Video server, broadcasting system, and read control method

Abstract

To execute read control in consideration of a channel type when reading data of a plurality of channels at each predetermined time.SOLUTION: A video server according to an embodiment comprises: a memory unit that includes a semiconductor memory for storing data of a plurality of channels including a priority channel, which is a channel for giving priority to a read retry, and a non-priority channel, which is a channel other than the priority channel; a server control unit that, when read errors occur in both the priority channel and the non-priority channel in reading the data of the plurality of channels from the memory unit at each predetermined time, preferentially executes the read retry of the priority channel over the read retry of the non-priority channel and executes the read retry of the non-priority channel after the read retry of the priority channel succeeds; and an output unit that outputs the data read from the memory unit by the server control unit.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] Embodiments of the present invention relate to a video server, a broadcast system, and a read control method.

Background Art

[0002] In recent years, due to the progress of miniaturization of semiconductor memories, the probability of error occurrence during data reading has been increasing. Therefore, the frequency of read retry when a data read error occurs has also been increasing. Such semiconductor memories may also be used in a broadcast video server.

[0003] In a broadcast video server, for example, data of a plurality of channels is read every predetermined time (for example, about several tens of milliseconds). And when a read error occurs, a read retry is performed. It is desirable to complete (succeed) the reading every predetermined time including such read retry.

[0004] Also, among the plurality of channels, there are multiple types of channels such as a channel for playback data and a channel for file output.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the above prior art, if the amount of data to be read or the number of channels to be read is large within a predetermined time, there may be a channel for which data reading cannot be completed. Also, depending on the type of channel, the necessity of completing the reading every predetermined time is different. Therefore, there is room for improvement in the data reading method that does not consider the types of channels in the prior art.

[0007] Therefore, the object of the embodiments of the present invention is to provide a video server, a broadcasting system, and a read control method that can perform efficient read control that takes into account the type of channel when reading data from multiple channels at predetermined time intervals. [Means for solving the problem]

[0008] The video server of the embodiment includes a memory unit having semiconductor memory that stores data for a plurality of channels, including a priority channel which is a channel that is given priority for read retries, and non-priority channels which are channels other than the priority channel; a server control unit which, when reading data for the plurality of channels from the memory unit at predetermined time intervals, prioritizes the read retry of the priority channel over the read retry of the non-priority channel when a read error occurs in both the priority channel and the non-priority channel, and after the read retry of the priority channel is successful, executes the read retry of the non-priority channel; and an output unit which outputs the data read from the memory unit by the server control unit. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a block diagram showing an overview of the broadcasting system according to the embodiment. [Figure 2] Figure 2 shows the readout control at a first default time in the embodiment. [Figure 3] Figure 3 shows the readout control at a second default time in the embodiment. [Figure 4] Figure 4 is a flowchart showing the readout control by the video server of the embodiment within a predetermined time. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the present invention, including a video server, a broadcasting system, and a readout control method, will be described with reference to the drawings.

[0011] Figure 1 is a block diagram illustrating an overview of the broadcasting system 1 of an embodiment. The broadcasting system 1 is used, for example, in a television broadcasting station and comprises an operating terminal 2, a camera device 3, a playback deck 4, an editing device 5, broadcasting equipment 6, a monitoring device 7, and a video server 10.

[0012] Broadcasting system 1 records content data (source data), such as video data transmitted from external devices like camera equipment 3, playback deck 4, and editing equipment 5, and outputs the recorded content data to broadcasting equipment 6, etc. Hereinafter, content data will also be simply referred to as "data."

[0013] The operating terminal 2 is, for example, a higher-level control unit or a maintenance terminal, and transmits various data to the video server 10 in response to user operations. Here, various data include, for example, control commands and playback lists. Control commands include, for example, instructions for selecting content data to play, instructions to start playback (on-air instructions), and instructions to end playback (for example, instructions to stop playback).

[0014] Camera device 3 captures video based on user input and records audio via a microphone (not shown). Camera device 3 generates content data by associating (synchronizing) the captured image data (video data) with the recorded audio data. Camera device 3 transmits the generated content data to video server 10 based on user input.

[0015] The playback deck 4 transmits content data recorded on various recording media to the video server 10 based on user operation. These recording media include, for example, flash memory (semiconductor memory), tape media, and hard disks. Alternatively, the recording media may also be, for example, film or audio cassettes. The playback deck 4 may also transmit the content data to the video server 10 via, for example, a baseband signal.

[0016] The editing device 5 transmits (transfers) the edited content data to the video server 10 based on user operations. The editing device 5 may transmit the content data in, for example, the MXF (Material eXchange Format) file format.

[0017] In this embodiment, the camera device 3, playback deck 4, and editing device 5 are examples of transmission devices that send content data to the video server 10.

[0018] The video server 10 records (records) content data of broadcast programs for on-air from transmitting devices such as the camera device 3, playback deck 4, and editing device 5, and selectively plays (transmits) the corresponding content data according to on-air instructions. The video server 10 controls the writing and reading of content data according to instructions based on user operations.

[0019] The video server 10 also includes an acquisition unit 11, a memory device 12, an output unit 13, and a server control unit 14.

[0020] The acquisition unit 11 acquires content data such as video signals sent from, for example, the camera device 3, the playback deck 4, the editing device 5, etc., and executes a recording process for encoding the acquired content data. The acquisition unit 11 executes this recording process based on the control of the server control unit 14 described later, and outputs the encoded content data to the memory device 12. Here, the content data includes, for example, video data, audio data, etc. The acquisition unit 11 has, for example, an encoder for encoding various forms of data.

[0021] The memory device 12 is a storage device that stores (memorizes) content data based on the control of the server control unit 14. The memory device 12 includes a memory control unit 120 and a plurality of memory units 100.

[0022] The memory control unit 120 is a processor including, for example, a CPU (Central Processing Unit), etc., and comprehensively controls the memory device 12. The memory control unit 120, for example, distributes the content data input to the memory device 12 to each memory unit 100 for storage. Also, the memory control unit 120, for example, reads out content data from the memory unit 100 based on the control of the server control unit 14, and outputs the read content data to the output unit 13. Also, the memory control unit 120 transmits a notification of a warning (alarm) received from the memory unit 100 to the server control unit 14.

[0023] The memory unit 100 includes a memory management unit 101, a storage unit 102, and a semiconductor memory 103.

[0024] The memory management unit 101 controls the writing / reading of data to / from the memory unit 100. The memory management unit 101 is, for example, an integrated circuit such as an FPGA (Field Programmable Gate Array).

[0025] The memory unit 102 stores various types of information for controlling the memory unit 100. These types of information include, for example, management information, statistical information, and alarm information.

[0026] Management information includes, for example, information about the write location and area, such as write pages and write blocks, in the semiconductor memory 103, as well as information about free areas, such as free pages and free blocks.

[0027] Statistical information includes, for example, the number of read retries per page / block and the number of read operations for the semiconductor memory 103.

[0028] Alarm information, for example, is information about currently occurring alarms to prevent duplicate alarm notifications.

[0029] The semiconductor memory 103 is, for example, an MLC-type NAND flash memory LSI (Large Scale Integration). Here, MLC type refers to a type that stores multiple levels in a single memory cell.

[0030] The semiconductor memory 103 stores data, and has pages, which are units for reading data and detecting data errors, and blocks, which are units that can be erased all at once.

[0031] The output unit 13, for example, has a decoder for decoding data in various formats, decodes the content data read from the memory device 12, and performs playback processing to output the decoded content data (e.g., video signals). Note that the output unit 13 may be provided separately for each type of data to be output (playback data, file output data, etc.).

[0032] The server control unit 14 is a processor, such as a CPU, and comprehensively controls the video server 10. The server control unit 14 causes the content data acquired by the acquisition unit 11 to be recorded in the memory unit 100 of the memory device 12, and also reads the content data recorded in the memory unit 100 from the memory unit 100.

[0033] Furthermore, the server control unit 14 controls the main processing of the video server 10, such as content data recording, playback, output, and deletion.

[0034] Furthermore, the server control unit 14 classifies the multiple channels into priority channels (channels that have a high need to complete reading within a predetermined time, for example, channels for playback data) and non-priority channels (channels that do not have a low need to complete reading within a predetermined time, for example, channels for file output data), and stores them in the memory unit 100.

[0035] When the server control unit 14 reads data from multiple channels from the memory unit 100 at predetermined intervals (for example, several tens of milliseconds), if a read error occurs in both the priority channel and the non-priority channel, it prioritizes retrying the read operation of the priority channel over retrying the read operation of the non-priority channel. Subsequently, after the read retry of the priority channel is successful, the server control unit 14 performs a read retry on the non-priority channel.

[0036] Furthermore, when reading data from a priority channel, the server control unit 14 calculates how many read retries can be performed on each channel within a predetermined time, based on the data read time per channel, the read retry time per channel, and the number of channels to be read within that predetermined time. It then performs read retries until error-free data reading is completed, a predetermined maximum number of retries is reached, or the predetermined time has elapsed.

[0037] Furthermore, when reading data from a non-priority channel, the server control unit 14 calculates how many read retries can be performed on each channel within a predetermined time, based on the data read time per channel and the read retry time per channel. If error-free data reading is not completed within the predetermined time and the predetermined maximum number of retries is not reached, the remaining read retries are performed at the next predetermined time.

[0038] Furthermore, when the server control unit 14 performs read retries on priority and non-priority channels, for example, it recalculates how many read retries can be performed on each channel within a predetermined time, because the number of channels to be read may have changed due to the start of new playback or file output. It then performs read retries until error-free data is read, the predetermined maximum number of retries is reached, or a predetermined time has elapsed.

[0039] Furthermore, the server control unit 14 terminates the read retry if it fails to read error-free data after performing read retries on the priority channel and non-priority channel a predetermined maximum number of retries.

[0040] The broadcasting equipment 6 receives the reproduced content data from the output unit 13 of the video server 10. The broadcasting equipment 6 broadcasts the reproduced content data. The broadcasting equipment 6 may also broadcast the content data via wired or wireless connection.

[0041] The monitoring device 7 receives the played content data from the output unit 13 of the video server 10. The monitoring device 7 displays the image as content data as a preview on the screen. The monitoring device 7 may also output the audio as content data from a speaker (not shown).

[0042] Next, an example of read control will be explained using Figures 2 and 3. Figure 2 shows the read control at the first default time (the default time immediately preceding the second default time in Figure 3) in the embodiment. Here, it is assumed that predetermined amounts of data from five priority channels "1" to "5" and predetermined amounts of data from six non-priority channels "1" to "6" will be read within the first default time (time t1 to t5).

[0043] First, at times t1 to t2, readouts are performed for the five priority channels "1" to "5". Assume that all readouts for the five priority channels "1" to "5" have failed.

[0044] Next, at times t2 to t3, readouts are performed from the six non-priority channels "1" to "6". Assume that all readouts from the six non-priority channels "1" to "6" have failed.

[0045] Next, at times t3 to t4, read retries are performed for the five priority channels "1" to "5". Note that read retries take longer than the initial read. At this point, we assume that all read retries for the five priority channels "1" to "5" are successful.

[0046] Furthermore, for example, if only priority channel "1" among the five priority channels "1" to "5" failed to read at times t1 to t2, then the system can retry reading priority channel "1" up to six times from time t3 onward.

[0047] Next, since there is some time remaining after time t4, a read retry will be performed on non-priority channel "1" among the six non-priority channels "1" to "6" between times t4 and t5. The read retry for non-priority channel "1" will be considered successful. Read retries for non-priority channels "2" to "6" will be performed at the next predetermined time.

[0048] Figure 3 shows the readout control at the second default time in the embodiment. Here, it is assumed that predetermined amounts of data from the three priority channels "1" to "3" and predetermined amounts of data from the five non-priority channels "2" to "6" that could not be read at the first default time in Figure 2 are read within the second default time (time t11 to t16).

[0049] First, at times t11 to t12, readouts are performed from the three priority channels "1" to "3". Assume that all readouts from the three priority channels "1" to "3" have failed.

[0050] Next, at times t12-t13, readout (retries) is performed for the five non-priority channels "2" through "6". Assume that all readouts for the five non-priority channels "2" through "6" have failed.

[0051] Next, at times t13-t14, read retries are performed for the three priority channels "1" to "3". It is assumed that all read retries for the three priority channels "1" to "3" are successful.

[0052] Next, since there is some time remaining, a read retry will be performed on non-priority channels "2" through "5" out of the five non-priority channels "2" through "6" at times t14-t15. The read retry for non-priority channel "6", which could not be performed due to insufficient time, will be performed at the next predetermined time.

[0053] Next, with reference to Figure 4, the flow of read control within a predetermined time by the video server 10 of the embodiment will be described. Figure 4 is a flowchart showing the read control within a predetermined time by the video server 10 of the embodiment.

[0054] First, in step S1, the server control unit 14 reads the priority channel (times t1 to t2 in Figure 2).

[0055] Next, in step S2, the server control unit 14 reads the non-priority channel (times t2 to t3 in Figure 2).

[0056] Next, in step S3, the server control unit 14 performs read retries on the priority channel (times t3 to t4 in Figure 2). At this time, the server control unit 14 calculates how many read retries can be performed on each channel within a predetermined time, based on, for example, the data read time per channel, the read retry time per channel, and the number of channels to be read within that predetermined time.

[0057] Next, in step S4, the server control unit 14 determines whether the termination conditions for the priority channel read retry have been met. If Yes, it proceeds to step S5; otherwise, it returns to step S3. The termination conditions here are, for example, that at least one of the following (1) to (3) has been met. (1) Error-free data reading complete (2) Reaching the predetermined maximum number of retries (3) The predetermined time has elapsed.

[0058] If (3) is met, steps S5 and S6 are skipped and the processing for the predetermined time is terminated.

[0059] Next, in step S5, the server control unit 14 performs read retries on non-priority channels (times t4 to t5 in Figure 2). At this time, the server control unit 14 calculates how many read retries can be performed on each channel within a predetermined time, based on, for example, the data read time per channel and the read retry time per channel.

[0060] Next, in step S6, the server control unit 14 determines whether the termination condition for reading retries on non-priority channels has been met. If Yes, it terminates the process; otherwise, it returns to step S5. The termination condition here is, for example, the same as in (1) to (3) above.

[0061] Furthermore, if the server control unit 14 fails to complete the reading of error-free data within a predetermined time and does not reach a predetermined maximum number of retries, it will perform the remaining read retries at the next predetermined time.

[0062] Thus, according to the video server 10 of this embodiment, when multiple channels are classified into priority channels and non-priority channels, and data from multiple channels is read at predetermined intervals, priority is given to priority channels for read retries, thereby enabling efficient read control that takes into account the type of channel.

[0063] Furthermore, when reading data from priority channels, the possibility of priority channel read failures can be reduced by calculating how many read retries can be performed on each channel within a predetermined time, based on the data read time per channel, the read retry time per channel, and the number of channels to be read within that predetermined time.

[0064] Furthermore, when reading data from a non-priority channel, if the error-free data reading is not completed within the predetermined time and the predetermined maximum number of retries is not reached, the remaining read retries will be performed at the next predetermined time, allowing the data to be read faster without interfering with the reading of the priority channel.

[0065] Furthermore, when performing read retries on priority and non-priority channels, the number of channels being read may have changed. By recalculating how many read retries can be performed on each channel within a predetermined time, more efficient processing can be achieved.

[0066] Alternatively, the processing for each configuration of the video server 10 described above may be performed by recording a program for realizing the functions of each configuration of the video server 10 in the embodiment onto a computer-readable recording medium, loading the program recorded on this recording medium into a computer system, and executing it. Here, "loading the program recorded on the recording medium into a computer system and executing it" includes installing the program into the computer system. Here, "computer system" includes hardware such as the OS (Operating System) and peripheral devices.

[0067] Furthermore, "computer system" may include multiple computer devices connected via a network, including communication lines such as the Internet, WAN (Wide Area Network), LAN (Local Area Network), and dedicated lines. Also, "computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, ROM (Read Only Memory), CD (Compact Disc)-ROMs, and storage devices such as hard disks built into computer systems. Thus, the recording medium storing the program may also be a non-transient recording medium such as a CD-ROM.

[0068] Furthermore, the recording medium also includes internal or external recording media accessible from the distribution server for distributing the program. The program may be divided into multiple parts, downloaded at different times, and then combined in each configuration of the video server 10, or each divided program may be distributed by a different distribution server. Additionally, "computer-readable recording medium" includes volatile memory (RAM (Random Access Memory)) within computer systems that act as servers or clients when a program is transmitted over a network, which retains the program for a certain period of time. Moreover, the program may be intended to implement only a portion of the functions described above. Furthermore, the program may be a so-called differential file (differential program) that can implement the functions described above in combination with a program already recorded in the computer system.

[0069] Furthermore, some or all of the above-mentioned functions may be implemented as integrated circuits such as LSIs. Each of the above-mentioned functions may be implemented as a separate processor, or some or all of them may be integrated into a single processor. In addition, the method of implementing integrated circuits is not limited to LSIs; they may also be implemented as dedicated circuits or general-purpose processors. Furthermore, if advances in semiconductor technology lead to the emergence of integrated circuit technologies that can replace LSIs, integrated circuits using such technologies may be used.

[0070] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0071] For example, the semiconductor memory 103 is not limited to MLC-type NAND flash memory LSI, but may be other types of semiconductor memory. [Explanation of symbols]

[0072] 1...Broadcasting system, 2...Operation terminal, 3...Camera device, 4...Playback deck, 5...Editing device, 6...Broadcasting equipment, 7...Monitor device, 10...Video server, 11...Acquisition unit, 12...Memory device, 13...Output unit, 14...Server control unit, 100...Memory unit, 101...Memory management unit, 102...Storage unit, 103...Semiconductor memory, 120...Memory control unit

Claims

1. A memory unit comprising semiconductor memory that stores data for multiple channels, including a priority channel which is a channel for on-air playback data that prioritizes read retries, and non-priority channels which are channels other than the priority channel, When reading data from the memory unit for the multiple channels at predetermined time intervals, if a read error occurs in both the priority channel and the non-priority channel, the server control unit prioritizes the read retry of the priority channel over the read retry of the non-priority channel, and after the read retry of the priority channel is successful, it performs the read retry of the non-priority channel. A video server comprising: an output unit that outputs data read from the memory unit by the server control unit to broadcasting equipment.

2. The video server according to claim 1, wherein, when reading data from the priority channels, the server control unit calculates how many read retries can be performed for each channel within the predetermined time based on the data read time per channel, the read retry time per channel, and the number of channels to be read within the predetermined time, and performs read retries until error-free data reading is completed, a predetermined maximum number of retries is reached, or the predetermined time has elapsed, and if the time for read retries for the non-priority channels is insufficient, read retries for the non-priority channels are performed at the next predetermined time.

3. The video server according to claim 2, wherein the server control unit, when reading data from the non-priority channels, calculates how many read retries can be performed on each channel within the predetermined time based on the data read time per channel and the read retry time per channel, and if error-free data reading is not completed and the predetermined maximum number of retries is not reached before the predetermined time has elapsed, it performs the remaining read retries at the next predetermined time.

4. The video server according to claim 3, wherein, when performing the read retry, the server control unit recalculates how many read retries can be performed for each channel within the predetermined time, because the number of channels to be read may have changed, and continues to perform read retries until error-free data is read, a predetermined maximum number of retries is reached, or the predetermined time has elapsed.

5. The video server according to claim 3, wherein the server control unit terminates the read retry if it fails to complete the reading of error-free data even after performing the read retry a predetermined maximum number of retries.

6. A video server according to any one of claims 1 to 5, A transmitting device that transmits the aforementioned data to the video server, Broadcasting equipment for broadcasting the data output from the video server, A broadcasting system equipped with these features.

7. A read control method comprising a server control step in which, when reading data from a plurality of channels at predetermined time intervals from a memory unit equipped with semiconductor memory that stores data for a plurality of channels, including a priority channel which is a channel for on-air playback data that is given priority for read retries, and non-priority channels which are channels other than the priority channel, if a read error occurs in both the priority channel and the non-priority channel, the read retry of the priority channel is given priority over the read retry of the non-priority channel, and after the read retry of the priority channel is successful, the read retry of the non-priority channel is performed, and the data read from the memory unit is output to the broadcast equipment.

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