JP2011217185A - Device and method for receiving/reproducing digital broadcast - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method for receiving and reproducing digital broadcast accurately detecting a scene change point of 12-seg digital terrestrial broadcasting.SOLUTION: This device for receiving and reproducing digital broadcast has: a first scene change point detection part for detecting a scene change point of an image of one-segment broadcast; a second scene change point detection part for detecting a scene change point of an image of 12-segment broadcast; a synchronization time detection part for obtaining the difference between a broadcast time of a reproduction time of the one-segment broadcast and that of the 12-segment broadcast as a synchronization time; and a control part for setting a synchronizing picture of the 12-segment broadcast as a scene change point when a scene change point of an image of the 12-segment broadcast synchronizing with a scene change point of an image of the one-segment broadcast does not exist.

Description

  Embodiments described herein relate generally to a digital broadcast receiving / reproducing apparatus and a digital broadcast receiving / reproducing method capable of reproducing or recording a program that has received a digital broadcast.

  Conventionally, when playing or recording a video signal in a digital broadcast, the scene change picture is detected and recorded in association with the video signal to be used for program search or to grasp the program. It is used to create still images and thumbnail videos for

  The scene change point is detected by analyzing the video signal and detecting a boundary point in the video signal. For example, the scene change point is detected based on the analysis result of the similarity between a plurality of frames included in the video signal, that is, when similar frames are continuous, it is determined that there is no scene change, and the difference The point where the frames are connected is determined as the scene change point. Alternatively, the scene change point is detected based on the analysis result of the luminance signals of a plurality of frames included in the video information.

  However, in the method as described above, when a scene change point is detected, the amount of calculation for detecting the scene change point becomes large, so the appearance period of the I picture is detected and becomes shorter than the predetermined period. In such a case, it has been devised to use the I picture at that time as a scene change point (see, for example, Patent Document 1).

JP 2002-10254 A

  In 12-segment (12 segment) broadcasting in terrestrial digital broadcasting, MPEG (Moving Picture Experts Group) 2 system is adopted as a video encoding system. There are two types of picture encoding methods called intra-picture encoding that encodes only a single picture and inter-picture encoding that uses information on the difference between adjacent pictures. The former is called I picture and the latter is called P picture or B picture.

  In order to decode an encoded video signal, it is necessary to first decode from an I picture. Therefore, in terrestrial digital broadcasting, it is stipulated as an operation rule that I pictures be inserted periodically. When a scene change point exists within the appearance cycle of the I picture, the appearance interval of the I picture is different, so that the scene change point can be detected by monitoring the change in the appearance interval of the I picture.

  However, when the cycle of the I picture matches the scene change point, there is a problem that the scene change point cannot be detected. In addition, there is an I picture that is not a scene change point even though it is an I picture with a different period. For this reason, there is a problem that the scene change point cannot be detected accurately only by monitoring the fluctuation of the cycle in which the I picture appears.

  Further, there are cases where an I picture is not inserted even though it is a scene change point. That is, the P picture or B picture may be the scene change point. In such a case, the scene change point cannot be detected simply by monitoring the fluctuation of the cycle in which the I picture appears. Further, when the P picture or B picture is a scene change point, the change in the code amount must be monitored.

  The present invention has been made in view of the circumstances as described above, and provides a digital broadcast receiving / reproducing apparatus and a digital broadcast receiving / reproducing method capable of detecting a scene change point of 12-segment terrestrial digital broadcasting with high accuracy. For the purpose.

  In order to achieve the above object, a digital broadcast receiving and reproducing apparatus according to an embodiment includes a receiving means for receiving a broadcast wave of a terrestrial digital broadcast including a one-segment broadcast and a 12-segment broadcast, and video data of the one-segment broadcast. A first scene change point detection unit for detecting a scene change point of the one-segment broadcast image by detecting an intra picture having a different appearance period of the intra-picture, and the intra-picture from the video data of the 12-segment broadcast A second scene change point detection unit for detecting a scene change point of an image of the 12-segment broadcast by detecting an intra picture having a different appearance period, and a broadcast time difference between the one-segment broadcast and the 12-segment broadcast A synchronization time detecting unit for obtaining the synchronization time, and the synchronization time Therefore, when there is no scene change point of the 12-segment broadcast image synchronized with the scene change point of the one-segment broadcast image, the 12-segment broadcast image of the 12-segment broadcast is synchronized with the scene change point. A control unit that causes the second scene change point detection unit to detect a picture as a scene change point of the image of the 12-segment broadcast.

1 is a block diagram showing the configuration of an embodiment of a digital broadcast reception / playback apparatus. The figure which showed the structure of the video data encoded as several types of pictures. The figure which showed the example which the scene change point appeared inside the appearance period of I picture. The figure which showed the case where a scene change point corresponds with the appearance period of I picture. The flowchart which showed the operation | movement procedure of the scene change point detection process.

  Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an embodiment of a digital broadcast reception / playback apparatus 1. The antenna 2 is an antenna for terrestrial digital broadcast or satellite digital broadcast for receiving broadcast radio waves transmitted from the broadcast station 29.

  The tuner 3 selects a broadcast signal of a desired channel from broadcast signals of 12-segment broadcasting and one-segment broadcasting of simultaneous terrestrial digital broadcasting or satellite digital broadcasting, and the received broadcast radio wave video signal, audio signal Is demodulated to MPEG-TS (Transport Stream). The tuner 3 is composed of a plurality of tuner units, and can receive a plurality of broadcasts at the same time.

  The demultiplexing processing unit 4 separates into 12-segment MPEG-TS (corresponding to high-vision terrestrial digital broadcasting) 6 and 1-segment MPEG-TS (corresponding to terrestrial digital broadcasting for portable devices).

  The decode processing unit 5 has functions such as an MPEG decoder and a video / audio decoder. The decode processing unit 5 sections the MPEG-TS data transmitted from the demultiplexing processing unit 4 and decodes program information data. Video ES (Packetized Elementary Stream) is converted to video ES (Elementary Stream), and audio PES is converted to audio ES to decode video data and audio data. The decode processing unit 5 decodes the reproduction data from the recording device 18.

  The superimposition processing unit 6 performs plane management of video data from the decoding processing unit 5 and data broadcasting transferred via the bus 12 and window drawing by a GUI (Graphical User Interface) control unit 27 to superimpose the video data. The images are combined and sent to the video processing unit 7.

  The video processing unit 7 converts the format (number of pixels, frame frequency, scanning method) that can be displayed on the display device 8 or arbitrarily adjusts the display color, and outputs it to the display device 8 to display the video on the screen. 9 is displayed.

  The audio processing unit 10 converts the digital audio data transmitted from the decoding processing unit 5 into an analog audio signal that can be reproduced by the speaker 11, and then outputs the analog audio signal to the speaker 11 to reproduce the audio.

  In the digital broadcast receiving / reproducing apparatus 1, all the operations including the above-described receiving operation are comprehensively controlled by the control unit 13. The control unit 13 is equipped with an MPU (Micro Processing Unit) 14 and controls each component connected via the bus 12.

  A RAM (Random Access Memory) 15 is a read / write memory that stores various data necessary for data processing of the control unit 13 and operates as a buffer memory that stores video data and the like. A ROM (Read Only Memory) 16 is a read only memory and stores a control program executed by the MPU 14.

  The flash memory 17 is a non-volatile semiconductor memory that can be rewritten and does not lose data even when the power is turned off. The flash memory 19 has a function of storing recorded program information, recording reservation information, and the like.

  The recording device 18 is a recording device including an HDD (Hard Disk Drive), an SSD (Solid State Drive), an ODD (Optical Disc Drive), or the like. The recording device 18 is equipped with an encoder and a decoder for recording / reproducing information on the recording device, and 12-segment or one-segment MPEG-TS data is modulated via the encoder and decoder and recorded on the HDD, SSD, or ODD. And play again. The reproduction data is decoded by the decoding processing unit 5.

  The external interface 19 is an interface such as USB (Universal Serial Bus), IEEE 1394 (Institute of Electrical and Electronic Engineers 1394), eSATA (external Serial ATA (AT Attachment)), SD (Secure Digital) (registered trademark) memory card, or the like. Yes, an external storage device 20 including drives such as a USB memory, a USB external device, an SD memory card, an HDD, an SSD, a CD-R / RW, and a DVD writer is connected. Broadcast programs can be recorded in the external storage device 20 via the external interface 19. The user can select whether the program is recorded in the recording device 18 or the external storage device 20.

  The operation reception unit 21 receives an operation signal transmitted from the operation device 22 and transfers the operation signal to the control unit 13. The operation device 22 is, for example, a remote controller using a wireless communication such as infrared or Bluetooth, a wired or wireless keyboard, and the like, and transmits an operation signal. The operation receiving unit 21 receives an operation signal from the remote controller, the keyboard, or the like.

  The digital broadcast reception / playback apparatus 1 is connected to a network 30 such as the Internet via a transmission / reception unit 23. As a result, the digital broadcast reception / playback apparatus 1 can perform information transmission via the transmission / reception unit 23 with a device such as the server 31 on the network 30.

  The control unit 13 has functions of a first scene change detection unit 24, a second scene change detection unit 25, and a synchronization time detection unit 26. These functions are applications executed by the MPU 14 of the control unit 13 and are normally stored in the ROM 16 and read and executed by the MPU 14 when used.

  The first scene change detection unit 24 detects a scene change point of a one-segment broadcast image from video data encoded as a plurality of types of pictures of a one-segment broadcast that is being simultaneously broadcast. The detected scene change point is temporarily recorded in the RAM 15.

  The second scene change detection unit 25 detects a scene change point of an image of 12 segment broadcast from video data encoded as a plurality of types of pictures of 12 segment broadcast. The detected scene change point is temporarily recorded in the RAM 15.

  The synchronization time detection unit 26 detects the time difference between the broadcast time of the 12-segment broadcast and the one-segment broadcast that has been simulcast, and calculates the synchronization time. In digital broadcasting, it is necessary to establish synchronization between the reference time of the transmitting side and the receiving side, and the calibration data of the reference time is called PCR (Program Clock Reference) and is included in MPEG-TS. The synchronization time detection unit 26 calculates the time difference between the MPEG-TS PCR of 12-segment broadcasting and the MPEG-TS PCR of one-segment broadcasting transmitted from the demultiplexing processing unit 4, and MPEG-TS of 12-segment broadcasting. And how much the reference time of the broadcast time of MPEG-TS of one-segment broadcasting is shifted, and the synchronization time T is calculated.

  The control unit 13 has the function of the GUI control unit 27. The GUI control unit 27 generates GUI data, and the generated GUI data is transmitted to the superimposition processing unit 6 via the bus 12. The GUI data sent to the superimposition processing unit 6 is superimposed on the video data or processed as a GUI single screen, transmitted to the video processing unit 7 and displayed on the screen 8.

  FIG. 2 is a diagram showing a configuration of video data encoded as a plurality of types of pictures of digital terrestrial broadcasting. FIG. 2A shows the configuration of video data in 12-segment terrestrial digital broadcasting, and FIG. 2B shows the configuration of video data in one-segment terrestrial digital broadcasting. MPEG2 is the video encoding method for 12-segment digital terrestrial broadcasting, and H. H.264 is adopted.

  There are two types of picture encoding methods called intra-picture encoding that encodes only a single picture and inter-picture encoding that uses information on the difference between adjacent pictures. In the case of MPEG2, the former is an I picture (Intra Picture), H.264. In the case of H.264, it is called an IDR picture (Instantaneous Decoding Refresh Picture), and in the case of MPEG2, the latter is called a P picture (Predictive Picture) or B picture (Bidirectionally Predictive Picture). H.264 is called a non-IDR picture. Here, for convenience, the IDR picture is also called an I picture. In FIG. 2B, the non-IDR picture is represented as an N picture.

  In order to decode the encoded video signal, it is necessary to first decode from the I picture. For this reason, in terrestrial digital broadcasting, periodically inserting I-pictures is defined as an operation rule of the ARIB standard.

  The appearance period of 12-segment I-pictures is 0.5 seconds in Japan according to the operating rules of the ARIB standard (ARIB-STD B32). Since the frame rate is 30 frames / second, an I picture appears every 15 frames.

  In Japan, the appearance period of one-segment I-pictures is usually 2 seconds (maximum 5 seconds) according to the operational rules of the ARIB standard (ARIB TR-B14). In the case of 2 seconds, for example, when the frame rate is 15 frames / second, an I picture appears every 30 frames.

  A portion where a video scene is switched is called a scene change. However, since the correlation with the previous picture is low at a scene change point, intra-screen coding is often performed. Therefore, an I picture is often inserted at a scene change point. When a scene change point exists within the appearance cycle of the I picture, the appearance interval of the I picture is different, so that the scene change point can be detected by monitoring the change in the appearance interval of the I picture.

  The first scene change detection unit 24 detects the scene change point of the image of the one segment broadcast by monitoring the change in the appearance interval of the I picture from the video data encoded as a plurality of types of pictures of the one segment broadcast. To do. The second scene change detection unit 25 detects the scene change point of the image of the 12 segment broadcast by monitoring the change in the appearance interval of the I picture from the video data encoded as a plurality of types of pictures of the 12 segment broadcast. .

  FIG. 3 is a diagram showing an example in which a scene change point appears in the appearance cycle of an I picture. In FIG. 3, a frame indicated by A in 12-segment broadcasting is an I picture, which is the ninth frame from the previous I picture indicated by B. Therefore, the second scene change detection unit 25 determines that the frame indicated by A is a scene change point.

  In FIG. 3, the frame indicated by C in the one-segment broadcasting is an I picture, which is the 13th frame from the previous I picture indicated by D. Accordingly, the first scene change detection unit 24 determines that the frame indicated by C is a scene change point.

  If the same scene change point is found from the synchronization time T calculated by the synchronization time detection unit 26, the relationship between the 12-segment broadcast PTS (Presentation Time Stamp) value and the one-segment broadcast PTS value is known. That is, it becomes possible to determine which picture having a PTS value of 12-segment broadcasting corresponds to which picture of PTS value of one-segment broadcasting.

  FIG. 4 is a diagram showing a case where the scene change point coincides with the appearance cycle of the I picture. When a scene change point of a 12-segment broadcast image is detected by monitoring a change in the appearance interval of an I picture, the scene change point cannot be detected if the scene change point matches the appearance period of the I picture. The problem arises. For example, in FIG. 4, when the frames indicated by F, G, and H are scene change points, it is determined as an I picture that appears periodically, and is not determined as a scene change.

  However, in the case of one-segment broadcasting, since the appearance cycle of an I picture is 2 seconds, it can be detected when a picture corresponding to F, G, H is a scene change point. For example, when the frame indicated by E in the one-segment broadcasting is an I picture, the first scene change detection unit 24 determines the frame indicated by E as a scene change point and records it in the RAM 15. The control unit 13 checks whether a scene change point registered in the one-segment broadcasting has a PTS value corresponding to the 12-segment broadcasting registered as a scene change point. Register as a scene change point for Seg broadcasting. Accordingly, the frame indicated by G is registered as a scene change point.

  As described above, scene change points that cannot be detected only by the second scene change detection unit 25 can be detected, and scene change points of 12-segment terrestrial digital broadcasting can be detected with high accuracy.

  The detected scene change point is temporarily recorded in the RAM 15 and then recorded in the recording device 18 as additional data of the broadcast program when the recording device 18 records the broadcast program. When a recorded program is reproduced, it is read out as a scene change point and used for chapter registration and the like.

  FIG. 5 is a flowchart showing the operation procedure of the scene change point detection process. In S11, the second scene change detection unit 25 extracts an I picture whose I picture interval is smaller than the I picture period from video data encoded as a plurality of types of pictures of 12 segment broadcast, and detects it as a scene change point. And register.

  In S12, the first scene change detection unit 24 extracts an I picture whose I picture interval is smaller than the I picture period from video data encoded as a plurality of types of pictures of one-segment broadcasting, and detects it as a scene change point. And register.

  In S13, the synchronization time detection unit 26 calculates the time difference between the MPEG-TS PCR for 12-segment broadcasting and the MPEG-TS for one-segment broadcasting, and MPEG-TS for 12-segment broadcasting and MPEG-TS for one-segment broadcasting. By detecting how much the reference time of TS is deviated, the synchronization time T is calculated. It is possible to determine which picture having a PTS value of 12 segments corresponds to a picture having a PTS value of one segment.

  In S14, the control unit 13 determines whether a frame having a PTS value corresponding to a scene change point registered in the one-segment broadcasting is registered as a scene change point in the 12-segment broadcasting. If it is not registered as a scene change point, the process proceeds to S15, and if it is registered, the process proceeds to S16.

  In S15, the control unit 13 registers a frame having a PTS value corresponding to the scene change point registered in the one-segment broadcasting as a scene change point in the 12-segment broadcasting. In 12-segment broadcasting, if the scene change point coincides with the appearance cycle of the I picture, and the P picture or B picture may be the scene change point, the second scene change detection unit 25 cannot detect it. The scene change point that cannot be detected only by the second scene change detection unit 25 can be detected.

  In S16, the control unit 13 determines whether a frame having a PTS value corresponding to the scene change point registered in the 12-segment broadcast is registered as a scene change point in the one-segment broadcast. If it is not registered as a scene change point, the process proceeds to S17, and if it is registered, the process ends.

  In S17, the control unit 13 sets the scene change point of the 12-segment broadcast in which the frame having the PTS value corresponding to the scene change point registered in the 12-segment broadcast is not registered as the scene change point as the scene change point. Do not. It deletes from RAM15 and complete | finishes. In 12-segment broadcasting, even if an I picture has an I picture interval smaller than the I picture period, it may not be a scene change point, and the second scene change detection unit 25 detects it incorrectly, so the second scene change detection unit 25 This is effective in that scene change points that are erroneously detected can be deleted.

  As described above, the scene change point data of the 12-segment broadcast by the second scene change detection unit 25 is complemented by the data of the scene change point of the one-segment broadcast by the first scene change detection unit 24, so that the second scene The scene change point that cannot be detected by the change detection unit 25 can be detected, and the scene change point erroneously detected by the second scene change detection unit 25 can be deleted, and the scene change point of 12-segment terrestrial digital broadcasting can be increased. It can be detected with accuracy.

  Further, it is not necessary to monitor the amount of generated codes by combining the data of scene change points of one segment, and the load of detecting scene change points can be reduced.

  Note that the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

DESCRIPTION OF SYMBOLS 1 Digital broadcast receiving / reproducing apparatus 2 Antenna 3 Tuner 4 Demultiplexing processing part 5 Decoding processing part 6 Superimposition processing part 7 Video processing part 8 Display apparatus 9 Screen 10 Audio | voice processing part 11 Speaker 12 Bus 13 Control part 14 MPU
15 RAM
16 ROM storage unit 17 Flash memory 18 Recording device 19 External interface 20 External storage device 21 Operation reception unit 22 Operation device 23 Transmission / reception unit 24 First scene change detection unit 25 Second scene change detection unit 26 Synchronization time detection unit 27 GUI control unit 29 Broadcasting station 30 Network 31 Server

Claims (7)

Receiving means for receiving broadcast waves of terrestrial digital broadcasting including one-segment broadcasting and 12-segment broadcasting;
A first scene change point detection unit that detects a scene change point of the image of the one-segment broadcast by detecting an intra-picture different from the appearance period of the intra-picture from the video data of the one-segment broadcast;
A second scene change point detection unit for detecting a scene change point of the image of the 12 segment broadcast by detecting an intra picture different from the appearance cycle of the intra picture from the video data of the 12 segment broadcast;
A synchronization time detector that obtains a broadcast time difference between the one-segment broadcast and the 12-segment broadcast as a synchronization time;
When there is no scene change point of the 12-segment broadcast image synchronized with the scene change point of the one-segment broadcast image based on the synchronization time, the 12 segment synchronized with the scene change point of the one-segment broadcast image A digital broadcast receiving and reproducing apparatus, comprising: a control unit that causes the second scene change point detection unit to detect the picture of the segment broadcast as a scene change point of the image of the 12 segment broadcast.   The control unit, when there is no scene change point of the one-segment broadcast image synchronized with the scene change point of the 12-segment broadcast image based on the synchronization time, the scene change point of the 12-segment broadcast image 2. The digital broadcast receiving / reproducing apparatus according to claim 1, wherein the scene change point is not used.   The first scene change point detection unit detects an intra picture appearance period in the encoded video data of the one-segment broadcast, and when the appearance period becomes shorter than a predetermined period, 3. The digital broadcast receiving / reproducing apparatus according to claim 1, wherein a scene change point is used.   The second scene change point detection unit detects an intra picture appearance period in the encoded video data of the 12-segment broadcast, and when the appearance period becomes shorter than a predetermined period, 3. The digital broadcast receiving / reproducing apparatus according to claim 1, wherein a scene change point is used.   5. The digital broadcast receiving / reproducing apparatus according to claim 1, further comprising a recording device for recording the encoded video data and scene change point data. A receiving step of receiving broadcast waves of terrestrial digital broadcasting including one-segment broadcasting and 12-segment broadcasting;
A first scene change point detection step of detecting a scene change point of the image of the one-segment broadcast by detecting an intra-picture different from the appearance period of the intra-picture from the video data of the one-segment broadcast;
A second scene change point detection step of detecting a scene change point of the image of the 12-segment broadcast by detecting an intra-picture different from the appearance period of the intra-picture from the video data of the 12-segment broadcast;
A synchronization time detecting step for obtaining a broadcast time difference between the one-segment broadcast and the 12-segment broadcast as a synchronization time;
When there is no scene change point of the 12-segment broadcast image synchronized with the scene change point of the one-segment broadcast image based on the synchronization time, the 12 segment synchronized with the scene change point of the one-segment broadcast image And a control step of causing the second scene change point detection unit to detect the picture of the segment broadcast as a scene change point of the image of the 12 segment broadcast.   In the control step, when there is no scene change point of the one-segment broadcast image synchronized with the scene change point of the 12-segment broadcast image based on the synchronization time, the scene change point of the 12-segment broadcast image 6. The digital broadcast receiving / reproducing method according to claim 5, wherein a scene change point is not set.

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