JPH11341492A - Base stock coding and transmission method and base stock coding and transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and quickly replace a range to be replaced of a base stock that is coded and sent from a key station with another base stock without causing a processing delay and deterioration in image quality due to coding in a local station. SOLUTION: This method replaces a range to be replaced 22 included in a 1st bit stream 200 coded according to a 1st form with a 2nd bit stream 21 coded according to a 2nd form. At this time, a sequence header 23 in which the information relating to the 2nd coding form is described, is provided to a head part of the 2nd bit stream 21 and a sequence header 24 in which the information relating to the 1st coding form is described, is provided to a head part of a range 25 at the back side from the range to be replaced 22 in the 1st bit stream 200.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for encoding and transmitting a video material by encoding and transmitting the same, and more particularly, to a method of converting a first material received on a receiving side into another material. Regarding what to replace.

[0002]

2. Description of the Related Art Heretofore, in the case of a local station in broadcasting by terrestrial broadcasting or the like, a predetermined range of materials transmitted analogously from a key station is broadcast as it is as a local station, and a necessary range is broadcast as a local station. The broadcast is performed by replacing with the material prepared by.

[0003] That is, as shown in FIG. 7, for material data 70 transmitted from a key station to a local station, news 1, CM (commercial video) 1 and program 1 are broadcast as they are at the local station. News 3, CM
4 to 6 are replaced in the local station and broadcast as material data 71.

In digital broadcasting, such replacement is performed in the same manner.
Is compressed by encoding, transmitted to the local station, and decoded (decompressed) by the local station.
News 3 and CMs 4-6 prepared by local stations
Are encoded and replaced with a material such as, and broadcast or retransmitted as the material data 71.

[0005]

However, in the method in which the coded and transmitted material data is temporarily decoded, returned to the original material level, and then replaced, the replacement is performed at the broadcast stage. Re-encoding has to be performed, which causes a problem that a delay corresponding to the time of the encoding / decoding process occurs on the local station side, and the frequency of encoding increases, thereby deteriorating the image quality.

For this purpose, a method of directly performing replacement in the state of a coded bit stream can be considered. For example, in a repeat field or a closed GOP, material data from a key station and material data to be replaced by a local station are used. When continuity at the connection point cannot be maintained, since ending / starting the data at an arbitrary point in the material may cause a problem in decoding, since continuity is required between was there.

Accordingly, the present invention has been made in view of the above circumstances, and an object of the present invention is to transmit data from a key station without causing processing delay and image quality deterioration due to, for example, encoding at a local station. It is an object of the present invention to provide a material transmission method and apparatus capable of quickly and easily replacing a range to be replaced of an encoded material with another material.

[0008]

In order to achieve the above object, according to a first aspect of the present invention, there is provided a material coded transmission method, comprising: a replacement range included in a first bit stream encoded according to a first format; Is replaced by a second bitstream encoded according to a second format, wherein the second bitstream is added to the beginning of the second bitstream.
And the information about the first encoding format is described at the head of a range behind the range to be replaced in the first bit stream.

Further, the material coded transmission apparatus according to claim 2 of the present invention transfers the first bit stream coded according to the first format to a head portion of a range behind the range to be replaced included therein. Transmitting means for describing information on the first encoding format and transmitting the information; receiving means for receiving the transmitted first bit stream; and the second encoding format at the head of the second bit stream. And a replacement unit for replacing the range to be replaced with the described information.

[0010] The "description of information related to the encoding format"
For example, information on the quantization coefficient used in the encoding process at the time of encoding is included.

According to the first or second aspect of the present invention, even if the coding format of the replaced second bit stream is different from that of the preceding first bit stream, the coding format is Decoding can be accurately performed based on the contents described in the information on the first bit stream, and can be accurately decoded by using the information on the coding format even in the portion after the replacement range of the first bit stream. it can.

[0012] According to a third aspect of the present invention, there is provided a material coded transmission method, wherein a permuted range included in a first bit stream coded according to a first format is converted into a second range coded according to a second format. Replacing the second bitstream with the first bitstream.
Of the first bit stream so as not to depend on the bit stream immediately before the range to be replaced, and the portion of the first bit stream immediately after the range to be replaced so as not to depend on the second bit stream. To start.

[0013] Also, the material coded transmission apparatus according to claim 4 of the present invention converts a portion immediately after the permutation range included in the first bit stream coded according to the first format into a second bit stream, according to the second format. Transmitting means for starting and transmitting the data without relying on the bit stream;
Receiving means for receiving the bit stream of the first bit stream and a second bit stream which is started so as not to depend on the bit stream immediately before the range to be replaced in the received first bit stream
And a replacing means for replacing the range to be replaced with the bit stream.

According to the third or fourth aspect of the present invention, for example, the first and second bit streams are GO
Even when the subsequent bit stream depends on the preceding bit stream at the time of decoding, such as the P (Group Of picture) format, the first,
The continuity at the connection point can be maintained without having to consider the difference in the encoding format of the second bit stream, and as a result, the replacement processing can be performed quickly, and the processing accompanying the replacement processing can be performed. Delay can be prevented.

[0015] According to a fifth aspect of the present invention, there is provided a material coded transmission method, wherein a permuted range included in a first bit stream coded according to a first format is converted into a second range coded according to a second format. A method of replacing by a bit stream, wherein a part immediately before the range to be replaced in the first bit stream is terminated without affecting the second bit stream, and the second bit stream is terminated. In the first bit stream so as not to affect the bit stream immediately after the range to be replaced.

[0016] Further, the material coded transmission apparatus according to claim 6 of the present invention converts the portion immediately before the permutation range included in the first bit stream coded according to the first format into a second bit stream. Transmitting means for terminating the stream so as not to affect the stream, transmitting means for receiving the transmitted first bit stream, and receiving means for receiving the transmitted first bit stream; Replacement means for replacing the range to be replaced with the second bit stream which is terminated so as not to affect the bit stream immediately after the range.

According to the fifth or sixth aspect of the present invention, for example, when the first and second bit streams are in the repeat field format, when the continuity of the VBV buffer value is required, etc. Even when the preceding bit stream affects the following bit stream, there is no need to consider the formats of the first and second bit streams, and continuity at the connection point can be easily ensured. .

According to a seventh aspect of the present invention, there is provided a material coded transmission method, wherein a replacement range included in a first bit stream coded according to a first format is converted into a second range coded according to a second format. A method of performing replacement by a bit stream, wherein information on the replacement range is described in a portion of the first bit stream that is ahead of the replacement range.

Here, the "information on the range to be replaced" includes information such as the start time and the range length of the range to be replaced.

According to the invention of claim 7 of the present application, since the information on the replacement range is transmitted prior to the replacement range, the replacement process can be started with this information, whereby the replacement process can be started. The replacement of the replacement range can be easily and accurately performed.

According to a seventh aspect of the present invention, when the replacement range is replaced by a second bit stream, the description of the information on the replacement range is deleted.

According to the invention of claim 8 of the present application, it is possible to prevent the information on the replacement range from being broadcast or retransmitted.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail. FIG. 1 shows a material coded transmission device 100 used in the present embodiment. In the figure, a material encoding and transmitting apparatus 100 encodes a material in a key station, transmits the encoded data to a local station, and replaces a predetermined replacement range in the local station.

More specifically, on the key station side, a client 1 that manages the broadcast contents of the key station and controls each device, a camera 1 that provides the material, a VTR 1 or a material server 1, and an encoding of the material And a bit stream server 1 for storing the already coded material. On the other hand, the local station side manages the broadcast contents of the local station and A client 2 for controlling each device, a camera 2 for providing materials,
A VTR 2 or a material server 2, a material encoding device 2 for encoding and transmitting the material, and a bit stream server 2 for storing the already encoded material are provided.

The client 1 manages the broadcast content at the key station and the broadcast content to be replaced at the local station. The client 1 relates to the replacement at the local station based on a request from the client 2 at each local station. It creates information and gives instructions to the bit stream server 1 and the selector 1.

The material encoding apparatus 1 broadcasts or encodes an encoder 1 for encoding the material, and appropriately selects a code encoded by the encoder 1 and a code transmitted from the bit stream server 1. And a selector 1 for performing transmission.

The bit stream server 1 stores a previously encoded bit stream, and sends out the bit stream in accordance with an instruction from the client 1.

With such a configuration, in the key station, the material provided by the camera 1 or the like and encoded by the encoder 1 or the material stored in the bit stream server 1 is transmitted in accordance with an instruction from the client 1. ,
By switching the selector 1, the broadcast is broadcast as a key station broadcast or transmitted as a first bit stream to a local station via satellite broadcast or a network.

On the other hand, the client 2 transmits various requests to the key station according to the broadcast contents of the local station, and controls the selector 2, the selector 3, the bit stream server 2 and the like to control the broadcast of the local station. Is to manage.

The material coding apparatus 2 replaces the first bit stream transmitted from the key station with the second bit stream prepared by the local station. Specifically, the material encoding apparatus 2 transmits the first bit stream transmitted from the key station. A code analyzer 1 for analyzing a first bit stream, an encoder 2 for encoding a material supplied from a camera 2, a VTR 2, or a material server 2, and a selector 2 and a selector 3 for switching codes Is what is done.

The code analyzer 1 reads the contents of the received first bit stream, and analyzes information on the encoding and additional data contained therein, and the result of the analysis is sent to the selector 2. The selector 2 is switched based on the information.

The selector 2 appropriately selects the first bit stream sent from the code analyzer 1 and the second bit stream sent from the selector 3 in accordance with an instruction from the client 2 and broadcasts the data from the local station. To transmit a bit stream.

The selector 3 supplies the material prepared by the local station to the selector 2 as a second bit stream. Specifically, the selector 3 encodes the data by the encoder 2 in accordance with an instruction from the client 2. The selected bit stream and the bit stream transmitted from the bit stream server 2 are appropriately selected and transmitted to the selector 2.

The bit stream server 2 stores the coded bit stream and sends out the bit stream according to the broadcast contents managed by the client 2.

With such a configuration, in the local station, the bit stream generated by encoding the material provided by the camera 2, the VTR 2 or the material server 1 by the encoder 2, and the bit stream server 2 The selector 3 selects the supplied bit stream and supplies it to the selector 2 as a second bit stream. The first bit stream received from the key station is analyzed by the code analyzer 1 and transmitted to the selector 2. . Then, by switching the selector 2 based on the analysis result of the code analyzer 1, the predetermined replacement range is replaced with the second bit stream, and this is broadcast as a local station.

Hereinafter, the replacement process in the local station will be described in detail according to the first and second bit stream types. FIG. 2 shows that a first bit stream 200 transmitted from a key station is an MPEG (Moving Picture Image).
It is a figure which shows typically the aspect of a replacement process in the case of a (Codubg Experts Group) format.

In the figure, the first transmitted from the key station is
Range 22 included in the bit stream 200 of
Is replaced by the second bit stream 21 at the local station.

In the first bit stream 200, a sequence header 24 is provided at the beginning of a range 25 behind the range 22 to be replaced, and the sequence header 24 describes information about the first encoding format. Have been.

The sequence header 24 is added in the key station material encoding device 1 and describes quantization information and the like necessary for decoding the encoded first bit stream 25. I have. Based on the sequence header 24, the first bit stream 25 is restored to a video material.

At the head of the second bit stream 21, a sequence header 23 is provided. In the sequence header 23, information about the second encoding format is described. This sequence header 23
Is added to the second bit stream by the encoder 2 at the local station. Like the sequence header 24 described above, quantization information and the like necessary for decoding the encoded bit stream 21 are The first bit stream 21 is described into a video material based on the description.

Then, such a sequence header 23
The first permuted by the second bit stream 21 having
Is broadcast at a local station. At this time, even if the encoding format of the second bit stream 21 replaced by the local station is different from the encoding format of the key station, it is correctly decoded based on the information described in the sequence header 23. In addition, it is possible to accurately decode the portion of the first bit stream 200 after the replacement range by using the information described in the sequence header 24.

FIG. 3 illustrates a case where the first bit stream 300 transmitted from the key station is encoded in a GOP (Group Of Picture) format.

In the figure, the first bit stream 30
0 is coded by a sequence of I, P, and B, I indicates an I picture to be decoded based on information that the device itself has, and P indicates I or P in the front. B indicates a P picture to be decoded with reference to, and B indicates a B picture to be decoded with reference to I or P in both forward and backward directions.

In the present embodiment, by starting the second bit stream 33 with a so-called closed GOP, the second bit stream 33 is started so as not to depend on the bit stream immediately before the range to be replaced 31 in the first bit stream 300. That is, the second bit stream 31
For the B near the head of, only the I at the rear is referred to, and the I or P at the front is not referred to.

The encoding using such a closed GOP is performed by the encoder 2 of the local station, and by appropriately switching the selector 3 and the selector 2, the replacement range included in the first bit stream is replaced. Done.

On the other hand, the portion 32 of the first bit stream 300 immediately after the replacement range 31 is also a closed GOP.
To start the second bit stream 33 without depending on the last I or P of the second bit stream 33. Such encoding by the closed GOP is performed by the encoder 1 of the key station, and is transmitted to the local station by switching the selector 1.

By starting the second bit stream 33 and the first bit stream 32 behind the range to be replaced 31 by a closed GOP in this manner, the second bit stream 33 does not depend on the preceding bit stream 30 or 31. And the preceding bit stream 3
Since the decoding can be performed independently without being affected by 0 or 31, there is no need to consider the continuity of the GOP format at the time of replacement. Processing delay can be prevented.

FIG. 4 illustrates a case where the first bit stream transmitted from the key station is encoded in a repeat field format. The repeat field format is a method of encoding a film image having 24 frames per second while duplicating a part of the film image so as to conform to a video image having 60 frames per second.

In this embodiment, the portion 40 immediately before the range 41 to be replaced in the first bit stream 400 is
By terminating with a format that does not use the repeat field format described above, the second bit stream 4
3 and the second bit stream 43 is also terminated in a format other than the repeat field format, so that the bit stream 42 of the first bit stream 400 immediately after the range 41 to be replaced. So that it does not affect In the present embodiment, the replacement range 41 is also terminated in a format that does not use a repeat field.

Thus, the preceding bit stream 40
Or by terminating 43 without depending on the repeat field format, there is no need to consider the repeat field format of the connected bit stream 43 or 42,
Continuity at connection points can be easily ensured.

FIG. 5 schematically shows the VBV buffer value (VBV buffer occupancy) of the first bit stream 500 transmitted from the key station.

In this embodiment, the VBV buffer value at the end P1 of the immediately preceding part 50 of the range 51 to be replaced in the first bit stream 500 matches the VBV buffer value at the start P2 of the second bit stream 53. By doing so, the second bit stream 53 is not affected, and the VBV buffer value at the end P4 of the second bit stream 53 and the VBV buffer value of the first bit stream 500 immediately after the range 51 to be replaced are included. By matching the VBV buffer value at the beginning P3 of the bit stream 52, the connected bit stream 52 is not affected.

The bit stream 5 connected in this way
By matching the end and start VBV buffer values of 0 to 52, continuity at the connection point can be maintained, and the VBV buffer can be prevented from being broken due to overflow or underflow.

FIG. 6 shows a modified embodiment of the first bit stream transmitted from the key station.

In the figure, the first bit stream 6
In 00, additional data 63 describing information on the replacement range 63 is provided in a portion 60 ahead of the replacement range 61.

The additional data 63 is added, for example, by the encoder 1 of the key station, and describes information such as the starting point and the section length of the range 63 to be replaced. And
The content of the additional data 63 is read by the code analyzer 1 of the local station, and the replacement of the replacement range 63 is performed in response to this. In the present embodiment, when the replacement range 63 is replaced by the second bit stream,
The additional data 63 is deleted by the code analyzer 1 and broadcast.

In such a modified embodiment, the replacement range can be easily and reliably replaced based on the contents of the additional data 63. In addition, since the additional data 63 is deleted when broadcasting, it is possible to prevent the information regarding the replacement range from being broadcast. For example, when the replacement range is a CM, CM cut recording is performed. Can be avoided.

[0058]

As described above, according to the method and the apparatus for encoding and transmitting the material of the present invention, the material is transmitted from the key station without causing processing delay and image quality deterioration due to encoding at the local station, for example. The replacement range of the encoded material can be quickly and easily replaced with another material.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a material coded transmission device according to an embodiment of the present invention.

FIG. 2 is a diagram schematically showing first and second bit streams used in the present embodiment.

FIG. 3 shows first and second bit streams used in the present embodiment, and is a GOP (Group Of Picture).
It is a figure which shows what was encoded by the format typically.

FIG. 4 is a diagram schematically showing first and second bit streams used in the present embodiment, which are encoded in a repeat field format.

FIG. 5 is a diagram schematically illustrating VBV buffer values of first and second bit streams used in the present embodiment.

FIG. 6 illustrates a first embodiment used in a modified embodiment of the present invention.
FIG. 3 is a diagram schematically showing a bit stream of FIG.

FIG. 7 is a diagram illustrating an example of material replacement in a material coded transmission method according to the related art.

[Explanation of symbols]

20, 30, 40, 50, 60 First bit stream (part preceding the range to be replaced) 21, 33, 43, 53, 61 Second bit stream 22, 31, 41, 51, 61 Range to be replaced 25 , 32, 42, 52, 62 First bit stream (rear part of range to be replaced) 23 Sequence header (information on second encoding format) 24 Sequence header (information on first encoding format) 63 Additional data (Information on Replaced Range) 200, 300, 400, 500, 600 First Bitstream

Claims (8)

[Claims] 1. A method of replacing a replacement range included in a first bit stream encoded according to a first format with a second bit stream encoded according to a second format, The information about the second encoding format is described at the beginning of the second bit stream, and the first encoding format is placed at the beginning of the first bit stream in a range behind the range to be replaced. A material coded transmission method characterized by describing information on the material. 2. A method according to claim 1, wherein the first bit stream encoded according to the first format is described with information about the first encoding format at a head portion of a range behind a permutation range included in the first bit stream. Transmitting means for transmitting; receiving means for receiving the transmitted first bit stream; and information about the second encoding format described at the head of a second bit stream. A material coded transmission device comprising: a replacement unit that replaces a range. 3. A method for replacing a replacement range included in a first bit stream encoded according to a first format with a second bit stream encoded according to a second format, wherein The second bit stream is started so as not to depend on the bit stream immediately before the range to be replaced in the first bit stream, and a portion of the first bit stream immediately after the range to be replaced is replaced by A material-encoded transmission method characterized by starting without depending on a second bitstream. 4. A part of a first bit stream encoded according to a first format immediately after a permuted range included in the first bit stream is transmitted without being dependent on the second bit stream. Transmitting means for receiving the first bit stream transmitted, and receiving means for receiving the first bit stream transmitted from the first bit stream, the second bit stream being started so as not to depend on the bit stream immediately before the range to be replaced. And a replacement means for replacing the range to be replaced with the bit stream. 5. A method for replacing a replacement range included in a first bit stream encoded according to a first format by a second bit stream encoded according to a second format, wherein A portion of the first bit stream immediately before the range to be replaced is ended so as not to affect the second bit stream, and the second bit stream is replaced with the first bit stream. A material-encoding transmission method, which is terminated so as not to affect a bit stream immediately after a range to be replaced. 6. A first bit stream encoded according to a first format, in which a portion immediately before a permuted range included in the first bit stream is terminated so as not to affect the second bit stream. Transmitting means for transmitting; receiving means for receiving the transmitted first bit stream; and terminating the received first bit stream so as not to affect the bit stream immediately after the range to be replaced. And a replacing means for replacing the replacement range with the second bit stream to be replaced. 7. A method for replacing a replacement range included in a first bit stream encoded according to a first format with a second bit stream encoded according to a second format, wherein A material coded transmission method, characterized in that information on the replacement range is described in a portion of the first bit stream ahead of the replacement range. 8. The material-encoded transmission method according to claim 7, wherein, when the replacement range is replaced by a second bit stream, a description of information on the replacement range is deleted. The material coded transmission method.