JP2006245715A - Receiver for digital broadcast - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a receiver that can convert digital broadcast where the bit rate of stream data recorded on an HDD. <P>SOLUTION: The receiver for digital broadcast comprises a first means of making a user select stream data becoming the object of recompression processing among stream data recorded on an HDD, a second means of making the user set the compression mode of stream data becoming the object of recompression processing, a third means of reading out the stream data becoming the object of recompression processing selected by the first means from the HDD, performing AV decoding and NTSC encoding on the stream data thus read out, performing MPEG encoding on the AV data thus obtained in compression mode set by the second means and recording the stream data, thus obtained on the HDD, and a fourth means for deleting the stream data of recompression object for which read out from the HDD by the third means has ended from the HDD. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a digital broadcast compatible receiving apparatus having a built-in HDD.

  In a recording device using a general HDD, the storage area is limited, so when several programs are recorded and the remaining area of the HDD becomes small, the content on the HDD is transferred to the DVD. In general, after saving to a removable medium such as the above, the contents on the HDD are deleted to secure an empty area. However, in order to secure such free space, it is necessary for the recording apparatus to support removable media other than the HDD, leading to an increase in cost.

  In addition, a digital recording apparatus generally has several types of recording modes (bit rates) such as high image quality / standard image quality / low image quality (long-time mode), but an installed HDD When it is necessary to store a large amount of content in the HDD, it is difficult to select a high image quality mode that consumes a large amount of capacity.

  It is an object of the present invention to provide a digital broadcast-compatible receiving apparatus that can convert the bit rate of stream data recorded in an HDD and thereby increase the free capacity of the HDD.

  According to the first aspect of the present invention, in the digital broadcast compatible receiving apparatus with a built-in HDD, the first means for allowing the user to select the stream data to be recompressed from the stream data recorded in the HDD, Second means for allowing the user to set the compression mode of stream data to be compressed, the stream data to be recompressed selected by the first means is read from the HDD, and AV decoding processing is performed on the read stream data And the third means for performing the MPEG encoding process on the obtained AV data in the compression mode set by the second means and recording the obtained stream data on the HDD after performing the NTSC encoding process and the NTSC encoding process; Stream data to be recompressed that has been read from the HDD by the means. Characterized in that it comprises a fourth means for deleting data from the HDD.

  According to a second aspect of the present invention, in the first aspect of the invention, the fourth means is a target of the recompression target that has been read from the HDD by the third means after the recompression processing by the third means is completed. The stream data is deleted from the HDD.

  The invention according to claim 3 is the invention according to claim 1, wherein the fourth means deletes the stream data to be recompressed, which has been read from the HDD by the third means, from the HDD at every predetermined time. It is characterized by being.

  According to a fourth aspect of the invention, there is provided a fifth means for automatically executing the recompression process by the third means when the digital broadcast compatible receiving apparatus is in a standby state.

  According to the present invention, the bit rate of the stream data recorded on the HDD can be converted, so that the free capacity of the HDD can be increased.

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

  FIG. 1 shows the configuration of a digital broadcast-compatible receiving device with a built-in HDD.

  This digital broadcast-compatible receiving device has a function of receiving digital television broadcast and analog television broadcast, outputting video / audio of the received digital television broadcast program, and recording it on the HDD. It also has a function of playing back video / audio recorded in the HDD. Furthermore, a bit rate conversion function is also provided such that a file recorded on the HDD is once read, recompressed, and then recorded on the HDD.

  The digital broadcast compatible receiver includes a digital tuner 1, an analog tuner 3, an AV signal processing unit 4, an input switcher 5, an MPEG encoder 6, a digital signal analysis / control unit 2, an HDD controller 7, an HDD 8, an AV decoder 9, an OSD 10, A monitor 11, an NTSC encoder 12, an output switcher 13, an external output terminal 14, and a CPU 10 are provided.

  The digital tuner 1, analog tuner 3, input switcher 5, MPEG encoder 6, digital signal analysis / control unit 2, HDD controller 7 and output switcher 13 are controlled by the CPU 10. The CPU 10 includes a ROM, a RAM, and a nonvolatile memory (not shown). In addition, a remote control signal from a remote controller (not shown) is input to the CPU 10 via a remote control signal receiver (not shown).

[1] Description of digital broadcast recording processing In digital broadcasting, a plurality of services (corresponding to analog broadcasting channels) are transmitted by one transport stream (TS), and the tuner is controlled in units of TS. Necessary frequency information is uniquely determined. The correspondence between the TS and the frequency information is described in a table called a network information table (NIT). The network information table (NIT) is transmitted in units of networks.

  The digital tuner 1 controls a frequency / transport stream ID (TS_ID) corresponding to a desired service, thereby outputting a TS including the desired service to the digital signal analysis / control unit 2.

  The digital signal analysis / control unit 2 separates an elementary stream (ES) such as video / audio corresponding to a desired service from the input TS. An individual packet ID (ES_PID) is added to the ES, and the correspondence between the desired service and the corresponding ES_PID is transmitted by a table called a program massaging table (PMT). The PMT is transmitted for the service transmitted in the TS, and the PID is indicated by a table called a program association table (PAT). The PAT PID is fixed, and only one PAT is transmitted to the TS.

  Therefore, in order to isolate an ES corresponding to a desired service, first, a PAT is acquired. By analyzing the PAT after completing the PAT acquisition, the PMT_PID corresponding to the desired service can be determined and the PMT corresponding to the desired service can be acquired. By analyzing the PMT after completing the acquisition of the PMT, the PID of the ES corresponding to the desired service can be determined and the ES corresponding to the desired service can be separated. The separated ES is sent to the AV decoder 9 and AV decoding processing is performed, whereby a video / audio signal corresponding to a desired service is obtained.

  The video signal obtained by the AV decoder 9 is combined with the on-screen image signal from the OSD 10 and then sent to the monitor 11 for display. The audio signal obtained by the AV decoder 9 is output from a speaker (not shown).

  Further, the ES or the like acquired by the digital signal analysis / control unit 2 is stored in the HDD 8 via the HDD controller 7. By the way, when a service selected on the HDD 8 is recorded, it is wasteful to record the TS obtained from the digital tuner 1 as it is because it includes data for services other than the selected service. . In digital broadcasting, an ES is usually scrambled and transmitted, and a descrambling process is performed by using control information called ECM (Entitlement Control Message) in which the PID is determined by the PMT and an IC card corresponding to the control information. Although the decoding process by the AV decoder becomes possible for the first time, it is not preferable from the viewpoint of protection of this encryption method to record the TS including the control information without releasing the scramble.

  Therefore, the digital signal analysis / control unit 2 generates a partial TS called a partial transport stream (PTS) composed of PAT, PMT corresponding to the selected service, ES and descrambled ES, and PCR. It is common to output. The HDD controller 7 writes this PTS in the HDD 8. The PAT included in the PTS is a PAT obtained by deleting a description other than the selected service from the acquired PAT. Further, the PMT included in the PTS is a PMT obtained by deleting a description other than the selected ES / PCR from the acquired PMT.

  FIG. 2 shows a data structure on the HDD.

  When the PTS output from the digital signal analysis / control unit 2 is stored in the HDD 8 as stream data, the PTS (stream data) including video / audio and the incidental information corresponding to the PTS are independently provided. The PTS and incidental information are stored in the HDD 8 so that they can be managed.

  The accompanying information includes a valid flag, recording date / time, recording file name, recording time, recording data type, reproduced flag, pointer to stream data, and reproduction start pointer. The meaning of each piece of information is as follows.

  Recording date and time: Time stamp of file generation start and data that cannot be rewritten by the user.

  Recording file name: Title information for the user to recognize the contents recorded in the HDD. When the file list is displayed, it is possible to check all data in the HDD and to select a file to be played back according to the recording file name. If the recording is in units of programs, such as program reservation, the program name may be automatically registered. The recording file name is data that can be rewritten by the user.

  Recording time: Information indicating the length of the recording time of the file (PTS), which is written after the recording is completed.

  Recording data type: Information for identifying whether the data of the file is data generated from digital broadcasting or data generated from analog broadcasting (or analog input). In the case of data generated from digital broadcasting, the recording mode (HD / SD) is also recorded. As will be described later, when recording data is generated from analog broadcasting (or analog input), control information of image quality and file size is given to the MPEG encoder, and the control information at that time is also recorded. Here, for simplification of description, it is assumed that there are three types of image quality: high image quality, standard image quality, and low image quality.

  The image quality including digital and analog is assumed to be digital HD, digital SD, analog high image quality, analog standard image quality, and analog low image quality in descending order.

  Played flag: This flag indicates that the file has already been played. Files that have not been reproduced are not subject to automatic bit rate conversion processing, which will be described later.

  Pointer to stream data: When the file is selected for reproduction from the file list, a stream to start decoding is selected according to this pointer, and decoding is started. If deletion of the file is specified from the file list, the associated information is deleted after deleting the corresponding stream based on this pointer.

  Playback start pointer: A pointer for starting playback from the point where playback was interrupted when the next playback starts when playback is interrupted due to playback interrupted by a user operation or power off while the file is being played. .

  Valid flag: This flag indicates whether or not information for the file is confirmed.

[2] Description of Analog Broadcast Recording Processing The signal from the analog tuner 3 is converted into a video / audio signal by the AV signal processing unit 4 in the same procedure as a normal analog playback device, and then sent to the input switcher 5 It is done. Although not shown in the figure, when an AV signal is directly input from an analog input terminal, it is not necessary to convert it to a video / audio signal and is sent to the input switcher 5 as it is.

  The input switcher 5 is one of an AV signal input from the analog tuner 3 via the AV signal processing unit 4 (or an AV signal input from the analog input terminal) and a signal from the NTSC encoder 12 described later. Is sent to the MPEG encoder 6.

  When reproducing or recording an AV signal input from the analog tuner 3 via the AV signal processing unit 4 (or an AV signal input from the analog input terminal), the input switcher 5 selects these AV signals. Then, control is performed so as to send to the MPEG encoder 6.

  Based on the control by the digital signal analysis / control unit 2, the MPEG encoder 6 generates a screen display TS signal (decoding TS signal) given to the AV decoder 9 from the video / audio signal input to the MPEG encoder 6. Then, two types of TS signals, that is, a TS signal for recording on the HDD 8 (recording TS signal), are generated and output. The decoding TS signal is an encoding signal with the highest image quality, and the recording TS signal is an encoding signal in a recording mode set by the user.

  In this embodiment, an analog AV signal is converted into a digital TS signal and then displayed on the screen via an AV decoder. However, when an analog AV signal is displayed on the screen, it is output from the input switcher 5. The analog AV signal may be displayed on the screen as it is.

  Unlike the case of digital broadcasting, each TS signal (decoding TS signal, recording TS signal) input from the MPEG encoder 6 to the digital signal analysis / control unit 2 includes only one service, Only one video and one audio are described in the PMT in each TS signal. Therefore, it is not necessary to select a PMT corresponding to the selected service from the PAT as in the case of digital broadcasting. Further, the recording TS signal is a TS signal composed of only one service of video and audio, and it is not necessary to generate a PTS. Therefore, when recording the TS signal for recording, this signal is stored in the HDD 8 as it is through the HDD controller 7 without being changed.

  When the recording TS signal encoded by the MPEG encoder 6 is recorded on the HDD 8, the incidental information shown in FIG. 2 is recorded on the HDD 8 as in the case of digital broadcast recording. The content according to the encoding condition of the MPEG encoder 6 is set in the recording data type in the accompanying information.

[3] Explanation of recorded file playback processing When playing back a recorded file, the CPU 10 displays a list of files recorded in the HDD 8 based on an instruction from the user and plays back the file. Let the user select The CPU 10 determines the stream (PTS) to be sent to the digital signal analysis / control unit 2 via the HDD controller 7 and the reading position of the stream from the incidental information of the selected file, and sends the PTS to the HDD controller 7. Start reading.

  The digital signal analysis / control unit 2 acquires the PAT in the PTS, and then acquires the PMT and extracts the ES in the PMT, as in the normal digital broadcast decoding process. Since there is only one description, that is, only one PMT is included in the stream, the corresponding ES may be sent to the AV decoder 9 after the PMT acquisition is completed. As described above, the ES in the PTS is a non-scrambled ES that does not require descrambling processing.

  The AV decoder 9 performs AV decoding processing on the ES sent from the digital signal analysis / control unit 2. Thereby, a video / audio signal is obtained. The video signal obtained by the AV decoder 9 is combined with the on-screen image signal from the OSD 10 and then sent to the monitor 11 for display. The audio signal obtained by the AV decoder 9 is output from a speaker (not shown).

  The video / audio signal obtained by the AV decoder 9 is output to an external output terminal (recording terminal) 14 via the NTSC encoder 12 and the output switcher 13.

  In this embodiment, the video / audio signal obtained by the AV decoder 9 is input to the MPEG encoder 6 via the NTSC encoder 12 and the input switcher 5 in order to realize the bit rate automatic conversion processing described later. The re-compression process of the recording file can be performed.

[4] Description of Automatic Bit Rate Conversion Process for Recorded File In this embodiment, the bit for the recompressed file set by the user among the recorded files stored in the HDD 8 during standby of the receiver. Rate conversion processing (downsizing processing) is automatically performed. In this embodiment, only recorded files stored in the HDD 8 that have been reproduced at least once (only those that have been reproduced by the reproduced flag) are reproduced. It becomes a compression target.

  The bit rate at the time of recompression may be set for each file to be recompressed, or the bit rate at the time of recompression is uniformly set to the long time mode (analog low image quality mode). Also good. When the recompression bit rate is set for each file, the recompression bit rate is also set when the recompression target file is set.

  FIG. 3 shows an automatic bit rate conversion processing procedure performed when the receiver is on standby.

  When the receiver enters a standby state (step S1), it is determined whether or not it is necessary to execute a standby receiver process at the present time (step S2). The standby receiver process refers to an operation to be executed by the receiver during standby, and includes a reserved program start time monitoring process, EMM energization control, download process, EPG data acquisition process, and the like.

  If it is determined at this time that it is necessary to execute the standby receiver process, the process is executed (step S3). Then, when the process ends (step S4), the process returns to step S2.

  If it is determined in step S2 that it is not necessary to execute the standby receiver processing at the present time, it is determined whether or not a file exists in the HDD 8 (step S5). If the file does not exist in the HDD 8, the process returns to step S2.

  If it is determined in step S5 that a file exists in the HDD 8, it is determined whether or not there is data that has been interrupted during the recompression process (intermediate data in the recompression process) (step S6). The case where the recompression process is interrupted is a case where a power-on operation of the remote control is performed during the recompression process, as shown in step S11 described later. Whether there is halfway data in the recompression process is determined based on information (see step S32 in FIG. 4) indicating that recompression is being held in the nonvolatile memory at the start of recompression.

  If there is no halfway data in the recompression process, it is determined whether there is a file set as a recompression target (a file set for recompression) (step S7). If there is no recompressed file, the process returns to step S2.

  If it is determined in step S7 that a file set for recompression exists, it is determined whether or not the recompression processing for the file to be recompressed will be completed before the next schedule processing is started. (Step S8). The schedule process is a process that needs to be woken up at a specified date and time from the standby state. The process for executing a reserved program (reserved viewing program and / or reserved recording program), EMM energization control process, download process , EPG data acquisition processing and the like. If it is determined in step S8 that the recompression process for the file to be recompressed does not end before the next schedule process is started, the process returns to step S2.

  If it is determined in step S8 that the recompression process for the file to be recompressed will be completed before the next schedule process is started, the recompression process is started (step S9). In the recompression process, the file to be recompressed is read from the HDD 8 and the ES is AV-decoded by the AV decoder 9 as in the recording file reproduction process. The video / audio signal obtained by the AV decoder 9 is sent to the MPEG encoder 6 via the NTSC encoder 12 and the input switcher 5. The MPEG encoder 6 compresses the input AV signal at a recompression bit rate set by the user, and generates a recording TS signal. The recording TS signal obtained by the MPEG encoder 6 is recorded on the HDD 8 by the digital signal analysis / control unit 2 and the HDD controller 7 in the same manner as the recording process of the analog broadcast.

  Although the file may be deleted when the recompression of the file is completed, in this embodiment, the file to be recompressed is deleted in a predetermined time unit during the recompression process. Details of the process for deleting the recompressed file and the process for generating the new file after the recompression will be described later.

  When the recompression process is started, it is monitored whether or not a power-on operation is performed by the remote controller (step S10). After the recompression process is started, if the recompression process is completed without performing a power-on operation by the remote controller (NO in step S10, YES in step S11), the process returns to step S7.

  If a power-on operation is performed by the remote controller after the recompression process is started and before the recompression process ends (YES in step S10, NO in step S11), the recompression process is interrupted. (Step S12). And it waits until power-off operation by a remote control is performed (step S13). When the power-off operation is performed by the remote controller, the state shifts to the standby state (step S1).

  If it is determined in step S6 that there is halfway data in the recompression process, it is determined whether or not the recompression process for the halfway data is completed before the next schedule process is started (step S14). ). If the recompression process for the midway data does not end before starting the next schedule process, the process returns to step S2.

  If it is determined in step S14 that the recompression process for the midway data is finished before the next schedule process is started, the recompression process for the midway data is started (step S15). And it waits until a recompression process is complete | finished (step S16). When the recompression process ends, the process returns to step S6.

  FIG. 4 shows a file control processing procedure in the recompression processing.

  Here, the file to be recompressed is referred to as file A, and the new file generated after recompression is referred to as file A ′.

  When the recompression process for the file A is started, the process for reading the file A and the process for writing the file A ′ are performed in parallel.

  In the process related to reading of file A, first, reading of data of file A from HDD 8 and transfer to digital signal analysis / control unit 2 are performed (step S21). Then, it is determined whether or not data has been read for a predetermined time (in this example, 1 minute) (step S22). If no data has been read for one minute, it is determined whether or not reading of all data in the file A has been completed (step S25). If reading of all data in file A has not been completed, the process returns to step S21.

  If it is determined in step S22 that data has been read for 1 minute, the data read during that time is erased (step S23). Thereafter, the content of the incidental information of file A is changed (step S24). For example, the recording time, the pointer to the stream data, etc. are updated. Then, it is determined whether or not reading of all data of the file A is completed (step S25). If reading of all data in file A has not been completed, the process returns to step S21.

  On the other hand, regarding the processing related to the writing of the file A ', it is determined whether or not information indicating that the file A is being recompressed is held in the nonvolatile memory (step S31). If information indicating that recompression is being performed is not held in the nonvolatile memory, information indicating that file A is being recompressed is stored in the nonvolatile memory (step S32). Then, incidental information for the file A ′ is provisionally generated (step S33). That is, the recording date and time, the file name, and the recording time, which are supplementary information for the file A ′, are generated by copying the supplementary information of the file A. Further, the image quality in the recording data type is an image quality according to the MPEG encoding condition. The pointer to the stream data is used as a pointer for starting decoding of the file A ′. The reproduction start pointer is used as a write pointer for the file A ', and is updated at any time during writing. Note that the valid flag is set as indeterminate.

  When the incidental information for the file A ′ is provisionally generated, writing of the data of the file A ′ is started (step S34). Thereafter, the file A 'generation process is performed (step S35).

  If it is determined in step S31 that information indicating that the file A is being recompressed is already stored in the nonvolatile memory, that is, after the recompression of the file A is interrupted, the file A When the re-compression of the file A ′ is resumed, since the incidental information for the file A ′ has already been temporarily generated, the writing of the data of the file A ′ is started (step S34). Thereafter, the file A 'generation process is performed (step S35).

  If it is determined in step S25 that reading of all data has been completed, data that has not yet been erased in file A is erased (step S26). Next, the incidental information confirmation process for the file A 'is performed (step S27). In the incidental information confirmation process, the valid flag is validated, and the regenerated flag is set to a value indicating completion of recompression and completion of reproduction. Also, the playback start pointer is set to the head position of the data of file A.

  Next, the incidental information of file A is deleted (step S28). Then, the information indicating that the file A in the nonvolatile memory is being recompressed is deleted (step S29). Thereby, the recompression process for the file A is completed.

  According to the above embodiment, stream data recorded in the HDD can be recompressed (downsized), and the free capacity of the HDD can be increased.

  Further, according to the above-described embodiment, the recompression processing of the stream data recorded on the HDD can be performed during the standby of the receiver, so that the viewing and recording of the received broadcast program by the user is not hindered.

It is a block diagram which shows the structure of the digital broadcast corresponding | compatible receiving apparatus with which HDD was incorporated. It is a schematic diagram which shows the data structure on HDD. It is a flowchart which shows the bit rate automatic conversion processing procedure performed at the time of standby of a receiver. It is a flowchart which shows the file control processing procedure in a recompression process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Digital tuner 2 Digital signal analysis and control part 3 Analog tuner 4 AV signal conversion part 5 Input switcher 6 MPEG encoder 7 HDD controller 8 HDD
9 AV decoder 12 NTSC encoder

Claims (4)

In the receiver for digital broadcasting with built-in HDD,
First means for allowing a user to select stream data to be recompressed among stream data recorded in the HDD;
A second means for allowing the user to set the compression mode of the stream data to be recompressed;
The stream data to be recompressed selected by the first means is read from the HDD, AV decoding processing and NTSC encoding processing are performed on the read stream data, and the obtained AV data is set by the second means Third means for performing MPEG encoding processing in the compressed mode and recording the obtained stream data on the HDD, and deleting the stream data to be recompressed, which has been read from the HDD by the third means, from the HDD means,
A receiver for digital broadcasting, which has a built-in HDD. The fourth means is characterized in that after the recompression processing by the third means is completed, the stream data to be recompressed, which has been read from the HDD by the third means, is deleted from the HDD. The receiving apparatus corresponding to digital broadcasting described in 1. 4. The digital broadcast compatible reception according to claim 1, wherein the fourth means deletes the recompressed stream data, which has been read from the HDD by the third means, from the HDD at every predetermined time. apparatus. 4. The fifth means according to claim 1, further comprising fifth means for automatically executing recompression processing by the third means when the digital broadcast compatible receiving apparatus is in a standby state. Receiver for digital broadcasting.

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