since only, within a macro block Al to A4, with the block size is 16 × 16 in the inter-frame prediction, and the number of those is a motion vector (0, 0) and _{N z.}

The information of the (0, 0) motion vector in units of 16 × 16 pixels means that the immediately preceding macroblock is determined to be optimal by the actual inter-screen prediction. Therefore, when _Nz is large, similarly to _Nc The possibility that the stationary determination target block is stationary increases.

As described above, using the obtained ΔDC, N _c , and N _z , the stationary determination result is output as true when all three conditions expressed by the following equation (17) are true in step S65.

Here, TH _ΔDC and TH _Nc are threshold values for ΔDC and N _c , and TH _Nz is a threshold value for N _z . However, the information N _z about the motion vector of the neighboring macroblock, the number of blocks that can be referenced in the corresponding frame and the previous frame are different, as in the following equation (18), the combination of three picture type, respectively prepared threshold Keep it. If one or more conditions are false, the stillness determination result is output as false.

  As described above, according to the algorithm according to the fourth embodiment, the risk of misjudgment with respect to the stationary determination when the object suddenly enters the stationary area, which occurs at the boundary between the stationary area and the moving area. Can be reduced by using the conditions for the stationary time of the neighboring macroblocks, the inter-intra mode information of the neighboring macroblocks, and the motion vector information, and a robust stationary judgment can be performed with a low calculation.

  Further, the calculation method of ΔDC in the fourth embodiment is a range in which the pixels of the entire macroblock are added as shown in FIG. 5A, but in FIG. 5B and FIG. As described above, by limiting the pixel range calculated by ΔDC in the macroblock, it is possible to reduce the amount of calculation associated with the evaluation of the pixel value change amount. Further, not only for ΔDC but also for SAD, even if the target pixel range of the sum of absolute differences is limited to FIG. 5B or FIG. Yes.

  In addition, although not the configuration of the fourth embodiment, the calculation of ΔDC may be omitted depending on the macroblock that has a particularly long stationary time and is considered as the background in the video screen. FIG. 18 is a conceptual diagram showing a state in which macroblocks having a certain spatial coordinate are arranged in time series and the evaluation of the pixel value change amount for the macroblock is omitted. The dark gray macroblocks (N-2, N-1, and N) indicate that the SAD evaluation method determines that the macroblock is stationary, and the macroblock of the Nth frame is evaluated by the SAD pixel value change amount evaluation. This shows a situation where it is determined that the camera is stationary, the stationary time has become sufficiently large, and the state has shifted from the (N + 1) th frame to the stationary stationary state.

  Further, after the (N + 1) th frame determined to be stationary still, light gray indicates that it was determined to be stationary by the ΔDC evaluation method, and white indicates that ΔDC was not evaluated and that it was determined to be stationary. Show. In the (N + 2) th, (N + 4) th, and (N + 6) th frames in which the evaluation of ΔDC is omitted, the determination is performed based on the stationary determination condition represented by the following equation (19), which excludes the ΔDC condition under the condition of step S65 in FIG.

  The macro block of the (N + 3) th frame is evaluated for the pixel value change amount by ΔDC, but the macro block of the (N + 2) th frame is not evaluated for ΔDC. For this reason, if the reference is the macroblock of the (N + 2) th frame, the total value of both macroblocks must be calculated. Therefore, in this case, the partial total value calculated for the macroblock of the (N + 1) th frame is held by the macroblock of the (N + 2) th frame, and only the partial total value of the macroblock of the (N + 3) th frame is calculated, Evaluation is based on the absolute value of the difference from the total value of the macro blocks of the (N + 1) th frame held by the macro block. As described above, by using the information of neighboring macroblocks, the simplification of the pixel value change amount evaluation (lower calculation amount) can be limited not only in the space but also in the time direction.

  FIG. 19 is a block diagram illustrating a configuration of a stillness determination processing device that realizes a stillness determination method according to the fourth embodiment. As shown in FIG. 19, the stillness determination processing apparatus according to the fourth embodiment includes a stillness determination unit 1b and an encoding processing unit 2b. The stillness determination unit 1b receives macroblock intra / inter mode information and motion vector information of each frame as input, and supplies the stillness determination result to the encoding processing unit 2b. The encoding processing unit 2b supplies intra / inter mode information and motion vector information to the stillness determination unit 1b, encodes a macroblock to be encoded according to the stillness determination result, and outputs the encoded macroblock as binary data.

  FIG. 20 is a block diagram illustrating a configuration of the stillness determination unit 1b according to the fourth embodiment. Note that portions corresponding to those in FIGS. 7 and 13 are denoted by the same reference numerals and description thereof is omitted. In FIG. 20, the stationary time processing unit 11b receives the spatial coordinate position information of the macroblock and the system time as input information, and also determines the stationary determination result from the normal stationary determination unit 15 and the stationary stationary determination unit 17b. As a result of the determination, spatial coordinate position information of neighboring macroblocks is received. In addition, the simple still determination unit 17b receives intra / inter mode information, motion vector information, and the still time of neighboring macroblocks from the still time processing unit 11b as encoded information.

  FIG. 21 is a block diagram showing a configuration of the stationary time processing unit 11b according to the fourth embodiment. Note that portions corresponding to those in FIGS. 8 and 14 are denoted by the same reference numerals and description thereof is omitted. In FIG. 21, in the stationary time processing unit 11 b, the stationary time control unit 111 b receives the spatial coordinates, the system time, and the stationary determination result at the immediately preceding frame and sends them to the stationary time calculation unit 113. If the stationary time calculation unit 113 is not stationary according to the previous stationary determination result, the stationary time calculating unit 113 updates the stationary start time information to the system time of the current frame in the stationary start time information storage unit 112, writes the value, and The absolute value of the difference between the system time of the current frame and the stationary start time information is sent as a stationary time to the time control unit 111b. Finally, the stationary time control unit 111b sends the stationary time to the stationary stationary determination unit 12 shown in FIG.

  The stationary stationary determination unit 12 determines whether or not the macroblock is stationary stationary according to the stationary time, and sends the result (true or false) to the pixel value change evaluation method switching unit 13. The pixel value change evaluation method switching unit 13 selects a stillness determination method according to the received stationary stillness determination result. If the stationary stationary determination result is false, the macroblock is regarded as non-stationary stationary, the SAD calculation is performed in the normal pixel value change evaluating unit 14, and the calculated SAD value is used as the normal stationary determining unit 15. To send. The normal stillness determination unit 15 determines whether or not the macroblock is still according to the received SAD value and a predetermined threshold, and sends the result to the encoding processing unit 2b shown in FIG. The encoding processing unit 2b simplifies inter-screen encoding according to the stillness determination result.

  Further, if the stationary stationary determination result is true, it is regarded as stationary stationary, and the pixel value change evaluation method switching unit 13 selects the simple pixel value change evaluating unit 16, and the macro block and the immediately preceding macro block are changed. The ΔDC of the pixel value change is calculated, and ΔDC is sent to the simple still determination unit 17b. Based on the received ΔDC, the motion vector information of the time / space neighboring macroblock received from the encoding processing unit 2b, and the stationary time of the neighboring macroblock received from the stationary time processing unit 11b, the simple stillness determination unit 17b A determination is made, and if true, the result is sent to the encoding processing unit 2b.

In addition, the above example corresponds to classifying the stationary stationary level into two levels by one threshold, but the stationary stationary level may be classified into a plurality of levels by providing a plurality of thresholds. As a result, it becomes possible to simplify the stillness determination step by step according to the stationary stillness level. For example, using still start time information CNT (m, n), system time P of the frame, threshold TH _CNT (1), TH _CNT (2) (0 <TH _CNT (1) <TH _CNT (2)) Is defined as the following equation (20).

FIG. 22 is a flowchart for explaining the operation of stillness determination processing according to the fourth embodiment. In FIG. 22, one branch process is added in accordance with the change in the number of stationary stationary levels from 2 to 3. In the stationary determination process, first, it is determined to which stationary stationary level it belongs (step S71). If it is determined to be the first steady rest level (first steady rest level in step S71), SAD is calculated (step S72), and a macroblock (formula) is used by using the threshold TH _SAD given from the outside. The state of (see (3)) is determined by the stillness determination condition, and true is output if it is stationary, and false is output if it is not stationary (step S73).

On the other hand, when it is determined to be the second stationary stationary level (second stationary stationary level in step S71), the stationary determination target macroblock (Equation (4)) and the same coordinate macroblock (Equation (4)) one frame before ) Is calculated using ΔDC1 defined by Equation (8) (step S74). Next, as shown in FIG. 5B, by limiting the target pixel range to be summed and using ΔDC1, the number of blocks N _c , and the number of blocks N _z , according to the truth of the three conditions shown in the figure, The stillness determination result is output as true (still), and if it is false, the stillness determination result is output as false (non-stationary) (step S75).

When it is determined that the third stationary stationary level is satisfied (third stationary stationary level in step S71), ΔDC2 is defined as the following equation (21), whereby ΔDC2, block number N _c , block number N _z Is used to output the stillness determination result as true (stationary) according to the true / false of the three conditions shown in the figure, and if it is false, the stillness determination result is output as false (non-stationary) (step S77). In this way, the pixel value change amount is more easily evaluated by a calculation lower than ΔDC1 of the first steady stationary level.

  FIG. 23 is a block diagram illustrating a configuration of the stillness determination unit 1c according to the fourth embodiment. Note that portions corresponding to those in FIG. 20 are denoted by the same reference numerals and description thereof is omitted. In FIG. 23, the stillness determination device 1c according to the fourth embodiment is a pixel value change evaluation method switching unit 13c for performing switching in three stages with respect to the configuration of the stillness determination device 1b shown in FIG. The first simple stillness determination unit 16c and the first simple stillness determination unit 17c that perform evaluation, and the second simple stillness determination unit 16d and the first simple stillness determination unit 17d that perform evaluation using ΔDC2 are added. As described above, when the number of stages of the stationary stationary level is further increased, the apparatus can be expanded by adding a module to the pixel value change evaluation method switching unit 13c.

  According to the first to fourth embodiments described above, by calculating the still time by reflecting the still determination result to the still start time information corresponding to the coordinates of each macro block of the original video signal, the macro block However, it is possible to grasp how long the station is stationary. It is considered that the longer the macro block is stationary, the lower the possibility that the pixel value changes in the same coordinate macro block in the immediately subsequent frame. Therefore, for macroblocks that are determined to be stationary for a certain time or longer, evaluation of the amount of change in pixel values between macroblocks is performed using a calculation formula with a lower amount of computation, while reducing computation costs. It is possible to suppress a decrease in the accuracy of stationary determination.

  The application range of the present invention is H.264. The present invention can be applied not only to H.264 / AVC but also to standard video encoding such as MPEG2 and MPEG4.

  Further, by recording a program for realizing each step by the video stillness determination apparatus described above on a computer-readable recording medium, causing the computer system to read and execute the program recorded on the recording medium, Processing may be performed. Here, the “computer system” may include an OS and hardware such as peripheral devices. Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used. The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a CD-ROM, a hard disk built in a computer system, etc. This is a storage device.

  Further, the “computer-readable recording medium” means a volatile memory (for example, DRAM (Dynamic DRAM) in a computer system that becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Random Access Memory)), etc., which hold programs for a certain period of time. The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

DESCRIPTION OF SYMBOLS 1, 1a Stillness determination part 2, 2a Encoding processing part 11, 11a, 11b Still time processing part 12 Stationary stillness determination part 13, 13c Pixel value change evaluation method switching part 14 Normal pixel value change evaluation part 15 Normal stillness determination part 16 , 16c, 16d Simple pixel value change evaluation unit 17, 17b, 17c, 17d Simple still determination unit 111, 111a, 111b Still time control unit 112 Still start time information storage unit 113 Still time calculation unit

Claims (10)

In a video encoding preprocessing, a video stillness determination method for determining whether or not a macroblock having a video frame is still with respect to a macroblock located at the same coordinate of a previous frame,
Initializing still start time information given to the spatial coordinates of each macroblock with time information of an initial frame;
If the stillness determination result of the same block of the previous frame of the macroblock is non-still, setting the still start time information of the macroblock to the current frame time information;
Obtaining a still time from the absolute difference between the still frame start time information corresponding to the coordinates of the macroblock and the current frame time information;
Comparing the rest time with a predetermined threshold;
Determining whether or not the macroblock is stationary for a predetermined time or more based on the comparison result;
Based on the determination result, the SAD (Sum of Absolute Difference) that limits the calculation target pixel, the total difference absolute value of the respective pixel values of the preceding and following two blocks, or a part of the target pixels of the preceding and following two blocks Calculating a pixel value change amount using any one of absolute differences between values obtained by summing the pixel values of
A still image determination method comprising: determining stillness based on the calculated pixel value change amount and a threshold value of the macroblock. In a video encoding preprocessing, a video stillness determination method for determining whether or not a macroblock having a video frame is still with respect to a macroblock located at the same coordinate of a previous frame,
Initializing still start time information given to the spatial coordinates of each macroblock with time information of an initial frame;
If the stillness determination result of the same block of the previous frame of the macroblock is non-still, setting the still start time information of the macroblock to the current frame time information;
Obtaining a still time from the absolute difference between the still frame start time information corresponding to the coordinates of the macroblock and the current frame time information;
If the macroblock is located at the screen edge, the smaller first threshold value of the two threshold values having different sizes is compared with the stationary time. If the macroblock is located at the center of the screen, Comparing the larger second threshold value of the two different threshold values with the rest time;
Determining whether or not the macroblock is stationary for a predetermined time or more based on the comparison result;
Based on the determination result, the SAD (Sum of Absolute Difference) that limits the calculation target pixel, the absolute difference of the sum of the pixel values of the two preceding and following blocks, or a part of each of the preceding and following two blocks Calculating a pixel value change amount using any one of absolute differences between values obtained by summing pixel values of pixels;
A still image determination method comprising: determining stillness based on the calculated pixel value change amount and a threshold value of the macroblock.   When prediction prediction error is larger than a predetermined third threshold when inter-picture prediction coding is performed using the stillness determination result, the still start time information of the macroblock is corrected to time information of the current frame The video stillness determination method according to claim 1, further comprising a step of:   In addition to the comparison result between the calculated pixel value change amount and the macroblock threshold value, the stationary time of the neighboring macroblock, the inter / intra mode information of the neighboring macroblock, and the motion vector of the neighboring macroblock are used. The video stillness determination method according to claim 1 or 2, wherein the video stillness is determined. In a video encoding pre-processing, a video stillness determination device that determines whether a macroblock in a video frame is still with respect to a macroblock located at the same coordinate of a previous frame,
Initialization means for initializing the static start time information given to the spatial coordinates of each macroblock one by one with the time information of the initial frame;
If the still determination result of the same block of the previous frame of the macroblock is non-still, setting means for setting the still start time information of the macroblock to the current frame time information;
A still time calculation means for calculating a still time from a difference absolute value between the still frame start time information corresponding to the coordinates of the macroblock and the time information of the current frame;
A comparison means for comparing the stationary time with a predetermined threshold;
Determination means for determining whether or not the macroblock is stationary for a predetermined time or more based on a comparison result by the comparison means;
Based on the determination result by the determination means, SAD (Sum of Absolute Difference) in which calculation target pixels are limited, the total difference absolute value of the respective pixel values of the preceding and following two blocks, or a part of each of the preceding and following two blocks Pixel value change amount calculating means for calculating a pixel value change amount using any of absolute differences between values obtained by summing the pixel values of the target pixels of
A video stillness determination device comprising: a stillness determination unit that performs stillness determination based on a pixel value change amount calculated by the pixel value change amount calculation unit and a threshold value of the macroblock. In a video encoding pre-processing, a video stillness determination device that determines whether a macroblock in a video frame is still with respect to a macroblock located at the same coordinate of a previous frame,
Initialization means for initializing the static start time information given to the spatial coordinates of each macroblock one by one with the time information of the initial frame;
If the still determination result of the same block of the previous frame of the macroblock is non-still, setting means for setting the still start time information of the macroblock to the current frame time information;
A still time calculation means for calculating a still time from a difference absolute value between the still frame start time information corresponding to the coordinates of the macroblock and the time information of the current frame;
If the macroblock is located at the screen edge, the smaller first threshold value of the two threshold values having different sizes is compared with the stationary time. If the macroblock is located at the center of the screen, A comparing means for comparing the second threshold value of the larger one of the two threshold values having different sizes with the stationary time;
Determination means for determining whether or not the macroblock is stationary for a predetermined time or more based on a comparison result by the comparison means;
Based on the determination result by the determination means, the SAD (Sum of Absolute Difference) that limits the calculation target pixel, the difference absolute value of the sum of the pixel values of the preceding and following two blocks, or one of each of the preceding and following two blocks A pixel value change amount calculating means for calculating a pixel value change amount using any one of absolute values of differences between values obtained by summing the pixel values of the target pixels of the unit;
A video stillness determination device comprising: a stillness determination unit that performs stillness determination based on a pixel value change amount calculated by the pixel value change amount calculation unit and a threshold value of the macroblock.   When prediction prediction error is larger than a predetermined third threshold when inter-picture prediction coding is performed using the stillness determination result, the still start time information of the macroblock is corrected to time information of the current frame The video stillness determining apparatus according to claim 5, further comprising a correcting unit that performs the correction.   The stillness determination means includes the comparison result between the pixel value change amount calculated by the pixel value change amount calculation means and the macroblock threshold value, as well as the still time of the neighboring macroblock and the inter / intra of the neighboring macroblock. 7. The video stillness determination apparatus according to claim 5, wherein mode information and motion vectors of neighboring macroblocks are used. In the pre-processing of video encoding, the computer of the video stillness determination device for determining whether a macroblock with a video frame is still with respect to a macroblock located at the same coordinate of the previous frame,
An initialization function for initializing the static start time information given to the space coordinates of each macroblock with the time information of the initial frame;
A setting function that sets the still start time information of the macroblock to the current frame time information if the stillness determination result of the same block of the previous frame of the macroblock is non-still,
A still time calculation function for calculating a still time from a difference absolute value between the still frame start time information corresponding to the coordinates of the macroblock and the time information of the current frame;
A comparison function for comparing the stationary time with a predetermined threshold;
A determination function for determining whether or not the macroblock is stationary for a predetermined time or more based on a comparison result by the comparison function;
Based on the determination result by the determination function, the SAD (Sum of Absolute Difference) in which the calculation target pixel is limited, the total difference absolute value of the respective pixel values of the preceding and following two blocks, or a part of each of the preceding and following two blocks A pixel value change amount calculation function for calculating a pixel value change amount using any one of absolute differences between values obtained by summing pixel values of target pixels of
A program for realizing a stillness determination function for performing stillness determination based on a pixel value change amount calculated by the pixel value change amount calculation function and a threshold value of the macroblock. In the pre-processing of video encoding, the computer of the video stillness determination device for determining whether a macroblock with a video frame is still with respect to a macroblock located at the same coordinate of the previous frame,
An initialization function for initializing the static start time information given to the space coordinates of each macroblock with the time information of the initial frame;
A setting function that sets the still start time information of the macroblock to the current frame time information if the stillness determination result of the same block of the previous frame of the macroblock is non-still,
A still time calculation function for calculating a still time from a difference absolute value between the still frame start time information corresponding to the coordinates of the macroblock and the time information of the current frame;
If the macroblock is located at the screen edge, the smaller first threshold value of the two threshold values having different sizes is compared with the stationary time. If the macroblock is located at the center of the screen, A comparison function for comparing the second threshold value, which is the larger one of the two threshold values having different sizes, with the stationary time;
A determination function for determining whether or not the macroblock is stationary for a predetermined time or more based on a comparison result by the comparison function;
Based on the determination result by the determination function, the SAD (Sum of Absolute Difference) that limits the calculation target pixel, the total difference absolute value of the respective pixel values of the preceding and following two blocks, or each of the preceding and following two blocks. A pixel value change amount calculation function for calculating a pixel value change amount using any one of absolute differences between values obtained by summing pixel values of target pixels of the unit,
A program for realizing a stillness determination function for performing stillness determination based on a pixel value change amount calculated by the pixel value change amount calculation function and a threshold value of the macroblock.

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