JP2007215068A - Image processing apparatus and method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology of shortening a time required for station selection in terrestrial digital television broadcasting. <P>SOLUTION: A broadcast time error detection section 48 compares a program (frame) of a prescribed channel supplied from an analog tuner section 44 with a program (picture) broadcast through a channel corresponding to the channel selected by the analog tuner section 44 and supplied via a digital tuner section 46 and a decode section 47. Then the broadcast time error detection section 48 measures a time until the picture discriminated to be the same scene is acquired and stores the time to a broadcast time error storage section 49. When the decode section 47 starts decoding, the error stored in the broadcast time error storage section 49 is used, a frame corresponding to the picture required at decode starting is particularized from frames stored in an analog broadcast storage section 45 and the particularized frame is converted into the picture for digital broadcasting. The technology above can be applied to television receivers or the like. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image processing apparatus, method, and program, and more particularly, to an image processing apparatus, method, and program for shortening a time during which a video generated when switching channels is not displayed in terrestrial digital television broadcasting. .

  In recent years, television broadcasting has been switched from terrestrial digital broadcasting to terrestrial digital broadcasting. Until the transition from analog broadcasting to digital broadcasting is complete, programs with the same content are broadcast by analog broadcasting and digital broadcasting (such broadcasting is called simulcast).

  For simulcasting, for example, as described in the Ministry of Internal Affairs and Communications H15.4.6 “Preliminary License for Terrestrial Digital Broadcasting Stations”, the requirement for granting a preliminary license is that the ratio of simulcasting should be 60% or more It is said. That is, at least 60% of programs are broadcast simultaneously.

  FIG. 1 is a diagram illustrating a configuration of an example of a receiving device that receives terrestrial digital broadcasting. The receiving apparatus 10 includes an antenna 11, a tuner unit 12, and a decoding unit 13. The decoding unit 13 includes a demultiplexer 14, a video decoder 15, an audio decoder 16, and a reorder 17.

  The broadcast wave of the digital television broadcast received by the antenna 11 is supplied to the tuner unit 12. The tuner unit 12 selects a channel designated by the user or the like, and extracts data corresponding to the channel. The extracted data is data (transport stream) in which video data and audio data are multiplexed.

  The data extracted by the tuner unit 12 is supplied to the demultiplexer 14 of the decoding unit 13. The demultiplexer 14 separates the supplied data into video data and audio data, and supplies video data (video transport stream) to the video decoder 15 and audio data (audio transport stream) to the audio decoder 16. .

  Data supplied to the video decoder 15 is encoded by a predetermined encoding method. The video decoder 15 performs decoding using a decoding method corresponding to the supplied data. The video data decoded by the video decoder 15 is supplied to the reorder 17. The decoding process performed by the video decoder 15 and the reorder 17 will be described later with reference to FIG.

  Data supplied to the audio decoder 16 is encoded by a predetermined encoding method. The audio decoder 16 performs decoding using a decoding method corresponding to the supplied data. The audio data decoded by the audio decoder 15 is supplied to another device (for example, a speaker) not shown.

  FIG. 2 is a diagram for explaining the decoding process performed by the video decoder 15 and the reorder 17. Video data in terrestrial digital broadcasting is encoded and decoded by the MPEG (Motion Picture Experts Group) -2 system. In the MPEG system, three types of pictures are defined: I picture, B picture, and P picture.

  An I picture is an intra coded picture, and is a picture (frame) for intra (intra-screen) coding that is coded independently of other screens. The P picture is a predictive coded picture, is a forward predictive coding screen, and is a picture that is coded by performing predictive coding from an I picture located in the past in time. A B picture is a bi-directionally predictive coded picture, which is a bi-directional predictive coding picture, and is predictive coded from a forward, backward, or bi-directional picture using I pictures or P pictures that are positioned in front and back in time. This is a picture that is encoded by performing.

  In FIG. 2, the notation “I” indicates an I picture, the notation “B” indicates a B picture, and the notation “P” indicates a P picture. The I1 picture is encoded independently in the screen. The B2 picture is encoded with reference to the I1 picture and the P3 picture. The P3 picture is encoded with reference to the I1 picture. The B4 picture is encoded with reference to the P3 picture and the P5 picture. Further, the P5 picture is encoded with reference to the P3 picture.

  In this way, B pictures and P pictures other than I pictures are encoded by referring to other pictures. Similarly for decoding, an I picture is decoded using only I picture data, while a B picture and a P picture are decoded by referring to other pictures.

  FIG. 3 is a diagram for explaining the timing at which video data such as an I picture arrives and the timing at which decoding is started in the receiving apparatus 10. As described above, the video data is data composed of an I picture, a B picture, and a P picture. These pictures are grouped by a predetermined number. Such a group is referred to as a GOP (Group Of Picture), and one GOP includes one I picture and a predetermined number of B pictures and P pictures.

  As shown in FIG. 3, it is assumed that reception is started at time T1, for example, when the power is turned on or a channel change is instructed. At time T1, a B2 picture is received, and subsequent pictures are sequentially received. In this case, the I1 picture included in GOP1 has not been received. Therefore, GOP1 including the I1 picture cannot be decoded. In other words, the received B2 to B15 pictures (including P pictures such as P4 pictures) included in GOP1 cannot be decoded because there are no I pictures.

  Therefore, even if reception is started from the B2 picture included in GOP1, GOP1 cannot be decoded, and as a result, decoding is started from GOP2 received at the timing next to GOP1. That is, in FIG. 3, decoding starts at time T2 after the I16 picture is received.

  As described above, the timing at which decoding is started differs depending on the timing at which reception is started (the timing at which a channel is selected). Therefore, in the situation as shown in FIG. 3, the decoding is not performed from time T1 to time T2, and there is no image provided to the user. Here, such a time is appropriately described as a delay time.

  The cause of the time when images are not provided to the user is not only due to the timing of such decoding, but, for example, in digital terrestrial broadcasting described in ARIB (Association of Radio Industries and Businesses) standard STD-B32. Based on the maximum value of the processing time required for channel selection, 500 ms out of about 2300 ms is the delay time due to such decoding timing.

In order to shorten such a delay time, Patent Document 1 discloses a terrestrial analog broadcast program broadcast as a simulcast broadcast of a selected broadcast station during the terrestrial digital broadcast channel selection process. It is described that an EPG (Electric Program Guide) is used for searching, and the searched terrestrial analog broadcast program is broadcast until the terrestrial digital broadcast program can be reproduced (decoded).
JP 2001-285552 A

  As described above, in terrestrial digital broadcasting, there is a time when an image (video) is not provided to the user at the time of channel selection. The time is 2 seconds or more at the maximum. If the video is not displayed at the time of channel selection, the user thinks that the channel selection has not been processed successfully, and that the user has operated the same button again (struck repeatedly), switched to another channel, etc. Will be processed. In other words, if there is a delay time, it causes anxiety to the user and causes an extra operation to be performed.

  Also, even if terrestrial analog broadcasting and terrestrial digital broadcasting are simulcast, in other words, even if they are transmitted simultaneously, the same scene of the same program is not provided to the user at the same time. . Specifically, since terrestrial digital broadcasting includes processing (for example, encoding and decoding) that is not terrestrial analog broadcasting at the time of transmission and reception, a predetermined scene (referred to as scene A) of terrestrial digital broadcasting is included. Is received (provided to the user) after scene A of the terrestrial analog broadcasting.

  That is, when the method proposed in Patent Document 1 is applied, after the scene A in the terrestrial analog broadcast is provided to the user, the user is switched to the terrestrial digital broadcast and the scene A is provided again. Happens. The fact that the same scene is provided to the user twice in this way may cause the user to misunderstand that the scene A has been broadcast twice in the broadcast itself, or to give a sense of anxiety as if it was out of order. Might give you. Therefore, it is not preferable.

  The present invention has been made in view of such a situation. By not acquiring a reference picture, the above-described situation in which the user feels uncomfortable does not occur.

  An image processing apparatus according to an aspect of the present invention selects a broadcast station storage unit that stores data associated with broadcast stations that broadcast the same program in different formats, and a first broadcast station that broadcasts in the first format And a second broadcasting station that broadcasts in the second system associated with the first broadcasting station when channel selection means instructs the channel selection means to select the first broadcasting station. Specifying means for referring to the data stored in the broadcast station storage means, program storage means for storing program data from the second broadcast station, and from the first broadcast station Error storage means for storing a temporal error for providing the same scene in the program and the program from the second broadcast station, and the first broadcast station selected by the first channel selection means From the time channel selection was started, the data necessary to process the program from Acquisition means for acquiring from the program data from the second broadcast station stored in the program storage means at a time prior to the error stored in the recording error storage means, and specified by the specifying means; Conversion means for converting the data acquired by the acquisition means so as to become an image similar to an image based on the data of the first method.

  The acquisition unit may acquire data serving as a reference picture.

  When the first data of the program from the first broadcasting station is matched with the second data of the program from the second broadcasting station, and the matching result is equal to or greater than a predetermined threshold, the first data The second data and the second data are determined to be the same scene data, and the difference between the time when the first data and the second data determined to be the same scene are respectively acquired. , And can be stored in the error storage means.

  The program storage means may store programs from a plurality of the second broadcast stations from a time point before the first broadcast station is selected by the first channel selection means.

  An image processing method or program according to an aspect of the present invention includes a broadcasting station management step for managing data associated with broadcasting stations that broadcast the same program in different formats, and a first broadcasting station that broadcasts in the first format. When a channel selection step for channel selection and channel selection of the first broadcast station in the process of the channel selection step are instructed, a second broadcast is performed in the second scheme associated with the first broadcast station. A specifying step of specifying two broadcasting stations with reference to the data managed in the broadcasting station management step, a program storage control step of controlling storage of program data from the second broadcasting station, An error storage control step for controlling storage of temporal errors for providing the same scene in the program from the first broadcast station and the program from the second broadcast station, and the first channel selection step Selected by The program storage control step is performed at a time point before the error is controlled in the error storage control step from the time point when the channel selection is started. The acquisition is acquired from the program data from the second broadcasting station specified in the specifying step, and the data acquired in the processing of the acquiring step is stored in the first method. A conversion step for converting the image into an image similar to the image based on the data.

  In the image processing apparatus and method and the program according to one aspect of the present invention, when the first broadcast station is selected, data from the second broadcast station corresponding to the first broadcast station is stored, From the second broadcasting station required to decode the data from the first broadcasting station in consideration of the temporal error in which the same scene is provided by the first broadcasting station and the second broadcasting station Is selected from the stored data, an image based on the selected data is used as a reference picture, and data from the first broadcasting station is processed.

  According to one aspect of the present invention, even when a reference picture is not acquired, it is possible to perform the same processing as when a reference picture is acquired.

  Embodiments of the present invention will be described below. Correspondences between constituent elements of the present invention and the embodiments described in the specification or the drawings are exemplified as follows. This description is intended to confirm that the embodiments supporting the present invention are described in the specification or the drawings. Therefore, even if there is an embodiment which is described in the specification or the drawings but is not described here as an embodiment corresponding to the constituent elements of the present invention, that is not the case. It does not mean that the form does not correspond to the constituent requirements. Conversely, even if an embodiment is described here as corresponding to a configuration requirement, that means that the embodiment does not correspond to a configuration requirement other than the configuration requirement. It's not something to do.

  The image processing apparatus according to one aspect of the present invention (for example, the receiving apparatus 30 in FIG. 4) is a broadcasting station storage unit (for example, the simultaneous in FIG. Broadcast station storage unit 42), channel selection means (for example, digital tuner unit 46 in FIG. 4) for selecting a first broadcast station to be broadcast in the first system, and channel selection of the first broadcast station. When instructed by the channel selection means, refer to the data stored in the broadcast station storage means for a second broadcast station that broadcasts in the second system associated with the first broadcast station. Identification means (for example, the simulcast station storage unit 42 in FIG. 4), and program storage means (for example, the analog broadcast storage unit 45 in FIG. 4) for storing program data from the second broadcast station; , Programs from the first broadcast station and the second broadcast The error storage means (for example, the broadcast time error storage section 49 in FIG. 4) that stores the temporal error for providing the same scene in the program from the above, and the channel selected by the first channel selection means Data necessary for decoding the program data from the first broadcasting station is stored in the program storage means at a time before the error stored in the error storage means from when the channel selection is started. The acquisition means (for example, the decoding unit 47 in FIG. 4) that is stored and acquired from the data of the program from the second broadcasting station specified by the specifying means, and the data acquired by the acquisition means, Conversion means (for example, the conversion unit 50 in FIG. 4) for converting the image so as to be the same as the image based on the data of the first method is provided.

  A conversion unit (for example, the conversion unit 50 in FIG. 4) that converts the data acquired by the acquisition unit into an image similar to the image based on the data of the first method can be further provided.

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

  FIG. 4 is a diagram showing a configuration of an embodiment of a receiving apparatus to which the present invention is applied. The receiving device 30 shown in FIG. 4 has a function of receiving and processing a program based on terrestrial analog television broadcasting and a program based on terrestrial digital television broadcasting. Hereinafter, “terrestrial analog television broadcasting” will be described as “analog broadcasting”, and “terrestrial digital television broadcasting” will be described as “digital broadcasting” where appropriate.

  Here, the description is continued as a receiving device 30 that processes two broadcasts of analog broadcasting and digital broadcasting. However, the receiving device 30 is a device that can process two or more broadcasts that broadcast a program in different manners. The present invention can be applied as an apparatus incorporated in a device that processes television broadcasting such as a John receiver, a set top box (STB), or a hard disk recorder.

  4 includes an operation unit 41, a simulcast station storage unit 42, a control unit 43, an analog tuner unit 44, an analog broadcast storage unit 45, a digital tuner unit 46, a decoding unit 47, and a broadcast time error detection unit. 48, a broadcast time error storage unit 49, and a conversion unit 50. The analog tuner unit 44 of the receiving device 30 is connected to an antenna 31 that receives analog broadcasts, and the digital tuner unit 46 is connected to an antenna 32 that receives digital broadcasts.

  The receiving device 30 is configured to perform processing for eliminating (shortening) time during which video (image) is not provided to the user side during processing related to channel selection for digital broadcasting. Further, at the time of channel selection, a process is performed in which an inconvenient situation in which the same scene is provided to the user in duplicate does not occur and the channel is switched without causing a sense of incongruity.

  The operation unit 41 may be incorporated in the same housing as the receiving device 30 or may be a separate body (commonly, a device called a remote controller). The operation unit 41 is provided to transmit an instruction from the user to the receiving device 30. Here, the following description will be continued on the assumption that the instruction from the user is an instruction for selecting a broadcasting station broadcasting the program desired by the user.

  An instruction from the operation unit 41 is supplied to the control unit 43. The control unit 43 controls each unit of the receiving device 30 based on an instruction from the user (for example, controls processing when a digital broadcast channel is changed as described later) and an instruction from the user. Even when there is no signal, a predetermined process is controlled (for example, as described later, a process related to a broadcast time error is controlled).

  The simulcast station storage unit 42 stores an analog broadcast channel of a predetermined broadcast station (hereinafter referred to as an analog broadcast station as appropriate) and a digital broadcast channel (hereinafter described as a digital broadcast station as appropriate) in association with each other. is doing.

  Simul broadcasting means broadcasting a program broadcasted by analog broadcasting as a digital broadcasting program. The same broadcasting program differs from simulcasting station by analog broadcasting and digital broadcasting (the same program is different). It is a broadcasting station that broadcasts in (system).

  Based on an instruction from the control unit 43, the analog tuner unit 44 selects a program from an analog broadcasting station from among programs from a plurality of receivable broadcasting stations. An antenna 31 is connected to the analog tuner unit 44, and programs from a plurality of analog broadcasting stations are received by the connected antenna 31 and supplied to the analog tuner unit 44.

  The antenna 32 is also connected to the digital tuner unit 46 so that programs from a plurality of digital broadcasting stations are received (supplied). FIG. 4 shows a configuration required for the following description, and portions not related to the following description are omitted as appropriate.

  The program by the analog broadcast station selected by the analog tuner unit 44 is supplied to the analog broadcast storage unit 45 and stored therein. The analog broadcast storage unit 45 stores analog broadcast programs (frames) for a predetermined time. Hereinafter, program data from an analog broadcasting station is described as a frame. The frame stored in the analog broadcast storage unit 45 is supplied to the conversion unit 50 according to an instruction from the decoder unit.

  The conversion unit 50 converts the frame supplied from the analog broadcast storage unit 45 into digital broadcast program data (pictures) and supplies the data to the decoder unit 47. Hereinafter, program data from a digital broadcasting station is described as a picture. At this time, it may be supplied to the display.

  Based on an instruction from the operation unit 41, the digital tuner unit 46 selects a program from a digital broadcast station from among a plurality of receivable broadcast stations and supplies the selected program to the decoding unit 47. Since the data from the digital tuner unit 46 is encoded (encoded), the decoding unit 47 decodes the supplied data. The data (picture) decoded by the decoding unit 47 is supplied to a display (not shown).

  The broadcast time error detection unit 48 is supplied with the program (frame) from the analog tuner unit 44 and the picture decoded by the decoding unit 47. As will be described in detail later, the broadcast time error detection unit 48 detects a temporal error (difference) when the same scene is broadcast in the analog broadcast and the digital broadcast from the supplied frame and picture. The detected error is supplied to the broadcast time error storage unit 49.

  The broadcast time error storage unit 49 supplies the stored error to the decoding unit 47 in accordance with an instruction from the control unit 43.

  FIG. 5 is a diagram illustrating an internal configuration example of the decoding unit 47. The decoding unit 47 includes an inverse quantization unit 61, an inverse DCT (Discrete Cosine Transform) unit 62, an addition unit 63, and a reference image storage unit 64. Data from the digital tuner unit 46 is supplied to the inverse quantization unit 61. The supplied data is data encoded on the transmission side, and the encoding is executed by performing discrete cosine transform (DCT) or quantization.

  The discrete cosine transform is performed, for example, by performing a two-dimensional discrete cosine transform on the difference between the motion compensated image and the image to be processed with a block size of 8 × 8 pixels. The DCT transform coefficient generated by the discrete cosine transform is quantized using a matrix table or the like.

  The inverse quantization unit 61 generates a DCT transform coefficient from the supplied data by executing a process reverse to the quantization process on the encoding side. The generated DCT transform coefficient is supplied to the inverse DCT unit 62. The inverse DCT unit 62 calculates a pixel value (luminance or color difference) from the supplied DCT conversion coefficient by executing a process reverse to the DCT conversion process on the encoding side. The calculated pixel value is supplied to the adding unit 63.

  The pixel value supplied to the adding unit 63 is a difference value from other pictures. As described with reference to FIG. 2, for example, the data related to the P3 picture is a difference value from the I1 picture. In order to decode the P3 picture, the difference value from the I1 picture is added to the data of the I1 picture. It is necessary to add. Therefore, the addition unit 63 adds the difference value from the inverse DCT unit 62 to the reference image (the picture that has already been decoded) stored in the reference image storage unit 64 to thereby process the picture to be processed. Are generated.

  The output from the adding unit 63 is output to a display not shown. The output from the adding unit 63 is stored in the reference image storage unit 64 as data of a picture for which decoding has been completed. Further, the output from the addition unit 63 is also supplied to the conversion unit 50.

  An operation of the receiving apparatus 30 having such a configuration will be described. When a broadcasting station for digital broadcasting is selected, the receiving device 30 acquires time required for the processing of the channel selection (data required until decoding is started and an image is provided to the user). (Time) is shortened, and the channel is switched so as not to give the user a sense of incongruity at the time of channel selection.

  As described with reference to FIGS. 2 and 3, for example, when decoding data encoded in MPEG2, if an I picture included in a GOP is not acquired, a picture included in the GOP is decoded. I can't. Therefore, if there is a time during which such a decoding process cannot be started, a time during which an image cannot be provided to the user side occurs (longens). Processing that shortens such time is executed in the receiving device 30.

  The operation of the receiving device 30 will be described with reference to the flowchart of FIG. The process of the flowchart of FIG. 6 is executed when a user selects a digital broadcast station.

  In step S11, an analog broadcast station corresponding to the digital broadcast station designated by the user is specified. When the operation unit 41 is operated, a signal representing an instruction from the user is supplied from the operation unit 41 to the control unit 43. The control unit 43 analyzes the supplied signal, and in this case, specifies the instructed digital broadcasting station and supplies the digital tuner unit 46 and the analog tuner unit 44 with a signal for selecting the specified broadcasting station. To do. The analog tuner unit 44 refers to the simulcast station storage unit 52 and specifies an analog broadcast station corresponding to the digital broadcast station selected as a channel selection target.

  In order to execute such processing, the simulcast station storage unit 42 stores a table in which digital broadcast stations and analog broadcast stations are associated with each other. Although the description will be continued here assuming that the table is stored, the relationship between the digital broadcast station and the analog broadcast station may be stored (managed) in a format other than the table. Such a table may be stored in the simulcast station storage unit 42 when the receiving device 30 is manufactured, or acquired when the receiving device 30 is actually used on the user side. It may be stored.

  When the table is acquired when the receiving device 30 is actually used on the user side, for example, the table is also included in the data broadcast by analog broadcasting or digital broadcasting (for example, EPG data). The broadcast table may be received by the receiving device 30 and stored in the simulcast station storage unit 42 in the same format as that of the program.

  Or, for example, one frame of a predetermined program from a broadcasting station selected by the analog tuner unit 44 is compared with a picture decoded by the decoding unit 47, and there is a broadcasting station that has a frame and a picture determined to be the same. A table may be created by associating each other with the broadcast time error detection unit and stored in the simultaneous broadcast station storage unit 42.

  Alternatively, a table may be created by referring to the EPG and searching between broadcast stations broadcasting the same program (broadcast stations broadcasting the same program name by text search or the like). . Furthermore, a mechanism set by the user may be provided.

  Alternatively, it may be acquired via a network such as the Internet. Further, data such as EPG necessary for creating a table may be acquired via a network.

  As described above, the simulcast station storage unit 42 stores a table in which analog broadcast stations and digital broadcast stations are associated (that is, data of broadcast stations that perform simulcasting are stored). The stored table is referred to by the analog tuner unit 44, whereby an analog broadcast station corresponding to the digital broadcast station is specified.

  In step S12, the analog tuner unit 44 selects an analog broadcast station identified with reference to a table stored in the simultaneous broadcast station storage unit 42, and a program (frame) by the selected analog broadcast station is selected. The data is stored in the analog broadcast storage unit 45. In this way, analog broadcast frames for a predetermined time are stored in the analog broadcast storage unit 45.

  The analog broadcast frames are stored in the analog broadcast storage unit 45. The storage may store all frames for a predetermined time, for example, one frame every two frames. You may do it. Further, when it can be determined that the video has little change, a representative frame may be selectively stored.

  In step S13, the digital tuner unit 46 selects a digital broadcasting station indicated by the signal from the control unit 43.

  The process in the digital tuner unit 46 and the process in the analog tuner unit 44 are performed in parallel. That is, in the flowchart of FIG. 6, for convenience of explanation, it is described that the processing is executed in time series, but the processing of step S11 and step S12 is executed by the analog tuner unit 44 and the like. Processing in the digital tuner unit 46 and the like after step S13 is also executed.

  In step S14, the decoding unit 47 determines whether the picture to be decoded is a picture without a reference picture. A picture without a reference picture is a picture that can be decoded without referring to another picture. In the case of MPEG decoding, it is an I picture.

  Therefore, in other words, in step S14, the picture to be decoded by the decoding unit 47 (the data of the selected digital broadcast program supplied from the digital tuner unit 46) is an I picture. This is a process for determining whether or not there is.

  If it is determined in step S14 that the picture to be decoded by the decoding unit 47 is a picture having no reference picture (I picture), the process proceeds to step S21. If the picture to be decoded is an I picture, it is in a state where decoding can be started with only that picture, so decoding is started in step S21.

  On the other hand, when it is determined in step S14 that the picture to be decoded is not a picture (I picture) having no reference picture in the decoding unit 47, in other words, in this case, it is a B picture or a P picture. If it is determined, the process proceeds to step S15.

  In step S15, the control unit 43 determines whether there is an analog broadcast program that matches the digital broadcast. The control unit 43 performs the determination in step S15 by confirming the EPG, for example.

  For example, the control unit 43 reads the program name of the program broadcast on the analog broadcast station selected by the analog tuner unit 44 from the EPG, and similarly, the digital broadcast station selected by the digital tuner unit 46 The program name of the program broadcasted in is read from the EPG, and it is determined whether or not the program name is the same, thereby determining in step S14. It should be noted that the determination of whether or not the program names are the same does not require a strict determination such as determining whether or not the program names completely match (accuracy may be low). . This is because the present invention has a function of checking the error even if the determination in step S15 is wrong in the subsequent processing.

  If it is determined in step S15 that there is no analog broadcast program that matches the digital broadcast program, the process proceeds to step S16. In step S16, the process is put on standby until a picture without a reference picture, that is, in this case, an I picture is received. When the I picture is received, the process proceeds to step S21, and decoding is started.

  On the other hand, in step S15, when it is determined that there is an analog broadcast program that matches the digital broadcast program, that is, when it is determined that the simulcast is being performed, such a determination result is received from the control unit 43. The information is transmitted to the decoding unit 47, and the process proceeds to step S17. In step S17, decoding information is acquired. The decoding unit 47 obtains decoding information necessary for decoding the picture (in this case, a B picture or a P picture) supplied from the digital tuner unit 46 (FIG. 4). The decoding information is acquired by, for example, counting the number of blocks of the supplied picture, information that stores the sequence header included in the MPEG data that was previously selected.

  In step S18, an error is acquired. The decoding unit 47 acquires an error from the broadcast time error storage unit 49. The acquired error is a value indicating how many seconds after the same scene is broadcast by analog broadcasting, the digital scene is broadcast.

  In general, even if the same scene is broadcast at the same timing in analog broadcasting and digital broadcasting, the scene is provided to the user side in digital broadcasting at a later timing than in analog broadcasting. Digital broadcasting includes processing different from analog broadcasting, for example, encoding processing is performed on the transmission side and decoding processing is performed on the reception side. As a result, a deviation (error) occurs in the timing.

  Such an error is detected by the broadcast time error detection unit 48 (the processing relating to this detection will be described later with reference to the flowchart of FIG. 8) and stored in the broadcast time error storage unit 49. In step S18, an error is acquired from the broadcast time error storage unit 49.

  In step S19, a frame to be a picture target is specified. The decoding unit 47 specifies a frame to be a reference picture such as an I picture or a P picture among the frames stored in the analog broadcast storage unit 45. For example, referring to FIG. 3, when reception is started from a B2 picture, frames that become an I1 picture and a P4 picture are specified from the frames stored in the analog broadcast storage unit 45.

  This specification is performed based on the error acquired in step S18. That is, a frame at a time before the time when the process is performed and a time obtained by adding the time to the required picture and the error is specified as a frame that is a target of the picture. This will be described with reference to FIG.

  The upper side of FIG. 7 represents a frame in analog broadcasting, and the lower side of FIG. 7 represents a picture in digital broadcasting. When an instruction to select a digital broadcast station is given by the user at time t1, reception of analog broadcast is started at time t2. That is, between time t1 and time t2, based on a signal from the operation unit 41, the simulcast station storage unit 42 uses an analog corresponding to a digital broadcast station based on a table held by the simulcast station storage unit 42. A broadcast station is specified, the specified analog broadcast station is selected by the analog tuner unit 44, and frame storage in the analog broadcast storage unit 45 is started. Here, the description will be continued on the assumption that an analog broadcast station corresponding to a digital broadcast station is specified based on the table, but other methods based on the table (a specific example will be described later) are performed. May be.

  The analog broadcast frames are stored in the analog broadcast storage unit 45 in order from the frame A4 by starting the processing described above after time t2.

  Processing by the digital tuner unit 46 (processing by the decoding unit 47) is started at time t3. From time t3, the digital tuner unit 46 selects a digital broadcast station designated by the user and receives a program from the selected digital broadcast station. Then, the pictures are supplied to the decoding unit 47 in order from the picture D5.

  The decoding unit 47 cannot start decoding unless the supplied picture D5 is an I picture. As shown in FIG. 7, it is assumed that the picture D5 is a picture that is decoded with reference to the picture D4 (in FIG. 7, an arrow from the picture D5 to the picture D4 indicates a reference relationship).

  In FIG. 7, a frame and a picture connected by dotted arrows indicate that they are the same scene. For example, the frame A3 and the picture D3 are the same scene (picture). For example, the frame A7 and the picture D7 are the same scene. The time from when the frame A7 is received until the picture D7 is received is the broadcast time error. That is, a time difference in which the same scenes of the frame A7 and the picture D7 are processed is a broadcast time error.

  At time t3, the picture D5 is received and decoding is started. However, since the picture D5 is decoded by referring to the picture D4, the picture D5 cannot be decoded unless the picture D4 is acquired. Therefore, an analog broadcast frame A4 that is the same scene as the digital broadcast picture D4 is specified as a frame to be converted into a picture.

  In such a case, the frame received (processed) at the time before the picture D4 by the broadcast time error is identified as the frame A4. As described above, an analog broadcast frame acquired at a time before the required picture by the broadcast time error is specified as a frame to be a picture target.

  In step S20, the frame specified in step S19 is converted into a picture. That is, the analog broadcast frame is converted into a digital broadcast picture by the conversion unit 50.

  For example, pixel interpolation is performed to convert an SD image into an HD image. Also, analog broadcasts and digital broadcasts may have different aspect ratios, so in analog broadcasts, the aspect ratio can be adjusted by cutting off the left and right sides of the digital broadcast video or adding blank bands on the top and bottom sides. Processing is performed. As an inverse conversion of such conversion, analog broadcasting can be performed by changing the aspect ratio of the video clipped on the left and right sides, or removing the blank band for video with blank bands added on both sides. Even if the program is used as a digital broadcast program in a pseudo manner, it is possible to provide a video without causing the user to feel uncomfortable.

  In step S21, the decoding unit 47 starts decoding. Even when only a B picture or a P picture is received, the decoding unit 47 is supplied with the picture converted by the conversion unit 50, and the picture is a picture corresponding to an I picture or P picture as a reference picture. Therefore, it is possible to decode a received B picture or P picture by using a picture corresponding to the reference picture as a reference picture instead.

  By performing the processing in this way, it is possible to prevent the occurrence of an inconvenient state in which the received B picture or P picture cannot be decoded because the reference picture could not be received as in the prior art. Become. Therefore, it is possible to shorten an inconvenient time that an image is not provided to the user during processing related to channel selection during digital broadcasting.

  By the way, when the decoding unit 47 (FIG. 5) performs decoding, decoding information such as a quantization matrix (quantization information) required when the inverse quantization unit 61 executes an inverse quantization process is necessary. is there. Information relating to quantization and information such as image size are described in a sequence header existing (received) before the I picture.

  When the I picture cannot be acquired, the sequence header cannot be acquired. When the sequence header cannot be obtained, the quantization information included in the sequence header cannot be obtained, so the inverse quantization unit 61 (FIG. 5) assumes (sets) a default value as a quantization matrix, Inverse quantization is performed with the default value.

  However, if the set default value is different from the value that should be set originally (when the assumption is wrong), the inverse quantization process cannot be performed correctly. As a result, An inappropriate image will be provided to the user.

  In the present embodiment, as described above, even when a reference picture cannot be obtained, a picture corresponding to the reference picture can be obtained from the corresponding analog broadcast program, and the obtained reference picture from the analog broadcast is obtained. Are used to process B pictures and P pictures acquired from digital broadcasting. However, as described above, when the sequence header is not acquired, there is a possibility that the inverse quantization process is executed with incorrect quantization information.

  In the present embodiment, it is possible to prevent the inverse quantization due to such erroneous quantization information. That is, the conversion unit 50 (FIG. 5) compares the data decoded with the default value (the data output from the addition unit 63) with the data read from the analog broadcast storage unit 45, so that correct decoding is performed. Judge whether or not.

  For example, if decoding is performed with an incorrect default value, the data output from the adder 63 and the data read from the analog broadcast storage unit 45 are different. In such a case, the data is decoded with an incorrect default value. Can be judged. When it is determined that it has been decoded with an incorrect default value, the correct value is inferred. The conversion unit 50 estimates a value such that the data from the addition unit 63 matches (becomes close to) the data read from the analog broadcast storage unit 45 and supplies the estimation result to the inverse quantization unit 61. To do.

  Such processing is executed, for example, as processing when a frame is converted into a picture in step S20.

  Thus, in the present embodiment, even if it is decoded with incorrect information, it can be corrected, so that it is possible to reduce the probability of providing an inappropriate picture to the user. Become. Such correction includes correction of determination of whether or not simultaneous broadcasting (determination in step S15), as well as other decoding information such as the screen size.

  Next, a method for acquiring the error (broadcast time error) acquired in step S18 will be described. The broadcast time error is detected by the broadcast time error detection unit 48 (FIG. 4) and stored in the broadcast time error storage unit 49. Error detection by the broadcast time error detection unit 48 will be described with reference to the flowchart of FIG.

  In step S <b> 41, the broadcast time error detection unit 48 (FIG. 4) acquires a frame from the analog tuner unit 44. The broadcast time error detection unit 48 determines an analog broadcast station and a digital broadcast station that detect errors. For example, the error is detected periodically, and when the error detection period comes, the processing is sequentially performed from the top broadcast station in the table stored in the simultaneous broadcast station storage unit 42. Set it.

  When processing is started (a frame is acquired), EPG or the like is referred to, and it is determined whether or not the same program is being broadcast by analog broadcasting and digital broadcasting, and the same program is being broadcast. When it is determined that the frame is acquired, a frame may be acquired. As will be described later, since an error is acquired by detecting the same scene in analog broadcasting and digital broadcasting, the same scene needs to be broadcast, and the same program is broadcast. It is necessary.

  In step S41, a frame is acquired, and in step S42, time measurement is started. In step S43, the channel of the digital tuner unit 46 is selected for a digital broadcasting station corresponding to the analog broadcasting station selected by the analog tuner unit 44, and a picture is acquired. The picture acquired by the broadcast time error detection unit 48 is a picture decoded by the decoding unit 47.

  In this way, the broadcast time error detection unit 48 acquires a frame from the analog tuner unit 44 and acquires a picture from the decoding unit 47. In step S44, the broadcast time error detection unit 48 compares the acquired frame with the picture. As a result of this comparison, it is determined in step S45 whether or not the scenes are the same.

  This comparison and determination is performed by, for example, matching processing. For the matching part, the entire frame or picture or a part thereof is used. If a portion is used, it may be preferable to use the central portion. As described above, analog broadcasting and digital broadcasting have different aspect ratios, so the left and right and top and bottom of the video may be cut off and bands may be added, so such processing can be performed. It is considered that it is a preferable form to use the inferior center portion for the matching process.

  The matching may be performed, for example, by comparing pixels within a predetermined range in the center portion of the frame and the picture and calculating the ratio of matching pixels. If this ratio is larger than the value set as the threshold value, the scenes are set to be determined to be the same.

  By such a method, it is determined whether or not the scenes are the same. In step S45, it is determined whether or not the scenes can be determined to be the same. If it is determined that the scenes are not the same, the process returns to step S43 and the subsequent processes are repeated. That is, by returning the process to step S43, a new picture is acquired, and the picture is compared with the already acquired frame to determine whether or not they are the same scene.

  As described above, since the same scene is processed later in digital broadcasting than in analog broadcasting, one scene (frame) of analog broadcasting is fixed and the same scene as that scene is detected from digital broadcasting. Such processing is performed.

  On the other hand, if it is determined in step S45 that it is possible to determine the same scene as a result of the comparison between the acquired frame and the picture, the process proceeds to step S46. In step S46, time measurement is stopped, and the time at that time (the time from when a frame is acquired until a picture that is determined to be the same scene is acquired) is set as a broadcast time error. The The set error is associated with the digital broadcast station and stored in the broadcast time error storage unit 49.

  In addition, a broadcast time error may be detected by comparing temporal changes in feature quantities such as luminance and color, and the intensity and / or frequency of voice.

  Such processing is performed for each digital broadcasting station. In addition, for example, if such a process is set to be executed when the user does not use the receiving device 30 (when the user does not view the television broadcast), the use of the user is affected. Can be done without giving.

  As described above, the decoding unit 47 cannot perform decoding unless it has received an I picture (the process of the flowchart of FIG. 6 is executed after the process of the flowchart of FIG. 8 is executed and an error is acquired). Since the process is performed, at the stage where the error is acquired, the decoding unit 47 cannot start decoding unless an I picture is acquired.

  In consideration of such a situation, the processing of the flowchart shown in FIG. 8 is in a state where decoding can be started, that is, after the I picture is acquired, the decoding unit 47 starts decoding and can continue decoding. After that, the processing after step S41 may be performed.

  In this way, the broadcast time error is acquired. Then, using the acquired broadcast time error, the processing at the time of channel selection of the digital broadcast station is executed as described above.

  By the way, at the timing shown in FIG. 7, a digital broadcast picture can be generated using an analog broadcast frame. That is, the time between the output (time t3) from the digital tuner unit 46 (FIG. 4) and the output (time t2) from the analog tuner unit 44 is a broadcast time error (in this case, a time corresponding to about 3 frames). ) And the reference picture (in this case, the picture D4), if it is larger than the sum of the temporal distances (in this case, the distance between D4 and D5), the substitute picture of the reference picture from the analog broadcast (in this case, the frame A4) Can be obtained.

  However, in the case of the state shown in FIG. 9, in other words, unlike the state shown in FIG. 7, when the output timing from the analog tuner unit 44 is the timing at which the frame A5 is acquired, Since the above condition is not satisfied, a substitute image for the reference picture cannot be acquired.

  Referring to FIG. 9, the substitute image for picture D4 is frame A4, but after analog tuner output start time t2, frame A5 is received and frame A4 is not received. Therefore, in such a situation, the frame A4 cannot be acquired.

  Even in such a situation, the analog tuner unit 44 and the analog broadcast storage unit 45 of the receiving device 30 may be configured as shown in FIG. 10 so that a substitute image can be acquired. The analog tuner unit 44 shown in FIG. 10 includes N tuner units, analog tuner units 44-1 to 53-N. Similarly, the analog broadcast storage unit 45 includes N storage units called analog broadcast storage units 45-1 to 54-N.

  In this way, by providing a plurality of tuner units and storage units, it is possible to prevent a situation in which a substitute image cannot be acquired. That is, as shown in FIG. 10, if a plurality of analog tuner units 44-1 to 53-N are provided, it is possible to receive an analog broadcast from a point before the digital broadcast station is selected. It becomes.

  For example, if analog tuners 44 are provided as many as the number of assumed analog broadcast stations, it is possible to always receive analog broadcasts, and substitute images can always be acquired if they are always received. It becomes possible to do so. Further, even if the number of analog tuner units 44 is not provided as many as the number of analog broadcasting stations assumed (even if only two analog tuner units 44-1 and 44-2 are provided), one analog tuner unit 44 is provided. Compared with the case where the analog tuner unit 44 is provided, the possibility of occurrence of a situation in which a substitute image cannot be acquired can be reduced.

  Note that all of the analog tuner units 44-1 to 53-N may not be incorporated in the receiving device 30. In recent years, home networks and the like are becoming widespread, and there are devices (for example, DVD recorders and STBs) connected to the receiving device 30 through such networks and having a function of receiving analog broadcasts. Such a device can be used as a tuner unit constituting the analog tuner unit 44.

  In addition, a USB connection, a wireless LAN such as IEEE802.11g, an Ethernet (registered trademark), a high-definition multimedia interface (HDMI), or the like can be used as the network. In addition, the digital tuner unit 46 (FIG. 4) can also be used by appropriately protecting a device connected to the receiving device 30 via the network.

  Depending on the number of tuner units constituting the analog tuner unit 44, analog broadcast storage units 45-1 to 54-N for storing analog broadcast programs received by the analog tuner units 44-1 to 53-N are also required. However, a plurality of storage units may be used instead of a single recording medium such as a hard disk or a memory. Further, it can be shared with a part for storing information, such as the simulcast station storage unit 42.

  As described above, when a digital broadcast station is selected, an analog broadcast image is used as a substitute image, thereby shortening the time required for channel selection. This will be described with reference to FIG. 11 and FIG.

  As shown in FIG. 11, when the reception starts from the picture B2, conventionally, since the I1 picture is not received, the pictures constituting the GOP1 cannot be decoded, and the I16 picture is Decoding starts after being received. However, according to the present embodiment, the I1 picture can be acquired from the analog broadcast as a substitute image, and as a result, each picture constituting GOP1 can be decoded. Then, the decoding start timing can be made after time T2 when the B2 picture is received.

  Thus, decoding can be started from GOP1, and decoding can be started at a time earlier than the conventional decoding start time.

  Further, with reference to FIG. 12, the time required to complete the channel selection process includes a front-end process, a video decoding process, a reorder process, and other processes. Among these, by applying the present invention, it is possible to shorten the worst value of time related to the video decoding process. Therefore, as shown in FIG. 12, compared with the conventional method, the method of the present invention can shorten the worst value of the total time required for completion of channel selection.

  It should be noted that a function for determining whether a substitute image (frame) substituted for a picture is a correct substitute is provided so that a broadcast time error is corrected or whether a conversion method is correct is verified. good.

  In addition, for example, even when the broadcast time posted on the EPG is changed, it is possible to cope with it.

  In the above-described embodiment, analog broadcasting and digital broadcasting have been described as examples. However, analog broadcasting and digital broadcasting are not limited to terrestrial waves, and may be satellite television broadcasting, cable television broadcasting, or the like.

  In other words, in the above-described embodiment, there are a first broadcast station called a digital broadcast station and a second broadcast station called an analog broadcast station, and the first broadcast station and the second broadcast station play the same program. It has been described that the broadcasting stations broadcast by different systems (digital system and analog system) (broadcast stations broadcasting simultaneous broadcasting). Further, different systems (or different routes (satellite and cable, etc.) such as a third broadcast station and a fourth broadcast station may be used) in the simultaneous broadcast station storage unit 42 in the first broadcast station and the second broadcast station. It is also possible to store the information in a state associated with each other so that the processing as described above is performed. That is, the scope of application of the present invention is not limited to only two broadcasting stations.

  FIG. 13 is a block diagram showing an example of the configuration of a personal computer that executes the above-described series of processing by a program. A CPU (Central Processing Unit) 201 executes various processes according to a program stored in a ROM (Read Only Memory) 202 or a storage unit 208. A RAM (Random Access Memory) 203 appropriately stores programs executed by the CPU 201 and data. These CPU 201, ROM 202, and RAM 203 are connected to each other by a bus 204.

  An input / output interface 205 is also connected to the CPU 201 via the bus 204. Connected to the input / output interface 205 are an input unit 206 composed of a keyboard, mouse, microphone, and the like, and an output unit 207 composed of a display, a speaker, and the like. The CPU 201 executes various processes in response to commands input from the input unit 206. Then, the CPU 201 outputs the processing result to the output unit 207.

  The storage unit 208 connected to the input / output interface 205 includes, for example, a hard disk, and stores programs executed by the CPU 201 and various data. The communication unit 209 communicates with an external device via a network such as the Internet or a local area network.

  Further, a program may be acquired via the communication unit 209 and stored in the storage unit 208.

  A drive 210 connected to the input / output interface 205 drives a removable medium 211 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, and drives the programs and data recorded therein. Get etc. The acquired program and data are transferred to and stored in the storage unit 208 as necessary.

  The series of processes described above can be executed by hardware or can be executed by software. When a series of processing is executed by software, a program constituting the software executes various functions by installing a computer incorporated in dedicated hardware or various programs. For example, the program is installed in a general-purpose personal computer from the program storage medium.

  As shown in FIG. 13, a program storage medium that stores a program that is installed in a computer and can be executed by the computer includes a magnetic disk (including a flexible disk), an optical disk (CD-ROM (Compact Disc-Read Only). Memory), DVD (including Digital Versatile Disc)), magneto-optical disk (including MD (Mini-Disc)), or removable media 211, which is a package medium made of semiconductor memory, or the program is temporary or permanent ROM 202 stored in the hard disk, a hard disk constituting the storage unit 208, and the like. The program is stored in the program storage medium using a wired or wireless communication medium such as a local area network, the Internet, or digital satellite broadcasting via a communication unit 209 that is an interface such as a router or a modem as necessary. Done.

  In the present specification, the step of describing the program stored in the program storage medium is not limited to the processing performed in time series according to the described order, but is not necessarily performed in time series. Or the process performed separately is also included.

  Further, in this specification, the system represents the entire apparatus constituted by a plurality of apparatuses.

  The embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

It is a figure which shows the structure of an example of the conventional receiver. It is a figure explaining encoding. It is a figure explaining the timing of decoding. It is a figure which shows the structure of one Embodiment of the receiver which applied this invention. It is a figure which shows the structural example of a decoding part. It is a flowchart explaining operation | movement of a receiver. It is a figure explaining the timing of decoding. It is a flowchart explaining detection of an error. It is a figure explaining the timing of decoding. It is a figure explaining the other structure of an analog tuner part. It is a figure explaining the timing of decoding. It is a figure explaining that the time concerning channel selection is shortened. It is a figure explaining a recording medium.

Explanation of symbols

  30 receivers, 31, 32 antennas, 41 operation units, 42 simulcast station storage units, 43 control units, 44 analog tuner units, 45 analog broadcast storage units, 46 digital tuner units, 47 decoding units, 48 broadcast time error detection units , 46 Broadcast time error storage unit, 50 conversion unit

Claims (6)

Broadcast station storage means for storing data associated with broadcast stations that broadcast the same program in different formats;
Channel selection means for selecting the first broadcasting station to be broadcast in the first system;
When the channel selection means is instructed to select the first broadcast station, a second broadcast station that broadcasts in the second system associated with the first broadcast station is designated as the broadcast station storage means. Specifying means for specifying with reference to the data stored in
Program storage means for storing program data from the second broadcasting station;
Error storage means for storing a temporal error for providing the same scene in the program from the first broadcast station and the program from the second broadcast station;
Data necessary for decoding the program data from the first broadcasting station selected by the first channel selection means is stored in the error storage means from the time when the channel selection is started. Acquisition means for acquiring from the program data from the second broadcasting station that is stored in the program storage means at a time before an error amount that is specified and specified by the specifying means;
An image processing apparatus comprising: conversion means for converting the data acquired by the acquisition means so as to become an image similar to an image based on the data of the first method. The image processing apparatus according to claim 1, wherein the acquisition unit acquires data serving as a reference picture. Matching the first data of the program from the first broadcasting station with the second data of the program from the second broadcasting station;
When the result of matching is equal to or greater than a predetermined threshold value, the first data and the second data are determined to be data of the same scene,
The image processing apparatus according to claim 1, wherein a difference in time at which the first data and the second data determined to be the same scene are acquired is stored in the error storage unit. 2. The image according to claim 1, wherein the program storage unit stores programs from a plurality of the second broadcasting stations from a time point before the first broadcasting station is selected by the first channel selection unit. Processing equipment. A broadcast station management step for managing data associated with broadcast stations that broadcast the same program in different formats;
A channel selection step of selecting a first broadcasting station to be broadcast in the first format;
When channel selection of the first broadcasting station in the channel selection step is instructed, a second broadcasting station that broadcasts in a second scheme associated with the first broadcasting station is transmitted to the broadcasting A specific step of identifying with reference to the data managed in the station management step;
A program storage control step for controlling storage of program data from the second broadcasting station;
An error storage control step for controlling storage of temporal errors for providing the same scene in the program from the first broadcast station and the program from the second broadcast station;
Data necessary for decoding the program data from the first broadcasting station selected in the first channel selection step is stored in the error storage control step from the time when the channel selection is started. An acquisition step in which storage is controlled in the program storage control step at a time before the controlled error, and acquisition is performed from data of the program from the second broadcasting station specified by the specifying step;
A conversion step of converting the data acquired in the processing of the acquisition step so as to become an image similar to an image based on the data of the first method. A broadcast station management step for managing data associated with broadcast stations that broadcast the same program in different formats;
A channel selection step of selecting a first broadcasting station to be broadcast in the first format;
When channel selection of the first broadcasting station in the channel selection step is instructed, a second broadcasting station that broadcasts in a second scheme associated with the first broadcasting station is transmitted to the broadcasting A specific step of identifying with reference to the data managed in the station management step;
A program storage control step for controlling storage of program data from the second broadcasting station;
An error storage control step for controlling storage of temporal errors for providing the same scene in the program from the first broadcast station and the program from the second broadcast station;
Data necessary for decoding the program data from the first broadcasting station selected in the first channel selection step is stored in the error storage control step from the time when the channel selection is started. An acquisition step in which storage is controlled in the program storage control step at a time before the controlled error, and acquisition is performed from program data from the second broadcast station specified in the specification step; and processing in the acquisition step A program that causes a computer to execute a process including a conversion step of converting the data acquired in step 1 into an image similar to an image based on the data of the first method.

Images