JP3674607B2 - Video signal discriminating apparatus and method, recording medium, and program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a video signal discriminating apparatus and method, a recording medium, and a program, and in particular, a video signal discriminating apparatus and method capable of reliably judging whether or not it is a film video signal with a simple configuration. , A recording medium, and a program.
[0002]
[Prior art]
Recently, in order to enable a video signal to be viewed with less flicker, an interlace video signal has been frequently converted to a progressive video signal.
[0003]
An NTSC video signal is composed of 60 fields (30 frames) per second. On the other hand, the number of frames per second of a signal photographed by a movie film is 24 frames. Therefore, when a movie image is converted into an NTSC video signal, the conversion process is performed using the 3-2 pull-down method. When this conversion process is performed, the same frame image is arranged in two consecutive fields, and the same image of the next frame is arranged in the subsequent three fields. As a result, 24 frames of images can be assigned to 60 fields.
[0004]
As described above, in the film video signal subjected to the 3-2 pull-down conversion, the video signal in the first field and the third field in the three consecutive fields are exactly the same video signal. When an interlace video signal is converted into a progressive video signal, if the same video signal has already been encoded, the processing of the second video signal can be omitted. Therefore, when it is known in advance whether or not it is a film video signal, more efficient encoding is possible.
[0005]
Therefore, a method for determining whether or not the film video signal has undergone 3-2 pull-down conversion is disclosed in, for example, US Pat. No. 4,982,280.
[0006]
FIG. 1 shows the principle of the system proposed in this US patent. As shown in the figure, the video signal is a signal in which fields of odd (O) and even (E) appear alternately. In the case of a video signal subjected to 3-2 pull-down conversion, the first frame A image (luminance signal) is a video signal of two fields, odd field Ao and even field Ae.
[0007]
The image of the next frame B is arranged in three fields of an odd field, an even field, and the next odd field. That is, the first field is an odd field Bo, the next field is an even field Be, and the third field is an odd field Bo. Therefore, the first odd field Bo and the third odd field Bo of the three fields are exactly the same signal.
[0008]
Hereinafter, the video signals of each frame of the film such as frame C, frame D, frame E, and frame F are similarly assigned to the fields of the video signal.
[0009]
Now, assuming that the original signal that is not delayed among the luminance signals is F0, the original signal F0 is delayed by one field to be a signal F1. This signal F1 is further delayed by one field to be a signal F2.
[0010]
The frame difference value obtained by subtracting the signal F2 from the signal F0 outputs 1 when subtracting the color difference signals of different fields, and outputs 0 when subtracting the color difference signals of the same field. Then, as shown in FIG. 1, the values of the signals F0 and F2 are the same for Bo, De, Fo, He. As a result, the value of F0-F2 becomes 1101111011110. That is, with 5 fields as a period, the value becomes 0 once in each period.
[0011]
On the other hand, in the case of a normal NTSC video signal that is not a 3-2 pull-down converted video signal, the frame difference is 11111111.
[0012]
Therefore, it can be determined whether or not it is a film video signal from the difference in the pattern of the frame difference.
[0013]
By the way, in the case of the PAL system, it is 25 frames (50 fields) 1 second. When converting a film image into a PAL video signal, 2-2 pull-down conversion is performed at a 4% speed.
[0014]
FIG. 2 shows F0-F1 and F0-F2 at the time of this 2-2 pull-down conversion.
[0015]
The values of F0-F2 are Bo-Ao, Be-Ae, Co-Bo, Ce-Be,..., And are the differences between the signals of different frames. ...
[0016]
On the other hand, the values of F0-F1 are Ae-Ao, Bo-Ae, Be-Bo, Co-Be,..., And the difference between the fields of the same frame is calculated every other field. Therefore, a pattern of 010101... Is obtained.
[0017]
On the other hand, in the case of a normal PAL video signal (in the case of a video signal not subjected to 2-2 pull-down processing), the values of F0-F1 and F0-F2 are all 11111. Therefore, whether or not the video signal has been subjected to 2-2 pull-down conversion can be determined by F0-F1.
[0018]
[Problems to be solved by the invention]
By the way, as shown in FIG. 2, the field difference at the time of 2-2 pull-down conversion becomes a pattern of 01010101..., Because the odd field and even field images generated from the same frame (frame). It is assumed that there is a high correlation.
[0019]
However, for example, an image having a high frequency component in the vertical direction may exist in the video signal. Such an image is particularly abundant in an image output by a progressive camera and an image by computer graphics. Such an image may be less correlated even if it is an odd field and even field image generated from the same frame. For example, it is well known that an image with fine horizontal stripes has a low correlation between the odd field and the even field.
[0020]
Therefore, conventionally, the determination threshold for detecting a video signal subjected to 2-2 pull-down conversion is set to a small value. However, in such a case, even in the case of a normal video signal, a pattern 101010... Appears, and it is impossible to accurately detect that the signal has been subjected to 2-2 pulldown conversion. there were.
[0021]
The present invention has been made in view of such a situation, and a film video signal can be accurately detected even if there is no correlation between odd field and even field images generated from the same frame. It is what you want to do.
[0022]
[Means for Solving the Problems]
The video signal discriminating apparatus of the present invention delays a color difference signal composed of pixels of the same value in the upper and lower lines by one field, and delays by one field by the color difference signal and the delay means. Calculating means for calculating a difference from the color difference signal, an adding means for accumulating and adding the difference calculated by the calculating means for one field, and a signal obtained by adding by the adding means as a predetermined reference value Comparing and outputting 1 when the signal is greater than the reference value, and outputting 0 when the signal is smaller than the reference value, and a code sequence obtained by arranging a plurality of fields of the codes obtained by the comparing means in sequence, Judgment means for judging whether or not it is a film video signal is provided. With such a configuration, it is possible to accurately detect whether the image is a film video signal without being affected by the correlation between the odd field and even field images.
[0023]
The color difference signal may be one of color difference signals compressed in a 4: 2: 0 format.
[0024]
The video signal discrimination method of the present invention includes a delay step for delaying a color difference signal by one field, and a calculation step for calculating a difference between the color difference signal and the color difference signal delayed by one field by the processing of the delay step. An addition step of accumulating and adding the difference calculated by the processing of the calculation step for one field, and a signal obtained by adding the processing of the addition step as a predetermined reference value A comparison step that outputs 1 if the signal is greater than the reference value, and outputs 0 if the signal is less than the reference value, and a code sequence obtained by arranging a plurality of fields in order in the comparison step, And a determination step of determining whether or not it is a film video signal.
[0025]
The recording medium program of the present invention includes a delay step for delaying the color difference signal by one field, and a calculation step for calculating a difference between the color difference signal and the color difference signal delayed by one field by the processing of the delay step. An addition step of accumulating and adding the difference calculated by the processing of the calculation step for one field, and a signal obtained by adding the processing of the addition step as a predetermined reference value A comparison step that outputs 1 if the signal is greater than the reference value, and outputs 0 if the signal is less than the reference value, and a code sequence obtained by arranging a plurality of fields in order in the comparison step, And a determination step of determining whether or not it is a film video signal.
[0026]
The program of the present invention includes a delay step for delaying a color difference signal by one field, a calculation step for calculating a difference between the color difference signal and the color difference signal delayed by one field by the processing of the delay step, An addition step of accumulating and adding the difference calculated by the processing for one field, and a signal obtained by adding the processing of the addition step as a predetermined reference value A comparison step that outputs 1 if the signal is greater than the reference value, and outputs 0 if the signal is less than the reference value, and a code sequence obtained by arranging a plurality of fields in order in the comparison step, The computer is caused to execute a determination step of determining whether the signal is a film video signal.
[0027]
In the present invention, the difference between the color difference signal delayed by one field and the non-delayed color difference signal is accumulated for one field to determine whether it is a film video signal.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3 shows a configuration example of a DVD player to which the film video signal discrimination device of the present invention is applied. In this configuration example, a DVD (Digital Versatile Disc) (not shown) is reproduced by the DVD drive 1. On this DVD, interlaced video signals are recorded in the 4: 2: 0 format. FIG. 4 is a diagram for explaining the 4: 2: 0 format.
[0029]
In the case of this format, the luminance signal has a predetermined value for each pixel as shown in FIG. 4A. On the other hand, the color difference signal BY and the color difference signal RY have the same value for 4 pixels of 2 × 2, as shown in FIGS. 4B and 4C, respectively.
[0030]
The video signal reproduced from the DVD by the DVD drive 1 is supplied to an MPEG2 (Moving Picture Expert Group) decoder 2 and decoded. Of the signals decoded by the MPEG2 decoder 2, the vertical synchronization signal Vs is supplied to the addition circuit 6 and the comparison circuit 7. The luminance signal Y and the color difference signals BY and RY are respectively supplied to the one-field delay circuit 3 of the detection circuit 21. The 1-field delay circuit 3 delays the input signal by one field and then supplies the delayed signal to the subsequent 1-field delay circuit 4. The signal output from the 1-field delay circuit 3 is also supplied to the subtraction circuit 5 and the time axis compression circuit 10.
[0031]
The 1-field delay circuit 4 further delays the signal input from the 1-field delay circuit 3 by one field, and then outputs it to the selector 9. The selector 9 is also supplied with the non-delayed luminance signal Y output from the MPEG2 decoder 2 and the color difference signals BY and RY.
[0032]
The subtracting circuit 5 outputs the color difference signal BY or RY out of the undelayed signal F0 output from the MPEG2 decoder 2 and the image delayed by one field output from the one-field delay circuit 3. The difference between the color difference signals BY and RY in the signal F1 is calculated.
[0033]
The output from the subtracting circuit 5 is supplied to the adding circuit 6, and the output value is cumulatively added for each field. The value output from the adder circuit 6 is supplied to the comparator circuit 7 and compared with a predetermined reference value set in advance for each field.
[0034]
The output of the comparison circuit 7 is supplied to the controller 8. The controller 8 determines from the output of the comparison circuit 7 based on the sequence whether or not the currently input video signal is a film video signal.
[0035]
Then, the controller 8 controls the selector 9, and the signal F0 of the non-delayed field output from the MPEG2 decoder 2 and the signal delayed by 2 fields with respect to the signal F0 by the 1-field delay circuit 4 after all. One of F2 is selected and output to the time axis compression circuit 11. That is, the controller 8 selects, based on the signal F1 delayed by one field output from the one-field delay circuit 3, the signal F0 and the signal F2 of the previous and subsequent fields that are closer to the signal F1.
[0036]
The time-axis compression circuit 10 double-speed converts the signal F1 output from the 1-field delay circuit 3 by one field by time-axis compression and outputs it to the selector 12. The time axis compression circuit 11 also doubles the signal input from the selector 9 by time axis compression and outputs it to the selector 12. The selector 12 is controlled by the controller 8 and selects one of the signals input from the time axis compression circuit 10 or the time axis compression circuit 11 and outputs the selected signal to the D / A converter A13. The D / A converter A13 D / A converts the input signal and outputs it as a progressive video signal. The controller 8 also generates and outputs a horizontal synchronization signal and a vertical synchronization signal.
[0037]
Next, the operation of the DVD player in FIG. 3 will be described with reference to the flowchart in FIG. FIG. 6 is a diagram for explaining the principle of 3-2 pull-down detection in the present invention. This will be described with reference to FIG. 6 as necessary.
[0038]
When the reproduction is instructed, the DVD drive 1 reproduces the loaded DVD and outputs the video signal. The MPEG2 decoder 2 decodes the video signal input from the DVD drive 1 by the MPEG method, and outputs the luminance signal Y, the color difference signal BY, and the color difference signal RY to the 1-field delay circuit 3 and the selector 9, respectively. Further, only the color difference signal BY or RY is input to the subtraction circuit 5.
[0039]
Here, the video signal reproduced and output by the DVD drive 1 is a signal of 4: 2: 0 format as shown in FIG. In the case of this format, for example, the color difference signal BY (odd field color difference signal BY) corresponding to the first line and the color difference signal BY (even field color difference) corresponding to the second line in FIG. 4A. The signal BY is the same value.
[0040]
In step S <b> 1, the 1-field delay circuit 3 delays the input color difference signal BY or RY by one field and outputs it to the subtraction circuit 5.
[0041]
In step S2, the subtraction circuit 5 takes in the color difference signal (FIG. 6B) from the undelayed signal F0 output from the MPEG2 decoder 2 and is delayed by one field output from the one-field delay circuit 3. The color difference signal (FIG. 6C) of the obtained signal F1 is captured and F0−F1 is calculated (FIG. 6D). In the subtraction of F0-F1, 0 is always output if the signal is the corresponding frame or frame, and 1 is output if the signal is a different frame or frame.
[0042]
In step S3, the difference signal (FIG. 6D) output from the subtraction circuit 5 is output to the addition circuit 6, and the value for one field is added. In step S4, the comparison circuit 7 compares the addition value for one field supplied from the addition circuit 6 with a preset reference value. This reference value is set to an intermediate value between the maximum value and the minimum value of the accumulated difference values.
[0043]
When the addition value is larger than the reference value, the comparison circuit 7 proceeds to step S6 and outputs a logic 1, and when the addition value is not larger than the reference value, the comparison circuit 7 proceeds to step S5 and outputs a logic 0. Since addition for one field is necessary, the output of the comparison circuit 7 (FIG. 6D) is delayed by one field.
[0044]
In FIG. 6, in the first field, the value of the non-delayed color difference signal F0 (FIG. 6B) is B, and the value of the color difference signal F1 (FIG. 6C) delayed by one field is A. Their values are different. In that case, 1 is output from the subtracting circuit 5 in step S2, the value for one field is added by the adding circuit 6 in step S3, and at the timing of the second field (delayed by one field), step S4 Then, the comparison circuit 7 compares the added value for one field supplied from the adder 6 with a predetermined reference value, and 1 is output from the comparison circuit 7 (FIG. 6D).
[0045]
In the second field, the value of the color difference signal F0 (FIG. 6B) not delayed and the value of the color difference signal F1 (FIG. 6C) delayed by one field are both B, and both are the same. In this case, 0 is output from the subtracting circuit 5 in step S2, and the value for one field is added by the adding circuit 6 in step S3. At the timing of the third field (delayed by one field), step S4 is performed. Then, the comparison circuit 7 compares the added value for one field supplied from the adder 6 with a predetermined reference value, and 0 is output from the comparison circuit 7 (FIG. 6D).
[0046]
In step S7, the controller 8 determines from the logic 1 and logic 0 patterns (FIG. 6D) output from the comparison circuit 7 whether or not the video signal being reproduced and output by the DVD drive 1 is a film video signal. To do.
[0047]
Therefore, as shown in FIG. 6D, the field difference pattern output from the comparison circuit 7 is 10010100101... In the case of a 3-2 pull-down video signal. In this way, it is possible to determine the film video signal and its sequence (phase).
[0048]
FIG. 7 is a diagram for explaining the principle of detection of a normal moving image video signal, FIG. 8 is a diagram for explaining the principle of detection of a normal still image video signal, and FIG. It is a figure explaining the principle of a video signal of a 2-2 pulldown system. In the case of such a normal video signal, since the video is encoded in units of fields in the case of a moving image, the pattern of F0-F1 is 111111 as shown in FIG. In the case of a still image, since encoding is performed in units of frames, 00000... Is obtained as shown in FIG. Therefore, it is possible to reliably determine whether the signal is a film video signal or a normal video signal from the difference in pattern.
[0049]
In the case of a 2-2 pull-down video signal, the pattern of F0-F1 is 10101010... As shown in FIG. In the conventional technique, it is assumed that the odd field and even field images generated from the same frame (frame) have a high correlation, but in the present embodiment, the video signal is 4: 2: Since the fact that it is recorded in the 0 format is used, it is possible to make a determination even when there is no correlation between images.
[0050]
FIG. 10 is a diagram for explaining the principle of progressive signal conversion in the present invention. 10A, 10B, 10D, and 10G are the same as FIGS. 6A, 6B, 6C, and 6D, respectively. In FIG. 3, the selector 9 is controlled by the controller 8 and, as shown in FIG. 10H, 2 fields output from the 1-field delay circuit 4 at a rate of once every 3 fields, once every 3 fields. The delayed signal F2 is selected. At other times, the selector 9 selects the signal F0 signal that has not been delayed.
[0051]
The signal output from the selector 9 is supplied to the time axis compression circuit 11 for conversion to the progressive method, and double speed conversion is performed by time axis compression. The time axis compression circuit 10 double-speed converts the signal F1 delayed by one field output from the one field delay circuit 3 by time axis compression.
[0052]
FIG. 11 shows input and output timings in the time axis compression circuit 10 and the time axis compression circuit 11. 12, 13, and 14 show enlarged portions from the period T <b> 1 to T <b> 3 in FIG. 11.
[0053]
In these figures, for convenience of explanation, each field is composed of 6 lines.
[0054]
As shown in FIG. 10H, the selector 9 selects the signal of the field F0 or the field F2. As a result, the luminance signal among the outputs becomes as shown in FIG. 10I, and the color difference signal is shown in FIG. 10J. It becomes a signal like this.
[0055]
The time axis compression circuit 10 writes the first line data of the signal F1 output from the 1-field delay circuit 3 in the odd field period T1 shown in FIGS. Output to. The time axis compression circuit 11 compresses the second line data supplied from the selector 9, and the time axis compression circuit 10 outputs the first line data, and then outputs the data to the selector 12.
[0056]
Similarly, the time axis compression circuit 10 sequentially compresses and outputs the data of the third line and the fifth line, and the time axis compression circuit 11 sequentially compresses and outputs the data of the fourth line and the sixth line. To do.
[0057]
The selector 12 alternately selects the data of each line output from the time axis compression circuit 10 or the time axis compression circuit 11, thereby the first line, the second line, the third line, the fourth line, and the fifth line. And output to the D / A converter 13 in the order of the sixth line. The D / A converter 13 D / A converts the input data and outputs it.
[0058]
As shown in FIGS. 11 and 13, in the even-field period T2, the time-axis compression circuit 10 sequentially compresses and outputs the data of the second line, the fourth line, and the sixth line. 11 sequentially compresses and outputs the data of the first line, the third line, and the fifth line.
[0059]
Even in this case, the selector 12 selects and outputs the data of the first line to the sixth line in order by alternately selecting the outputs of the time axis compression circuit 10 and the time axis compression circuit 11.
[0060]
In the odd field period T3 shown in FIGS. 11 and 14, the same processing as in the period T1 is executed.
[0061]
The series of processes described above can be executed by hardware, but can also be executed by software. In this case, for example, the DVD player is configured by a computer as shown in FIG.
[0062]
The computer shown in FIG. 15 includes at least a CPU (Central Processing Unit) 41, a ROM (Read Only Memory) 42, a RAM (Random Access Memory) 43, and a drive 50. The CPU 41 is a program stored in the ROM 42. Alternatively, various processes are executed in accordance with a program loaded from the storage unit 48 to the RAM 43. The RAM 43 also appropriately stores data necessary for the CPU 41 to execute various processes.
[0063]
The CPU 41, ROM 42, and RAM 43 are connected to each other via a bus 44. An input / output interface 45 is also connected to the bus 44.
[0064]
The input / output interface 45 includes an input unit 46 including a keyboard and a mouse, a display including a CRT and an LCD, an output unit 47 including a speaker, a storage unit 48 including a hard disk, a modem, a terminal adapter, and the like. A communicator 49 is connected. The communication unit 49 performs communication processing via a network including the Internet.
[0065]
A drive 50 is connected to the input / output interface 45 as necessary, and a magnetic disk 61, an optical disk 62, a magneto-optical disk 63, a semiconductor memory 64, or the like is appropriately mounted, and a computer program read from these is loaded. It is installed in the storage unit 48 as necessary.
[0066]
When the above-described series of processing is executed by software, various functions can be realized by installing a program that constitutes the software in a dedicated hardware or by installing various programs. For example, a general-purpose personal computer that can be executed is installed from a network or a recording medium.
[0067]
As shown in FIG. 15, the recording medium is distributed to provide a program to the user separately from the main body of the apparatus, and includes a magnetic disk 61 (including a floppy disk) on which the program is recorded, an optical disk 62 ( CD-ROM (compact disk-read only memory), DVD (including digital versatile disk)), magneto-optical disk 63 (including MD (mini-disk)), or semiconductor memory 64. In addition to this, it is configured by a ROM 42 in which a program is recorded and a hard disk included in the storage unit 48 provided to the user in a state of being pre-installed in the apparatus main body.
[0068]
In the present specification, the step of describing the program recorded on the recording medium is not limited to the processing performed in chronological order according to the described order, but is not necessarily performed in chronological order. It also includes processes that are executed individually.
[0069]
Further, in this specification, the system represents the entire apparatus constituted by a plurality of apparatuses.
[0070]
Needless to say, the video signal discriminating apparatus of the present invention can be applied not only to a DVD player but also to a digital broadcast receiver that receives a digital broadcast that has been compression-encoded by MPEG2.
[0071]
【The invention's effect】
As described above, according to the video signal discriminating apparatus and method, the recording medium, and the program of the present invention, since it is determined whether or not it is a film video signal based on the color difference signal, a reliable determination can be made. It becomes possible.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining the principle of detection of a conventional 3-2 pull-down method.
FIG. 2 is a diagram for explaining the principle of detection of a conventional 2-2 pull-down method.
FIG. 3 is a block diagram showing a configuration of a DVD player to which the present invention is applied.
FIG. 4 is a diagram illustrating a 4: 2: 0 format.
FIG. 5 is a flowchart illustrating a film video signal determination process according to the present invention.
FIG. 6 is a diagram illustrating the principle of detection of a 3-2 pull-down video signal according to the present invention.
FIG. 7 is a diagram for explaining the principle of detection of a video signal of a normal moving image.
FIG. 8 is a diagram for explaining the principle of detection of a normal still image video signal;
FIG. 9 is a diagram illustrating the principle of detection of a video signal of the 2-2 pulldown method according to the present invention.
FIG. 10 is a diagram illustrating the principle of progressive signal conversion according to the present invention.
11 is a timing chart for explaining writing and reading of the time axis compression circuit in the DVD player of FIG. 3;
12 is a timing chart showing an enlarged portion of a period T1 in FIG.
13 is an enlarged timing chart showing a portion of a period T2 in FIG.
14 is an enlarged timing chart showing a portion of a period T3 in FIG.
FIG. 15 is a block diagram illustrating a configuration example of a computer to which the present invention is applied.
[Explanation of symbols]
1 DVD drive, 2 MPEG2 decoder, 3, 4 1 field delay circuit, 5 subtraction circuit, 6 addition circuit, 7 comparison circuit, 8 controller, 9 selector, 10, 11 time axis compression circuit, 12 selector, 13 D / A converter

Claims (8)

Delay means for delaying a color difference signal including pixels having the same value in at least an odd-numbered scan line and an even-numbered scan line by one field;
Arithmetic means for calculating a difference between the color difference signal and the color difference signal delayed by one field by the delay means;
Adding means for accumulating and adding the difference calculated by the calculating means for one field;
Comparing means for comparing the signals obtained by the addition means with a predetermined reference value , outputting 1 when the signal is larger than the reference value, and outputting 0 when the signal is smaller than the reference value;
A video signal discriminating apparatus comprising: a judgment unit that judges whether or not the video signal is a film video signal based on a code string in which a plurality of fields of the codes obtained by the comparison unit are arranged in order . The video signal discriminating apparatus according to claim 1, wherein the color difference signal is one of color difference signals compressed into a 4: 2: 0 format. A delay step of delaying a color difference signal including pixels having the same value in at least an odd-numbered scan line and an even-numbered scan line by one field;
A calculation step of calculating a difference between the color difference signal and the color difference signal delayed by one field by the processing of the delay step;
An addition step of accumulating and adding the difference calculated by the processing of the calculation step for one field;
A comparison step of comparing the signal obtained by the addition in the process of the addition step with a predetermined reference value , outputting 1 when the signal is larger than the reference value, and outputting 0 when the signal is smaller than the reference value;
And a determination step of determining whether the signal is a film image signal based on a code string in which a plurality of fields are sequentially arranged in the order of the codes obtained by the process of the comparison step . The video signal determination method according to claim 3, wherein the color difference signal is one of color difference signals compressed into a 4: 2: 0 format. A delay step of delaying a color difference signal including pixels having the same value in at least an odd-numbered scan line and an even-numbered scan line by one field;
A calculation step of calculating a difference between the color difference signal and the color difference signal delayed by one field by the processing of the delay step;
An addition step of accumulating and adding the difference calculated by the processing of the calculation step for one field;
A comparison step of comparing the signal obtained by the addition in the process of the addition step with a predetermined reference value , outputting 1 when the signal is larger than the reference value, and outputting 0 when the signal is smaller than the reference value;
A computer-readable program comprising: a determination step for determining whether or not the signal is a film video signal based on a code string in which a plurality of fields are sequentially arranged in the code obtained by the process of the comparison step Recording medium on which is recorded. The recording medium according to claim 5, wherein the color difference signal is one of color difference signals compressed into a 4: 2: 0 format. A first delay step for delaying a color difference signal including pixels having the same value in at least an odd-numbered scan line and an even-numbered scan line by one field;
A calculation step of calculating a difference between the color difference signal and the color difference signal delayed by one field by the processing of the first delay step;
An addition step of accumulating and adding the difference calculated by the processing of the calculation step for one field;
A comparison step of comparing the signal obtained by the addition in the process of the addition step with a predetermined reference value , outputting 1 when the signal is larger than the reference value, and outputting 0 when the signal is smaller than the reference value;
A program for causing a computer to execute a determination step of determining whether or not the signal is a film video signal based on a code string in which a plurality of fields of codes obtained by the comparison step are arranged in order. The program according to claim 7, wherein the color difference signal is one of color difference signals compressed into a 4: 2: 0 format.

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