JP4020818B2 - Recording apparatus, computer-readable program, and method. - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording device that writes data broadcast in a digital format to a randomly accessible recording medium such as an HDD or a DVD in a compressed and encoded state, and a computer-readable device that realizes the function of the recording device. In particular, the present invention relates to an improvement in writing data using a user's manual operation as a trigger.
[0002]
[Prior art]
In recent years, TV broadcasting has entered a transition period from analog to digital. In the transition period, recording devices for digital broadcasting are becoming mainstream. In digital broadcasting, a moving image constituting a TV program is transmitted through a transmission path while being compressed and encoded. The video in a compressed and encoded state takes the form of a transport stream (TS) packet. The recording apparatus of the digital broadcast compatible model writes the moving image on the recording medium in the form of this TS packet. Since there is no quantization loss associated with decoding or encoding, such a recording apparatus can record a TV program on a recording medium with high image quality and high sound quality. However, the reproduction of digital broadcasting by such a device has characteristics that are significantly different from those of the analog system. The characteristic is that a video frame delayed in time from a currently received video frame is reproduced.
[0003]
The time difference between the video frame being received and the video frame being played back is due to a buffering delay in the recording apparatus. In a digital broadcast playback system, in order to obtain frame data, TS packets corresponding to a time zone of about 1 second must be stored. Since buffering is necessary to obtain frame data, the buffering delay is large.
[0004]
As techniques for recording a moving image broadcast in an analog manner on a recording medium, those disclosed in Patent Documents 1 and 2 below are known.
[0005]
[Patent Document 1]
Japanese Patent No. 3028517
[0006]
[Patent Document 2]
Japanese Patent No. 3069324
[0007]
[Problems to be solved by the invention]
By the way, the time difference between frames caused by the buffering delay adversely affects manual recording by the user. Manual recording is a process of recording data being received with a recording operation by the user as a trigger. Since manual recording is performed when a video frame is reproduced and output, the user performs a recording operation with an internal intention to record from the currently reproduced video frame. However, as described above, there is a time difference between frames. Even if the user views a video frame during playback and performs a recording operation, the video frame being played back is considerably delayed from the frame being received, and has already reached the recording device. Since the video frame being reproduced does not already exist, a moving image recorded by manual recording has a lack of the first plurality of frames. There is optimism that “is it missing a few frames?”, But considering the performance comparison with the analog broadcast-compatible model, there is nothing like that. In other words, in the recording apparatus of the analog broadcast compatible model, the video frame being played back and the video frame being received almost coincide with each other, and the top video is not lost at the time of manual recording. The fact that the latest digital broadcasting model can not do what analog broadcasting models can do is a ground for the reputation that “digital broadcasting models are inferior in function”, and it is a product strategy for manufacturers that expect replacement demand Drop a dark shadow.
[0008]
An object of the present invention is to provide a recording apparatus capable of avoiding missing frame data during manual recording even with a large buffering delay.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, a recording apparatus according to the present invention is a recording apparatus that writes a plurality of packets transmitted by digital broadcasting to a recording medium when a user who views the playback output of the digital broadcasting performs a recording operation. In the playback output, there is a buffering delay for storing a group of packets in a playback buffer (i) and converting the packet group into a video frame (ii). A recording buffer in which packet groups are stored; copy means for copying the packet groups and storing them in the recording buffer; and writing the group of packets stored in the recording buffer to a recording medium in accordance with a user's recording operation , Recording means for writing subsequent packets to the recording medium, and each packet on the recording buffer A buffer management table indicating the address of the group in association with the display start time of the video frame corresponding to each packet group; When a user performs a recording operation, The recording means obtains the display time of the video frame being played back. Then, the display time of the acquired video frame is compared with the display start time of the video frame corresponding to each packet group of the buffer management table, and the display start time is earlier than the acquired display time. The packet group address corresponding to the display start time closest to the displayed display time is acquired, and the packet group stored in the recording buffer is written to the recording medium based on the acquired packet group address. It is characterized by that.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the recording apparatus according to the present invention will be described. First, among the implementation actions of the recording apparatus according to the present invention, the mode of use action will be described. The recording device according to the present invention forms a home server system together with a television and a remote controller, and the recording device is used for manual recording of a broadcast to be displayed on the television.
[0011]
In this embodiment, the target of recording is digital TV broadcasting. A video frame in digital TV broadcasting has a time length of about 33 msec (exactly 1 / 29.97 sec). Data displayed in the video frame is referred to as frame data.
Frame data in digital TV broadcasting means picture data for displaying one image. This picture data includes Bidirectionally Predictive (B) pictures that have been inter-frame compression encoded using correlation with images to be reproduced in the past and future directions, and images to be reproduced in the past direction. Predictive (P) picture that is inter-frame compression encoded using correlation, intra-frame compression encoding is performed using spatial frequency characteristics within an image for one frame without correlation There are types such as Intra (I) picture. The smallest unit that can be decoded in TV broadcasting is called GOP (Group Of Picture). The GOP includes at least one I picture and has a playback time of about 0.5 seconds to 1.0 seconds.
[0012]
Next, a description will be given of the form of the production action among the implementation actions of the recording apparatus according to the present invention. The recording apparatus according to the present invention can be industrially produced based on the internal configuration shown in FIG. As shown in FIG. 1, the recording apparatus includes an HDD 1, a GOP management table 2, playback section information 3, a digital tuner 4, a TS decoder 5, an AV decoder 6, a playback buffer 7, a recording buffer 8, a buffer management table 9, and a user interface. Part 10 and a system control part 11.
[0013]
The HD drive 1 is a randomly accessible recording medium on which a stream file is recorded. The stream file is a file that stores only TS packets extracted by the TS decoder 5 among a plurality of TS packets included in the broadcast full transport stream.
The GOP management table 2 includes information (records) about each GOP in the stream file. A record in the GOP management table is composed of OFFSET from the head of the stream file to each GOP, the size of the GOP, and the head PTS of the GOP, and is used when performing jump playback or special playback.
[0014]
The playback section information 3 is information for specifying a playback section on the stream file based on a combination of playback start time and playback end time. The TS file corresponding to a plurality of GOPs is stored in the stream file, whereas the playback start time and playback end time in the playback section information 3 are recorded on the stream file with the time accuracy of the video frame (1 / 29.97 sec). Specify the playback section.
[0015]
The digital tuner 4 receives a digital signal transmitted from a broadcasting station and outputs a full transport stream.
The TS decoder 5 partializes the full transport stream output from the digital tuner 4. Partialization refers to extracting only those having a PID designated from the outside from among a plurality of TS packets multiplexed in a full transport stream, and is also called “demultiplexing”. In this extraction work, the TS decoder 5 receives the designation of the PID from the system control unit 11 and writes only the TS packets having the designated PID to the reproduction buffer 7 among the TS packets constituting the full transport stream. Made. There are two buffers to be written to: a reproduction buffer 7 and a recording buffer 8. The purpose of writing TS packets not only in the reproduction buffer 7 but also in the recording buffer 8 is to copy a plurality of TS packets to be decoded into frame data to the recording buffer 8. Since the output speed from the TS decoder 5 is fast, it is easy to write one TS packet in both buffers. In addition to partialization, the TS decoder 5 has a GOP detection function.
[0016]
The GOP detection function is a function that detects a leading GOP from a TS packet obtained by partialization. The GOP is detected by detecting a random access indicator from the application field of the TS packet. The application field is a field in which information about the system layer of the video stream is described. The random access indicator is whether the first frame of the access point of the video stream is stored in the payload portion of the TS packet. Show. An access point is a unit within a stream that can be decoded independently, and a random access indicator indicates whether or not the first frame (I picture) of a GOP exists. By detecting this random access indicator, it is possible to know from which TS packet to which TS packet constitutes one GOP. This detection reveals from which TS packet to which TS packet is one GOP. This GOP detection function is not a general function of the TS decoder but a function added for the present embodiment. Thereby, it is possible to calculate how much size each GOP forms in the state of the TS packet.
[0017]
The AV decoder 6 includes a system decoder (1) that separates a plurality of TS packets obtained by the partialization of the TS decoder 5 into audio data and frame data, an audio decoder (2) that decodes the separated audio data, and a TS packet In the embodiment, a video decoder (3) that decodes and decompresses frame data in a compressed and encoded state, and stores the frame data for two frames in order to rearrange the decompressed frame data in the display order. An internal buffer (4) is provided. The results of decoding by the video decoder and audio decoder are sent to a monitor connected to the recording device. The TS stream is sent to the AV decoder 6 so that the internal buffer does not underflow. Basically, the broadcasting station transmits TS packets so that the internal buffer of the AV decoder 6 does not underflow. Therefore, an underflow in the AV decoder 6 cannot occur except during an abnormality such as a failure in the transmission path.
[0018]
The reproduction buffer 7 is a dual port type FIFO memory, and is interposed between the TS decoder 5 and the AV decoder 6. A plurality of TS packets obtained by the partialization of the TS decoder 5 are stored in the reproduction buffer 7. When converted to a unit of frame data, the TS packet stored in the reproduction buffer 7 is frame data constituting 1 GOP. Since the reproduction buffer 7 is interposed, the AV decoder 6 can acquire a GOP in a compression-coded state. Since a reproduction buffer 7 exists between the TS decoder 5 and the AV decoder 6 and an internal memory also exists inside the AV decoder 6, the buffering delay in the recording apparatus is large. FIG. 2 is a diagram schematically illustrating a buffering delay caused by the AV decoder 6 and the reproduction buffer 7. In FIG. 2, a numerical value of time xx: yy means a yy frame of xx seconds (in the example of FIG. 2, the number of frames per second is approximated to 30 frames). In FIG. 2, three frame data (time 05:01 to 05:03) are buffered in the internal memory of the AV decoder 6, and the remaining frames (time 05:04 to 05:30) of the GOP are buffered. Is buffered in the reproduction buffer 7, a buffering delay of about 1 second occurs between the TS decoder 5 and the monitor.
[0019]
The recording buffer 8 is a D-RAM, SD-RAM, or RD-RAM, and is used as a ring buffer. The ring buffer is a ring buffer that stores from a TS packet received several seconds ago to a currently received TS packet, and has a size that is an integral multiple of the TS packet. A plurality of TS packets stored in the recording buffer 8 constitute a plurality of GOPs. Since it is a ring buffer, when the recording buffer 8 is filled with TS packets, the oldest TS packet existing there is overwritten with a new TS packet. By controlling in this way, a new TS packet is always temporarily stored in the recording buffer 8. What kind of TS packet is stored in the recording buffer 8 when the AV decoder 6 is decoding the frame data at time 05:01 and the TS decoder 5 is receiving the frame data at time 06:04 Is shown in FIG. As shown in FIG. 3, the recording buffer 8 stores TS packets (these constitute GOP # K + 1) constituting frame data from time 05:01 to time 05:30. In addition, frame data from time 06:01 to time 06:02 (these constitute GOP # K + 2), frame data from time 04:01 to time 04:30 (these are GOP # K Are also stored in the recording buffer 8.
[0020]
The buffer management table 9 is information indicating the minimum PTS of the GOP and the start address (buffer address) on the recording buffer 8 for the GOP to which the frame data on the recording buffer 8 belongs, and is generated by the system control unit 11. Since the buffer address is associated with the PTS by this buffer management table, a search process of retrieving the buffer address of the GOP from the PTS is possible. By this search, the GOP corresponding to the video frame currently being played back can be obtained. Can be read out. FIG. 3 shows what kind of buffer management table 9 is generated when three GOPs #K, # K + 1, and # K + 2 called GOP are stored in the recording buffer 8. The buffer management table 9 in FIG. 3 includes the minimum PTS (04:01, 05:01, 06:01) of GOP # K, # K + 1, and # K + 2 and the addresses on the buffer (adr1, adr2, adr3 ) Is written in correspondence.
[0021]
The user interface unit 10 is a user interface compatible with a normal VTR, and accepts a user's selection operation, recording operation, playback operation, and stop operation. These operations are accepted by pressing a key on the remote control or the front panel, as in the case of a conventional VTR. The above-described writing from the recording buffer 8 to the HDD is performed when a recording operation is commanded in the same interface as this normal VTR.
[0022]
The system control unit 11 is a general-purpose microcomputer system including a CPU, a ROM, and a RAM. The CPU executes a program stored in the ROM, thereby realizing reproduction control for the AV decoder 6 and write control for the HDD 1. . In the write control, the system control unit 11 inquires of the AV decoder about the current display time, searches for frame data composed of TS packets in the recording buffer 8 that matches the current display time, and is searched. The frame data after the frame data is written to the HDD in the state of the compression-encoded TS packet. FIG. 4 shows what frame data is written to the HDD when the AV decoder 6 decodes the frame data at time 05:01 and the TS decoder 5 is receiving the data at time 06:04. FIG. As shown in FIG. 4, the recording buffer 8 stores TS packets constituting frame data from time 05:01 to time 05:30. If the frame data at time 05:01 being currently reproduced is the head of GOP # K + 1, the frame data after time 05:01 is read from the recording buffer 8 and written to the HDD as indicated by the arrow yf1. be able to.
[0023]
The above is the internal configuration of the recording apparatus. Subsequently, processing procedures of the TS decoder 5 and the system control unit 11 will be described with reference to a flowchart.
FIG. 5 is a flowchart showing the processing procedure of the TS decoder 5. This flowchart forms an event wait loop that waits for the occurrence of an event of receiving a TS packet (step S1). If a TS packet is received, a series of processing from step S2 to step S9 is performed, and the process goes to step S1. Return.
[0024]
In steps S2 to S9, after the processing in steps S2 to S4, the TS packet is written after the write destination address of the reproduction buffer (step S5), and the TS packet is written after the write destination address of the recording buffer 8 (step S5). Step S6).
Step S2 determines whether or not the PID of the received TS packet is a PID instructed from the system control unit 11, and if it does not have the instructed PID, the process returns to step S1.
[0025]
Step S3 is a determination of whether or not there is a random access indicator in the header of the TS packet. If a random access indicator is detected, the address and PTS of the TS packet are notified to the system control unit 11 in step S4, and step S5 is performed. Migrate to
Both step S7 and step S8 are update of the write destination address. Which update is performed is defined in step S9. Step S9 is a determination as to whether or not the sum of the write destination address and the TS packet size is greater than or equal to the end address of the recording buffer 8. If not, the TS packet size is set to the current write destination address. The write destination address is updated by adding together (step S7). If so, the write destination address is set as the start address of the recording buffer 8 (step S8). With such an update, the old TS packet in the recording buffer 8 is overwritten. Therefore, the recording buffer 8 functions as a ring buffer. The reason why the write destination address is updated to the start address of the recording buffer 8 is that the size of the recording buffer 8 is assumed to be an integral multiple of the TS packet size in this embodiment. If the size of the recording buffer 8 is a non-integer multiple of the TS packet size, the TS packet is divided into a front end portion and a rear end portion, and the front end portion is written from the write destination address to the end address. The part is written after the start address. The processing procedure of the TS decoder 5 has been described above.
[0026]
The processing procedure of the system control unit 11 is configured on the assumption that the TS decoder 5 performs such processing. 6 and 7 are flowcharts showing the processing procedure of the system control unit 11. The system control unit 11 is realized by describing the processing procedure of this flowchart in a computer description language and causing the CPU to read it.
Steps S11 to S15 show a series of procedures until a PID is set in the TS decoder 5. This PID setting waits for reception of a channel selection request by the user (step S11). If there is a channel selection request, the digital tuner is controlled to receive the selected channel (step S12), and PAT / PMT If these are detected, the PAT / PMT is analyzed and the PID is obtained (step S14). If the TS decoder is set so as to extract the TS packet having the PID (step S15), the process proceeds to a loop process including steps S16 to S17. This loop processing is an event waiting loop that waits for whether the recording key is pressed (step S16), whether the TS decoder 5 has acquired the address of the minimum PTS of the GOP and the write destination buffer (step S17), PTS, If the address on the recording buffer 8 is notified (Yes in step S17), these are added to the buffer management table 9 (step S18), and the GOP after the READ POINTER in the reproduction buffer 7 is read out to the AV decoder and reproduced. (Step S19), after updating the READ POINTER on the reproduction buffer 7 (Step S20), the process returns to the loop process of Steps S16 to S17. Since the playback video is sequentially displayed through the above steps S16 to S20, the user can view the playback video.
[0027]
If the recording key is pressed, GOP writing to the HDD is executed. Steps S21 to S24 are processes executed prior to the writing, and specify a GOP (GOPi) to be written to the stream file. This GOPi is specified by querying the AV decoder for the current display time (step S21), acquiring the current display time (step S22), and stored in the recording buffer among the plurality of PTSs in the buffer management table 9. Of the plurality of GOPs, the GOP having the PTS closest to the acquired display time is acquired earlier than the acquired display time (step S23), and the GOP of the acquired PTS is set to GOPi (step S24).
[0028]
A process of searching for a GOP in the recording buffer 8 based on the current time notified from the AV decoder 6 is schematically shown in FIG. In this figure, the GOP including the current time being decoded by the AV decoder 6 is searched from the recording buffer 8 as indicated by an arrow gt1. It is assumed that GOP # K + 1 is obtained by this search. Since the buffer management table describes the GOP # K + 1 buffer address, the Read pointer of the recording buffer 8 is set to the GOP # K + 1 buffer address.
[0029]
The subsequent steps S25 and S26 are generation of the stream file, GOP management table, and playback section information. The stream file, GOP management table, and playback section information are created (step S25), and the display time acquired from the AV decoder is set. A process of setting to the playback start time of the playback section information (step S26) is performed.
[0030]
After these processes, GOP writing is finally executed. Steps S31 to S33 are GOP write processing. The GOPi buffer address is acquired from the buffer management table 9 and set to READ POINTER (step S31), and GOPi after READ POINTER is written to the stream file ( Step S32) and READ POINTER are updated (Step S33). Steps S34 and S35 are processing for updating the playback section information 3 and the GOP management table accompanying GOP writing. The GOPi PCR is set to the playback end time of the playback section information (step S34), and the GOPi in the stream file is set. The offset, GOPi size, and GOPi minimum PTS are set in the i-th record (record i) of the GOP table (step S35).
[0031]
The reason why the playback section information is set in step S34 is to eliminate this gap when there is a gap between the GOP head and the current time. That is, when the current time acquired from the AV decoder 6 is in the middle of a GOP, it is necessary to prohibit the reproduction output of frame data from the beginning of the GOP to the middle during reproduction. This is because the playback section information points to the playback section with the time accuracy of the video frame, and therefore, the portion inside the GOP that does not belong to the playback section must not be played back. In order to realize the output prohibition during reproduction, the reproduction section information acquired from the AV decoder 6 is set as the reproduction section information.
[0032]
FIG. 9 is a diagram showing what GOP is stored in the stream file and how the playback section information is set when the current time 05:06 is acquired from the AV decoder 6. Since the current time belongs to GOP # K + 1 from time 05:01 to time 05:30, this GOP # K + 1 is searched as indicated by an arrow gt1. Then, the frame data at time 05:01, which is the first frame data of GOP # K + 1, is written to the stream file. On the other hand, the current time 05:06 acquired from the AV decoder 6 is set as the playback start time of the playback section information.
[0033]
Step S36 is a process of updating the first one of the remaining GOPs in the recording buffer 8 to GOPi, and after this GOPi is updated, the process proceeds again to steps S31 to S35. As long as the remaining GOPs exist in the recording buffer 8, the processes in steps S31 to S36 are repeated. As a result, GOPs present in the recording buffer 8 are sequentially written into the stream file. In this writing, the playback end time of the playback section information is updated as needed using GOPi PCR (step S34), and the GOPi offset, GOPi size, and GOPi minimum PTS in the stream file are added as record i in the GOP table. (Step S35).
[0034]
Step S37 defines the exception processing of this loop processing, and determines whether or not there is a GOP in the recording buffer 8. If there is no GOP from the recording buffer 8, it is determined whether there is a GOP detection notification from the TS decoder (step S38). If there is a GOP, the GOP stored in the recording buffer 8 is set to GOPi (step S39). Return to step S31.
[0035]
Step S40 defines loop processing end requirements. The termination requirement is pressing the STOP key (step S40). If the STOP key is pressed, the AV decoder is inquired about the current time (step S41), and waits for the reception of the current time (step S42). The current time obtained from the AV decoder is set as the playback end time of the playback section information (step S43).
[0036]
Thereafter, GOPi after READ POINTER is written to the stream file (step S44), and the GOPi offset, GOPi size, and GOPi minimum PTS in the stream file are written to the record i of the GOP table (step S45). Thereafter, the stream file is closed (step S46), and the process ends.
As described above, according to the present embodiment, since the same one output from the TS decoder 5 to the AV decoder 6 is stored in the recording buffer 8 in advance, even if manual recording is instructed by the user, the current display is performed. The same frame data as the inside can be read from the recording buffer 8 and written to the HDD 1. Therefore, even if there is a time difference between the currently displayed video frame and the currently received video frame, the moving image can be recorded on the recording medium without any video frame being lost.
[0037]
The writing from the recording buffer 8 to the HDD 1 is performed by a copy operation such as “copy from one medium to another medium” or an edit operation such as “edit data recorded on a certain recording medium”. It is not a trigger. It is triggered by an operation that is also performed in an existing VTR called a recording operation. Therefore, even users who are not prepared to copy and edit between media, or old users who can only use the old VTR, if the scene they want to see appears in front of them, The frame data can be written from the recording buffer 8 to the recording medium.
[0038]
(Second embodiment)
In the first embodiment, recording is performed from the beginning of the GOP including the frame data corresponding to the current time. However, if the frame data is a B picture existing at the head of the GOP, the decoding of the B picture requires an I picture or a P picture included in the GOP before the GOP. The second embodiment deals with such a case.
[0039]
More specifically, when the current time is acquired from the AV decoder 6, the GOP immediately before the GOP is acquired as GOPi, not the GOP of the frame data corresponding to the current time. Then, the GOP buffer address is set to READ POINTER, and the addresses after the buffer address are written to the HDD 1.
FIG. 10 is a diagram showing the GOPi search process in the second embodiment in the same notation as FIG. In FIG. 10, when the frame data corresponding to the current time exists in GOP # K + 1 (see arrow gt2), this GOP # K + 1 is not set to GOPi but before GOP # K + 1. Set this GOP # K to GOPi. By doing this, even if the frame data corresponding to the current time is a B picture referring to the P picture in GOP # K (broken line rr1), the frame data corresponding to the current time can be decoded. It becomes possible.
[0040]
(Remarks)
Although it has been described based on the above embodiment, it is merely presented as an example of a system that can be expected to have the best effect in the present situation. The present invention can be modified and implemented without departing from the gist thereof. As typical modified embodiments, there are the following (A), (B), (C),...
[0041]
(A) The recording apparatus in the first embodiment to the second embodiment is a type of recording apparatus that is used by being connected to a television monitor, but may be a recording apparatus that is integrated with a liquid crystal display. Good. In addition, the recording apparatus shown in the first embodiment includes the TS decoder 5 and the AV decoder 6 in advance. However, the recording apparatus may not be provided and may be connected via an IEEE1394 connector. Furthermore, in the recording apparatus of each embodiment, only the system control unit 11 that constitutes an essential part of the processing may be a recording apparatus.
[0042]
Since these recording apparatuses are inventions described in the present specification, any of these aspects is based on the internal configuration of the recording apparatus shown in the first to second embodiments. The act of manufacturing the recording device is an implementation act of the invention described in the specification of the present application. The act of transferring the recording apparatus shown in the first embodiment to the second embodiment for a fee or free of charge (sale if paid, or gift if free), lending or importing is also an implementation of the present invention. . The act of applying to the general user to transfer or lend them through store display, catalog solicitation, or pamphlet distribution is also an implementation of this recording device.
[0043]
(B) Information processing by the programs shown in FIGS. 5 to 7 is specifically realized using hardware resources such as a CPU, an MPEG encoder, and an HD drive. That is, the recording device shown in the first embodiment to the second embodiment is constructed by the specific means in which the program and the hardware cooperate to perform information processing according to the purpose of use.
[0044]
Since the information processing by the program is specifically realized using hardware resources, the program whose processing procedure is shown in the above flowchart can be regarded as the creation of a technical idea using the laws of nature. Stand alone as an invention. That is, the processing procedures shown in FIG. 5 to FIG. 7 disclose the mode of implementation of the program according to the present invention.
[0045]
In addition, although 1st Embodiment-2nd Embodiment showed the embodiment about the implementation act of the program based on this invention by the aspect integrated in the recording device, it isolate | separated from the recording device and 1st Embodiment. -The single program shown in the second embodiment may be executed. The act of implementing the program alone includes the act of producing these programs (1), the act of transferring the program for a fee (2), the act of lending (3), the act of importing (4), There is an act of offering to the public via an electronic communication line (5), an act of offering to the general user transfer or rental of the program by store display, catalog solicitation, pamphlet distribution.
[0046]
There are two types of provision (5) via a two-way electronic communication line: the provider sends the program to the user, causes the user to use the program (program download service), and leaves the program at the provider's hand There is an act of providing only the function of the program to the user through the electronic communication line (function providing ASP service).
(C) The “time” element of each step executed in time series in the flow charts of FIGS. 5 to 7 is considered as an indispensable matter for specifying the invention. Then, it can be seen that the processing procedure by these flowcharts discloses the usage mode of the recording method. These flowcharts are the embodiments of the usage of the recording method according to the present invention. If the processing of these flowcharts is performed so that the original purpose of the present invention is achieved and the operations and effects are achieved by performing the processing of each step in time series, the recording according to the present invention is performed. Needless to say, this is an implementation of the method.
[0047]
(D) In the first embodiment to the second embodiment, the description has been made assuming that the recording medium is an HDD, but the physical properties of the HDD do not contribute much to the operation and effect of the present invention. Similar to the HDD, other recording media may be adopted as long as the recording medium has a capacity capable of recording a broadcast program. For example, other optical disks such as CD-R, CD-RW, DVD-R, DVD-RW, DVD-RAM, DVD + R, DVD + RW, and Blue-ray Disc other than HDD may be used. Nor. Further, it may be a magneto-optical disk such as PD or MO. Further, it may be a semiconductor memory card such as an SD memory card, a compact flash (registered trademark) card, a smart media, a memory stick, a multimedia card, and a PCM-CIA card. It may be a flexible disk, a magnetic recording disk such as SuperDisk, Zip, or Clik !, or a removable hard disk drive such as ORB, Jaz, SparQ, SyJet, EZFley, or a microdrive.
[0048]
(E) In the first and second embodiments, assuming that the input speed from the TS decoder 5 to the reproduction buffer 7 greatly exceeds the output speed from the reproduction buffer 7 to the AV decoder 6, the TS decoder 5 Frame data was written to both recording buffers 8. However, if the output speed from the playback buffer 7 to the buffer management table 9 is as fast as the input speed, the data may be written directly from the playback buffer 7 to the HDD 1.
[0049]
(F) In the first embodiment, the TS packet is recorded in the HDD as it is, but may be recorded in a format with an extension header added.
The extension header is called TP_extra_header and includes “Arribval_Time_Stamp” and “copy_permission_indicator” and has a data length of 4 bytes.
“Arribval_Time_Stamp” indicates the time when the TS packet reaches the device. This Arribval_Time_Stamp is used to refer to time stamps such as PCR and PTS during stream reproduction. In general, a stream in MPEG2-TS format transmitted from a broadcasting station is set in PCR and PTS on the assumption that it is received and reproduced in real time. However, in the accumulation and reproduction, the MPEG2-TS format stream is once accumulated in the HDD and then reproduced with a considerable delay in time. In this accumulation reproduction, PCR and PTS values adjusted for real-time reproduction are wasted. Therefore, Arribval_Time_Stamp in TP_extra_header indicates the time when the TS packet reaches the recording device. Therefore, by referring to this Arribval_Time_Stamp at the time of playback, even if the MPEG2-TS format stream is stored on the HDD and played back, playback timing control by PTS and PCR can be realized as in real time playback. it can.
[0050]
“Copy_permission_indicator” is copy control information in the MPEG2-TS format digital stream. If “00”, normal copy free, “11” “No More Copy”, “01” is encrypted. However, there is no requirement for copy free, and “10” means EPN Asserted copy free.
TS packets with extension headers are grouped every 32 and written in three sectors. The group consisting of 32 TS packets with extension headers is 6144 bytes (= 32 × 192 (= 188 + 4)), because this matches 3 sector sizes of 6144 bytes (= 2048 × 3). is there.
[0051]
【The invention's effect】
As described above, the recording apparatus according to the present invention is Configured as described above Therefore, since the same group as the packet that was played back is stored in the recording buffer, even if manual recording is instructed by the user, the group of packets corresponding to the currently displayed frame data is read from the recording buffer and recorded. Can be written to media. Therefore, even if the currently displayed video frame is considerably delayed from the currently received video frame, it is possible to record a moving image on the recording medium without missing the video frame.
[0052]
Writing from the recording buffer to the recording medium is performed by performing a copying operation such as “copying from one medium to another medium” or an editing operation such as “editing data recorded on a certain recording medium”. It is not a trigger. It is triggered by an operation that is also performed in an existing VTR called a recording operation. Therefore, even users who are not prepared to copy and edit between media, or old users who can only use the old VTR, if the scene they want to see appears in front of them, The frame data can be written from the recording buffer to the recording medium.
[0053]
From the viewpoint of reducing the amount of memory mounted, when the receiving means stores a new packet group in the recording buffer, the oldest packet group in the recording buffer is overwritten using the new packet group. You may do it.
[Brief description of the drawings]
FIG. 1 is a diagram showing an internal configuration of a recording apparatus according to the present invention.
FIG. 2 is a diagram schematically illustrating a buffering delay caused by an AV decoder 6 and a reproduction buffer 7;
FIG. 3 shows what TS packet is in the recording buffer 8 when the AV decoder 6 is decoding the frame data at time 05:01 and the TS decoder 5 is receiving the frame data at time 06:04. It is a figure which shows whether it is stored.
FIG. 4 shows what frame data is written to the HDD when the AV decoder 6 is decoding the frame data at time 05:01 and the TS decoder 5 is receiving the data at time 06:04. FIG.
FIG. 5 is a flowchart showing a processing procedure of the TS decoder 5;
FIG. 6 is a flowchart showing a processing procedure of the system control unit 11;
7 is a flowchart showing a processing procedure of the system control unit 11. FIG.
FIG. 8 is a diagram schematically showing a process of searching for a GOP in the recording buffer 8 based on the current time notified from the AV decoder 6;
FIG. 9 is a diagram showing frame data written to the HDD when a 05:06 video frame is decoded by an AV decoder;
FIG. 10 is a diagram illustrating a GOPi search process in the second embodiment with the same notation as in FIG. 8;
[Explanation of symbols]
1 HD drive
2 GOP management table
3 Playback section information
4 Digital tuner
5 TS decoder
6 AV decoder
7 Playback buffer
8 Recording buffer
9 Buffer management table
10 User interface section
11 System controller

Claims (9)

A recording device that writes a plurality of packets transmitted by digital broadcasting to a recording medium when a user who views the playback output of the digital broadcasting performs a recording operation,
The playback output has a buffering delay for storing a group of packets in a playback buffer (i) and converting the packet group into a video frame (ii),
A recording buffer storing the packet group and packet groups received before and after the packet group;
A copy means for copying the packet group and storing it in a recording buffer;
A recording unit that writes a group of packets stored in the recording buffer to a recording medium according to a user's recording operation, and then writes subsequent packets to the recording medium;
A buffer management table indicating the address of each packet group on the recording buffer in association with the display start time of the video frame corresponding to each packet group;
When a user performs a recording operation,
The recording means acquires the display time of the video frame being played back and compares the acquired display time of the video frame with the display start time of the video frame corresponding to each packet group in the buffer management table. The address of the packet group corresponding to the display start time closest to the acquired display time having the display start time before the acquired display time is acquired, and the recording is performed based on the acquired packet group address. A recording apparatus for writing a packet group stored in a buffer to a recording medium . When the recording buffer is full,
The recording apparatus according to claim 1, wherein the copy unit overwrites the oldest packet group in the recording buffer by using the new packet group. The recording apparatus according to claim 2, wherein the video frame is inter-frame encoded using another video frame. The inter-frame encoded video frame is
It has a dependency with the video frame corresponding to the previous packet group, and the recording means
The recording apparatus according to claim 3, wherein a packet group positioned before and after the packet group including the video frame is read from a recording buffer and written to a recording medium. A computer-readable program for causing a computer having a reproduction buffer and a recording buffer to perform a process of writing a plurality of packets transmitted by digital broadcasting on a recording medium when a user who views the reproduction output of the digital broadcasting performs a recording operation. Because
The playback output has a buffering delay for storing a group of packets in a playback buffer (i) and converting the packet group into a video frame (ii),
The recording buffer stores the packet group and packet groups received before and after the packet group,
A copy step of copying the packet group and storing it in a recording buffer;
Recording step for performing a recording process by writing a group of packets stored in the recording buffer to a recording medium in accordance with a user's recording operation, and writing subsequent packets to the recording medium, and generating step for generating a buffer management table To the computer,
The buffer management table indicates the address of each packet group on the recording buffer in association with the display start time of the video frame corresponding to each packet group,
When a user performs a recording operation,
The recording step acquires the display time of the video frame being played back and compares the display time of the acquired video frame with the display start time of the video frame corresponding to each packet group of the buffer management table. The address of the packet group corresponding to the display start time closest to the acquired display time having the display start time before the acquired display time is acquired, and the recording is performed based on the acquired packet group address. A computer-readable program for writing a packet group stored in a buffer to a recording medium . The copying step includes
6. The computer-readable program according to claim 5, wherein when the recording buffer becomes full, the oldest packet group in the recording buffer is overwritten with the new packet group. The computer-readable program according to claim 6, wherein the video frame is inter-frame encoded using another video frame. The inter-frame encoded video frame is
It has a dependency with the video frame corresponding to the previous and next packet groups,
The recording step includes
The computer-readable program according to claim 7, wherein a packet group positioned before and after the packet group including the video frame is read from a recording buffer and written to a recording medium. A recording method for causing a computer having a reproduction buffer and a recording buffer to perform a process of writing a plurality of packets transmitted by digital broadcasting on a recording medium when a user who views the reproduction output of the digital broadcasting performs a recording operation. ,
The playback output has a buffering delay for storing a group of packets in a playback buffer (i) and converting the packet group into a video frame (ii),
The recording buffer stores the packet group and packet groups received before and after the packet group,
A copy step of copying the packet group and storing it in a recording buffer; writing a group of packets stored in the recording buffer to a recording medium in accordance with a user's recording operation; and subsequently writing subsequent packets to the recording medium. A recording step for performing a recording process and a generation step for generating a buffer management table are performed.
The buffer management table indicates the address of each packet group on the recording buffer in association with the display start time of the video frame corresponding to each packet group,
When a user performs a recording operation,
The recording step acquires the display time of the video frame being played back and compares the display time of the acquired video frame with the display start time of the video frame corresponding to each packet group of the buffer management table. The address of the packet group corresponding to the display start time closest to the acquired display time having the display start time before the acquired display time is acquired, and the recording is performed based on the acquired packet group address. A recording method comprising writing a packet group stored in a buffer to a recording medium .

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