JPH08280028A - Device and method for encoding image signal - Google Patents

Abstract

PURPOSE: To set an arbitrary frame or field image to a leading frame or field by setting the frame or field image corresponding to a specified identification signal to the leading frame or field of a group-of-the-picture(GOP) when that identification signal is detected. CONSTITUTION: A controller 2 supplies a designated time record STC as a desired frame image designate signal and a GOP number designate signal SGOP for designating the number of GOPs from a desired frame image to a video signal encoder 4. A VTR 3 sends a time record SVTC to the video signal encoder 4 as the identification signal of frame image. When, a cue code is detected from scheduled data SD corresponding to the time record SVTC, synchronously with the frame image, the video signal encoder 4 sets the frame image corresponding to the scheduled data SD containing this cue code to the leading frame of GOP.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention will be described in the following order. Field of Industrial Application Conventional Technology (FIG. 14) Problem to be Solved by the Invention (FIGS. 14 and 15) Means for Solving the Problem Action Example (1) First Example (FIGS. 1 to 12) (1-1) Configuration of Encoding System (FIG. 1) (1-2) Video Signal Encoding Device (1-2-1) Time Code Reading Unit (FIGS. 2 and 3) (1-2-2) Video Signal input unit (Figs. 4 and 5) (1-2-3) Motion prediction detection unit (Figs. 6 and 7) (1-2-4) Encoding unit (Figs. 8 and 9) (1-2 5) Data acquisition unit (FIGS. 10 and 11) (1-3) Operation of the first embodiment (1-4) Effect of the first embodiment (2) Second embodiment (FIG. 13) (3) Other Example Effect of the invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image signal encoding method and an image signal encoding apparatus, and is particularly suitable for application when extracting a data stream of a designated length from an arbitrary frame image as a file.

[0003]

2. Description of the Related Art Conventionally, in a system for transmitting a video signal to a remote place such as a digital TV (television) broadcast, in order to efficiently use a transmission line,
The video signal is compressed and encoded by using the line correlation and the frame correlation of the video signal. As such a video signal encoding method, for example, MPEG (Moving Picture Experer) is used.
ts Group) standard has been proposed.

According to the MPEG standard, the video signal is I (Intra-
coded) picture, P (Predictive) picture, B (Bi
directionally predictive-coded) It is encoded as three types of pictures. Therefore, the MPEG encoded video data is composed of I-picture, P-picture and B-picture.

A picture structure (A) before encoding here
FIG. 14 shows the picture structure (B) after encoding. The I-picture is a frame that directly encodes an input signal without using prediction, and can be used as an edit point (IN point) or a decoding start point. P-picture is a frame that uses motion-compensated prediction in one direction, and is predicted (forward prediction) from I-picture that precedes itself in time. B-picture is a frame that uses bi-directional prediction, and includes both forward prediction from the I-picture or P-picture that precedes itself and backward prediction from the I-picture or P-picture that follows after itself. Is predicted using.

As shown in FIG. 14 (B), when each picture is compressed and encoded, the order of the I picture and the P picture is changed before the B picture which precedes these pictures in time (this order change is performed). Hereinafter called ordering). In the MPEG stream after ordering, the I-picture is the head and the pictures before the next I-picture are grouped together, that is, one I-picture and a plurality of P-pictures and B-pictures are grouped together. (Group of Picture, hereinafter referred to as GOP) is a unit of coding.

Here, the number of pictures in a GOP is represented by N, and the cycle in which an I picture or a P picture appears is represented by M.
In (A), N = 15 and M = 3, and as shown in FIG. 14B, the frame appearing at the beginning of the GOP after ordering the picture is the Mth frame (frame image in FIG. 14).

[0008]

Generally, a VTR
When extracting a clip (so-called program) from the video of (Video Tape Recorder), specify the start point (start time code) and end point (end time code) and edit in frame units. However, M
When taking out a certain clip as a file from the PEG stream, the unit of cutting is a multiple of GOP. Therefore, the frame image of the clip start point is G
There is no guarantee that it will be the first frame of the OP, and as shown in FIG. 15, the start point may deviate from the target start point by a maximum of N.

Further, when a certain clip is taken out as a file from the MPEG stream, since the head picture of the GOP is the B picture, the predicted value is obtained from the picture that should have already been cut and should not exist. That is, it is not possible to perform forward prediction, and as a result, the display of several B pictures (two for M = 3 as shown in FIG. 14) becomes unpredictable.

For example, when two clips are decoded in succession, the B-picture at the beginning of the second clip has a predicted value obtained from the value of the last P-picture at the first clip, and therefore the combination of the clips. Therefore, although the image is disturbed differently, it is different from the original image in any case. By the way, since the last frame of GOP is P picture, the image is not disturbed at the end of the file.

There is a closed GOP to solve such a problem. This is a prediction mode in which the front B pictures are only backward predicted but not forward predicted. When encoded in this prediction mode, each G
Although never separated connexion also disturbed image at any GOP for OP is independent, compression efficiency because there is no correlation between GOP is deteriorated, resulting connexion quality of coarse quantization has been made is lowered .

In addition, a variable delay of several frames occurs from the input of the video signal to the MPEG encoding device to the output of the encoded data stream.
For example, delay due to frame synchronizer etc. at input,
There is a delay caused by the encoding process and a delay caused from the input of encoded data to the output of the buffer. This delay value is not a fixed value, but a variable delay that varies depending on the design.

For this reason, when the output data of the encoding device is extracted as a clip from the target GOP, it is not possible to determine when the encoded data will be output. Therefore, the head GOP of the output data stream can be determined. There is no guarantee that the first frame of is the target frame,
There was a problem that it was difficult to take out the clip accurately.

The present invention has been made in consideration of the above points, and proposes an image signal encoding method and an image signal encoding apparatus capable of setting an arbitrary frame image as the first frame of a group of pictures. It is a thing.

[0015]

In order to solve such a problem, in the present invention, a designation signal for designating a desired frame image or a field image among a plurality of consecutive frame images or field images is generated, and each frame image is generated. Or generating an identification signal for identifying the field image,
When the identification signal corresponding to the designated signal is generated in synchronization with the frame image or the field image and the identification signal corresponding to the designated signal is detected, the frame image or the field image corresponding to the detected identification signal is grouped into a group of pictures. Set to the first frame or the first field of Y.

Further, in the present invention, the designation signal generation means generates a designation signal for designating a desired frame image or field image among a plurality of continuous frame images or field images, and the first identification signal generation means , An identification signal for identifying each frame image or field image is generated, and the second identification signal generation means generates an identification signal corresponding to the designation signal in synchronization with the frame image or field image, and detects the identification signal. The means, when detecting the identification signal corresponding to the designation signal, sets the frame image or the field image corresponding to the detected identification signal to the head frame or head field of the group of pictures.

[0017]

Operation: A designation signal for designating a desired frame image or field image and an identification signal for identifying each frame image or field image are generated, and an identification signal corresponding to the designation signal is generated in synchronization with the frame image or field image. To generate. When the identification signal corresponding to the designated signal is detected, the frame image or field image corresponding to the detected identification signal is set as the head frame or head field of the group of pictures. Thereby, an arbitrary frame image or field image can be set as the head frame or field of the group of pictures.

A group of pictures having a frame image or a field image corresponding to the detected identification signal as a head frame or a head field is set as a closed group of pictures. By this means, it is possible to obtain correlation between consecutive GOPs, and it is possible to avoid a reduction in compression coding rate.

A designation signal for designating the number of grooves of picture from the frame image or field image designated by the designation signal is generated, and a frame image from the first frame or head field to the designated number of group of pictures or Compress and encode up to the field image. As a result, the data stream of the designated length can be extracted as a file from the designated frame image or field image.

The motion prediction value for each frame image or field image calculated at the time of compression encoding is saved, the motion prediction value for each saved frame image or field image is analyzed, and the analyzed motion prediction is performed. The picture type of each frame image or field image is determined based on the value. This makes it possible to predict the motion of the frame image in the optimum picture format.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

(1) First Embodiment (1-1) Configuration of Encoding System FIG. 1 shows the configuration of the encoding system according to the first embodiment of the present invention.
Shown in In the encoding system 1, the schedule field data SD synchronized with each frame image is used to extract a data stream of a designated length from a frame image of a designated time code as a file. In this embodiment, the video signal is encoded according to the MPEG2 standard.

As shown in FIG. 1, the encoding system 1 includes a controller 2 as a designation signal generating means and a video tape recorder (VTR) as a first identification signal generating means.
3, video signal encoding device 4 and storage device 5
It is composed by. The controller 2 controls the video signal encoding device 4, and a designated time code (Star) as a designated signal for designating a desired frame image.
t Point (IN point) S _TC and GO as a designation signal for designating the number of GOPs from the desired frame image
The P number designation signal S _GOP is sent to the video signal coding device 4. The VTR 3 supplies the video signal S _AV to the video signal encoding device 4 and, for example, via a RS422 control line (not shown), a time code S _VTC as an identification signal for identifying a frame image. Is transmitted to the video signal encoding device 4.

When the video signal encoding device 4 detects the queue code Cue from the schedule data SD corresponding to the time code S _VTC in synchronization with the frame image, the frame image corresponding to the schedule data SD including the queue code Cue. Is set as the head frame of the GOP, and the frame images from the head frame to the GOP number designated by the GOP number designation signal S _GOP are compression-encoded and output to the storage device 5 as a file.

(1-2) Video Signal Encoding Device The video signal encoding device 4 includes a time code reading unit 6, a video signal input unit 7, and a second identification signal generating means.
The motion prediction detection unit 8 as the identification signal detection unit, the encoding unit 9 as the encoding unit, and the data acquisition unit 10 are configured. Hereinafter, each processing block of the video signal encoding device 4 will be described in detail.

(1-2-1) Time Code Reading Unit FIG. 2 shows the configuration of the time code reading unit 6. Time code (Time Code) comparison circuit 6A receives the designation time code S _TC supplied from the controller 2 via the control bromide poke-in tough Ace 6B. Further, the designated time code S _TC and the GOP number designation signal S _GOP supplied from the controller 2 are sent to the data fetching section 10 via the control block interface 6B. Here, since the data after the ordering is input from the encoding unit 9 to the data capturing unit 10, the time code value of IN point + (M−1) is actually transmitted to the data capturing unit 10.

Time code reading circuit 6
C is the time code S from the VTR 3 via the RS422 control interface (not shown) at the timing of the frame pulse _SFP supplied from the video signal input unit 7.
Read the _VTC, time code comparing the time code S _VTC circuits 6A and Sukeji user field data creating circuit 6D
Send to. That is, the time code reading circuit 6C is
Frame pulse S _FP supplied from the video signal input unit 7
The time code S _VTC is read from the VTR 3 on the basis of the time code read signal S _READ supplied from the frame pulse detection circuit 6E when the frame pulse detection circuit 6E detects the logic "H" level.

The frame pulse S _FP Here, as described later, a pulse synchronized with the vertical synchronizing signal of the video signal (VSYNC), a timing for sending the Sukeji user field data SD. Therefore, the schedule field data SD is generated for each frame image.

The time code comparison circuit 6A has a designated time code S _TC from the controller 2 and the time code S read from the VTR 3 by the time code reading circuit 6C.
_When these time codes match when compared with _VTC , the schedule code data creation unit 6D displays the queue code Cu
Sends e. The schedule field data creation unit 6D uses the queue code Cue supplied from the time code comparison circuit 6A and the designated time code S supplied from the time code reading unit 6B as information relating to the processing of the frame image.
_TC and data are placed on the data and sent to the video signal input unit 7 as schedule field data SD.

Here, the queue code Cue is, as described later, the schedule field data S including the queue code Cue.
This is a signal for setting the frame image D _F corresponding to D to the head frame of the GOP and setting only the GOP to the closed GOP.

The operation of the time code reading section 6 will be described with reference to the flow chart of FIG. Starting from step SP1, and starting from step SP2, the controller 2 specifies the specified time code S _TC (Start Point) and the number of GOPs S.
_{The GOP} is input, and in step SP3, the designated time code S _TC and the GOP number S _GOP are transferred to the data capturing section 10. Then in step SP4, when the frame pulse detection circuit 6E does not detect a logical "H" level of the frame pulse S _FP, the processing of step SP4 until it detects a logical "H" level of the frame pulse S _FP is Repeated.

The frame pulse detection circuit 6E has a logic "H".
When the level frame pulse S _FP is detected, the time code reading signal S _READ is sent to the time code reading circuit 6
Output to C and proceed to step SP5. In step SP5, the time code reading circuit 6C proceeds to connexion step SP6 reading the time code S _VTC (Time Code) from the VTR 3, the time code comparing circuit 6A and the time code S _VTC with One read from VTR 3, specifying a time code of the controller 2 It is determined whether or not S _TC matches.

Time code S _VTC and designated time code S
_{If TC} matches, the time code comparison circuit 6A outputs the queue code Cue to the schedule field data creating section 6D, and in step SP7, the schedule field data creating section 6D outputs the queue code Cue and the designated time code S.
_TC and data are sent on the data and sent to the video signal input section 7 as schedule field data SD.

Time code S _VTC and designated time code S
_{If TC} and _TC do not match, only the time code S _{VT C} is input to the schedule field data creation section 6C in step SP8, and the schedule field data creation section 6C is input.
C carries the time code S _VTC on the data and sends it to the video signal input section 7 as schedule field data SD. When the logic "H" level of the frame pulse _SFP is thus detected, the processing loop from step SP4 to step SP7 or step SP8 is executed.

(1-2-2) Video Signal Input Unit FIG. 4 shows the configuration of the video signal input unit 7. The vertical synchronization signal (VSYNC) detection circuit 7A detects the vertical synchronization signal VSYNC from the analog video signal S _AV input from the VTR 3 and outputs the frame pulse S _FP synchronized with the vertical synchronization signal VSYNC to the frame of the time code reading unit 6. The analog video signal S _AV is sent to the pulse detection circuit 6E and is also output to the analog digital conversion circuit (A / D conversion circuit) 7B. The A / D conversion circuit 7B converts the analog video signal S _AV into a digital video signal S _DV , and the motion prediction detection unit 8
Send to.

The schedule field data SD sent from the time code reading unit 6 is input to the delay circuit 7C. The delay circuit 7C delays the schedule field data SD by the delay amount generated in the video signal input unit 7, that is, the time required for the A / D conversion processing in the A / D conversion circuit 7B, and sends it to the motion prediction detection unit 8. To do. As a result, the digital video signal S _DV and the schedule field data SD are sent from the video signal input unit 7 to the motion prediction detection unit 8 at the same timing.

The operation of the video signal input section 7 will be described with reference to the flow chart of FIG. First, in step SP2, starting from step SP1, the vertical synchronizing signal detection circuit 7A detects the vertical synchronizing signal VSYNC from the input analog video signal S _AV , and in step SP3, the frame synchronized with the detected vertical synchronizing signal VSYNC. Pulse _SFP
Is sent to the time code reading unit 6.

Next, in step SP4, the analog video signal S _AV is converted into the digital video signal S _DV by the A / D conversion circuit 7B and sent to the motion prediction / detection section 8, and the schedule field data SD is sent by the delay circuit 7C. A / D
The motion prediction detection unit 8 is delayed by the time required for the conversion process.
To the vertical sync signal VSYNC.
Is detected.

(1-2-3) Motion Prediction Detection Unit FIG. 6 shows the configuration of the motion prediction detection unit 8. As shown in FIG. 6, the ordering circuit 8A switches the switch 8B so that each frame image _DF of the digital video data S _DV input from the video signal input unit 7 is transferred to the first frame memory 8C ₁ and the _first frame memory 8C ₁ . 2 frame memory 8C ₂ ,
The frame images D _F are stored in the third frame memory 8C ₃ and the switch 8D is switched to display these frame images D _F in a predetermined order (for example, the order shown in FIG. 14B).
C _1, 8C _2, 8C ₃ outputs to the motion prediction circuit 8E than.

For example, in the original data of FIG. 14 (A),
The frame image which is the first frame of the GOP is stored in the _first frame memory 8C ₁ , and the frame image is the second frame.
Frame memory 8C ₂ and the frame image is stored in the third frame memory 8C ₃ . At this time, the frame image is output from the third frame memory 8C ₃ , the frame image is stored in the third frame memory 8C ₁ , and then the first frame memory frame 8C ₁
Output a frame image from the second frame memory 8C ₁ and store the frame image in the _first frame memory 8C ₁ , then output a frame image from the second frame memory 8C ₂ to store the frame image in the second frame memory 8C _2. Is stored.

That is, the ordering circuit 8A converts the input frame image D _F into M as shown in FIG.
The PEG data is ordered and output to the motion prediction / detection circuit 8E in order.

When the queue code detection circuit (Cue detection circuit) 8F detects the queue code Cue in the schedule field data SD input from the video signal input unit 7, the ordering control signal S _CONT is sent to the ordering circuit 8.
Output to A and 8G. When receiving the ordering control signal S _CONT , the ordering circuit 8A receives the frame image D corresponding to the schedule field data SD including the queue code Cue.
_In order to compose a GOP from _F , the frame image D _F
Be the first frame of GOP (that is, B picture),
According to the method described above, the MPEG data is ordered in the order shown in FIG. 14B and output to the motion prediction circuit 8E.

For example, in the above example, the queue code Cu
If the frame image D _F corresponding to Sukeji user field data SD including the e has been filed in the frame image, first, the frame image is stored from the first frame memory 8C ₁ is a frame image output to the frame memory 8C ₁ of the first The frame image is output from the first frame memory 8C ₁ and the frame image is stored, and then the second frame memory 8C ₁ is stored.
The frame image is output from the frame memory 8C _{2 of the above,} and the frame image is stored, and then the frame image is output from the third frame memory 8C ₃ and the frame image is stored.

That is, when the frame image D _F corresponding to the schedule field data SD including the queue code Cue is a frame image, the frame images are output in this order to the motion prediction circuit 8E. Therefore, in this case, the frame image is the target start frame (designated time code S
_Since it is a frame image designated by _TC ), the motion prediction circuit 8E processes the frame image as I-picture, the frame image as B-picture, and the frame image as B-picture.

When the queue code Cue is detected in this way, the schedule field data SD including the queue code Cue is detected.
GO frame image D _F (frame image) corresponding to
It is set in the first frame of P, is ordered in the order of MPEG data as shown in FIG. 14B, and is output to the motion prediction circuit 8E.

Therefore, even when the target start frame is not the head frame image D _F of the GOP, the queue code Cue
It is possible to set the frame image D _F corresponding to the schedule field data SD including GOP as the first frame of the GOP and to compose the GOP from the frame image D _F, so that the target start frame and the actual start frame of the program are Can be matched.

The motion prediction unit 8E detects the motion vector V between the frame images D _F output from the ordering circuit 8A and sends it to the coding unit 9. Cue code here Cue
Is sent to the motion prediction unit 8B, and the motion prediction unit 8B closes the GOP headed with the frame image D _F corresponding to the schedule field data SD including the queue code Cue.
For P, for the first (M-1) B pictures (frame image in the above example), forward prediction is prohibited and the motion vector is detected using only backward prediction. . That is, in the above example, the frame image,
Is a frame image processed as P picture
No forward prediction from 15 is made.

As described above, by setting only the GOP having the frame image D _F corresponding to the schedule field data SD including the queue code Cue as the closed GOP, correlation between consecutive GOPs can be obtained, and the image quality can be improved. It is possible to prevent deterioration. Therefore, the data can be taken out as a file from a necessary place without degrading the image quality.

The ordering circuit 8G switches the schedule field data SD input from the video signal input section 7 between the switches 8H, and the frame memories 8C ₁ , 8C ₂ ,
The schedule field data SD corresponding to the frame image D _F stored in 8C ₃ is stored in the memories 8I ₁ , 8I ₂ , and 8I ₃ , respectively, and the switch 8J is set in correspondence with the ordering for the frame image D _F in the ordering circuit 8A. It switches and outputs the schedule field data SD. Thus, the schedule field data SD can be output in the order corresponding to the frame image D _F output from the ordering circuit 8A.

The delay circuit 8K delays the schedule yield data SD input from the ordering circuit 8G by the time required for the motion prediction in the motion prediction circuit 8E and sends it to the encoding unit 9. Thereby, the motion vector V for each frame image D _F detected by the motion prediction circuit 8E and the schedule field data S corresponding to each frame image D _F.
D and D can be sent to the encoding unit 9 at the same timing.

The operation of the motion prediction section 8 will be described with reference to the flow chart of FIG. First, starting from step SP1, in step SP2, the ordering circuit 8A receives the frame image D _F of the input digital video data S _DV in the frame memories 8C ₁ and 8C in the above-described procedure.
₂ and 8C ₃ , and in step SP3, the ordering circuit 8G causes the schedule field data SD to correspond to the frame images _DF stored in the frame memories 8C ₁ , 8C ₂ and 8C ₃ of the ordering circuit 8A.
It is stored in C _I , 8C _P , and 8C _B.

Next, at step SP4, if the queue code Cue is detected from the schedule field data SD by the queue code Cue detection circuit 8F, step SP5.
Then, the ordering circuit 8A proceeds to the frame image D corresponding to the schedule field data SD including the queue code Cue.
_{The F} is set to the first frame of the GOP, and the MPEG data shown in FIG. 14B is ordered and output to the motion prediction circuit 8E, and the queue code Cue is output to the motion prediction circuit 8E to turn the GOP into a closed GOP. Set and proceed to step SP6.

In step SP4, the queue code Cu
If e is not detected, the frame memory 8
Frame images D stored in C ₁ , 8C ₂ , 8C _3
F is ordered in the order of the MPEG data shown in FIG. 14B and is output to the motion detection circuit 8E.
Proceed to. In step SP6, the motion prediction unit 8D detects a motion vector for the input frame image D _F according to the picture format, and sends the detected motion vector V to the encoding unit 9.

(1-2-4) Encoding Unit The configuration of the encoding unit 9 is shown in FIG. As shown in FIG. 8, the time code cutout circuit 9A extracts the time code S _VTC from the schedule field data SD input from the motion prediction detection unit 8 and outputs it to the header configuration unit 9B. The header configuration circuit 9B outputs the time code S output from the time code cutout circuit 9A when configuring a header to be added to the MPEG bit stream.
_{The VTC} is embedded in the header and output as the header information S _H to the stream configuration circuit 9C.

The encoding circuit 9D encodes the motion vector V input from the motion prediction / detection unit 8 in accordance with the MPEG2 standard, and outputs the encoded data D _ENC to the stream forming circuit 9C. The stream configuration circuit 9C uses the header information S _H supplied from the header configuration circuit 9B and the encoded data D _ENC output from the encoding circuit 9D,
Data is formed by a format specified by the MPEG2 standard, and an MPEG2 bit threshold is sent to the data capturing unit 10.

The operation of the encoder 9 will be described with reference to the flow chart of FIG. First, start from step SP1,
At step SP2, the time code cut-out portion 9A detects the time code S _VTC (Ti
me code). Next, at step SP3,
The header configuration circuit 9B constitutes an MPEG header and embeds a time code S _VTC in the header. Next step SP
4, the stream forming circuit 8D sends the MPEG2 bit stream BS from the encoded data D _ENC and the header information S _H to the data capturing section 10, and the step S
Return to P2.

(1-2-5) Data Acquisition Unit FIG. 10 shows the configuration of the data acquisition unit 10. As shown in FIG. 10, the header detection circuit 10A detects header information S _H from the MPEG2 bit stream BS input from the encoding unit 9, and detects the detected header information S _H by a time code detection circuit. 10B and the time code (Time Code) comparison circuit 10C. The time code detection circuit 10B detects the time code S from the header information S _H.
VTC is detected and the time code S _VTC is output to the time code comparison circuit 10C.

The time code comparison circuit 10C receives the designated time code (actually designated time code + (M-1) by ordering in the ordering circuit 8A) S _TC and the GOP number designation signal S from the time code reading section 6.
_{When GOP} is input, the counter circuit 10D in the time code comparison circuit 10C is set to the GOP number.

The time code comparison circuit 10C compares the designated time code S _TC with the time code S _VTC output from the time code detection circuit 10D. If these time codes match, the switching circuit 10E switches. Outputs switching signal S _SW . As a result, the switching circuit 10E is turned on, and the bit stream BS ₁ is output to the storage device 5 from the frame image (encoded data D _ENC ) when the designated time code S _TC and the time code S _VTC match.

Here, from the time when the output of the bit stream BS ₁ is started, the counter circuit 10E for counting the number of GOPs starts the counting operation, and the GOP number designation signal S
_{When the} number of GOPs designated by the GOP is reached, the switching signal S _SW is output from the time code comparison circuit 10C to the switching circuit 10E, the switch is turned off, and the output of the bit stream BS ₁ is stopped. As a result, the specified number of GOP data can be extracted from the frame image D _F specified by the specified time code S _TC . The counter circuit 10D counts the number of GOPs based on the header information S _H output from the header detection circuit 10B.

The operation of the data fetching section 10 will be described with reference to the flow chart of FIG. Is first started from step SP1, at step SP2, the set specified time code S _TC (Start Point) is the designated time code S _TC supplied from the time code reading section 6, in step SP3, from the time code reading section 6 The count number in the counter circuit 10D is set to the GOP number corresponding to the supplied GOP number designation signal S _GOP .

Next, at step SP4, the header detection circuit 10A receives the header information S _H from the bit stream BS.
And the time code detection circuit 10B detects the header information S
_The time code S _VTC is detected from _H and is output to the time code comparison circuit 10C. Then step S
At P5, the time code comparison circuit 10C specifies the specified time code (Start Point) S _TC and the time code (Time C
ode) If S _VTC does not match, the process returns to step SP4 to execute the processing loop of steps SP4 and SP5.

At step SP5, the designated time code (Start Point) S _TC and the time code (Time Code)
If the S _VTCs match, the process proceeds to step SP6, where the time code comparison circuit 10C outputs the switching signal S _SW to the switching circuit 10E to switch the switch of the switching unit 10E on and output the bit stream BS ₁ . At step SP7, the counter circuit 10D is activated. Next, in step SP8, if the counter value of the counter circuit 10D has not reached "0" (that is, if the specified GOP number has not been reached), the process proceeds to step SP9 and the counter value of the counter circuit 10D is counted in GOP. Each time it does, it decrements by "1" and returns to step SP8.

In step SP8, if the counter value of the counter circuit reaches "0", that is, the designated GOP number is reached, the process proceeds to step SP10. Step SP1
At time 0, the time code comparison circuit 10C outputs the switching signal S _SW to the switching circuit 10E to switch the switch of the switching circuit 10E off to stop the output of the bit stream BS ₁ , and at step SP11, the video encoding device 4 outputs. The process ends.

Thus, in the storage device 5, as shown in FIG. 12, frame images from the frame image D _F designated by the designated time code S _TC to the GOP number designated by the GOP number designation signal S _GOP , that is, a designated length. Data stream can be stored as a file.

(1-3) Operation of the First Embodiment In the above configuration, a designated time code S _TC as a designated signal for designating a desired frame image or a field image among a plurality of continuous frame images and the designated time. GO from the frame image specified by the code S _TC
GOP number designation signal S as a designation signal for designating the P number
_{A GOP} is generated, a time code S _VTC is generated as an identification signal for identifying each frame image, and schedule field data SD is generated as an identification signal corresponding to the time code S _VTC .

The time code S is synchronized with the frame image.
_When the queue code Cue is detected from the schedule field data SD corresponding to _VTC (including the time code S _VTC and the queue code Cue), the frame image corresponding to the schedule field data SD including the queue code Cue is set as the first frame of the group of pictures. The frame images from the first frame to the GOP number designated by the GOP number designation signal S _GOP are compressed and encoded.

(1-4) Effects of the First Embodiment According to the above configuration, the designated time code S_TCAnd time
Code S_VTCGenerates Cue code Cue when match
Then, write in the schedule data SD,
Added support for schedule field data including code Cue
Frame image D _FTo be the first frame of the GOP
Thus, as shown in FIG. 12, an arbitrary frame image is GO
Since it can be set to the first frame of P, the predetermined G
The data stream is forwarded regardless of the OP frame.
It can be taken out as an il.

Further, according to the above configuration, when the designated time code S _TC and time code S _VTC match, a queue code Cue is generated and written in the schedule field data SD, and the schedule field data S including the queue code Cue.
By setting the first GOP having the frame image D _F corresponding to D as the first frame as a closed GOP, correlation between consecutive GOPs can be obtained, so that deterioration of image quality can be prevented and image quality can be improved. The data stream can be extracted as a file from any frame image without deterioration.

Further, according to the above configuration, the IN point (start point) of the file is identified from the MPEG stream by writing the time code S _VTC that matches the designated time code S _TC in the schedule field data SD. Therefore, the required data can be extracted as a file from the MPEG stream.

Further, according to the above configuration, the time code S _VTC which matches the designated time code S _TC is written in the schedule field data SD, and the frame image in which the designated time code S _TC and the time code S _VTC are matched is MPEG-coded.
Output of the stream of the
By stopping the output of the bit stream when it reaches the number of the GOP specified in the _GOP, designated time code S
A data stream of specified length can be taken out as a file from the frame image specified by _TC .

Further, according to the above configuration, each frame image D _F and the schedule data SD corresponding to the frame image D _F are synchronized by being absorbed by the delay schedule data SD generated in the processing block. As a result, the head frame of the output stream can be matched with the target frame image, and the clip can be accurately extracted from the output stream.

(2) Second Embodiment In the above-described embodiments, the case where the motion prediction is performed with each frame image D _F of the input digital video signal having a picture structure as shown in FIG. 14 has been described.
The present invention is not limited to this, and the amount of data generated in each frame image calculated at the first encoding, that is, log data as a predicted value of the motion of each frame image is stored, and the log data is used as a basis. Then, the picture format corresponding to the frame image is determined and used at the time of the second encoding.

That is, in the MPEG encoding system,
To optimize the encoding, calculate the amount of data generated in each frame image at the first encoding,
There is a two-pass method in which encoding is performed again. For example, the frame image of the transition of the program scene has a low correlation with the preceding and following frame images, and thus it is better to use the I picture, and conversely, in the scene that hardly changes, it is better to reduce the I picture.

In this way, by controlling the picture format of each frame image, the overall image quality can be improved. As a concrete method, the data calculated for each frame image at the time of the first encoding is stored, and the picture format corresponding to each frame image is determined from these data and used at the time of the second encoding. .

An encoding system 20 according to the second embodiment of the present invention is shown in FIG. 13 in which parts corresponding to those in FIG.
Shows the configuration of. The storage unit 21 as a storage unit stores the data amount calculated for each frame image at the time of the first encoding as log data. Analysis unit 2 as analysis means
2 determines the picture format corresponding to each frame image based on the log data for each frame image stored in the recording unit 21 and sends it to the time code reading unit 6.

The time code reading unit 6 uses the schedule field data S in the schedule field data creating circuit 6D.
When D is created, information in the picture format of the corresponding frame image is embedded in the schedule field data SD.
Accordingly, the motion prediction detection unit 8 can perform motion prediction on each frame image in the optimum picture format. Thus, the usefulness as an encoding system can be further improved.

(3) Other Embodiments In the above embodiments, the case where the frame image is encoded according to the MPEG2 standard as the encoding algorithm has been described, but the present invention is not limited to this, and other codes are used. A conversion algorithm may be used.

In the above embodiment, the case where an arbitrary frame image is set as the head frame of the group of pictures has been described. However, the present invention is not limited to this, and an arbitrary field image is set as the group of pictures. Even if the leading field is set, the same effect as that of the above-described embodiment can be obtained.

[0080]

As described above, according to the present invention, a designation signal for designating a desired frame image or field image and an identification signal for identifying each frame image or field image are generated and corresponding to the designation signal. Generate an identification signal. When the identification signal corresponding to the designated signal is detected, the frame image or field image corresponding to the detected identification signal is set as the head frame or head field of the group of pictures. As a result, an arbitrary frame image or field image can be set as the head frame or field of the group of pictures, so that the data stream can be extracted as a file from the desired frame image or field image.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall configuration of an encoding system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a time code reading unit.

FIG. 3 is a flowchart for explaining the operation of the time code reading unit.

FIG. 4 is a block diagram showing a configuration of a video signal input unit.

FIG. 5 is a flowchart for explaining the operation of the video signal input unit.

FIG. 6 is a block diagram showing the configuration of a motion detection / prediction unit.

FIG. 7 is a flowchart for explaining the operation of the motion detection / prediction unit.

FIG. 8 is a block diagram showing the configuration of an encoding unit.

FIG. 9 is a flowchart for explaining the operation of the encoding unit.

FIG. 10 is a block diagram showing the configuration of a data acquisition unit.

FIG. 11 is a flowchart for explaining the operation of the data capturing unit.

FIG. 12 is a schematic diagram showing a stream structure obtained in an encoding system according to an embodiment of the present invention.

FIG. 13 is a block diagram showing the configuration of an encoding system according to a second embodiment of the present invention.

FIG. 14 is a schematic diagram for explaining a picture structure of MPEG data.

FIG. 15 is a schematic diagram for explaining problems in conventional program editing.

[Explanation of symbols]

1, 20 ... Encoding system, 2 ... Controller, 3
…… Video tape recorder, 4 …… Encoding device, 5 ……
Storage device, 6 ... Time code reading unit, 6
A: Time code comparison circuit, 6B: Control block interface, 6C: Time code reading circuit, 6D
...... Schedule field data creation circuit, 6E ...... Frame pulse detection circuit, 7 ...... Video signal input section, 7A ...... Vertical synchronization signal detection circuit, 7B ...... Analog digital conversion circuit, 7C, 8K ...... Delay circuit, 8 ...... Motion prediction detector, 8A, 8G …… Ordering circuit, 8B, 8D, 8
H, 8J ... Switch, 8C ... Frame memory, 8E
...... Motion estimation circuit, 8F ・ ・ ・ Queue code detection circuit, 8
I ... memory, 9 ... encoding unit, 9A ... time code cut-out circuit, 9B ... header configuration circuit, 9C ... stream configuration circuit, 9D ... encoding circuit, 10 ... data acquisition unit, 10A ... ... Header detection circuit, 10B ... Time code detection circuit, 10C ... Time code comparison circuit, 1
0D: Counter circuit, 10E: Switching circuit.

Claims (14)

[Claims] 1. An image signal encoding method for forming a group of pictures from a moving image composed of a plurality of continuous frame images or field images and compressing and encoding the moving image, wherein the plurality of frame images or field images are provided. Generate a designation signal for designating a desired frame image or field image, generate an identification signal for identifying each frame image or field image, and synchronize with the frame image or field image to obtain the designation signal. When the corresponding identification signal is generated and the identification signal corresponding to the designated signal is detected, the frame image or the field image corresponding to the detected identification signal is set as the head frame or head field of the group of pictures. , The above compression encoding can be performed from the first frame or the first field. Picture signal encoding method comprising. 2. The identification signal corresponding to the designation signal,
The identification signal for identifying each of the frame images or the field images, and the queuing signal generated when the identification signal and the designating signal match each other, and the queuing signal from the identification signal corresponding to the designating signal. The image according to claim 1, wherein the frame image or the field image corresponding to the identification signal including the queue signal is set to the head frame or the head field of the group of pictures when the image is detected. Signal coding method. 3. The group of pictures including the frame image or the field image corresponding to the detected identification signal as the head frame or field.
The image signal encoding method according to claim 1, wherein the image signal encoding method is set to closed group of pictures. 4. The identification signal corresponding to the designation signal is an identification signal for identifying each frame image or field image, and a queue signal generated when the identification signal and the designation signal match. When an identification signal corresponding to the specified signal including the queue signal is detected,
The frame image or the field image corresponding to the identification signal including the queue signal is set to the closed frame of the picture, the group of picture as the head frame or head field of the group of picture. The image signal encoding method according to claim 3. 5. A designation signal for designating the number of grooves of picture from the frame image or field image designated by the designation signal is generated, and designated by the designation signal from the head frame or head field. 2. The image signal coding method according to claim 1, wherein the compression coding is performed on the frame image or the field image up to the number of group of pictures that has been generated. 6. A motion prediction value for each frame image or field image calculated when performing the compression coding is stored, and the motion prediction value for each frame image or field image stored is analyzed, The image signal encoding method according to claim 1, wherein the picture format of each frame image or field image is determined based on the analyzed motion estimation value. 7. The image signal encoding method according to claim 6, wherein the analyzed motion prediction value is added to the identification signal corresponding to the designation signal. 8. An image signal coding apparatus for forming a group of pictures from a moving image composed of a plurality of continuous frame images or field images to compress and code the moving image, wherein the plurality of frame images or field images are used. A designation signal generating means for generating a designation signal for designating a desired frame image or a field image, a first identification signal generating means for generating an identification signal for identifying each frame image or field image, Second identification signal generating means for generating an identification signal corresponding to the designation signal in synchronization with the frame image or the field image; and detecting the identification signal corresponding to the designation signal,
Identification signal detection means for setting the frame image or field image corresponding to the detected identification signal to the head frame or field of the group of pictures, and a code for performing the compression encoding from the head frame or field. An image signal encoding device, comprising: an encoding unit. 9. The identification signal detecting means, as an identification signal corresponding to the designation signal, is a queue generated when the identification signal for identifying each frame image or field image and the designation signal match. When the signal is detected, the frame image or the field image corresponding to the identification signal corresponding to the designation signal including the queue signal is set to the first frame or the first field of the group of pictures. Item 9. The image signal encoding device according to item 8. 10. The identification signal detection means sets the group of pictures with the frame image or the field image corresponding to the detected identification signal as the head frame or head field as a closed group of pictures. The image signal encoding device according to claim 8, wherein 11. The identification signal detecting means, as an identification signal corresponding to the designation signal, is a queue generated when the identification signal for identifying each of the frame images or the field images coincides with the designation signal. When a signal is detected, the frame of picture or field corresponding to the identification signal corresponding to the specified signal including the queue signal, the group of pictures as the head frame or head field of the group of pictures, The image signal encoding device according to claim 10, wherein the image signal encoding device is set to a closed group of pictures. 12. The designating signal generating means generates a designating signal designating the number of the groove of picture from the frame image or the field image designated by the designating signal, and the coding means comprises the head portion. 9. The image signal coding according to claim 8, wherein the frame or head field to the frame image or field image up to the number of group-of-pictures designated by the designation signal are compression-coded. apparatus. 13. Storage means for storing a motion prediction value for each frame image or field image calculated at the time of compression coding, and motion prediction for each frame image or field image stored in the recording means. The encoding means determines the picture format of each frame image or field image based on the motion prediction value analyzed by the analyzing means. The image signal encoding device according to claim 8. 14. The image signal coding apparatus according to claim 13, wherein the second identification signal generation means adds the analyzed motion prediction value to an identification signal corresponding to the designation signal. .