JP2000270259A - Ts signal fade controller and method for controlling ts signal fade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain fade-out and fade-in of a picture. SOLUTION: The controller is provided with a picture type identification section 101 that detects a picture header from a received TS signal and provides an output of a picture type and an incidence timing signal of the picture type, an I picture storage section 102 that stores coded data in an I picture mode, a P picture storage section 103 that stores coded data in a P picture mode, and a B picture storage section 104 that stores coded data in a B picture mode, a changeover section 105 that selects coded data and outputs the selected data, an image synchronization signal generating section 106 that outputs a signal resulting from synchronizing a fade control signal received asynchronously with picture data including a received Ts signal, and a changeover device 107 that changes over the received Ts signal or the signal from a changeover section with a signal outputted from the image synchronization signal generating section 106.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fade control technique, and more particularly, to a TS signal fade control apparatus and a TS signal fade control apparatus capable of performing fade-out and fade-in of an image without decoding a compressed image signal. The present invention relates to a signal fade control method.

[0002]

2. Description of the Related Art FIG. 5 is a functional block diagram for explaining a first prior art TS signal fade control device. A case where fade-out and fade-in are performed on a conventional TS signal, that is, an MPEG-compressed image signal will be described with reference to FIG. The input input TS signal is once decoded by the decoding device 301. The decoded image becomes a normal image signal. The image synchronization signal generation unit 303 generates a fade control signal synchronized with the image signal based on a vertical synchronization signal input from the image signal decoded by the decoding device 301 and a fade control signal input asynchronously. Output. The black screen insertion device 302 outputs a black screen synchronized with the vertical synchronization signal input from the image signal decoded by the decoding device 301. Switch 30
5 selects the signal of the black screen insertion device 302 instead of the signal from the adjustment unit 304 when the fade control signal is valid by the synchronized fade control signal of the image signal output from the image synchronization signal generation unit 303. And output. The encoding device 306 performs a compression process again on the image signal subjected to the fade control, converts the image signal into an output TS signal, and outputs the output TS signal.

Another conventional technique is disclosed in, for example, Japanese Patent Application Laid-Open No. 6-90404 (second prior art). That is, in the second conventional technique, a fade control circuit that converts a video signal input at an arbitrary time into a signal that has been faded in or faded out by an external command and outputs the signal is provided with an external fade out command. When applied, it generates and outputs a comparison voltage that increases from a lower level to a higher level over a predetermined time, and outputs a higher-to-lower level when an external fade-in command is applied. And a comparison voltage generator that generates and outputs a comparison voltage that changes over a predetermined period of time, and generates and outputs an ON signal when the video signal and the comparison voltage are input and the level of the comparison voltage is greater than the level of the video signal. A comparator that generates and outputs an OFF signal when the level of the video signal exceeds the level of the comparison voltage; A switching circuit that outputs a constant black level signal when the output of the comparator is an ON signal, and outputs a video signal at the same level when the output of the comparator is an OFF signal; And a differential amplifier that converts the output of the switching circuit into a second input, converts the output of the switching circuit to a level obtained by subtracting the first input from the second input, and outputs the converted level. Thus, when the fade-out operation is performed, a smooth fade-out operation can be performed by gradually reducing the level of the entire video signal and shifting to a black level. This shows an effect that the signal level can be smoothly shifted from the black level to a normal image state, and the fluctuation of the black level can be reduced.

In the first and second prior arts, the TS
When fade-out and fade-in of signalized image data, that is, MPEG-compressed image data,
It was necessary to decode the MPEG-compressed image data once, replace it with a black image in the state of normal image data, and then encode again.

[0005]

However, the prior art has the following problems. The first problem is
This is to perform the decoding process once and the encoding process further. The reason is that re-compression is performed by decoding and encoding, and the image quality is degraded compared to the original signal. The second problem is that the device becomes large. The reason is that a decoding device and an encoding device are required.

The present invention has been made in view of such a problem, and an object of the present invention is to enable fade-out and fade-in of an image without decoding a compressed image signal. Another object of the present invention is to provide a TS signal fade control device and a TS signal fade control method.

[0007]

The gist of the present invention resides in a TS signal fade control capable of performing fade-out and fade-in of an image without decoding a compressed image signal. A picture type identification unit for detecting a picture header from an input TS signal and outputting a picture type and an appearance timing signal of the picture type; and encoding a digitally complete black image in an I picture mode. An I-picture storage unit for storing and holding coded data in the case of encoding, a P-picture storage unit for storing and holding encoded data in the case of digitally encoding a complete black image in the P-picture mode, and a B-picture mode A B picture storage unit for storing and holding coded data when a complete black image is digitally coded by the I picture storage unit A switching unit for switching and outputting coded data stored and held in each of the P picture storage unit and the B picture storage unit; and a switching unit for asynchronously inputting a fade control signal and image data included in the input TS signal. An image synchronization signal generation unit that outputs a synchronized signal, and a switch that switches the input TS signal and the signal of the switching unit with a signal output from the image synchronization signal generation unit. TS signal fade control device. The gist of claim 2 of the present invention is that the picture type identification unit is present in the input TS signal when the input TS signal is input to the picture type identification unit in a packet unit. 2. The TS signal fade control device according to claim 1, wherein the TS signal fade control device is configured to detect a packet of the image signal and to detect a picture header present in the detected packet of the image signal. The gist of claim 3 of the present invention is that the picture type identification unit detects a picture header and further includes information contained therein, that is, whether the frame is an I frame, a P frame, or a B frame. 3. The T according to claim 1, wherein said T is detected and output.
The S signal fade controller exists. Further, the gist of claim 4 of the present invention is that the switching unit is configured to output from the I picture storage unit, the P picture storage unit, and the B picture storage unit according to a picture type signal detected by the picture type identification unit. The coded data output when coded in the I picture mode, the coded data when coded in the P picture mode, and the coded data when coded in the B picture mode are switched and output to the switch. The TS signal fade control device according to any one of claims 1 to 3, wherein the TS signal fade control device is configured to perform the following. The gist of claim 5 of the present invention is that the image synchronization signal generation unit synchronizes the asynchronously input fade control signal with a frame synchronization timing of image data included in the input TS signal. The TS signal fade control device according to any one of claims 1 to 4, wherein the TS signal fade control device is configured to generate a signal and output the signal to the switch. The gist of claim 6 of the present invention is that the switching device comprises:
A signal output from the switching unit and the input TS signal are switched based on a signal in which the fade control signal and the image data are synchronized, which is output from the image synchronization signal generation unit, and is used as an output TS signal. The TS signal fade control device according to any one of claims 1 to 5, wherein the TS signal fade control device is configured to output the signal. According to a seventh aspect of the present invention, there is provided a TS signal fade control device capable of performing fade-out and fade-in of an image without decoding a compressed image signal. A picture type identification unit for detecting a picture header in the image data in the input TS signal, an I picture storage unit for storing and holding a digitally complete black image in advance, and a fade control signal input asynchronously to the input TS signal. An image synchronization signal generation unit that outputs the image data in a form synchronized with the picture of the image data in the signal, and the input T based on the synchronized fade control signal.
The present invention resides in a TS signal fade control device having a switching unit for selecting and outputting an S signal and a signal output from the I picture storage unit. Further, the gist of claim 8 of the present invention is a TS signal fade control method capable of performing fade-out and fade-in of an image without decoding a compressed image signal,
A picture type identification step of detecting a picture header from the input TS signal and outputting a picture type and an appearance timing signal of the picture type; and a code for digitally encoding a complete black image in the I picture mode I-picture storing step of storing and holding encoded data;
A P-picture storing step of storing and holding encoded data when a digitally complete black image is encoded in a picture mode; and a P-picture storing step of storing and retaining encoded data when a digitally complete black image is encoded in a B-picture mode. A B picture storing step of storing and holding; a first switching step of switching and outputting encoded data stored and held in each of the I picture storing step, the P picture storing step and the B picture storing step; An image synchronization signal generating step of outputting a signal obtained by synchronizing the fade control signal and the image data included in the input TS signal, and synchronizing the input TS signal and the signal of the first switching step with the image synchronization. A second switching step of switching with a signal output from the signal generation step. . The gist of claim 9 of the present invention is that the picture type identification step is present in the input TS signal when the input TS signal is input to the picture type identification step in a packet unit. The TS signal fade control method according to claim 8, further comprising a step of detecting a packet of the image signal and detecting a picture header present in the detected packet of the image signal. The gist of claim 10 of the present invention is that, in the picture type identification step, after detecting a picture header, information included in the picture header, that is, whether this frame is an I frame, a P frame, or a B frame. 10. The method of controlling a fade of a TS signal according to claim 8, further comprising the step of detecting and outputting the TS signal fade. The gist of claim 11 of the present invention is that the first switching step includes the step of determining whether or not the first switching step is performed based on the picture type signal detected in the picture type identification step.
Encoded data when encoded in the I picture mode, encoded data when encoded in the P picture mode, B picture output from each of the picture storage step, the P picture storage step, and the B picture storage step The method according to any one of claims 8 to 10, further comprising a step of switching coded data in the case of encoding in a mode and outputting the coded data to the second switching step. The gist of the twelfth aspect of the present invention is that the image synchronizing signal generating step synchronizes the asynchronously input fade control signal with a frame synchronization timing of image data included in the input TS signal. The method according to any one of claims 8 to 11, further comprising a step of generating a signal and outputting the signal to the second switching step. The gist of claim 13 of the present invention resides in the second aspect.
In the switching step, the signal output from the first switching step and the input TS signal are converted based on a signal in which the fade control signal and the image data are synchronized, which is output from the image synchronization signal generation step. The TS signal fade control method according to any one of claims 8 to 12, further comprising a step of switching and outputting the output TS signal. The gist of claim 14 of the present invention is:
TS that enables fade-out and fade-in of an image without decoding the compressed image signal
A signal fade control method, comprising: a picture type identification step of detecting a picture header in image data in an input input TS signal; an I picture storage step of storing and holding a digitally complete black image in advance; An image synchronization signal generating step of synchronizing a fade control signal input to the input TS signal with a picture of image data in the input TS signal; and outputting the input TS signal based on the synchronized fade control signal. And a first switching step of selecting and outputting a signal output from the I picture storage step.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of each embodiment described below are as follows.
By fading out and fading in the image while keeping the TS (transport stream) signal, the T
MPEG (Moving Picture) included in the S signal
re Experts Group) is to prevent decoding of image signals. As a result, it is possible to perform fade-out and fade-in of an image without decoding the compressed image signal. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a functional block diagram for explaining a TS signal fade control device according to a first embodiment of the present invention. Referring to FIG. 1, a TS signal fade control device according to the present embodiment detects a picture header from an input TS signal and outputs a picture type and its appearance timing signal.
1, an I-picture storage unit 102 for storing and holding encoded data when a digitally complete black image is encoded in the I-picture mode;
P picture storage section 103 for storing and holding data in picture mode, B picture storage section 104 for storing and holding data in B picture mode like I picture storage section 102, and switching section 105 for switching and outputting these data And an image synchronization signal generation unit 106 that outputs a signal obtained by synchronizing the asynchronously input fade control signal with the image data included in the input TS signal, and synchronizes the input TS signal and the signal of the switching unit 105 with the image. Signal generator 106
A switch 107 is provided for switching with a signal output from the switch.

[0010] When an input TS signal is input to the picture type identification unit 101 in a packet unit, the picture type identification unit 101 detects a packet of an image signal present in the input TS signal, and detects the detected image. Detect the picture header present in the signal packet. One picture header always exists for each frame of an image, and contains information defining the frame. Further, after detecting the picture header, the picture type identification unit 101 further includes information contained therein, ie,
It detects and outputs whether this frame is an I frame, a P frame, or a B frame.

The I-picture storage unit 102 previously generates and stores data when a completely black image is digitally encoded in the I-picture mode.

The P picture storage unit 103 previously generates and stores data when encoded in the P picture mode, like the I picture storage unit 102.

The B-picture storage unit 104 previously generates and stores data when encoded in the B-picture mode, like the I-picture storage unit 102.

The switching unit 105 outputs data output from each of the I picture storage unit 102, the P picture storage unit 103, and the B picture storage unit 104 according to the picture type signal detected by the picture type identification unit 101 (ie, the I picture mode Data when encoded with
(The data in the case of encoding in the picture mode and the data in the case of encoding in the B picture mode), and outputs the data to the switch 107.

The image synchronization signal generator 106 generates a signal for synchronizing the asynchronously input fade control signal with the frame synchronization timing of the image data included in the input TS signal, and outputs the signal to the switch 107.

The switching unit 107 converts the signal output from the switching unit 105 and the input TS signal based on the signal obtained by synchronizing the fade control signal and the image data output from the image synchronization signal generation unit 106. It outputs as an output TS signal by switching. As a result, it is possible to perform fade-out to a black image and fade-in to an input image without performing decoding processing, that is, decoding of the input TS signal.

Next, the operation of the TS signal fade control device (TS signal fade control method) shown in FIG. 1 will be described. FIG. 2 is a timing chart for explaining the TS signal fade control method according to the first embodiment of the present invention.
Referring to FIG. 2, the input TS signal is generally structured such that image data is divided and transmitted in a predetermined packet unit. In the present embodiment, for the sake of simplicity of description, a case in which they are considered in units of pictures, that is, in units of frames, is described. Normally, image data compressed by the MPEG method includes I picture, P picture, and B picture.
It is composed of data compressed in a mode called a picture.

An I-picture is obtained by compressing only its frame. The P picture is compressed using the correlation with the preceding P picture or I picture. A B picture is compressed using a correlation with a P picture or an I picture located before and after the B picture.

In the present embodiment, as shown in the input TS signal of FIG. 2, it is assumed that the input is performed in the order of I, B, B, P, B, B, P,. When the fade control signal is at the active level in the part (1), that is, when the fade control is started, the picture type identification unit 101 detects a picture header that appears first immediately after the part (1). FIG. 2 shows a picture header (denoted by PH in the figure) corresponding to the part (2). Picture header P
H is a header inserted for each picture at the head of the picture. After the picture header PH is detected, the output timing of the storage data synchronized with the input TS signal is output to the I picture storage unit 102, the P picture storage unit 103, and the B picture storage unit 104.

The stored data is output to each of the I picture storage unit 102, the P picture storage unit 103, and the B picture storage unit 104 at the timing.

The switching unit 105 selects and outputs the picture data detected by the picture type identification unit 101. However, at this time, as for the picture header PH, the picture header PH included in the input TS signal is output as it is. Since the image data of the original signal is always of variable length, it is necessary to make the data amount for each picture the same. Regarding this, after outputting the black image data stored in each of the I picture storage unit 102, the P picture storage unit 103, and the B picture storage unit 104, the stuffing byte "FF" is output and the picture of the next picture is output. Header P
Until H is detected, the stuffing byte FF is filled. This is a portion corresponding to "ST" of the output TS signal shown in FIG. Digital black image data is stored in MPEG (Moving Picture E)
Because of the xparts Group) compression algorithm, it cannot be larger than the input original image data, so that the stuffing byte FF is always inserted for each picture. Thereafter, while the fade control signal is active, that is, during the "image change period" shown in FIG. 2, the black image change processing is performed. When the fade control signal becomes inactive at the timing of the portion (3), the picture detected immediately before that, that is, the P picture of the portion (4) can be replaced with a black image.

As described above, according to the first embodiment, the following effects can be obtained. The first effect is MPE
This eliminates the need for G decoding. The reason is that each of the I-picture, P-picture, and B-picture has MPEG-compressed data of a black image. The second effect is that the image can be faded out and faded in without deteriorating the image quality. The reason is that when performing fade-out and fade-in, an image is not decoded by a decoding process.

(Second Embodiment) Next, another embodiment of the present invention will be described in detail with reference to the drawings. Note that the same parts as those already described in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. FIG. 3 shows a second example of the TS signal fade control device according to the present invention.
FIG. 2 is a functional block diagram for describing the embodiment. FIG.
Referring to FIG. 2, the TS signal fade control device according to the present embodiment includes a picture header detection unit 401 that detects a picture header in image data in an input TS signal, and a digitally complete black An I picture storage unit 402 that stores and holds an image; an image synchronization signal generation unit 403 that outputs a fade control signal that is input asynchronously to a picture of image data in an input TS signal, that is, in synchronization with a frame, A switch 404 is provided for selecting and outputting an input TS signal and a signal output from the I-picture storage unit 402 based on the synchronized fade control signal.

Next, the operation of the TS signal fade control device of FIG. 3 (TS signal fade control method) will be described. FIG. 4 is a timing chart for explaining a TS signal fade control method according to the second embodiment of the present invention.
Note that the same parts as those already described in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. As shown in FIG. 4, the TS signal fade control method according to the present embodiment uses the MPE
A black image is stored in advance by utilizing the fact that even if a picture (frame) compressed in the P-picture or B-picture mode is replaced with an I-picture in the G-compression algorithm, it does not hinder the decoding process. The portion is characterized in that only data encoded by an I picture is stored, that is, only the I picture storage unit 402 is required to store a black image. However, at this time, it is necessary to replace the part of the picture header detected from the input TS signal, that is, the part describing the identification of each of I picture, P picture, and B picture. Thereby, an effect similar to the effect described in the first embodiment can be obtained.

It should be noted that the present invention is not limited to the above embodiments, and each embodiment can be appropriately modified within the scope of the technical idea of the present invention. Further, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment,
The number, position, shape, and the like suitable for carrying out the present invention can be obtained. In each drawing, the same components are denoted by the same reference numerals.

[0026]

Since the present invention is configured as described above, the following effects can be obtained. The first effect is MPE
This eliminates the need for G decoding. The reason is that each of the I-picture, P-picture, and B-picture has MPEG-compressed data of a black image. The second effect is that the image can be faded out and faded in without deteriorating the image quality. The reason is that when performing fade-out and fade-in, an image is not decoded by a decoding process.

[Brief description of the drawings]

FIG. 1 is a functional block diagram for explaining a TS signal fade control device according to a first embodiment of the present invention.

FIG. 2 is a timing chart for explaining a TS signal fade control method according to the first embodiment of the present invention.

FIG. 3 is a functional block diagram for explaining a TS signal fade control device according to a second embodiment of the present invention.

FIG. 4 is a timing chart for explaining a TS signal fade control method according to a second embodiment of the present invention.

FIG. 5 is a functional block diagram for explaining a TS signal fade control device of the first related art.

[Explanation of symbols]

 101 ... Picture type identification unit 102 ... I picture storage unit 103 ... P picture storage unit 104 ... B picture storage unit 105 ... Switching unit 106 ... Image synchronization signal generation unit 107 ... Switcher 301 ... Decoding device 302 ... Black screen insertion Apparatus 303 ... Image synchronization signal generation unit 304 ... Adjustment unit 305 ... Switcher 306 ... Encoding device 401 ... Picture header detection unit 402 ... I picture storage unit 403 ... Image synchronization signal generation unit 404 ... Switch

Claims (14)

[Claims] 1. A compressed image signal is not decoded,
A TS signal fade control device capable of fading out and fading in an image, comprising detecting a picture header from an input TS signal and outputting a picture type and an appearance timing signal of the picture type. An identification unit, an I-picture storage unit that stores encoded data when a digitally complete black image is encoded in the I-picture mode, and a digitally encoded complete black image in the P-picture mode A P-picture storage unit for storing and holding encoded data of: a B-picture storage unit for storing and holding encoded data when a digitally complete black image is encoded in a B-picture mode; The P picture storage unit, the B picture
A switching unit for switching and outputting encoded data stored and held in each of the picture storage units; and outputting a signal obtained by synchronizing a fade control signal input asynchronously with image data included in the input TS signal. A TS signal fade control device comprising: an image synchronization signal generation unit; and a switch that switches the input TS signal and the signal of the switching unit with a signal output from the image synchronization signal generation unit. 2. The picture type identification unit detects a packet of an image signal present in the input TS signal when the input TS signal is input to the picture type identification unit in a packet unit. 2. The TS signal fade control device according to claim 1, wherein the TS signal fade control device is configured to detect a picture header present in a packet of the detected image signal. 3. The picture type identification unit detects a picture header, and further detects and outputs information included in the picture header, that is, whether the frame is an I frame, a P frame, or a B frame. The TS signal fade control device according to claim 1 or 2, wherein the TS signal fade control device is configured. 4. The I-picture mode, wherein the switching unit outputs from the I-picture storage unit, the P-picture storage unit, and the B-picture storage unit according to a picture type signal detected by the picture type identification unit. It is configured to switch between coded data when coded, coded data when coded in P-picture mode, and coded data when coded in B-picture mode and output to the switch. The TS signal fade control device according to claim 1, wherein: 5. The image synchronization signal generation section generates a signal for synchronizing the asynchronously input fade control signal with a frame synchronization timing of image data included in the input TS signal, and generates the signal. The TS signal fade control device according to any one of claims 1 to 4, wherein the TS signal fade control device is configured to output the signal. 6. The switcher outputs a signal output from the switching unit and the input based on a signal output from the image synchronization signal generator and synchronized with the fade control signal and image data. Switching between TS signal and output T
The TS signal fade control device according to any one of claims 1 to 5, wherein the TS signal fade control device is configured to output the signal as an S signal. 7. The method according to claim 1, wherein the compressed image signal is not decoded.
A TS signal fade control device capable of performing fade-out and fade-in of an image, comprising: a picture type identification unit that detects a picture header in image data in an input input TS signal; I to store and hold a nice black image
A picture storage unit, an image synchronization signal generation unit that outputs the asynchronously input fade control signal in a form synchronized with the picture of the image data in the input TS signal, and a video storage unit based on the synchronized fade control signal. A TS signal fade control device comprising: a switching unit that selects and outputs the input TS signal and a signal output from the I picture storage unit. 8. The compressed image signal is not decoded,
A TS signal fade control method capable of performing fade-out and fade-in of an image, comprising detecting a picture header from an input TS signal and outputting a picture type and an appearance timing signal of the picture type. An identification step; an I-picture storage step for storing and holding encoded data when a digitally complete black image is encoded in the I-picture mode; and a digitally encoding complete digital image in the P-picture mode. A P-picture storing step of storing and holding the coded data of: a B-picture storing step of storing and holding coded data when a digitally complete black image is coded in the B-picture mode; Codes stored and held in each of the P picture storing step and the B picture storing step A first switching step of switching and outputting data; an image synchronization signal generating step of outputting a signal obtained by synchronizing a fade control signal input asynchronously with image data included in the input TS signal; A TS signal fade control method, comprising: a second switching step of switching a signal and a signal of the first switching step with a signal output from the image synchronization signal generation step. 9. The picture type identifying step includes a step of inputting the input T to the picture type identifying step on a packet basis.
When an S signal is input, the method further comprises a step of detecting a packet of the image signal present in the input TS signal, and detecting a picture header present in the detected packet of the image signal. The method for controlling a fade of a TS signal according to claim 8. 10. The picture type identification step includes a step of, after detecting a picture header, detecting and outputting information contained in the picture header, that is, whether the frame is an I frame, a P frame, or a B frame. The TS signal fade control method according to claim 8, wherein the method is provided. 11. The I-picture storage step, the P-picture storage step, and the first switching step, wherein the I-picture storage step and the P-picture storage step are performed based on a picture type signal detected in the picture type identification step.
I output from each of the B picture storing steps
A step of switching between the encoded data when encoded in the picture mode, the encoded data when encoded in the P picture mode, and the encoded data when encoded in the B picture mode, and outputting the encoded data to the second switching step. The T according to any one of claims 8 to 10, comprising:
S signal fade control method. 12. The image synchronizing signal generating step generates a signal for synchronizing the asynchronously input fade control signal with a frame synchronization timing of image data included in the input TS signal, and generates the signal. 2. The method according to claim 1, further comprising a step of outputting to the switching step.
2. The TS signal fade control method according to claim 1. 13. The second switching step is output from the first switching step based on a signal that is output from the image synchronization signal generation step and is synchronized with the fade control signal and image data. 13. The TS signal fade control method according to claim 8, further comprising a step of switching between a signal and the input TS signal and outputting the signal as an output TS signal. 14. A TS signal fade control method capable of performing fade-out and fade-in of an image without performing decoding processing on a compressed image signal, the image signal comprising: A picture type identification step of detecting a picture header in I., and a digitally complete black image stored and held in advance
A picture storing step; an image synchronizing signal generating step of outputting an asynchronously input fade control signal in a form synchronized with a picture of image data in the input TS signal; and a synchronizing fade control signal based on the synchronized fade control signal. And a first switching step of selecting and outputting the input TS signal and the signal output from the I picture storage step.