JP4131032B2 - Data reproducing apparatus and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a data reproducing apparatus and method, and more particularly to a data reproducing apparatus and method suitably used for an AV server system such as a broadcasting station.
[0002]
[Prior art]
An AV server system that stores, reproduces, edits, and distributes AV (audio video) data includes a data storage device including a hard disk array that stores AV data, and a plurality of AV data input and output from the data storage device. AV data input / output interface (hereinafter referred to as channel), a system controller for controlling the entire system, and the like. Each channel includes a memory or the like for adjusting timing when AV data is output from the data storage device or when AV data is input to the data storage device.
[0003]
In the AV server system, the system controller controls these channels to be used in a time-sharing manner uniformly at a constant period, thereby realizing simultaneous parallel processing using multiple channels. In such an AV server system, the allocation time allocated to each channel (hereinafter referred to as a time slot) is periodic and fixed. This time slot is as short as possible because it is necessary to reduce the waiting time of each channel while securing a length that allows the data required for normal speed reproduction to be read into the memory of each channel. It is common to set the length.
[0004]
An AV server system used for business such as a broadcasting station is required to have good responsiveness at the start of AV data reproduction. Also, when editing AV data, variable speed playback such as high speed playback and reverse direction playback is performed, so when accelerating from normal playback to high speed playback, when decelerating from high speed playback to normal playback, Good response and operability are required when changing direction with reverse playback. Specifically, when these execution commands for variable speed reproduction are sent, it is required to promptly shift to smooth reproduction that is faithful to the specified speed / direction and does not drop frames.
[0005]
[Problems to be solved by the invention]
By the way, in a conventional AV server system, it is common to thin out data in units of frames and output them at the time of high-speed reproduction (hereinafter, this reproduction method is referred to as “frame thinning method”). For example, in the time when the image for 30 frames advances at the normal 1 × speed, the image for 60 frames advances in the 2 × speed reproduction. At this time, in the double-speed reproduction by the above-described frame thinning method, a total of 30 frames are output every other frame, for example, in the manner of frame 1, frame 3, frame 5.
[0006]
When high-speed playback using this frame thinning method is performed, the playback image is easy to see because it is completed for each frame, but on the other hand, information is discarded on a frame-by-frame basis. Will occur.
[0007]
Here, FIG. 8 shows output data at the time of double speed reproduction using the frame thinning method. As apparent from FIG. 8, in the playback method using the conventional frame thinning method, for example, frame 1, frame 3, frame 5, frame 7... It can be seen that the data is thinned out every other frame and the data is output at intervals of one frame. For this reason, for example, when searching for an image at the moment of flashing in editing and when the image exists in a frame that is not output (thinned out) such as frame 2 or frame 4, this Since an image is not displayed on a monitor or the like, it is very difficult to search at double speed playback. That is, according to the frame thinning method, there is a problem that work efficiency in editing or the like is poor because the probability that an image existing only in one frame is displayed on a monitor or the like is ½.
[0008]
FIG. 9 shows output data at the time of 4 × speed reproduction using the frame thinning method. As is apparent from FIG. 9, in the playback method using the conventional frame thinning method, for example, frame 1, frame 5, frame 9... By repeating the process of not outputting (thinning out) the data for 3 frames when the data is output, data for 1 frame is output every 4 frames. For this reason, when searching for an image at the moment when the above-mentioned flash is applied at the time of editing, the frame is not output (thinned out) such as frames 2, 3, 4, or frames 6, 7, etc. In such a case, since this image is not displayed on a monitor or the like, it is very difficult to search in 4 × speed reproduction. That is, in this case, since the probability that the image is displayed on a monitor or the like is 1/4, there is a problem that work efficiency in editing or the like is poor.
[0009]
Thus, when editing an image by high-speed playback in a conventional AV server system, when searching for an image recorded instantaneously in only one frame, the image is not displayed on the monitor. There was a problem such as. Therefore, in the AV server system, in order to improve editing efficiency, it has been required to reduce the number of frames discarded during high-speed playback, that is, the number of invisible frames.
[0010]
The present invention has been proposed in view of such a situation, and a data reproducing apparatus that realizes an improvement in searchability by substantially increasing the number of frames to be displayed when performing high-speed reproduction, and It aims to provide a method.
[0011]
[Means for Solving the Problems]
  In order to solve the above problems, a data reproducing apparatus according to the present invention provides:A plurality of data reproduction means for reading image data from a data accumulation means for accumulating image data, storing the read image data in a memory, and performing reproduction processing on the image data stored in the memory, and each data reproduction means Control means for controlling each data reproducing means to allocate time slots of a fixed period, read out the image data from the data storage means at the timing of each time slot and store them in the memory, the control means, A plurality of time slots are assigned to one data reproducing means for performing high-speed reproduction, the image data is read using the plurality of time slots, and the one data reproducing means is controlled to store the read image data in a memory. The one data reproducing means is the image data stored in the memory. For it, perform the reproduction process of generating an image of one frame using two fields different from the image data of two frames.
[0014]
In the data reproducing apparatus, a plurality of time slots are assigned from a control signal to one data reproducing unit that performs high-speed reproduction, and the one data reproducing unit uses the plurality of assigned time slots to convert image data. Read out, temporarily store the read image data, and generate one frame image using two different fields from the image data for two frames, thereby substantially reducing the number of frames to be thinned out To do.
[0017]
  Further, in order to solve the above-described problem, the data reproduction method according to the present invention allows image data to be received by a plurality of data reproduction means each assigned with its own time slot having a fixed period.Accumulated recording mediaIn the data reproduction method for reading out the image data from its own time slot, temporarily storing the read image data, and performing reproduction processing on the stored image data, a plurality of times The slot is assigned, and the one data reproducing means reads the image data using the assigned time slots, and reads the read image data.RememberFor the stored image data, an image of one frame is generated using two different fields from the image data of two frames.
[0018]
In the data reproduction method, a plurality of time slots are assigned to one data reproduction means for performing high-speed reproduction, and the one data reproduction means reads out image data using the assigned plurality of time slots, and reads the read image. By temporarily storing data and generating one frame image using two different fields from the image data for two frames, the number of frames to be thinned out is substantially reduced.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail with reference to the drawings. The AV server system 1 shown in FIG. 1 to which the present invention is applied performs storage, reproduction, editing, distribution, etc. of AV (audio video) data. The disk device 2 in which AV data is stored, and the disk device 2 and a plurality of AV data input / output interfaces 3 (3a, 3b... 3n) for inputting / outputting AV data and a system controller 4 for controlling the entire system.
[0020]
The disk device 2 is of a so-called multi-channel type using a RAID (Redundant Array of Inexpensive Disks) system in which a plurality of hard disk drives (HDDs) are arranged, and AV data is read from or written to a predetermined area of each hard disk. Each channel can be done independently at the same time. In this embodiment, various AV data is stored in a predetermined area of the hard disk in a file format.
[0021]
As shown in FIG. 1, the AV data input / output interface 3 includes a processor 5 and a memory 6. Here, the processor 5 accesses a predetermined area of each hard disk of the disk device 2 based on the time slot assigned by the system controller 4. Further, the processor 5 controls the storage / reading of data to / from the memory 6 based on the time slot assigned by the system controller 4, so that the AV data is output from the disk device 2 or the AV data to the disk device 2 is output. Adjust the timing when inputting. As shown in FIG. 2, the memory 6 includes three banks (Bank # A, Bank # B, and Bank # C). For convenience of explanation, the AV data input / output interfaces 3a, 3b,..., 3n are referred to as channel (ch) 1, channel 2,.
[0022]
In this AV server system 1, in order to perform recording or reproduction processing of AV data on n channels simultaneously with n channels, the time during which the system controller 4 can access the disk device 2 with respect to each channel (time slot) ) In time division. Specifically, as shown in FIG. 2, the system controller 4 sets one period as a fixed period, further divides this one period into n equal parts, and divides each period into channels 1 to n. They are assigned as time slots in order. Therefore, a time slot is assigned to one channel in a period of one cycle once every n times, which is 1 / n time of one cycle.
[0023]
Here, the length of the time slot allocated to one channel is the AV data that can be continuously reproduced during one period until the next time slot comes (hereinafter referred to as one time slot period). It is a time that can be stored from the device 2 in one bank of the memory 6 of the channel. For example, considering channel 1, when the time slot of channel 1 comes, data for one time slot period is stored in bank B, and the data stored in bank B at the same time as the time slot of channel 2 is stored. To play. Then, as shown in FIG. 2, when the time slot of channel 1 of the next period comes, data is stored in bank A, and data reproduction in bank B is continued until this storage is completed. . When the time slot of channel 2 is reached, the data reproduction of the bank B is completed, and the data stored in the bank A is reproduced at the same time.
[0024]
By performing such processing, in the AV server system 1, the AV from the bank of any one of the memories 6 until the time slot for own use (hereinafter referred to as the own time slot) comes in each channel. Since data is continuously output, it is possible to continue playback without interruption.
[0025]
On the other hand, when recording the input data, AV data is stored in one of the banks of the memory 6 during one time slot period by the reverse process to the above, and when the own time slot comes, A process of writing to the disk device 2 is performed. Therefore, the length of one time slot cycle is set so that AV data necessary for normal speed reproduction can be read and stored in one bank of the memory 6 and as short as possible. Is done.
[0026]
The system controller 4 controls the processor 5 of each channel based on the input / output control signal supplied from the external block. This input / output control signal includes commands such as data recording, reproduction, stop, high speed reproduction, reverse direction reproduction, etc. for each channel, and additional information such as reproduction magnification at high speed reproduction.
[0027]
Based on the control of the system controller 4, the processor 5 of each channel performs AV data recording / reproducing processing as follows. When the data is recorded, the processor 5 converts the AV data supplied from the external block into a data format to be recorded on the hard disk of the disk device 2, performs compression processing as necessary, Data is sequentially stored in each bank of the memory 6, and when the time slot comes, the data is transmitted to the disk device 2 and recorded. As the compression process, for example, an MPEG system using correlation between frames, a DV system which is intra-frame compression, or the like can be considered. Of course, the input data may be recorded as it is without being compressed.
[0028]
On the other hand, when reproducing the recorded data, the processor 5 reads the data for one time slot period from the disk device 2 at the time when the own time slot comes, stores it in any bank of the memory 6, and When the own time slot arrives, the data is decompressed as necessary, further converted into the AV data format and output to the external block. Are read out and stored in another bank of the memory 6.
[0029]
Furthermore, the system controller 4 in the AV server system 1 uses an unused channel when any channel shifts to a high-speed reproduction mode such as double speed or quadruple speed based on the supplied input / output control signal. And a process of assigning the time slot for the empty channel to the channel for performing the high-speed playback described above. Specifically, when any channel performs N-times high-speed playback, the system controller 4 assigns N time slots to the channel.
[0030]
By performing such control, the AV server system 1 can read a continuous area on the hard disk from the disk device 2, thereby eliminating the occurrence of insufficient reading caused by accessing a skipped area. Smooth playback without dropping frames according to the specified speed becomes possible.
[0031]
For example, considering the case of performing double-speed playback on channel 1, the system controller 4 detects an unused channel that is not used, and, as shown in FIGS. Are assigned as channel 1 time slots. As a result, the channel 1 reads data for two time slots together with its own time slot from the disk device 2, stores it in two banks of the memory 6, and outputs the reproduction magnification (in this case 2). By performing decimation in field units according to (double speed) and generating one frame image using two different fields from data for two frames, smooth image reproduction at a specified speed is realized.
[0032]
Specifically, the processor 5 of the channel 1 thins out the second field of the n frame and the first field of the (n + 1) frame with respect to the data stored in the memory 6, and the first field of the n frame and the (n + 1) ) The process of combining the second field of the frame and outputting it as an image of one frame is repeated.
[0033]
FIG. 5 shows data output when this double speed reproduction is performed. Here, FIG. 5 shows a case where the reproduction method of the present invention is applied to (a) and a case where the frame thinning method described above is applied to (b).
[0034]
When the frame decimation method is used, when performing double-speed reproduction, for example, frame 1, frame 3, frame 5, frame 7. Since data is output at intervals, as described above, the probability that an image recorded instantaneously in only one frame is displayed on a monitor or the like is ½.
[0035]
On the other hand, according to the AV server system 1, as shown in FIG. 5A, when performing double-speed playback, for example, the first field of frame 1 and the second field of frame 2 are synthesized. For all frames, such as an image, an image obtained by combining the first field of frame 3 and the second field of frame 4, an image obtained by combining the first field of frame 5 and the second field of frame 6, and so on. Will be output. Therefore, according to the AV server system 1, when searching for an image that is instantaneously recorded in one frame, such as the above-described flashing moment, when the editing is performed, Even if it exists in the frame, since this image is displayed on the monitor or the like, the search becomes very easy in terms of time and labor, and the efficiency of the editing work is greatly improved.
[0036]
FIG. 6 shows the output data when 4 × speed reproduction is performed. Here, FIG. 6 shows a case where the reproduction method of the present invention is applied to (a) and a case where the frame thinning method described above is applied to (b).
[0037]
In the conventional playback method, at the time of 4 × playback, for example, frame 1, frame 5, frame 9, etc., data for one frame is output in units of frames, but data for three frames is not output. By repeating the (thinning-out) process, data for one frame is output every four frames. As described above, the probability that an image recorded instantaneously in only one frame is displayed on a monitor or the like is 1/4.
[0038]
On the other hand, according to the AV server system 1, as shown in FIG. 6A, when 4 × speed reproduction is performed, for example, the first field of frame 1 and the second field of frame 2 are combined. More frames such as an image, an image obtained by combining the first field of frame 5 and the second field of frame 6, an image obtained by combining the first field of frame 9 and the second field of frame 10, and so on. An image about is output. Therefore, according to the AV server system 1, when searching for an image that is instantaneously recorded in one frame, such as the above-described flashing moment, when editing, the image is displayed on a monitor or the like. Since the probability of being displayed is high (in this case, the probability is ½), the search efficiency is greatly improved.
[0039]
Note that the output data when performing the 4 × speed reproduction is not limited to the above-described example, for example, an image obtained by combining the first field of frame 1 and the second field of frame 3, the first field of frame 5 and frame 7. May be performed, and an image obtained by combining the first field of frame 1 and the second field of frame 4, and the first field of frame 5 It is also possible to perform processing such as an image synthesized with the second field of the frame 8. Of course, the frames to be combined are generally closer to each other as the frames are separated from each other, and are difficult to see when displayed on a monitor or the like. The fields in different frames are combined.
[0040]
Next, an example of control when high-speed playback is performed using the editing apparatus 10 as the external block shown in FIG. 1 in the AV server system 1 will be described with reference to the flowchart of FIG. The editing apparatus 10 selects an arbitrary channel, transmits / receives a signal to / from the processor 5 and the system controller 4 of the selected channel, and displays AV data supplied from the selected channel. .
[0041]
In step S1, the processor 5 of one of the channels receives an open command for opening a predetermined file from the editing device 10. This open command is a command for acquiring an access right to a predetermined file. This is for prohibiting or permitting access to an open command target file, for example, when it is currently being recorded and its contents are constantly changing.
[0042]
In the next step S <b> 2, the processor 5 of the channel that has received this open command issues a command to the system controller 4 for acquiring information on which area of the disk device 2 the file is stored.
[0043]
In step S3, the system controller 4 notifies the processor 5 of the area of the disk device 2 in which the file is stored. Receiving this notification, the processor 5 transmits to the editing device 10 a permission command indicating that a playback command may be issued in the next step S4. That is, a permission notice for the above open command is transmitted. By this permission command, access to a file (either one file or a plurality of files) specified by the open command is permitted.
[0044]
In step S5, the editing apparatus 10 that has received this permission command transmits to the processor 5 a command that specifies the speed (magnification) for reproducing the file. This command is received by the system controller 4 via the processor 5.
[0045]
In step S6, the system controller 4 that has received this playback speed designation command detects a free time slot and assigns it to the channel to be used. As a result, a plurality of time slots are assigned per cycle for the channel. Specifically, in step S6, the system controller 4 assigns N time slots to the channel in one cycle when performing N-times speed playback as described above.
[0046]
In the next step S7, the processor 5 of the channel reads the AV data of the file from the storage area of the disk device 2 notified in step S3 according to the allocated time slot, and stores the data in a predetermined bank of the memory 6. To do. When the processor 5 of the channel finishes storing the data in one bank, it reproduces the data and outputs it to the editing apparatus 10 in subsequent step S8. At this time, the processor 5 thins out the data stored in the memory 6 in units of fields according to the reproduction magnification, synthesizes two different fields from the data of two frames, and generates a one-frame image. Is output to the editing apparatus 10. That is, when the file playback speed is double speed, the processor 5 thins out the second field of the n frame and the first field of the (n + 1) frame as described above, and the first field of the n frame and the ( n + 1) The process of combining the second field of the frame and outputting it as an image of one frame to the editing apparatus 10 is repeated. The same process is repeated at the time of 4 × speed reproduction or higher, and the process of combining different fields from 2 frames of data and outputting one frame is repeated.
[0047]
As a result, as described with reference to FIGS. 5 and 6, images for a larger number of frames are displayed on the editing apparatus 10, thereby greatly improving the search efficiency in editing work.
[0048]
As described above, according to the AV server system 1, the system controller 4 assigns a plurality of time slots to one channel for performing high-speed reproduction at N times speed, so that the one channel can be read from the disk device 2. When the reproduction process is performed with high-speed reproduction, it is possible to read and process a continuous area from the hard disk of the disk device 2. Further, the one channel performs thinning out in units of fields according to the reproduction magnification when outputting the read data, and synthesizes two different fields from the data for two frames and outputs as one frame image Therefore, the number of frames displayed on the monitor etc. will increase to a substantial number, and when searching for images etc. of objects that have been recorded instantaneously in several frames or objects that have crossed at high speed, the work efficiency Is greatly improved.
[0049]
In this embodiment, the disk device 2 is configured using an HDD. However, the present invention is not limited to this, and any recording medium capable of nonlinear access (random access) may be used. Therefore, the disk device 2 may be configured using an optical disk such as a DVD (Digital Video Disk) or an MO (Magneto-Optical disk), a magneto-optical disk, or the like.
[0050]
In this embodiment, the number of divisions in one period of the time slot is the same as the number of channels. However, the present invention is not limited to this, and the number of divisions in one period of the time slot is determined from the number of channels. In many cases, a so-called spare time slot may be provided. As a result, even when all channels are used, a spare time slot can be further allocated to a channel for high-speed playback, so that the operability of the entire system can be improved.
[0051]
【The invention's effect】
As described above in detail, according to the data reproducing apparatus and method of the present invention, when the recorded data is reproduced at a high speed, the data reproducing means stores two frames for the image data stored in the memory. By generating an image of one frame using two different fields from minute image data, the number of frames to be thinned out can be substantially reduced, and the number of frames to be displayed can be substantially increased. Searchability is improved.
[0052]
Further, according to the data reproducing apparatus and method of the present invention, a plurality of time slots are assigned from a control signal to one data reproducing means that performs high-speed reproduction, and the one data reproducing means is assigned to a plurality of assigned data reproducing means. By reading the image data using the time slot of the first time, storing the read image data once, and generating one frame image using two different fields from the image data of two frames for the stored image data. Since the number of frames to be drawn is substantially reduced and the number of frames to be displayed can be substantially increased, searchability is improved in an AV server system or the like that uses a plurality of data reproducing means in a time-sharing manner. It is done.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an AV server system to which the present invention is applied.
FIG. 2 is a diagram showing a memory configuration of each AV data input / output interface;
FIG. 3 is a diagram for explaining a case where high-speed playback is performed on channel 1;
FIG. 4 is a diagram for explaining a case where high-speed playback is performed on channel 1;
FIG. 5 is a diagram for explaining data output when performing double-speed playback in an AV server system;
FIG. 6 is a diagram for explaining data output when performing 4 × speed reproduction in an AV server system;
FIG. 7 is a flowchart illustrating an example of control when high-speed playback is performed using an editing apparatus.
FIG. 8 is a diagram for explaining data output when performing double speed reproduction by thinning out frames;
FIG. 9 is a diagram for explaining data output in the case of performing 4 × speed reproduction by thinning out frames.
[Explanation of symbols]
1 AV server system, 2 disk device, 3 (3a, 3b... 3n) AV data input / output interface, 4 system controller, 5 processor, 6 memory

Claims (7)

A plurality of data reproduction means for reading out the image data from the data storage means for storing the image data, storing the read image data in a memory, and performing a reproduction process on the image data stored in the memory;
A control means for allocating a time slot of a fixed period to each of the data reproduction means, and for controlling the data reproduction means so that image data is read from the data storage means and stored in the memory at the timing of each time slot. Prepared,
The control means assigns a plurality of time slots to one data reproducing means for performing high-speed reproduction, reads image data using the plurality of time slots, and stores the read image data in a memory. Control the playback means,
The one data reproduction means performs a reproduction process for generating an image of one frame using two different fields from the image data of two frames for the image data stored in the memory. . The one data reproduction means performs a reproduction process for generating an image of one frame by combining the first field of n frames and the second field of (n + 1) frames with respect to the image data stored in the memory. 2. The data reproducing apparatus according to claim 1, wherein 2. A data reproducing apparatus according to claim 1, wherein said control means assigns N time slots to one data reproducing means for performing high speed reproduction at N times speed . 2. The control unit according to claim 1, wherein the control unit detects a use state of each data reproducing unit, and assigns a time slot for another unused data reproducing unit to one data reproducing unit that performs high-speed reproduction. The data reproducing apparatus described .   The data reproducing apparatus according to claim 1, further comprising storage means for storing the image data.   2. The data reproducing apparatus according to claim 1, further comprising a memory for storing the image data read by the reproducing means.   The image data is read out from the recording medium storing the image data using the own time slot by a plurality of data reproducing means each assigned with a fixed period of the own time slot, and the read image data is temporarily stored and stored. In a data reproduction method for performing reproduction processing on image data,
  For one data playback means that performs high-speed playback, assign multiple time slots,
  The one data reproducing means reads the image data using the plurality of assigned time slots, stores the read image data, and stores two different fields from the image data for two frames for the stored image data. Use to generate one frame image
  A data reproduction method characterized by the above.

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