JP2002330409A - Caption program data converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital caption broadcast service without the need for an exclusive use transmission facility and an operator. SOLUTION: A video + caption analog signal and an audio analog signal are compressed/coded into an ES(Elementary Stream) by a video encoder 11 and an audio encoder 12 respectively, a packetizing processing 13 applies packetizing to the ES to obtain a PES(Packetized Elementary Stream), and a multiplexer 16 applies time division multiplex processing to the PES to obtain a TS(Transport Stream). The caption signal is converted into caption text data PES and caption management data PES resulting in becoming the TS through the time division multiplexing by the packetizing processing applied to the video ES. The video and caption TS and the audio TS are given to the multiplexer 16, in which they are re-multiplexed into one multiplexing signal. In this process, the video and the audio are synchronized with each other and a TS packet having a corresponding PID(Packet Identifier) is attached.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention separates and extracts subtitle program data from a teletext signal superimposed during a vertical blanking period of an analog broadcast television video signal and converts the data into a digital broadcast television subtitle program signal. Related to the device.

[0002]

SUMMARY OF THE INVENTION Following digital CS broadcasting, BS digital broadcasting started in 2000, and experiments for digitization by terrestrial waves have also started. Current BS
In broadcasting, video is transmitted in analog and audio is transmitted in digital. In the new generation of digital broadcasting, both video and audio are transmitted digital.

The greatest advantage of digitization is an increase in the number of channels due to compression and multiplexing using the international standard MPEG2. As a result, a single repeater can transmit a plurality of channels. The current analog method is 1
You need one repeater to send the video for the channel,
The burden on broadcasters was heavy due to the high usage fees for repeaters. However, if a single repeater can be shared and used by a plurality of broadcasters due to the digitization, the burden of expensive usage fees will be reduced, and it will be easier for new businesses to enter.

In Japan, terrestrial digital broadcasting is
It will be fully deployed by 2010, but current analog terrestrial broadcasting will last at least 2010. In addition, the current analog broadcasting continues in BS until 2007, and during that time, the analog broadcasting content is simultaneously broadcast in BS digital.
Therefore, at the beginning of digital broadcasting, a simulcast that broadcasts the same program in both analog broadcasting and digital broadcasting is required.

On the other hand, digital broadcasting has no upward compatibility with signals considered in the development process of analog broadcasting, and is a broadcasting using a completely new signal system. For this reason, broadcasting stations must make new capital investments, such as editing equipment, recording equipment, and transmission equipment, including cameras. However, broadcasting stations have a variety of broadcast materials that have been accumulated in analog broadcasting. These are materials from various fields such as dramas, documentaries, incidents, disasters, and education. In order to broadcast this material in digital broadcasting, it is necessary to convert analog broadcasting material into digital broadcasting material. In addition, although digital broadcasting is used, cameras and editing equipment can be created using existing equipment. Also in this case, it is necessary to convert analog broadcast materials created by these devices into digital broadcast materials.

[0006] Unlike digital broadcast materials, digital broadcast materials have independent program accompanying data such as video, audio, and subtitles. The MPEG2 encoder is shown in FIG.
As shown in an example, while the video and the audio are linked, they are individually input to the video encoder 11 and the audio encoder 12 and encoded (referred to as ES). It is divided into blocks, and packetized by adding header information (called PES).
Then, these video and audio PESs are individually time-division multiplexed into one multiplexed signal (referred to as TS). The subtitle program data is converted into subtitle sentence data PE by the packet conversion processing 18.
The video data is converted into S and caption management data PES, input to the video ES packetization process 13, and time-division multiplexed together with the video into one multiplex signal. At this time, PTS and DTS are added to the header of each PES as time information for performing synchronous reproduction based on the time STC14, which is a reference on the encoder side.
The packetization process 13 of the video ES includes the packet conversion process 1
8 has a function of setting the PTS in the header of the PES input from the PES. The PTS gives the decoder the display and playback time of the video, audio and subtitle program data, and the DTS gives the decoding start time of the video. Further, a program clock PCR is generated based on the STC 14 and added to the TS packet. After this,
The video / caption TS and the audio TS are input to the multiplexing unit 16 and remultiplexed into one multiplexed signal.

[0007] PMT and PAT corresponding to the program scheduling information PSI15 are generated and added to TS packets, respectively. At the same time, a PID for identifying a packet attribute such as video, audio, subtitle program data, or program scheduling information is added to the header of the TS packet. PAT and P
When selecting a program, the MT describes which program is to be selected from a plurality of programs, which packet is to be extracted, and how to decode the program. The PMT describes the PID of the TS packet constituting the program. The PAT specifies the P of the TS packet transmitting the PMT corresponding to the program number.
Specify ID.

When a program is selected, a PID TS packet that indirectly constitutes the program is extracted by designating a program number. Therefore, a TS packet with PID = 0 is received, the PAT is referred to, and the PID of the PMT corresponding to the program number specified from the PAT is known. Next, the PID receives the TS packet of this PID, refers to the PMT, and finds out the PID of the TS packet constituting the program of the designated program number from the PMT.
Then, the TS packet of this PID is extracted, and individual materials such as video, audio, and subtitle program data are decoded in synchronization with the PCR, and one program is reproduced.

As for video and audio, devices for converting analog broadcast material to digital broadcast material are already on the market, but there is no device for converting subtitle program data. In addition, dedicated transmission equipment such as editing equipment and transmission equipment is required. In addition, the caption text of the caption program data can be diverted to that for analog broadcasting, but registration work such as formation control information and operation management information that determine the transmission timing and transmission period of the caption text occurs, and an operator for that purpose is required. Is required.

Accordingly, an object of the present invention is to provide an apparatus capable of easily realizing a digital subtitle broadcasting service using an existing analog broadcasting signal without requiring a dedicated transmission facility or operator. It is.

[0011]

In order to achieve the above object, the present invention is configured as follows.

That is, subtitle program data separation / separation for separating / extracting subtitle program data from a teletext signal superimposed during a vertical blanking period of an analog broadcast television video signal.
Extraction means, caption sentence packet conversion means for converting a character signal of the captioned program data into a specified caption sentence packet (PES), and a predetermined caption management packet (PES) with reference to the index information of the captioned program data. And a caption management packet generating means for generating the caption program data.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a block diagram of a subtitle program data conversion device embodying the present invention. This device is shown in FIG.
Is a modification of the block diagram of the MPEG2 encoder shown in (1) in which new constituent parts according to the present invention are added.
Therefore, the same parts as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 1, analog signals of video + subtitle and audio are compressed and encoded by a video encoder 11 and an audio encoder 12, respectively, become ES, are packetized by a packetization process 13, become PES, and are time-division multiplexed. TS.

From the subtitle signal, a subtitle program packet is separated and extracted from the video signal by a separation / extraction process 17.
It is converted into ES and subtitle management data PES, and is time-division multiplexed by the packetization processing 13 of the video ES to become a TS. The TS output from this is a video / subtitle TS obtained by multiplexing video and subtitle program data. Next, the video / caption TS and the audio TS are input to the multiplexing processing 16 and re-multiplexed into one multiplexed signal. In this process, the video and audio are synchronized, and the PTS is added to the PES header based on STC14.
And DTS are added, and PCR is added to the TS packet. Also, the PMT is determined by PSI 15 input from outside.
And a PAT are generated, and a TS packet of the corresponding PID is added.

Referring to the signal waveform diagram of FIG. 2, the contents of the separation and extraction process will be described. The separation and extraction processing 17
Synchronizing the gate pulse (b) with the TSC video signal (a), the teletext packet (c) superimposed on 21H in the form of a pulse is extracted. Next, the slice (d) and sampling (e) operations are performed to perform 1/0 of the teletext packet (c).
An index information packet identifying the code and having an SI value of 37H;
Each of the subtitle program packets with the subtitle flag ON with the program number 999 is captured.

The packet conversion processing 18 converts the page data unit of the subtitle program packet into subtitle sentence data PES.
Convert to In addition, the transmission period of the subtitle program is recognized with reference to “with subtitle program” and “without subtitle program” in the index information packet, and the subtitle management data PES of a predetermined pattern is repeatedly generated at regular intervals during the transmission period. .

[0018]

As described above, the subtitle program data converter of the present invention separates and extracts subtitle program data from a text broadcast signal superimposed on an analog broadcast video signal, converts the data into a caption sentence packet, , And further generates a caption management packet. Therefore, according to the present invention, subtitle program data for analog broadcasting is automatically converted into a predetermined digital broadcasting signal, so that the existing analog broadcasting equipment can be used without newly introducing a dedicated transmission equipment. Digital caption broadcasting service can be easily implemented at low cost. Also, since the subtitle program data packet superimposed on the input NTSC signal has already been subjected to knitting control and transmission control, there is no need for knitting control and operation management for digital broadcasting, thereby reducing manpower and costs. it can.

[Brief description of the drawings]

FIG. 1 is an example of a block diagram of a subtitle program data conversion device embodying the present invention.

FIG. 2 is a signal waveform diagram of a separation and extraction process.

FIG. 3 is an example of a block diagram of an MPEG2 encoder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Video encoder 12 Audio encoder 13 Packetization processing 14 STC 15 PSI 16 Multiplexing processing 17 Separation extraction processing 18 Packet conversion processing

Claims (1)

[Claims] 1. A subtitle program data separating / extracting means for separating / extracting subtitle program data from a teletext signal superimposed during a vertical blanking period of an analog broadcast television video signal; A subtitle sentence packet conversion unit for converting into a predetermined subtitle sentence packet (PES); and a subtitle management packet generation unit generating a predetermined subtitle management packet (PES) by referring to the index information of the subtitle program data. A subtitle program data converter.