KR20100125148A - An apparatus for recording and playing broadcast signal and a method thereof using additional timestamp - Google Patents

Abstract

PURPOSE: An apparatus for recording and playing a broadcast signal and a method thereof using an additional timestamp are provided to adjust the synchronization between a video signal and a teletext subtitle by additionally generating the timestamp of teletetxt data when recording a broadcasting signal. CONSTITUTION: A broadcasting signal processor receives and decodes a broadcasting signal including a video signal and a data signal, and extracts the teletext data included in the data signal. A storage unit(170) stores data, and a controller(190) stores the video signal. The controller generates a time stamp at a certain time interval, and stores the generated additional timestamp at the storage unit with the teletext data.

Description

An apparatus for recording and playing broadcast signal and a method using additional timestamp}

The present invention relates to a broadcast signal processing method having a digital video recording (DVR) function.

More specifically, in the broadcast signal processing apparatus such as a TV having a DVR function, when the broadcast signal is recorded by the DVR, the time stamp of the teletext data is separately generated and stored together to reproduce the recorded broadcast signal. A method and apparatus for synchronizing video signals with teletext subtitles.

In general, as an example of data broadcasting information carried on a TV video signal, in analog broadcasting, there is additional information such as teletext and caption displayed on a vertical blanking interval (VBI) line, and in digital broadcasting, a bit stream included in a certain area. The type of information is detected and displayed to the user through data processing.

The data broadcast receiver includes a device for decoding data broadcast information superimposed on a video signal, a display device for displaying the video signal and the received data broadcast information, and the like.

In the case of the teletext subtitle, the time displayed during decoding is not determined differently from the DVB subtitle, so that the teletext data is displayed on the screen as soon as it is decoded (a DVB subtitle is provided with a separate time stamp. ). Accordingly, when the DVR decodes and outputs the recorded broadcast signal, the teletext subtitle is output earlier than the video signal, unlike when receiving and outputting the broadcast in real time due to the disparity according to the characteristics of each DVR chip. The case occurs.

In a signal processing device having a DVR function, when a recorded broadcast signal is played back, a buffer is inserted between the storage device and the decoder so that the video signal can be displayed on the screen without interruption. When the buffer is used in this way, it takes time to actually read the broadcast program stored in the storage medium and display it on the actual screen.

Teletext data, however, is passed directly from the storage medium to the decoder without a buffer, so it is displayed faster than the video data. For this reason, conventional broadcast signal processing apparatuses with DVRs are manufactured and sold in a state in which a sync is not achieved in some cases even when the subtitle function is not supported for the recorded broadcast program.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problem, and in a broadcast receiving apparatus having a broadcast recording function (DVR function) and a teletext subtitle providing function, video and teletext can be synchronized when a recording is played and a time shift function is operated. The purpose is to provide a way.

Broadcast signal recording method according to an embodiment of the present invention, receiving a broadcast signal including a video signal and a data signal; Extracting teletext data included in the data signal; Generating additional time stamps of a predetermined time interval; Storing the video signal; And storing the teletext data and the additional timestamp.

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

In accordance with another aspect of the present invention, a broadcast signal recording apparatus includes: a broadcast signal processor configured to receive and decode a broadcast signal including a video signal and a data signal, and extract teletext data included in the data signal; A storage unit for storing data; And a controller configured to store the video signal in the storage unit, generate additional time stamps at predetermined time intervals, and store the generated additional time stamp together with the teletext data in the storage unit.

According to an embodiment of the present invention, an apparatus for reproducing recorded data includes: a storage unit storing a video signal, teletext data, and additional time stamps stored at regular time intervals together with the teletext data; A decoder for decoding the stored video signal, teletext data and additional timestamp; An output unit for outputting the decoded video signal and teletext data; The teletext data and the additional timestamp are sequentially read from the storage, and if the read data is the teletext data, the previously read additional timestamp and the timestamp of the video signal are compared, and according to the comparison result. And a control unit controlling to stop or continue decoding of the teletext data.

According to the present invention, in a broadcast receiving device having a broadcast recording function and a teletext subtitle function, it is possible to synchronize the teletext when a recording is played, thereby providing a user with an improved teletext subtitle function.

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

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

As shown in FIG. 1, a broadcast signal recording and reproducing apparatus according to the present invention includes one or more tuners and demodulators 110 for receiving and demodulating broadcast data, and converting the demodulated broadcast data into video, audio, and additional data. A demultiplexer 120 for demultiplexing, a decoder 130 for decoding and outputting the demultiplexed video, voice, and additional data, a speaker 141 for outputting the decoded voice to the outside, and the decoded video Display unit 142 for outputting the data, a memory 150 for storing additional information, a storage device 170 for storing broadcast content, and an OSD generator for processing the additional information and outputting the processed information to the display unit 142. And a controller 190 that performs recording, reservation, and alarm functions by a user's key input.

The controller 190 additionally generates an additional time stamp for teletext of the broadcast signal when the broadcast signal is recorded, and stores the additional time stamp in the storage device 170, and when the recorded broadcast signal is reproduced, the stored time stamp and the time stamp of the video signal. By comparing, we synchronize the teletext.

Herein, the rest of the control unit 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 one storage unit such as a hard disk drive or a memory.

The decoder 120 includes an audio decoder 131 for decoding voice 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, and the data signal includes a teletext subtitle, program specific information (PSI) and PSIP (program specific information) required for processing the broadcast signal. and various section data such as system information protocol).

In the broadcast receiving apparatus 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, the tuner and demodulator 110 tunes, demodulates, and outputs a broadcast signal. Here, the tuner and demodulator 110 may be configured in plural for the function of the PIP.

The demultiplexer 120 demultiplexes the demodulated data in the inverse of the multiplexing method in the transmission system, and the demultiplexed audio, video, and additional information are output to the decoder 130.

The decoder unit 130 decodes 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 demultiplexed audio signal to the speaker 141. The video decoder 132 decodes the demultiplexed video signal and outputs the demultiplexed video signal to the display unit 142. Here, the display unit 142 processes the decoded video signal by a video processor (not shown) and outputs the processed video signal.

The data decoder 133 decodes the demultiplexed data signal and outputs teletext data such as subtitles, section data such as PSI (Program Specific Information), and broadcast guide information. Here, the PSI information and broadcast guide information may include a program map table (PMT), a program association table (PAT), a virtual channel table (VCT), a conditional access table (CAT), and network information (NIT). Table) and the like.

The program specific information (PSI) includes information required to perform a basic operation of the receiver, and includes a program association table (PAT), a conditional access table (CAT), a program management table (PMT), and the like. Is composed of practical information for program guidance, and this includes a network information table (NIT), a service description table (SDT), a time date table (TDT), and an event information table (EIT).

On the other hand, the digital broadcast program transmitted by the ATSC method can be recorded on the recording medium of the recording / playback apparatus through the IEEE1394 interface. The IEEE 1394 is specified to transmit information about a program using PAT, PMT, etc. of PSI (Program specification information).

The memory 150 stores other additional information such as EPG information. The memory 150 may be configured as an EEPROM. Here, the EPG information includes broadcasting station information (for example, KBS, MBC, SBS, etc.), program information for each broadcasting station (for example, program titles such as 9:00 news), start and end times of each program information, and the like. In addition, the memory 150 temporarily stores teletext data and additional time stamps when reproducing the recorded broadcast signal. This will be described later.

The controller 190 records the broadcast program received from the user or data input from the outside to the storage 170 when there is a recording request from the user. Here, the storage device 170 may be configured as, for example, an HDD as a mass storage device.

In addition, the controller 190 may extract the program information related to the input channel from the EPG information when inputting the user's jump (JUMP) key, channel setting or channel change key, etc., and then provide it through the OSD screen. In this case, when only channel information is input, program information currently broadcast is extracted and provided, and when channel information and time information are input, program information that satisfies two conditions may be provided. Also, in order to provide recorded program information to a storage device, a start position and program information of recorded programs may be stored in advance.

When storing the received broadcast signal in the storage device 170, a timestamp indicating a reproduction time of the video signal is also stored. According to an embodiment of the present invention, when storing the video signal in the storage device 170, in addition to the time stamp of the video signal, additional time stamps for teletext in the form shown in FIG. 2B are additionally generated and stored in the storage device 170. do. The additional time stamp may be generated and stored at a predetermined time, 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 additionally stored may be generated and stored to have the same PID as the teletext data.

FIG. 2A shows a basic data structure of an additional time stamp of the present invention, FIG. 2B shows a data structure of an additional 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 it is an additional time stamp. For example, as illustrated in FIG. 2B, "0x000001ff" may be used. In contrast, the header of teletext data contains "0x000001bd". By reading headers of the same type and sequentially read data, it is possible to determine whether the teletext data is actually used as a subtitle or additional time stamp data for synchronizing the teletext.

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 once stored in the storage device 170 is decoded and output through the decoder 130 as shown in FIG. 3. In this case, the buffer 115 is used between the storage device 170 and the decoder 132 to display the video signal on the screen without interruption. Unlike a data signal such as teletext, the video signal has a large amount of data to be processed, and the controller 190 may perform another task or the video signal may be disconnected due to other reasons.

When the buffer 115 is placed to output the video signal, it takes time to actually read the video data stored in the storage device 170 and display it on the actual screen, and a delay occurs. However, since teletext data is delivered directly from the storage device 170 without passing through the buffer, there is no delay. As a result, playing back the stored video data (program) results in a mismatch between the teletext and the video output.

As a result, when receiving and outputting a broadcast signal in real time, since both the video signal and the teletext data are passed directly to the decoder 130 without passing through the buffer 115, a sync problem does not occur, but the broadcast signal is stored once. If the video signal is stored and reproduced at 170, the video signal may not be synchronized with the teletext subtitle.

According to the present invention, the teletext data transmitted without passing through the buffer is not directly transmitted to the decoder and decoded, and according to the presentation time stamp (PTS) of the video signal, the sync is delayed by adaptively delaying the decoding time of the teletext. Will be corrected.

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

When the program stored in the storage device is played back, the time stamp included in the video signal is read and played along with the additional time stamp for teletext.

4 is a diagram illustrating a method for synchronizing sync using an additional time stamp for teletext according to the present invention.

In FIG. 4, the top is a timestamp of the video signal stored in the storage, and the bottom is an additional timestamp generated and stored according to the present invention.

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

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

Since the actual teletext data 42a and 42b are inserted according to the contents of the video signal, they are read at irregular time intervals. The video time stamp 43 is also inserted irregularly in the video signal and is read irregularly.

For example, as shown in FIG. 4, it is assumed that additional time stamps 41 are constantly inserted at 0.5 s intervals. And it is assumed that the actual teletext data 42a and 42b are in 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 outputted without delay, but since the video is outputted through a buffer, a delay is generated from the beginning. In this embodiment, the initial delay is about 0.8 s. Teletext data 42a before video decoding starts is ignored and is not output. Depending on the embodiment, the initial delay may not occur depending on the structure and performance of the broadcast processing apparatus.

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

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

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

Teletext data decoding is held until video decoding passes a timestamp 41a immediately preceding the current teletext data 42b (ie, additional timestamp 41a < = video timestamp).

If the video decoding progress time passes the time of the additional timestamp 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, when the teletext data is read while the video signal decoding continues without interruption, when the video signal and the teletext signal are synchronized by comparing the video signal decoding progress time and the additional timestamp time at that time, This is to stop teletext decoding.

In this embodiment, there may be a time difference of up to 0.5 s (time interval at 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 While this may not be correct, this error is such that it does not inconvenience the viewer to watch the teletext subtitle.

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

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

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

FIG. 5B illustrates the process of determining when to deliver teletext data to the decoder when the teletext data is read and stored in the process of FIG. 5A.

In some embodiments, FIGS. 5A and 5B may be implemented in one process.

In step S51 of FIG. 5A, additional time stamps and teletext data, such as the bottom of FIG. 4, are read sequentially.

In step S52, it is determined whether the read data is additional time stamp or teletext data. As described above, whether the additional time stamp or the teletext data can be determined based on the header part.

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

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

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 at the decoder. That is, it is determined how far the video signal has progressed.

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

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

In this manner, according to the present invention, the teletext of the recorded and stored broadcast signal can be synchronized with the video signal and output.

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

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

3 illustrates 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 illustrating a method for synchronizing sync using an additional time stamp for teletext according to the present invention.

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

** Description of the main parts of the drawing **

130: decoder 132: video decoder

133: data decoder 115: buffer

150: memory 170: storage

190: control unit

Claims (14)

Receiving a broadcast signal comprising a video signal and a data signal; Extracting teletext data included in the data signal; Generating additional time stamps of a predetermined time interval; Storing the video signal; And Storing the teletext data and the additional timestamp; Broadcast signal recording method comprising a. The method of claim 1, And the additional time stamp has the same structure as the teletext data. The method of claim 1, And the additional time stamp has the same PID as the teletext data. Reading teletext data and an additional timestamp stored with the teletext from a storage device; Determining whether the read data is teletext data or an additional timestamp; If the read data is an additional timestamp, storing the additional timestamp; If the read data is teletext data, comparing the stored time stamp with the stored time stamp of the video signal; And And stopping or continuing decoding of the teletext data according to the comparison result. The method of claim 4, wherein If the timestamp of the video signal is later in time than the additional timestamp, hold the decoding of the teletext data and decode the decoding of the teletext data when the timestamp of the video signal is ahead of the additional timestamp. Recording data reproduction method for starting the operation. The method of claim 4, wherein And the additional timestamp is stored to have the same PID as the teletext data. The method of claim 4, wherein And the additional stamp is generated at a predetermined time interval when the teletext data is stored. A broadcast signal processor that receives and decodes a broadcast signal including a video signal and a data signal, and extracts teletext data included in the data signal; A storage unit for storing data; And a controller configured to store the video signal in the storage unit, generate additional time stamps at predetermined time intervals, and store the generated additional time stamp together with the teletext data in the storage unit. The method of claim 8, The additional time stamp has the same structure as the teletext data and has a different header from the teletext data. The method of claim 8, And the additional time stamp has the same PID as the teletext data. A storage unit for storing an additional time stamp stored at a predetermined time interval together with a video signal, teletext data and the teletext data; A decoder for decoding the stored video signal, teletext data and additional timestamp; An output unit for outputting the decoded video signal and teletext data; The teletext data and the additional timestamp are sequentially read from the storage, and if the read data is the teletext data, the previously read additional timestamp and the timestamp of the video signal are compared, and according to the comparison result. And a control unit for controlling to stop or continue decoding of the teletext data. The method of claim 11, If the timestamp of the video signal is later in time than the additional timestamp, hold the decoding of the teletext data and decode the decoding of the teletext data when the timestamp of the video signal is ahead of the additional timestamp. Recorded data reproducing apparatus for initiating The method of claim 11, And the additional time stamp is stored to have the same PID as the teletext data. The method of claim 11, And the additional stamp is generated at a predetermined time interval when storing the teletext data.

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