KR101087103B1 - Method and Apparatus Random Access in Personal Video Recorder - Google Patents

Abstract

The present invention provides a personal video recorder (PVR) having a method and apparatus for implementing random access. The present invention provides a sequence header information table for sequence information and time information for each sequence during broadcast recording. A first step of doing; And a second step of receiving sequence header information of the corresponding position from the table for use in decoding if the position randomly accessed at the request of the user during the broadcast reproduction process after generating the table is not the starting point of the sequence. The present invention provides a random access method in a personal video recorder, which can implement random access even at a location.

According to the present invention, even if the random access to any position, even if the position is not the starting point of the sequence header can be reproduced.

MPEG-2, PVR, Sequence Headers

Description

Personal video recorder including random access method and device {Method and Apparatus Random Access in Personal Video Recorder}

1 is a view showing an embodiment of performing a random access by a PVR according to the prior art

2 is a block diagram showing an embodiment of a configuration of a PVR device for random access according to the present invention;

3 is a diagram illustrating an embodiment of a configuration of a sequence header information table according to the present invention.

4 is a diagram illustrating an embodiment of a configuration of a sequence header information table according to the present invention.

5 is a flowchart illustrating a process of performing random access during playback using a sequence header information table generated according to the present invention.

6 is a diagram illustrating a sequence header information table according to another embodiment according to the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

100: system decoder + download control unit 110: storage medium

120: index generator 130: VF extractor

140: sequence header information table generation unit 150: data broadcasting processing unit

160: upload control

170: sequence header information table control unit

180: video decoder 190: audio decoder

200: Video / Audio / OSD Mixer

The present invention relates to a PVR (Personal Video Recorder), and more particularly, to a method and apparatus for implementing random access when playing a recorded video stream.

The PVR is a device capable of storing digital broadcast signals on a hard disk, and provides not only basic recording functions, but also a time-shift function, instant replay function and other trick play functions while watching live broadcasts. It provides much improved functions than the conventional video cassette recorder (VCR).

In addition, by using the PVR, high definition (HD) -class digital broadcasting can be stored and viewed at any time on the hard disk, and various additional service functions can be provided to the user.

In addition, the PVR may provide a highlight function for the broadcast stream stored in the hard disk.

In the above, the highlight function is a hardware or software method that divides a corresponding broadcast (video) stream into scene sections having a meaning, analyzes the characteristics of each scene, and determines the importance of the scene. In determining the playback mode, the highlight function provides the user with the convenience of quickly and easily accessing or viewing a vast amount of recorded programs for a limited time.

However, in order to provide the above-described highlighting function, non-linear movement to a specific position within a broadcast (video) stream must be freely performed.

In the above, non-linear refers to a non-linear reproduction process such as trick play and random access in the broadcast reproduction process, rather than continuing from the start to the end of a program, basic playback, double speed, and the like.

In order to free the non-linear movement described above, when moving to a specific position within the video stream stored in the hard disk, the video must be accurately played from the starting point of the corresponding position, and the specific position is any One of the starting points of the frame.

The conventional video decoder is designed to start decoding the video stream after the sequence start code is input.

1 is a diagram illustrating an embodiment of performing random access in a PVR according to the prior art.

The skip pointer is defined as a target frame to be moved when the user wants to move to a specific frame in the video stream recorded by a user input or other automatic method while performing normal playback.

At this time, the PVR moves the play position to the skip pointer and plays the video stream from the start position.

However, if the skip pointer is not the starting point of the sequence, the video decoder cannot decode the incoming video stream until the next received parsing of the sequence header received by the absence of sequence header information. There is a problem that the section cannot be reproduced.

Therefore, in the conventional PVR, random access or other forms of trick play are possible, but when moving any section when performing the above operation, the skip pointer is limited to the beginning of the sequence header, each section is created when highlighting or scene division is performed. Constraints such as limiting the start point of the sequence to the start point of the sequence are followed.

Therefore, the decoder used in the conventional PVR apparatus is impossible to accurately reproduce video data without structural information included in the sequence header, and as a result, all data input before the sequence header information is input. It is designed to ignore and cannot input video data.

Therefore, when moving to a specific frame or playing from the frame within the recorded video stream, there is a problem in that video data from the point to the next sequence start point cannot be decoded if the point is not the start point of the sequence.

In addition, even in the implementation of nonlinear trick play such as a scene-by-scene skip function, there is a problem in that the scene split point should be limited to the start point of the sequence.

Therefore, no matter how precise and complex algorithms are used to segment the correct scene, the scene cannot be reproduced from the beginning of the extracted scene unless the starting point of the scene is the starting point of the sequence.

That is, the change of the actual scene may occur even in the same sequence or GOP (Group Of Picture) in the MPEG stream, but even if the conversion point is extracted accurately, the problem of not being able to play the video correctly at the corresponding point occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to perform a random access or other nonlinear trick play on a program recorded on a hard disk of a PVR, and to perform video at any position other than the beginning of the sequence. A method and apparatus for effectively reproducing a stream are provided.

In order to achieve the above object, the present invention includes a first step of generating a sequence header information table for the sequence header information and time information for each sequence in the broadcast recording process; And a second step of receiving sequence header information of the corresponding position from the table for use in decoding if the position randomly accessed at the request of the user during the broadcast reproduction process after generating the table is not the starting point of the sequence. The present invention provides a random access method in a personal video recorder, which can implement random access even at a location.

In the first step, the table is composed of a plurality of rows, comprising sequence header information specifying the content of the sequence header and time information specifying a section (frame number) of the video stream to which the sequence header information is applied. do.

The table may be prepared based on the sequence header information (A or B) by comparing and determining whether the previously stored sequence header information (A) is identical to the currently received sequence header information (B).

If the two sequence header information is the same as a result of comparing the two sequence header information (A, B), only the time information is updated.

If the two sequence header information is different as a result of comparing the two sequence header information, the time sequence immediately before the new sequence header information (B) is received is stored in the last part of the table, and then the new sequence is formed by forming a new part. The header information (B) is copied and input.

In the second step, sequence header information is received from the table for use in the decoding, and inserted into the front of corresponding video data.

According to still another embodiment of the present invention, in the individual video recorder including a storage medium, a sequence (frame number) to which sequence header information transmitted to the recorder and the sequence header information are applied in a broadcast recording process is applied. A sequence header information table generator configured to generate a table of time information specifying the time information, transmit the same to a storage medium, and store the same; And a sequence header information control unit configured to control the storage medium to decode and display the video stream using the sequence header information table stored in the storage medium during random access to an arbitrary position in a broadcast reproduction process. It provides a PVR comprising a.

The storage medium may be any storage medium corresponding to the ATA / ATAPI interface.

The sequence header information control unit may extract the header information and the time information necessary for the sequence from the table value generated, transmitted and stored in the storage medium so that the sequence header information table generating unit is located in front of the video stream to be decoded. It characterized in that to control.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described.

The same components as in the prior art are given the same names and the same reference numerals for convenience of description, and detailed description thereof will be omitted.

In addition, the terminology used in the present invention was selected as a general term that is widely used at present, but in certain cases, the term is arbitrarily selected by the applicant, and in this case, the meaning is described in detail in the description of the present invention. It is to be clear that the present invention is to be understood as the meaning of terms rather than names.

Hereinafter, a preferred embodiment of a method and apparatus for implementing random access in a PVR according to the present invention will be described with reference to the accompanying drawings.

First, the present invention relates to a sequence of MPEG 2 video, wherein the MPEG 2 video has one GOP in which an appropriate bundle of I, P, and B pictures (frames) is selected based on a frame meaning a single picture. And one or several GOPs together to form a sequence.

In addition, the sequence header informs the start of each sequence and is information including a parameter value commonly applied to all frames included in one sequence.

The sequence header includes main information necessary for video playback such as a sequence start code, a horizontal and vertical size of a video, a frame rate, and the like.

Therefore, when the video data is played back, if there is no information of the sequence header in the corresponding stream, the data cannot be played back.

2 is a block diagram illustrating an embodiment of a configuration of a PVR device for random access according to the present invention.

The PVR apparatus according to the present invention includes a system decoder and download controller 100, a storage medium 110, an index generator 120, a video feature (VF) extractor 130, and a sequence header information table. A generation unit 140, a data broadcasting block 150, an upload control 160, a sequence header information table control unit 170, a video decoder 190, a video / audio / OSD mixer ( 200).

In the system decoder and the download control unit 100, the system decoder decodes a broadcast stream (TP: TransPort) received from a transmitting end (broadcasting station), and the download control unit 100 stores the received broadcast stream. Characterized in that (110).

Decoding in the above is a concept of demuxing, in which a received broadcast stream is divided into a video, audio, and data stream.

The system decoder and download control unit 100 separates only the basic video stream separately from the received broadcast stream, and generates an index generator 120, a video feature (VF) extractor 130, and a sequence header information table generator 140, respectively. The TTP is transmitted to the storage medium 110, and the EPG signal is transmitted to the data broadcast processor 150.

In the above description, time-stamped TP (TTP) refers to being stored in the storage medium 110 in the form of a time stamp added to the broadcast stream.

In this case, a time stamp refers to a time of a specific action, such as arrival of a byte or presentation of a presentation unit, and refers to a system clock value or system at the time when the broadcast stream is received. It is determined by a predetermined relative time value in, and is then used as a means for adjusting the speed of upload when the stream is read from the storage medium 110.

The storage medium 110 receives and stores the TTP, Index / VF / SHT, and program information outputted through the configuration block of FIG. 2 in the received broadcast stream, and then stores information necessary for the decoder to reproduce the recorded broadcast. It is characterized in that to be able to transmit by decoding.

The storage medium 110 may be any storage medium corresponding to the ATA / ATAPI interface.

In the above, ATA generally refers to the standardization of the IDE (Integrated Device Electronics), which is one of the hard disk interfaces, by the American National Standards Institute (ANSI). In the above, there is an AT attachment packaged interface (ATAPI). In other words, the standard for connecting the IDE interface to the IDE interface, and most of the built-in CD-ROM and tape backup device to the ATAPI standard can be connected to the same interface in the same row as the hard disk.

The index generator 120 may generate location information of picture start codes of video data to smoothly implement trick play in the playback process of the stored broadcast stream.

That is, by displaying and storing the physical position of each frame in packet units of a broadcast stream, when the playback is to be moved to a specific position, the starting point of the frame or video section can be accurately found in the storage medium 110. It is responsible for creating indexes.

The generated index file is used in association with a table of a type such as a file allocation table (FAT) that specifies a physical location of a file stored in the storage medium 110.

In addition, the index generator 120 transmits not only the sequence start code but also information related to the picture start code to the sequence header information table generator 140.

The VF extractor 130 extracts histogram data for highlight or scene division and transmits the histogram data to the storage medium 110.

The sequence header information table generating unit 140 is a core part of the present invention, and is displayed by using sequence header information having content of a sequence header and a video section (frame number) or other means to which the sequence header information is applied. And generating a sequence header information table.

Instead of storing all the sequence header information in the video stream received when generating the sequence header information table, the corresponding information is stored in the table only when a meaningful change occurs in the contents of the sequence header.

The meaningful change is determined based on the sequence header information. For example, if the sequence header applied to frames 0 to 14 and the sequence header applied to the next frame section 15 to 29 are the same, Only one sequence header information is input to the table and time information is displayed from 0 to 29 in the section.

However, if the sequence header for the frame period applied from the frame 15 to 29 is different from the above, two sequence header information is input to the table, and the application interval is 0 to 14 and 15 to 29 Will be displayed.

The sequence header information table generated by the sequence header information table generating unit 140 may be used when random access is performed during a video reproduction process.

The data broadcast processor 150 receives and processes EPG (Electronic Program Guide) data, which is additional information about a corresponding program transmitted from the system decoder and the download control unit 100, and processes program information such as broadcast title and genre information. It is characterized in that the extraction and transmission to the storage medium (110).

Up to this point, the process of generating the sequence header table in the broadcast recording process has been described above, and the following describes using the sequence header table generated in the recording process in the reproduction process.

The upload control unit 160 outputs a broadcast program stored in the storage medium 110 to each video and audio decoder during a time shift or playback function, and is a time stamp stored in the storage medium 110. The upload speed of the storage medium 110 is controlled in order to reproduce the broadcast broadcast stream (TTP) with reference to the value specified in the time stamp.

The sequence header table control 170 is also a core part of the present invention. When the random header does not exist at the corresponding position when performing random access, the sequence header table control 170 is generated from the sequence header information table. And a function of controlling the information to be read and to insert the read sequence header information into the video data to be played back.

The reason for inserting the sequence header information into the video data to be reproduced is as in the above-described problem of the prior art. If the skip pointer portion is not the starting point of the sequence header due to random access, random access cannot be performed. In the present invention, by inserting the sequence header information into the skipped pointer portion randomly accessed, an arbitrary position is recognized as a starting point of the sequence header so that it can be reproduced.

After the storage is completed in the storage medium 110 through the above-described process, when a request for random access or the like is received, the storage medium 110 decodes an audio signal with a video decoder 180 that decodes a video signal. The decoder 190 transmits the corresponding information to the decoder 190 to decode it.

The video / audio / OSD (200) On Screen Display (OSD) mixer 200 performs a function of synchronizing and outputting a signal decoded by each decoder during a reproduction process, and the mixer is capable of displaying not only video signals but also graphic screens and audio signals. It is characterized by providing all to the user to synchronize.

Through the above-described process, an operation on the randomly accessed skip pointer is performed.

Referring now to the configuration of the sequence header table generated in advance during the broadcast recording process, which is a key part of the present invention, FIG. 3 is a diagram illustrating an embodiment of the configuration of the sequence header information table according to the present invention.

The sequence header information table includes a plurality of rows, and one row includes sequence header information specifying content of a sequence header and time information specifying a section of a frame in a video stream to which the sequence header information is applied. time information).

As described above, the update of the sequence header information is different from the previous sequence header, i.e., only when a meaningful change occurs in the contents of the sequence header, the input is additionally stored in the table and updated.

If the received sequence header information is the same in the program, the sequence header information table for the program will consist of only one row.

The above-described sequence header information table is generated during the broadcast recording process. Looking at the generation process in detail, FIG. 4 is a flowchart illustrating an embodiment of generating a sequence header information table according to the present invention.

First, the sequence header information table generator 140 of FIG. 2 receives the sequence header information and the picture start code from the input video stream and generates the sequence header information table using the sequence header information table.

Parse the first sequence header of the input video stream (step S10).

This is to first parse the first received sequence header for each channel from the broadcast signal received after initializing or initializing the PVR (ie, turning on the power).

The sequence header information including the contents of the parsing result sequence header is stored in the current row of the sequence header information table (step S20).

After storing the sequence header information, a frame is counted using a picture start code to extract time information to which the same sequence header information is applied (step S30).

It is determined whether new sequence header information is input while counting the frames. If the new sequence header information is not input as a result of the determination, the process returns to the previous step S30 to continue counting the frames (step S40).

However, if new sequence header information is input as a result of the determination, the sequence header information table generation unit 140 compares and determines whether the sequence header information stored in the last row of the table is equal to the new sequence header information. step)

As a result of the comparison and determination, if the two sequence header information is the same, only the time information field (frame information) needs to be stored in the current row (step S60).

However, if the two sequence header information is different as a result of the comparison and determination, the frame number counted so far is stored in the current row of the table (step S70).

After step S70, sequence header information and time information for one row are generated, and a new row is generated to store new sequence header information to apply new sequence header information (step S80).

The comparison and determination in the step S50 is to determine whether the sequence header information is the same, to distinguish and store the corresponding sequence header information and the frame section to which the respective sequence header information is applied, and to use the same during playback.

After the steps S60 and S80, the above-described process is repeated for the new row from step S30.

At this time, the time information of the row in which the sequence header information is stored in the table means a section to which the corresponding sequence header information is applied, and is indicated by a frame number in this embodiment.

The display method of the section may be represented by the first frame number and the last frame number of the section as described above.

Using the sequence header information table generated through the process of FIG. 4 described above, a process of implementing random access in the broadcast reproduction process will now be described with reference to the accompanying drawings.

5 is a flowchart illustrating a process of performing random access during playback using a sequence header information table generated according to the present invention.

After generating the sequence header information table in the recording process, in the process of playing the recorded video stream, the user performs random access such as skipping by an operation such as a remote controller or an automatic method (step S100). )

When a playback position is moved to a random position (frame) by the random access, it is determined whether a sequence header exists at the position, that is, whether the position is a starting point of the sequence header (step S110).

As a result of the determination, when the video data of the randomly accessed position starts from the sequence header, the video data is transmitted from the storage medium 110 to the input of the video decoder 180 to perform playback.

The process of inputting the video data from the storage medium 110 to the video decoder 180 is performed by the upload controller 150.

However, if the video data of the randomly accessed position is not the starting point of the sequence, the process proceeds to the next step.

Next, under the control of the sequence header information table controller 170, a row to be referred to in the sequence header information table is determined using the frame number of the video data of the randomly accessed position in the storage medium 110 (S120). )

That is, it first determines a row to be referred to using a time information field.

Then, the sequence header information applied to the corresponding video section is read from the sequence header information field of the row to be referred to (step S130).

Then, the read sequence header information is transmitted to the video decoder 180 (step S140).

After parsing the sequence header information received by the video decoder 180, the video data of the randomly accessed position is transmitted from the storage medium 110 to the video decoder 180 under the control of the upload controller 160. Decode by step S150.

Through the above-described process, the video decoder 180 can now normally reproduce the video data corresponding to the randomly accessed position even if the video data is not the starting point of the sequence header.

The above-described sequence header information table is configured by copying the contents of the sequence header information directly into the table. Alternatively, the sequence header information table can be configured by a method of indicating a physical location where the sequence header information is stored. An Example is described.

6 is a diagram illustrating a sequence header information table according to another embodiment according to the present invention.

In the present embodiment, the frame section to which the sequence header information is applied and the actual position information in the storage medium 110 in which the sequence header is stored are recorded in a table.

When the random access function is performed using the sequence header information table according to the present embodiment, when the sequence header does not exist at the randomly accessed location, the time information of the table is first used by using the frame number of the randomly accessed location. Use the time information field to determine the row to reference in the table.

When the row to be referred to is determined, the sequence header information is read from the storage medium 110 with reference to the pointer field of the row, and the sequence header information is transmitted to the video decoder 180.

When parsing of the sequence header information is completed in the video decoder 180, the video data of the location where the storage medium is accessed is transmitted to the video decoder 180 to decode the video data, thereby reproducing the playback process at the randomly accessed location. Is performed.

As described above, when the PVR apparatus according to the present invention performs random access to an arbitrary frame such as trick play, highlight playback, or the like for a recorded program, the conventional video decoder may be used even if the frame is not the starting point of the sequence header. You can play back video data from that location accurately without any modification to it.

The second embodiment of the PVR including the random access method and apparatus according to the present invention described above has the same basic configuration as the first embodiment described above.

However, in the second embodiment, the sequence header information table of the first embodiment is configured by copying the contents of the sequence header information directly into the table. However, in the second embodiment, the physical location where the sequence header information is stored is different. The difference is that you can organize the table in a way that tells.

The present invention is not limited to the above-described embodiments, and as can be seen in the appended claims, modifications can be made by those skilled in the art to which the invention pertains, and such modifications are within the scope of the present invention.

Personal video comprising the random access method and apparatus according to the present invention The effects of the recorder are explained as follows.

First, according to the present invention, when trying to play a broadcast program recorded in the PVR with an arbitrary frame as a starting point, even if a sequence header does not exist at the corresponding position, the video can be played correctly at the corresponding point. It works.

Second, according to the present invention, when generating a sequence header information table for the time information using the sequence header information and the frame number in the recording process of the broadcast program, and when playing the video stream at a specific position, the sequence header valid video for the point By inserting the data before the data, an accurate random access function can be performed using the conventional video decoder as it is.

Third, according to the present invention, it is possible to apply the trick play function to a broadcast program or a multimedia stream stored in a PVR or other video library, or the like, to accurately reproduce video data at an arbitrary position.

Claims (9)

Generating a sequence header information table for sequence header information and time information for each sequence in a broadcast recording process; And a second step of receiving sequence header information of the corresponding position from the table for use in decoding if the position randomly accessed at the request of the user during the broadcast reproduction process after generating the table is not the starting point of the sequence. You can also implement random access at location, The table is composed of a plurality of rows in the personal video recorder characterized in that the sequence header information specifying the content of the sequence header and the time information specifying the interval (frame number) of the video stream to which the sequence header information is applied Random access method. delete The method of claim 1, The table is a personal video, characterized in that the comparison is made based on the sequence header information (A or B) by comparing and determining whether the sequence header information (A) already stored and the currently received sequence header information (B) are the same. Random access method in the recorder. The method of claim 3, wherein If the two sequence header information is the same as a result of comparing the two sequence header information (A, B), only the time information is updated. The method of claim 3, wherein If the two sequence header information is different as a result of comparing the two sequence header information (A, B), the time information immediately before the sequence header information (B) is received is stored in the last part of the table, and then a new part is formed. And copy and input the received sequence header information (B). The method of claim 1, wherein in the second step, And receiving the sequence header information from the table and inserting it in front of the video data for use in the decoding. A sequence header information table generation unit for generating a table of sequence header information transmitted to a recorder and a time information specifying a section (frame number) to which the sequence header information is applied and transmitting the same to a storage medium during broadcast recording; And a sequence header information control unit configured to control the storage medium to decode and display a video stream using a sequence header information table stored in the storage medium when random access to a random position in a broadcast reproduction process. Including a device, And the storage medium is any storage medium corresponding to an ATA / ATAPI interface. delete The method of claim 7, wherein the sequence header information control unit, And controlling the storage medium to be located in front of a video stream to be decoded by extracting header information and time information necessary for the sequence from a table value generated, transmitted and stored in the storage medium by the sequence header information table generator. A personal video recorder comprising a random access device.

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