KR101539776B1 - An apparatus for recording and playing broadcast signal and a method thereof using additional timestamp - Google Patents

Abstract

In a broadcast signal processing apparatus such as a TV having a DVR function, when a broadcast signal is recorded on a DVR, a time stamp of the teletext data is separately generated and stored together. Thus, when a recorded broadcast signal is reproduced, , And a method and apparatus for aligning sync between teletext subtitles.

DVR, Teletext, subtitle, sync, sync, timestamp

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for recording and reproducing a broadcast signal using additional time stamps,

The present invention relates to a broadcast signal processing method having a DVR (Digital Video Recording) function.

More particularly, the present invention relates to a broadcast signal processing apparatus such as a TV having a DVR function, in which when a broadcast signal is recorded on a DVR, time stamps of teletext data are separately generated and stored together, To a method and apparatus for aligning a video signal with a teletext subtitle.

Generally, as an example of data broadcast information carried on a TV video signal, there are additional information such as teletext and caption carried on a vertical blanking interval (VBI) line in analog broadcasting. In digital broadcasting, a bit stream Type information is detected and displayed to a user through a data processing process.

Such a data broadcasting receiver comprises an apparatus for decoding data broadcasting information superimposed on a video signal, a display device for displaying a video signal and received data broadcasting information, and the like.

In the case of a teletext subtitle, the time displayed at the time of decoding is not set differently from the DVB subtitle, and the teletext data is displayed on the screen as soon as it is decoded (the DVB subtitle is serviced with a separate timestamp ). Accordingly, when the DVR decodes and outputs a broadcast signal, the DVR does not synchronize with the DVR chip, and the DVR receives and broadcasts the broadcast in real time. Therefore, the teletext subtitle is output faster than the video signal A case occurs.

Basically, in a signal processing apparatus having a DVR function, when a recorded broadcast signal is reproduced, in the case of a video signal, a buffer is inserted between the storage device and the decoder to display it on the screen seamlessly. When the buffer is used, it takes time to actually read the stored program from the storage medium and display it on the actual screen.

However, the teletext data is displayed on the screen faster than the video data because it is transmitted directly from the storage medium to the decoder without a buffer. For this reason, broadcast signal processing apparatuses having conventional DVRs are manufactured and sold in a state in which sync does not fit in some cases even when a recorded broadcast program does not support a subtitle function.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and it is an object of the present invention to provide a broadcast receiving apparatus having a broadcast recording function (DVR function) and a teletext subtitle providing function capable of synchronizing video and teletext The present invention is directed to providing a method that can be used in a variety of applications.

According to an aspect of the present invention, there is provided a broadcast signal recording method including: receiving a broadcast signal including a video signal and a data signal; Extracting teletext data included in the data signal; Generating additional time stamps at predetermined time intervals; Storing the video signal; And storing the teletext data and the supplemental time stamp.

According to an embodiment of the present invention, there is provided a method of reproducing recorded data comprising: reading teletext data from a storage device and additional timestamps stored together with the teletext; Determining whether the read data is teletext data or an additional time stamp; Storing the additional time stamp if the read data is a supplemental time stamp; If the read data is teletext data, comparing the stored additional time stamp with a time stamp of the video signal; And stopping or continuing to decode the teletext data according to the comparison result.

A broadcast signal recording apparatus according to an exemplary embodiment of the present invention includes a broadcast signal processor for receiving and decoding a broadcast signal including a video signal and a data signal, and extracting teletext data included in the data signal; A storage unit for storing data; And a controller for storing the video signal in the storage unit, generating additional time stamps at predetermined time intervals, and storing the generated additional time stamps together with the teletext data in the storage unit.

A recording data reproducing apparatus according to an embodiment of the present invention includes: a storage unit for storing a video signal, teletext data, and additional timestamps stored at predetermined time intervals together with the teletext data; A decoder for decoding the stored video signal, the teletext data and the additional time stamp; An output unit for outputting the decoded video signal and teletext data; Wherein the telemetry data and the additional time stamp are sequentially read from the storage unit, and if the read data is teletext data, the additional time stamp previously read is compared with the time stamp of the video signal, And control to stop or continue decoding the teletext data.

According to the present invention, the broadcast receiving apparatus having the broadcast recording function and the teletext subtitle function can synchronize the teletext in the reproduction of the recording, thereby providing the user with an improved teletext subtitle function.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 is a block diagram illustrating a broadcast receiving apparatus for a broadcast program information guide according to an embodiment of the present invention.

1, a broadcast signal recording and reproducing apparatus according to the present invention includes at least one tuner and a demodulator 110 for receiving and demodulating broadcast data, and demodulating the demodulated broadcast data into video, audio, and additional data A demodulator 130 for decoding the demultiplexed video, audio, and additional data, a speaker 141 for outputting the decoded audio to the outside, a demultiplexer 130 for demultiplexing the decoded video, A memory 150 for storing additional information, a storage unit 170 for storing broadcast contents, an OSD generating unit 170 for processing the additional information and outputting the processed additional information to the display unit 142, And a controller 190 for performing a recording, a reservation, and an alarm function by a user's key input.

The control unit 190 additionally generates a teletext supplementary time stamp of the broadcast signal at the time of recording the broadcast signal and stores the addition time stamp in the storage unit 170. When reproducing the recorded broadcast signal, So that the teletext is synchronized.

Here, the remaining portions except for the controller 190, the storage device 170, the memory 150, the speaker 141, and the display 142 may be referred to as received broadcast signal processing.

In addition, the storage device 170 and the memory 150 may be physically implemented as a single storage unit such as a hard disk drive or a memory.

The decoder unit 120 includes an audio decoder 131 for decoding audio data, a video decoder 132 for decoding a video signal, and a data decoder 133 for decoding a data signal.

The broadcast signal includes an audio signal, a video signal (AV signal) and a data signal. The data signal includes a teletext subtitle, program specific information (PSI) which is systemically required information for processing a broadcast signal, and system information protocol).

In the broadcasting receiver configured as described above, the subtitle synchronization method according to the present invention will be described with reference to the accompanying drawings.

Referring to FIG. 1, a tuner and a demodulator 110 demodulate and output a broadcast signal. Here, the tuner and demodulator 110 may be composed of a plurality of tuners for PIP and the like.

The demultiplexer 120 demultiplexes the demodulated data, and the demultiplexed audio, video, and additional information are output to the decoder 130. The demultiplexer 120 demultiplexes the demodulated data,

The decoder unit 130 decodes an encoding scheme inverse to the encoding scheme in the transmission system and includes an audio decoder 131, a video decoder 132, and a data decoder 133. The audio decoder 131 decodes the demultiplexed audio signal and outputs the decoded audio signal to the speaker 141. The video decoder 132 decodes the demultiplexed video signal and outputs the decoded video signal to the display unit 142. [ Here, the display unit 142 processes the decoded video signal by a video processing unit (not shown) and outputs the processed video signal.

The data decoder 133 decodes the demultiplexed data signal and outputs section data such as teletext data such as a subtitle, Program Specific Information (PSI), and broadcast guide information. Here, the PSI information and the broadcast guide information may include a PMT (Program Map Table), a PAT (Program Association Table), a Virtual Channel Table (VCT), a Conditional Access Table (CAT) Table).

The Program Specific Information (PSI) is information required to perform a basic operation of the receiver, such as a PAT (Program Association Table), a CAT (Conditional Access Table), a PMT (Program Management Table) (NIT), Service Description Table (SDT), Time Date Table (TDT), and Event Information Table (EIT).

Meanwhile, the digital broadcast program transmitted in the ATSC format can be recorded on the recording medium of the recording / reproducing apparatus through the IEEE 1394 interface. IEEE 1394 has specifications for transmitting information on a program using PSI, PMT, etc. of PSI (Program Specification Information).

The memory 150 stores other additional information such as EPG information. The memory 150 may be an EEPROM. Here, the EPG information includes broadcasting station information (e.g., KBS, MBC, SBS, etc.), program information for each broadcasting station (e.g., program title such as 9 o'clock news), and start time and end time of each program information. In addition, the memory 150 serves to temporarily store the teletext data and the additional time stamp when reproducing the recorded broadcast signal according to the present invention. This will be described later.

The control unit 190 records the received broadcast program or externally inputted data in the storage device 170 when there is a recording request from the user. Here, the storage device 170 may be a mass storage device, for example, an HDD.

In addition, when the user inputs a jump (JUMP) key, a channel setting, or a channel change key, the control unit 190 may extract program information related to an input channel from the EPG information, and then provide the program information through the OSD screen. In this case, when only channel information is input, the program information currently being broadcast is extracted and provided, and when channel information and time information are input, program information satisfying both conditions can be provided. In addition, the start position and the program information of the recorded programs may be stored in advance in order to provide the program information recorded in the storage device.

When the received broadcast signal is stored in the storage device 170, a timestamp indicating the playback time of the video signal is also stored. According to an exemplary embodiment of the present invention, when a video signal is stored in the storage device 170, an additional time stamp for teletext in the form of FIG. 2B is additionally generated in addition to the time stamp of the video signal, do. The additional time stamp may be generated and stored at a predetermined time interval, for example, 500 ms.

Teletext data is stored with a specific PID when it is stored. According to the present invention, the additional time stamp to be stored additionally can be generated and stored with the same PID as the teletext data.

FIG. 2A shows a basic data structure of the supplementary time stamp according to the present invention, FIG. 2B shows a data structure of the supplementary time stamp according to the present invention, and FIG. 2C shows a conventional teletext data structure.

The additional time stamp according to the present invention may be composed of a header and data each having 4 bytes as shown in FIG. 2A, which is the same as the teletext data structure of FIG. 2C.

The header includes an identifier indicating that the additional time stamp is used. For example, "0x000001ff" can be used as shown in FIG. 2B. On the other hand, the header of teletext data contains "0x000001bd ". It is possible to discriminate whether the teletext data used as the actual subtitle or the additional time stamp data for synchronizing the teletext is read out by reading the header of the data which are of the same type and are sequentially read.

Referring to FIG. 3, an operation of outputting a broadcast signal recorded and stored in the storage device 170 according to an embodiment of the present invention will be described.

The broadcast signal stored in the storage device 170 is decoded and output through the decoder 130 as shown in FIG. At this time, the buffer 115 is used between the storage device 170 and the decoder 132 in order to continuously display the video signal on the screen. Unlike the data signal such as teletext, the video signal may have a large amount of data to be processed, the control unit 190 may be performing another task, or the video signal may be disconnected for some other reason.

When the buffer 115 is provided for outputting a video signal, it takes a long time to read the video data stored in the storage device 170 and display it on the actual screen, and a delay occurs. However, since the teletext data is directly transmitted from the storage device 170 without going through the buffer, there is no delay. As a result, when the stored video data (program) is reproduced, the sync between the teletext and the video output becomes inconsistent.

As a result, when the broadcast signal is received and output in real time, neither the video signal nor the teletext data is transmitted to the decoder 130 without going through the buffer 115, so that the sync problem does not occur. However, The video signal and the teletext subtitle are not synchronized with each other.

According to the present invention, the teletext data transmitted without passing through the buffer is directly transmitted to the decoder and is not decoded, and the decoding time of the teletext is adaptively slowed down according to the time stamp (PTS: Presentation Time Stamp) It will fit.

As described above, according to the embodiment of the present invention, when storing a broadcast signal in a storage device, the additional timestamp for teletext as shown in FIG. 2B is separately generated and stored at predetermined time intervals.

When the program stored in the storage device is reproduced, the time stamp included in the video signal is read together with additional timestamps for teletext playback.

4 is a diagram for explaining a method of synchronizing a sink using a time stamp for teletext according to the present invention.

In Figure 4, the top is the timestamp of the video signal stored in the storage device, and the bottom is the additional timestamp created and stored in accordance with the present invention.

As shown in FIG. 4, when additional time stamps are generated and stored at regular intervals of 0.5s, they are read at intervals of 0.5s when they are read. The additional time stamp is not a teletext data, but a time stamp in which only time information is recorded.

Actual teletext data 42a and 42b are included in the middle of the additional time stamp 41. As the video is reproduced, the actual teletext data and the additional time stamp 41 are read and decoded and output. It can also be seen that an additional time stamp 41 is inserted between the actual teletext data 42a and 42b.

Actual teletext data 42a and 42b are inserted in accordance with the content of the video signal, and therefore can be read at irregular time intervals. Video timestamps 43 are irregularly inserted into the video signal and read irregularly.

For example, as shown in FIG. 4, it is assumed that the additional time stamp 41 is constantly inserted at intervals of 0.5s. It is assumed that the actual teletext data 42a and 42b are at 0.2s and 1.6s.

When the video signal stored in the storage device starts to be reproduced, the teletext data is immediately decoded and output without delay, but since the video is output through the buffer, a delay is generated from the beginning. In this embodiment, the initial delay is about 0.8s. The teletext data 42a before the start of video decoding is ignored and not output. Depending on the embodiment, an initial delay may not occur depending on the structure and performance of the broadcast processing apparatus.

The additional time stamp 41 having the same structure and having the same PID and the teletext data 42a and 42b are sequentially read. The additional time stamp 41 is read at regular intervals, and the teletext data 42a, 42b used as the actual subtitle in the middle is read.

When the teletext data 42b is read after the video decoding is started, the video progress time at that time is determined. The video timestamp 43 may be extracted from the video signal being decoded by the video decoder 132 of FIG. 3, and the precise current progress time of the video may be determined by reference to the video timestamps 43. Teletext data 42b has progressed to 1.6s, but the video signal is actually at a less advanced point than 1.6s.

For example, assuming that the current video is progressing to 0.7s at the time when the teletext data 42b is read (i.e., 1.6s), there is a delay of 0.9s between the teletext data and the video. The control unit 170 sequentially reads out the additional time stamps and when the teletext data 42b is read, the teletext data 42b and the immediately preceding additional time stamps 41a are stored in a queue (defined in the memory) And holds the decoding of teletext data 42b.

The teletext data decoding is held until the video decoding passes the timestamp 41a just before the current teletext data 42b (i.e., until the additional timestamp 41a <video timestamp).

When the video decoding progress time passes the time of the additional time stamp 41a immediately before the current teletext data 42b, the teletext data 42b is transmitted to the data decoder 133 to continue decoding.

That is, according to the present invention, video signal decoding continues without interruption, and when the teletext data is read, the video signal decoding progress time is compared with the additional time stamp time, and when the video signal and the teletext signal are synchronized To stop the teletext decoding.

In this embodiment, there may be a time difference of maximum 0.5s (time interval in which the additional time stamp is generated) between the additional time stamp 41a and the teletext data 42b so that the video signal and the teletext data 42b are perfectly Such an error may be a degree of error that does not inconvenience the viewer to watch the teletext subtitle.

5A and 5B illustrate a stored broadcast signal reproducing method according to an embodiment of the present invention. 5A and 5B, a more specific method of reproducing the recorded broadcast signal while synchronizing with the teletext will be described in detail.

In one embodiment of the present invention, a method of matching a teletext sync of a broadcast signal recorded through two slicers is presented. It will be appreciated by those skilled in the art that other variations of this embodiment are possible.

FIG. 5A shows a process of reading teletext data and additional time stamps from data stored in the storage device, separating them from teletext data or additional time stamps, and storing them in a queue.

5B shows a process for determining when teletext data is to be delivered to the decoder when the teletext data is read and stored, in the process of FIG. 5A.

Depending on the embodiment, Figures 5A and 5B may be implemented in a single process.

In step S51 of FIG. 5A, the additional time stamp and the teletext data as shown in the bottom part of FIG. 4 are sequentially read.

In step S52, it is determined whether the read data is an appended time stamp or teletext data. As described above, whether the additional time stamp or teletext data is available can be determined by looking at the header portion.

If the read data is an additional time stamp, in step S53, the read additional time stamp is stored. In the case of FIG. 4, for example, additional time stamps of 0s, 0.5s, 1.0s, and 1.5s are sequentially read and stored in the memory. Each time the additional timestamp is read, it is overwritten and updated with the latest additional timestamp.

If the read data is teletext data, the received teletext data is stored in the memory in step S54.

In this state, the process of FIG. 5B is called and performed. In step S55, the teletext data stored in the memory is read. Then, in step S56, the additional time stamp stored in the current memory is compared with the time stamp of the current video signal decoded by the decoder. That is, it is judged where the video signal has proceeded.

If the video signal has passed the additional time stamp stored in the current memory, the teletext data stored in the memory at that time is transmitted to the data decoder in step S57 so that the teletext data is output.

If the video signal has not yet passed the additional time stamp stored in the current memory, there is a delay in the video signal processing, so that it waits without transmitting the teletext data to the decoder.

According to the present invention, it is possible to output the teletext of the broadcast signal recorded and stored in sync with the video signal according to the present invention.

1 is a block diagram illustrating a broadcast receiving apparatus for a broadcast program information guide according to an embodiment of the present invention.

FIG. 2A shows a basic data structure of the supplementary time stamp according to the present invention, FIG. 2B shows a data structure of the supplementary time stamp according to the present invention, and FIG. 2C shows a conventional teletext data structure.

3 shows an operation of outputting a broadcast signal recorded and stored in a storage device according to an embodiment of the present invention.

4 is a diagram for explaining a method of synchronizing a sink using a time stamp for teletext according to the present invention.

5A and 5B illustrate a stored broadcast signal reproducing method according to an embodiment of the present invention.

Description of the main parts of the drawings

130: decoder 132: video decoder

133: Data decoder 115: Buffer

150: memory 170:

190:

Claims (14)

delete delete delete Reading teletext data from the storage device and additional timestamps stored with the teletext; Determining whether the read data is teletext data or an additional time stamp; Storing the additional time stamp if the read data is a supplemental time stamp; If the read data is teletext data, comparing the stored additional time stamp with a time stamp of the video signal; And And stopping or continuing the decoding of the teletext data according to the comparison result. 5. The method of claim 4, Decoding the teletext data if the time stamp of the video signal is later than the supplemental time stamp; and when decoding the teletext data when the time stamp of the video signal is temporally ahead of the supplemental time stamp, In the recording data. 5. The method of claim 4, Wherein the additional time stamp has the same PID as the teletext data. 5. The method of claim 4, Wherein the additional time stamp is generated at a predetermined time interval when the teletext data is stored. delete delete delete A storage unit for storing additional time stamps stored at predetermined time intervals together with the video signal, the teletext data and the teletext data; A decoder for decoding the stored video signal, the teletext data and the additional time stamp; An output unit for outputting the decoded video signal and teletext data; Wherein the telemetry data and the additional time stamp are sequentially read from the storage unit, and if the read data is teletext data, the additional time stamp previously read is compared with the time stamp of the video signal, And control to stop or continue the decoding of the teletext data. 12. The method of claim 11, Decoding the teletext data if the time stamp of the video signal is later than the supplemental time stamp; and when decoding the teletext data when the time stamp of the video signal is temporally ahead of the supplemental time stamp, The stored recording data reproducing apparatus 12. The method of claim 11, Wherein the additional time stamp has the same PID as the teletext data. 12. The method of claim 11, Wherein the additional time stamp is generated at a predetermined time interval when the teletext data is stored.

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