JP2004064366A - Information providing apparatus and method, information processing apparatus and method, recording medium, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain the real-time property of a motion image, regardless of the band of a network or an operation speed at a receiver side. <P>SOLUTION: A low-resolution encoder 20 generates a motion image having a resolution lower than that of an original motion image on the basis of the motion image provided from a decoder 13. A memory controller 15 controls the storage of the low-resolution motion image into a buffer memory 16. When a transmission request of a frame is received from the receiver side, a system control CPU 11 controls the transmission of a single frame which is lastly stored among the low-resolution motion images stored in the buffer memory 16 to the receiver side via a network 2. The CPU 11 makes the memory controller 15 delete frames stored before the transmitted frame. This apparatus is applicable to a recording/reproducing apparatus 1 constituting a communication system. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an information providing apparatus and method, an information processing apparatus and method, a recording medium, and a program, and particularly to an information providing apparatus and method for providing a moving image or reproducing the provided moving image, and an information processing apparatus. And a method, a recording medium, and a program.
[0002]
[Prior art]
It is common practice to transmit and receive low-resolution images or sounds via a network.
[0003]
First, images or sounds are transmitted and received for viewing.
[0004]
When an image or a sound is transmitted and received for viewing, the image or the sound is transmitted and received in a PLAY mode (so-called stream) in principle. When transmitting or receiving an image or sound in the PLAY mode, a buffer is generally provided on the receiving side, and the effect of the buffer absorbs fluctuations due to the network bandwidth and the calculation speed of the personal computer. Even in modes other than PLAY, transmission or reception of images or sounds is possible, but lacks real-time performance because a buffer is provided.
[0005]
Second, complete data may be transmitted and received as a file for online editing. In this case, no real-time property is required.
[0006]
Third, in order to create a file, an image or sound is transmitted and received in order to find the beginning of the file and the end point of the file. In this case, real-time property corresponding to reversal and speed change is strongly required.
[0007]
In particular, in the third application, real-time performance is strongly required, but when transmitting all image and audio data, when the network bandwidth is narrow relative to the required transmission speed, or when the personal computer on the receiving side is used. When the calculation speed is slow, the processing cannot be performed in time, and as a result, the real-time property deteriorates.
[0008]
[Problems to be solved by the invention]
As described above, when moving images are communicated, when the bandwidth of the network is narrow, or when the calculation speed of the personal computer on the receiving side is low, there is a problem that the real-time property may not be maintained.
[0009]
The present invention has been made in view of such a situation, and it is an object of the present invention to maintain the real-time property of a moving image irrespective of a network band or a calculation speed of a receiving side.
[0010]
[Means for Solving the Problems]
An information providing apparatus according to the present invention includes: a generation unit configured to generate a second moving image having a lower resolution than a first moving image based on a first moving image to be provided; Storage control means for controlling the storage of a moving image of a second moving image via a network, when a frame transmission request is received from a receiving side; Transmission control means for controlling transmission of one frame to the receiving side, and erasing means for erasing a frame stored before the transmitted frame.
[0011]
The information providing method according to the present invention includes a generating step of generating a second moving image having a lower resolution than a first moving image based on a first moving image to be provided; A storage control step of controlling the storage of a moving image of the second moving image, when a frame transmission request is received from the receiving side, the last stored one of the stored second moving images via the network. A transmission control step of controlling transmission of one frame to a receiving side; and an erasing step of erasing a frame stored before the transmitted frame.
[0012]
The program of the first recording medium according to the present invention includes: a generating step of generating a second moving image having a lower resolution than the first moving image based on the first moving image to be provided; A storage control step of controlling the storage of the stored second moving image, and, if a frame transmission request is received from the receiving side, the last of the stored second moving images via the network. A transmission control step of controlling transmission of one stored frame to a receiving side and an erasing step of erasing a frame stored before the transmitted frame are included.
[0013]
A first program according to the present invention includes a generating step of generating a second moving image having a lower resolution than a first moving image based on a first moving image to be provided; And a storage control step of controlling storage of the second moving image, and when a frame transmission request is received from the receiving side, the last stored second moving image of the stored second moving images via the network. The computer is characterized by causing a computer to execute a transmission control step of controlling transmission of one frame to a receiving side and an erasing step of erasing a frame stored before the transmitted frame.
[0014]
An information processing apparatus according to the present invention includes: a transmission control unit configured to control transmission of a transmission request of one frame of a moving image to an information providing apparatus that provides a moving image via a network; It is characterized by including reception control means for controlling reception of one frame of a moving image transmitted from the apparatus, and reproducing means for reproducing a moving image based on the received frame of the moving image.
[0015]
An information processing method according to the present invention includes a transmission control step of controlling transmission of a transmission request for one frame of a moving image to an information providing apparatus that provides a moving image via a network, and providing information via the network. The method includes a reception control step of controlling reception of one frame of a moving image transmitted from the apparatus, and a reproduction step of reproducing a moving image based on the received frame of the moving image.
[0016]
A program on a second recording medium according to the present invention includes a transmission control step of controlling transmission of a transmission request for one frame of a moving image to an information providing apparatus for providing a moving image via a network, A reception control step of controlling reception of one frame of the moving image transmitted from the information providing apparatus, and a reproduction step of reproducing the moving image based on the received frame of the moving image. And
[0017]
A second program according to the present invention includes: a transmission control step of controlling transmission of a transmission request for one frame of a moving image to an information providing apparatus for providing a moving image via a network; A computer controls a reception control step of controlling reception of one frame of a moving image transmitted from the providing apparatus, and a reproduction step of reproducing a moving image based on the received frame of the moving image. And
[0018]
In the information providing apparatus and method, the first recording medium, and the first program according to the present invention, based on the first video to be provided, the second video having a lower resolution than the first video. Is generated, and the generated second moving image is stored. When a frame transmission request is received from the receiving side, one last stored frame of the stored second moving images is transmitted to the receiving side via the network. Then, the frames stored before the transmitted frame are deleted.
[0019]
A network refers to a mechanism in which at least two devices are connected and information can be transmitted from one device to another device. Devices communicating via the network may be independent devices or internal blocks constituting one device.
[0020]
In addition, reception or transmission is not only reception or transmission by wireless and reception or transmission by wire, but also reception or transmission in which wireless and wire are mixed, that is, reception or transmission by wireless is performed in a certain section, and wired or wireless in another section. May be received or transmitted. Furthermore, reception or transmission from a certain device to another device may be performed by wire, and reception or transmission from another device to a certain device may be performed by wireless communication.
[0021]
The information providing device may be an independent device or a block that performs an information providing process of the information processing device.
[0022]
In the information processing apparatus and method, the second recording medium, and the second program according to the present invention, a transmission request for one frame of a moving image is transmitted to the information providing apparatus that provides the moving image via a network. One frame of a moving image transmitted from the information providing apparatus via the network is received. The moving image is reproduced based on the received frame of the moving image.
[0023]
A network refers to a mechanism in which at least two devices are connected and information can be transmitted from one device to another device. Devices communicating via the network may be independent devices or internal blocks constituting one device.
[0024]
In addition, reception or transmission is not only reception or transmission by wireless and reception or transmission by wire, but also reception or transmission in which wireless and wire are mixed, that is, reception or transmission by wireless is performed in a certain section, and wired or wireless in another section. May be received or transmitted. Furthermore, reception or transmission from a certain device to another device may be performed by wire, and reception or transmission from another device to a certain device may be performed by wireless communication.
[0025]
The information processing device may be an independent device or a block that performs information processing of an electronic device.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a diagram showing an embodiment of a communication system according to the present invention.
[0027]
The recording / reproducing device 1 is, for example, a VCR (Videocassette Recorder) or the like, and is connected to a personal computer 3 via a network 2 such as a local area network or the Internet.
[0028]
The recording / reproducing apparatus 1 is connected to the network 2 via a network cable 4-1 conforming to a standard such as 100Base-T, for example.
[0029]
The personal computer 3 is connected to the network 2 via a network cable 4-2 such as 100Base-T, for example.
[0030]
The recording / reproducing apparatus 1 records image and audio data or reads recorded image and audio data by an asynchronous operation as described later.
[0031]
The recording / reproducing apparatus 1 transmits image and audio data read from the mounted video cassette to the personal computer 3 via the network 2. The recording / reproducing apparatus 1 records image and audio data supplied from, for example, a personal computer 3 via a network 2 to a mounted video cassette.
[0032]
The personal computer 3 transmits a predetermined command to the recording / reproducing device 1 via the network 2 and controls the recording / reproducing device 1.
[0033]
When displaying an image, the personal computer 3 requests one frame of image data from the recording / reproducing apparatus 1 via the network 2.
[0034]
When one frame of image data is requested from the personal computer 3, the recording / reproducing apparatus 1 transmits one frame of image data to the personal computer 3 via the network 2.
[0035]
The personal computer 3 displays an image based on the image data of one frame transmitted from the recording / reproducing device 1.
[0036]
It should be noted that metadata such as time code data can be superimposed on the data transmitted from the recording / reproducing apparatus 1.
[0037]
In addition, as a method of the network 2, an arbitrary method such as a wired or wireless method can be adopted, and the present invention is not limited thereto.
[0038]
FIG. 2 is a block diagram illustrating a configuration of the recording / reproducing apparatus 1.
[0039]
The system control CPU (Central Processing Unit) 11 is, for example, an embedded computer having a built-in RAM (Random-Access Memory) or a ROM (Read-Only Memory), executes a predetermined control program, and executes the entire recording / reproducing apparatus 1. Control. The VCR system unit 12 runs a tape of a video cassette mounted on the recording / reproducing apparatus 1 under the control of the system control CPU 11 to record or reproduce image and audio data. The VCR system unit 12 reads out the image and audio data recorded on the mounted video cassette and reproduces the read image and audio data when reproducing the image and audio data recorded on the mounted video cassette. And audio data is supplied to the decoder 13. When recording the image and audio data on the mounted video cassette, the VCR system unit 12 records the image and audio data supplied from the encoder 14 on the video cassette.
[0040]
The decoder 13 decodes the image and audio data supplied from the VCR system unit 12 under the control of the system control CPU 11, and supplies the decoded image and audio data to the memory controller 15 and the low-resolution encoder 20. I do. For example, under the control of the system control CPU 11, the decoder 13 decodes image and audio data encoded by the motion JPEG (Joint Photographic Experts Group) system or the MPEG (Motion Picture Experts Group) 2 system.
[0041]
The encoder 14 encodes the image and audio data supplied from the memory controller 15 by a predetermined method under the control of the system control CPU 11, and supplies the encoded image and audio data to the VCR system unit 12. I do. For example, the encoder 14 encodes the image and audio data supplied from the memory controller 15 under the control of the system control CPU 11 using the motion JPEG method or the MPEG2 method.
[0042]
It should be noted that a desired method can be adopted as a method of image and audio data, and the present invention is not limited to this method.
[0043]
The memory controller 15 stores the image and audio data supplied from the decoder 13 or the TCP / IP processing unit 18 in the buffer memory 16 in order, and transfers the image and audio data stored in the buffer memory 16 to the encoder 14 or It is supplied to the TCP / IP processing unit 18 in order.
[0044]
The buffer memory 16 is a semiconductor memory having a predetermined capacity, such as a DRAM (Dynamic RAM), and stores image and audio data under the control of the memory controller 15, and stores the stored image and audio data. Is read. The buffer memory 16 is controlled by the memory controller 15 as, for example, a ring buffer.
[0045]
The memory monitor 17 acquires data indicating the amount of image and audio data stored in the buffer memory 16 from the memory controller 15 and supplies the acquired data to the system control CPU 11.
[0046]
The TCP / IP processing unit 18 executes TCP (Transmission Control Protocol) processing and IP (Internet Protocol) processing under the control of the system control CPU 11, and performs predetermined processing on image and audio data supplied from the memory controller 15. And supplies it to the network interface 19. When receiving a packet from the network interface 19, the TCP / IP processing unit 18 executes TCP processing and IP processing, extracts data stored in the packet, and supplies the extracted data to the memory controller 15. Alternatively, a command stored in the packet is extracted, and the extracted command is supplied to the command interpreter 21.
[0047]
The network interface 19 is composed of, for example, an NIC (Network Interface Card), and transmits a packet supplied from the TCP / IP processing unit 18 to the network 2 and supplies a packet received from the network 2 to the TCP / IP processing unit 18. I do.
[0048]
Under the control of the system control CPU 11, the low-resolution encoder 20 converts the image and audio data supplied from the decoder 13 into lower-resolution image and audio data, that is, data with a small amount of information per unit time (low data). Rate data), and supplies the converted image and audio data to the memory controller 15.
[0049]
The data supplied to the decoder 13 is high-rate data (data with a large amount of information per unit time), and if it is sent to the network 2 as it is, the bandwidth of the network 2 (the amount of data that can be communicated per unit time) is reduced. Due to the limitation, as described later, there is a high possibility that the reading of image and audio data from the video cassette of the VCR system unit 12 is stopped.
[0050]
Therefore, the output of the decoder 13 is passed through the low-resolution encoder 20 to be converted into low-rate image and audio data, and the low-rate image and audio data is stored in the buffer memory 16 via the memory controller 15. Add a route to be used.
[0051]
The command interpreter 21 interprets the command extracted from the packet supplied from the TCP / IP processing unit 18 and supplies data indicating the interpreted result to the system control CPU 11. For example, the command interpreter 21 interprets the VCR tape running control command extracted from the packet and supplies data indicating the interpreted result to the system control CPU 11.
[0052]
When data indicating a result of interpretation of a command is supplied from the command interpreter 21, the system control CPU 11 executes control corresponding to the command. For example, the system control CPU 11 executes speed control of the VCR system unit 12 based on data corresponding to a VCR tape running control command. The VCR system unit 12 reads image and audio data from the mounted video cassette based on speed control by the system control CPU 11 and supplies the read image and audio data to the decoder 13.
[0053]
The drive 22 reads a program or data from the mounted magnetic disk 41, optical disk 42, magneto-optical disk 43, or semiconductor memory 44 and supplies the read program or data to the system control CPU 11.
[0054]
Next, the operation of the recording / reproducing apparatus 1 when reproducing images and sounds recorded on the video cassette mounted on the VCR system unit 12 will be described.
[0055]
The memory monitor 17 constantly monitors the amount of image and audio data stored in the buffer memory 16. The memory monitor 17 notifies the system control CPU 11 when image and audio data having a threshold value or more stored in advance is stored in the buffer memory 16. For example, the memory monitor 17 notifies the system control CPU 11 when image and sound data of 85% or more of the capacity of the buffer memory 16 is stored in the buffer memory 16.
[0056]
The threshold value used for notification of the system control CPU 11 can be set arbitrarily.
[0057]
The memory monitor 17 simply notifies the amount of image and audio data stored in the buffer memory 16 to the system control CPU 11, and the system control CPU 11 sends the image and audio data having a threshold value or more to the buffer memory 16. It may be determined whether or not the data is stored.
[0058]
The system control CPU 11 causes the VCR system unit 12 to stop the running of the tape of the video cassette when the notification that the predetermined amount of image and sound data is stored in the buffer memory 16 is supplied from the memory monitor 17. And wait for the next reproduction.
[0059]
The memory monitor 17 notifies the system control CPU 11 when the amount of image and audio data stored in the buffer memory 16 becomes equal to or less than the threshold value stored in advance. For example, the memory monitor 17 notifies the system control CPU 11 when the amount of image and audio data stored in the buffer memory 16 becomes 15% or less of the capacity of the buffer memory 16.
[0060]
The threshold value used for notification of the system control CPU 11 can be set arbitrarily.
[0061]
The memory monitor 17 simply notifies the system control CPU 11 of the amount of image and audio data stored in the buffer memory 16, and the system control CPU 11 transmits the image and audio data stored in the buffer memory 16. May be determined as to whether or not the amount becomes equal to or less than a threshold value stored in advance.
[0062]
When the memory monitor 17 supplies a notification that the image and audio data stored in the buffer memory 16 has become equal to or less than a predetermined value, the system control CPU 11 sends the video cassette tape to the VCR system unit 12. Start running. The VCR system section 12 supplies image and audio data read from the video cassette to the decoder 13.
[0063]
As described above, the operation of stopping the reading of the image and audio data from the video cassette by the VCR system unit 12 and the operation of starting the operation are performed in accordance with the amount of the image and audio data stored in the buffer memory 16. Repeated.
[0064]
The decoder 13 decodes the image and audio data supplied from the VCR system unit 12 and supplies the decoded image and audio data to the memory controller 15 or the low-resolution encoder 20. When the image and sound data decoded by the decoder 13 are transmitted to the personal computer 3 as they are, the decoder 13 supplies the decoded image and sound data to the memory controller 15.
[0065]
The decoder 13 compares the decoded image and sound data to the low-resolution encoder 20 when transmitting the lower-resolution image and sound data to the personal computer 3 in comparison with the image and sound data decoded by the decoder 13. Supply.
[0066]
The low-resolution encoder 20 generates lower-resolution image and audio data based on the image and audio data supplied from the decoder 13. Here, the low resolution means the case where the resolution is low in the spatial direction, that is, the case where the number of pixels per frame is reduced, and the case where the resolution is low in the time direction, that is, the number of frames per unit time. Includes both cases in which is reduced.
[0067]
The low-resolution encoder 20 supplies the generated low-resolution image and audio data to the memory controller 15.
[0068]
The memory controller 15 stores the image and audio data supplied from the decoder 13 or the low-resolution encoder 20 in the buffer memory 16.
[0069]
The system control CPU 11 recognizes the amount of image and audio data stored in the buffer memory 16 based on the signal (memory storage information) supplied from the memory monitor 17. When a predetermined amount of image and audio data is stored in the buffer memory 16, the system control CPU 11 stores the image and audio data in the buffer memory 16 in the memory controller 15 in accordance with the band of the network 2. The image and audio data to be read are read. The memory controller 15 supplies the read image and audio data to the TCP / IP processing unit 18.
[0070]
The TCP / IP processing unit 18 stores the image and audio data supplied from the memory controller 15 in a predetermined packet, and supplies the packet to the network interface 19. The network interface 19 transmits the packet storing the image and audio data supplied from the TCP / IP processing unit 18 to the personal computer 3 via the network 2.
[0071]
As described above, in the recording / reproducing apparatus 1, the running of the tape of the video cassette by the VCR system unit 12 is controlled based on the amount of image and audio data stored in the buffer memory 16, and the Transmission of audio data is also controlled based on the amount of image and audio data stored in the buffer memory 16. That is, in the recording / reproducing apparatus 1, the operation of reading image and audio data from the video cassette and the operation of transmitting image and audio data to the network 2 are completely independent of each other with the buffer memory 16 as a boundary. (Asynchronous).
[0072]
Next, an operation of the recording / reproducing apparatus 1 when recording image and audio data received via the network 2 on a video cassette mounted on the VCR system unit 12 will be described.
[0073]
The network interface 19 is a packet storing image and audio data transmitted via the network 2 at an arbitrary rate equal to or lower than a rate that can be recorded on a video cassette mounted on the VCR system unit 12. And supplies the received packet to the TCP / IP processing unit 18.
[0074]
The TCP / IP processing unit 18 extracts image and audio data from the packet supplied from the network interface 19, and supplies the extracted image and audio data to the memory controller 15.
[0075]
The memory controller 15 stores the image and audio data supplied from the TCP / IP processing unit 18 in the buffer memory 16.
[0076]
The memory monitor 17 constantly monitors the amount of image and sound data stored in the buffer memory 16, and when image and sound data equal to or larger than a previously stored threshold value is stored in the buffer memory 16, This is notified to the system control CPU 11. The memory monitor 17 notifies the system control CPU 11 when the amount of image and audio data stored in the buffer memory 16 becomes equal to or less than a threshold value stored in advance.
[0077]
The process of determining whether or not image and audio data having a threshold value or more has been stored in the buffer memory 16 and whether or not the amount of image and audio data stored in the buffer memory 16 has become equal to or less than the threshold value May be executed by the system control CPU 11.
[0078]
The system control CPU 11 sends the image and sound data from the buffer memory 16 to the memory controller 15 when the memory monitor 17 receives a notification that the image data and the sound data of a certain amount or more are stored in the buffer memory 16. Read. The memory controller 15 supplies the read image and audio data to the encoder 14.
[0079]
The encoder 14 encodes the image and audio data supplied from the memory controller 15 by a predetermined encoding method, and supplies the encoded image and audio data to the VCR system unit 12.
[0080]
When a notice that more than a certain amount of image and sound data has been stored in the buffer memory 16 is supplied from the memory monitor 17, the system control CPU 11 The traveling is started, and the encoded image and sound data supplied from the encoder 14 is recorded on the video cassette.
[0081]
When the memory monitor 17 supplies a notification that the image and audio data stored in the buffer memory 16 has become equal to or less than a predetermined value, the system control CPU 11 sends the video cassette tape to the VCR system unit 12. Stop running and wait for the next record. At this time, the system control CPU 11 causes the memory controller 15 to stop reading image and audio data from the buffer memory 16.
[0082]
The operation of stopping the recording of the image and audio data on the video cassette by the VCR system unit 12 and the operation of starting the recording are repeated according to the amount of the image and audio data stored in the buffer memory 16. . When the recording is started after the recording of the image and audio data on the video cassette is stopped, the image and audio data are recorded following the last recorded image and audio data in the previous recording. .
[0083]
As described above, in the recording / reproducing apparatus 1, independently of the reception of the image and audio data from the network 2, the VCR system unit 12 performs the processing based on the amount of the image and audio data stored in the buffer memory 16. The running of the tape of the video cassette is controlled. That is, in the recording / reproducing apparatus 1, the operation of recording image and audio data on the video cassette and the operation of receiving image and audio data from the network 2 are completely independent of each other with the buffer memory 16 as a boundary. (Asynchronous). In other words, regardless of the rate of the image and audio data transmitted from the network 2, the VCR system unit in the recording / reproducing apparatus 1 is based on only the amount of the image and audio data stored in the buffer memory 16. 12 is independently controlled.
[0084]
FIG. 3 is a diagram illustrating the configuration of the personal computer 3. The CPU 101 actually executes various application programs and an OS (Operating System). The ROM 102 generally stores basically fixed data of programs used by the CPU 101 and calculation parameters. The RAM 103 stores programs used in the execution of the CPU 101 and parameters that change as appropriate in the execution. These are interconnected by a host bus 104 composed of a CPU bus and the like.
[0085]
The host bus 104 is connected to an external bus 106 such as a PCI (Peripheral Component Interconnect / Interface) bus via a bridge 105.
[0086]
The keyboard 108 is operated by a user when inputting various commands to the CPU 101. The mouse 109 as an example of a pointing device is operated by a user when pointing and selecting a point on the screen of the display 110. The display 110 includes a liquid crystal display device or a CRT (Cathode Ray Tube), and displays various information in text or images. An HDD (Hard Disk Drive) 111 drives a hard disk and records or reproduces a program or information executed by the CPU 101 on the hard disk.
[0087]
The drive 112 reads data or a program recorded on the mounted magnetic disk 131, optical disk 132, magneto-optical disk 133, or semiconductor memory 134 and transfers the data or program to the interface 107, external bus 106, bridge, 105 and the RAM 103 connected via the host bus 104. The keyboard 108 to the drive 112 are connected to an interface 107. The interface 107 is connected to the CPU 101 via an external bus 106, a bridge 105, and a host bus 104.
[0088]
The communication board 113 is connected to the network 2, stores the data supplied from the CPU 101 or the HDD 111 in a packet of a predetermined format, transmits the data via the network 2, and receives the data via the network 2. The data stored in the packet is output to the CPU 101, the RAM 103, or the HDD 111.
[0089]
The communication board 113 is connected to the CPU 101 via the external bus 106, the bridge 105, and the host bus 104.
[0090]
FIG. 4 is a flowchart illustrating a process of buffer memory control by the system control CPU 11 executing a control program when transmitting image and audio data recorded on the video cassette via the network 2.
[0091]
In step S11, the system control CPU 11 causes the VCR system unit 12 to start reproduction. That is, the system control CPU 11 causes the VCR system unit 12 to start an operation of reading image and audio data from the mounted video cassette, and supplies the read data to the decoder 13.
[0092]
In step S12, for example, based on the first threshold value stored in advance and the data supplied from the memory monitor 17, the system control CPU 11 determines that the amount of data stored in the buffer memory 16 is It is determined whether or not there is. If it is determined in step S12 that the amount of data stored in the buffer memory 16 is equal to or larger than a certain value, the process proceeds to step S13, where the system control CPU 11 causes the VCR system unit 12 to stop reproduction and wait.
[0093]
In step S14, based on the second threshold value stored in advance and the data supplied from the memory monitor 17, the system control CPU 11 determines whether the amount of data stored in the buffer memory 16 is equal to or less than a certain value. Determine whether or not. In the processing of step S12 and step S14, the amount of data serving as a criterion for determination may be the same value or a different value.
[0094]
If it is determined in step S14 that the amount of data stored in the buffer memory 16 is not equal to or smaller than the predetermined value, the process returns to step S14 and the determination process is repeated.
[0095]
In the process of step S13, the reproduction of the VCR system unit 12 is stopped, and the data stored in the buffer memory 16 is transmitted via the network 2 while the determination is repeated in the process of step S14. The amount of data stored in the buffer memory 16 decreases.
[0096]
If it is determined in step S14 that the amount of data stored in the buffer memory 16 is equal to or smaller than a certain value, the process returns to step S11, where the system control CPU 11 causes the VCR system unit 12 to start reproduction and repeats the processing. .
[0097]
If it is determined in step S12 that the amount of data stored in the buffer memory 16 is not equal to or more than the predetermined value, the process proceeds to step S15, and the system control CPU 11 performs reproduction based on a signal from an input unit (not shown). It is determined whether or not to end.
[0098]
If it is determined in step S15 that the reproduction is not to be ended, the process returns to step S12, and the process of determining whether the amount of data stored in the buffer memory 16 is equal to or more than a certain value is repeated.
[0099]
If it is determined in step S15 that the reproduction is to be ended, the processing ends.
[0100]
As described above, in the data transmission, the VCR system unit 12 reads or stops reading the image and audio data from the video cassette depending on the amount of the image and audio data stored in the buffer memory 16. You. In this way, even if the speed of data transmission via the network 2 changes, the buffer memory 16 does not overflow, and continuity of transmitted images and sounds is guaranteed.
[0101]
FIG. 5 is a flowchart illustrating a process of buffer memory control by the system control CPU 11 executing a control program when recording image and audio data received via the network 2 on a video cassette.
[0102]
In step S31, based on the first threshold value stored in advance and the data supplied from the memory monitor 17, the system control CPU 11 determines whether the amount of data stored in the buffer memory 16 is equal to or more than a certain value. Determine whether or not.
[0103]
If it is determined in step S31 that the amount of data stored in the buffer memory 16 is not equal to or greater than a certain value, the process returns to step S31, and the determination process is repeated until the amount of data becomes equal to or more than a certain value.
[0104]
When it is determined in step S31 that the data stored in the buffer memory 16 is equal to or more than a certain value, the process proceeds to step S32, and the system control CPU 11 causes the VCR system unit 12 to start recording. That is, the system control CPU 11 causes the VCR system unit 12 to acquire the image and sound data supplied from the encoder 14 and record the image and sound data on the attached video cassette.
[0105]
In step S33, based on the second threshold value stored in advance and the data supplied from the memory monitor 17, the system control CPU 11 determines whether the amount of data stored in the buffer memory 16 is equal to or less than a certain value. Determine whether or not. In the processing of step S12 and step S14, the amount of data serving as a criterion for determination may be the same value or a different value.
[0106]
If it is determined in step S33 that the amount of data stored in the buffer memory 16 is equal to or smaller than a certain value, the process proceeds to step S34, where the system control CPU 11 causes the VCR system unit 12 to stop recording and wait, Returning to step S31, the process is repeated from the process of determining the amount of data stored in the buffer memory 16.
[0107]
If it is determined in step S33 that the data stored in the buffer memory 16 is not equal to or less than the predetermined value, the process proceeds to step S35, where the system control CPU 11 ends recording based on a signal from an input unit (not shown). It is determined whether or not.
[0108]
If it is determined in step S35 that the recording is not to be ended, the process returns to step S33, and the process of determining whether the amount of data stored in the buffer memory 16 is equal to or less than a certain value is repeated.
[0109]
If it is determined in step S35 that the recording is to be ended, the processing ends.
[0110]
As described above, in the data reception, the VCR system unit 12 records the image and sound data on the video cassette or stops the recording depending on the amount of the image and sound data stored in the buffer memory 16. Is done. By doing so, even if the data reception speed changes, the buffer memory 16 does not overflow, and the received image and audio data are reliably recorded on the video cassette.
[0111]
Next, processing for transmitting low-rate image and audio data from the recording / reproducing apparatus 1 to the personal computer 3 will be described.
[0112]
The image and audio data set to a low rate by the low-resolution encoder 20 reach the personal computer 3 which is the target device without delay in most of the networks 2, and is VCR running control information transmitted from the personal computer 3. It is considered that the personal computer 3 can acquire image and audio data with good response to the command.
[0113]
However, when the bandwidth of the network 2 is narrower or when the computing capacity of the personal computer 3 is low, the transmission speed of the image and audio data from the recording / reproducing apparatus 1 to the personal computer 3 is low. Compared with the rate of storing image and audio data at the rate, the rate may be lower and the response may be lower. That is, the time lag between the image and audio data read from the recording / reproducing device 1 and the image or the audio output from the personal computer 3 increases, and the real-time performance may be reduced.
[0114]
Therefore, in response to a request for a frame from the personal computer 3, the recording / reproducing apparatus 1 transmits an image frame.
[0115]
In this case, the processing of communication of image and audio data by the recording / reproducing apparatus 1 executing the control program by the system control CPU 11 and the personal computer 3 executing the reproduction program by the CPU 101 will be described with reference to the flowchart of FIG. Will be explained.
[0116]
In step S101, the control program causes the low-resolution encoder 20 to convert image and sound data output from the decoder 13 into low-rate image and sound data. The low-rate image and audio data are supplied to the memory controller 15 and stored in the buffer memory 16 under the control of the memory controller 15.
[0117]
In step S201, the reproduction program causes the communication unit 113 to transmit a frame transmission request to the recording / reproduction device 1 via the network 2.
[0118]
In step S102, the control program causes the TCP / IP processing unit 18 and the network interface 19 to receive the frame transmission request transmitted from the personal computer 3. The received frame transmission request is supplied from the TCP / IP processing unit 18 to the command interpreter 21. The command interpreter 21 supplies data requesting transmission of one frame corresponding to the frame transmission request to the system control CPU 11.
[0119]
In step S103, the control program sends the latest one frame of data to the personal computer 3. That is, the control program causes the memory controller 15 to read the latest one-frame data (last stored in the buffer memory 16) from the buffer memory 16 and transfer the read one-frame data to the TCP / IP processing unit 18. To be supplied. The TCP / IP processing unit 18 generates a packet storing the latest one-frame data under the control of the system control CPU 11, and sends the generated packet to the personal computer 3 via the network 2 to the network interface 19. Send.
[0120]
In step S202, the playback program receives one frame of data transmitted from the recording and playback device 1.
[0121]
More specifically, CPU 101 executing the reproduction program causes communication unit 113 to receive the packet transmitted via network 2. The communication unit 113 extracts one frame of data stored in the packet, and causes the RAM 103 to store the extracted data.
[0122]
In step S203, the reproduction program reproduces an image or sound based on the data received in the processing of step S202, for example, displays the image on the display 110, outputs sound from a speaker (not shown), and Returning to S201, the reproduction process is repeated.
[0123]
In step S104, the control program causes the memory controller 15 to discard the data before the frame transmitted in the processing of step S104 from the image and audio data stored in the buffer memory 16, and returns to step S101. Repeat the transmission process. In the process of step S104, the data before the transmitted frame is discarded, that is, the old frame (the frame stored in the buffer 16 before the transmitted frame) is deleted from the buffer memory 16 as compared with the transmitted frame. Since the frame is erased, only the frames after the transmitted frame are stored in the buffer memory 16.
[0124]
The erasing of the frame in the process of step S104 is not limited to the process of rewriting the entity of the data of the frame to another data, and the frame cannot be read by changing the management data of the buffer memory 16 or the like. And the like. For example, when the buffer memory 16 is a ring buffer, moving a pointer to a state where frames cannot be read also means erasing a frame.
[0125]
By doing so, even when the bandwidth of the network 2 is narrow or the arithmetic capacity of the CPU 101 is low, the number of frames transmitted per unit time is reduced, The frame data is transmitted to the personal computer 3, and an extremely good response can be obtained. That is, based on the timing at which the VCR system unit 12 reads out image and audio data from the video cassette and the personal computer 3, based on the image and audio data read from the video cassette, an image is displayed and audio is output. The deviation from the timing can be minimized.
[0126]
More specifically, when a VCR tape travel control command such as playback or high-speed playback is transmitted from the personal computer 3 to the recording / reproduction device 1, recording / reproduction is performed quickly and in real time in response to the transmission of the VCR tape travel control command. The device 1 can respond.
[0127]
In this way, when a moving image is transmitted via a network, the receiving side can receive the moving image.
[0128]
Further, based on the first moving image to be provided, a second moving image having a lower resolution than the first moving image is generated, and storage of the generated second moving image is controlled. When a frame transmission request is received from the receiving side, transmission of the last stored one frame of the stored second moving image to the receiving side via the network is controlled and transmitted. If a frame stored before the stored frame is deleted, the real-time moving image can be maintained on the receiving side regardless of the bandwidth of the network or the calculation speed of the receiving side.
[0129]
When the moving image transmitted from the information providing apparatus is received via the network, the moving image can be reproduced.
[0130]
Also, transmission of a request for transmission of one frame of the moving image to the information providing apparatus that provides the moving image via the network is controlled, and one of the moving images transmitted from the information providing apparatus via the network is controlled. In the case of controlling the reception of two frames and reproducing the moving image based on the received frame of the moving image, the real-time property of the moving image can be maintained regardless of the network bandwidth or the calculation speed Become like
[0131]
Although it has been described that the image and audio data are recorded on a video cassette, the recording is not limited to a tape such as a video cassette, but may be recorded on another type of recording medium such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory. You may make it. Similarly, the recording / reproducing apparatus 1 as an example of the information providing apparatus is not limited to a VCR, but may be another type of apparatus such as a personal computer, a DVD recorder, an MD (Mini-Disc) (trademark) recorder, or a server. it can.
[0132]
Although it has been described that image and audio data is recorded and transmitted, the present invention is not limited to image and audio data, but may be data transmitted as a stream such as audio-only data, image-only data, or numerical data. For example, the present invention can be applied.
[0133]
Note that the personal computer 3 as an example of the information processing device may be another type of device such as a PDA (Personal Digital Assistant) or a mobile phone.
[0134]
The series of processes described above can be executed by hardware, but can also be executed by software. When a series of processing is executed by software, a program constituting the software may execute various functions by installing a computer built into dedicated hardware or installing various programs. It is installed from a recording medium into a possible general-purpose personal computer or the like.
[0135]
As shown in FIG. 2 or FIG. 3, this recording medium is distributed separately from a computer in order to provide a program to a user, and is recorded on a magnetic disk 41 or a magnetic disk 131 (including a flexible disk) on which the program is recorded. ), Optical disk 42 or optical disk 132 (including CD-ROM (Compact Disc-Only Memory), DVD (Digital Versatile Disc)), magneto-optical disk 43 or magneto-optical disk 133 (MD (Mini-Disc) (trademark)). Program) which is provided not only to a package medium including the semiconductor memory 44 or the semiconductor memory 134 but also provided to a user in a state where the program is incorporated in a computer in advance. ROM or ROM102 and not shown is provided inside the system control CPU 11, configured like HDD 111.
[0136]
The program for executing the above-described series of processes is installed on a computer via a wired or wireless communication medium such as a local area network, the Internet, or digital satellite broadcasting via an interface such as a router or a modem as necessary. May be performed.
[0137]
In this specification, the step of describing a program stored in a recording medium may be performed in chronological order according to the described order, or may be performed in parallel or not necessarily in chronological order. This also includes processes executed individually.
[0138]
In the present specification, the system represents the entire device including a plurality of devices.
[0139]
【The invention's effect】
As described above, according to the first aspect of the present invention, a moving image can be received on the receiving side.
[0140]
Further, according to the first aspect of the present invention, it is possible to maintain the real-time property of a moving image on the receiving side regardless of the bandwidth of the network or the calculation speed of the receiving side.
[0141]
According to the second aspect of the present invention, a moving image can be reproduced.
[0142]
Further, according to the second aspect of the present invention, it is possible to maintain the real-time property of the moving image regardless of the bandwidth of the network or the calculation speed.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a communication system according to the present invention.
FIG. 2 is a block diagram showing a configuration of the recording / reproducing apparatus 1.
FIG. 3 is a diagram illustrating a configuration of a personal computer 3.
FIG. 4 is a flowchart illustrating processing of buffer memory control when transmitting image and audio data recorded on a video cassette via a network 2.
FIG. 5 is a flowchart illustrating a process of controlling a buffer memory when recording image and audio data received via a network 2 on a video cassette.
FIG. 6 is a flowchart illustrating a process of communicating image and audio data.
[Explanation of symbols]
Reference Signs List 1 recording / reproducing device, 2 network, 3 personal computer, 11 system control CPU, 12 VCR system unit, 15 memory controller, 16 buffer memory, 17 memory monitor, 18 TCP / IP processing unit, 19 network interface, 20 low resolution encoder , 22 drive, 41 magnetic disk, 42 optical disk, 43 magneto-optical disk, 44 semiconductor memory, 101 CPU, 102 ROM, 103 RAM, 110 display, 111 HDD, 113 communication unit, 131 magnetic disk, 132 optical disk, 133 magneto-optical disk , 134 Semiconductor Memory

Claims (8)

Generating means for generating a second moving image having a lower resolution than the first moving image based on the first moving image to be provided;
Storage control means for controlling storage of the generated second moving image;
When a frame transmission request is received from the receiving side, transmission for controlling transmission of the last stored one frame of the stored second moving image to the receiving side via the network. Control means;
Erasing means for erasing a frame stored before the transmitted frame. A generating step of generating a second moving image having a lower resolution than the first moving image based on the first moving image to be provided;
A storage control step of controlling storage of the generated second moving image;
When a frame transmission request is received from the receiving side, transmission for controlling transmission of the last stored one frame of the stored second moving image to the receiving side via the network. A control step;
An erasing step of erasing a frame stored before the transmitted frame. A generating step of generating a second moving image having a lower resolution than the first moving image based on the first moving image to be provided;
A storage control step of controlling storage of the generated second moving image;
When a frame transmission request is received from the receiving side, transmission for controlling transmission of the last stored one frame of the stored second moving image to the receiving side via the network. A control step;
An erasing step of erasing a frame stored before the transmitted frame, wherein a program for causing a computer to execute an information providing process is recorded. A generating step of generating a second moving image having a lower resolution than the first moving image based on the first moving image to be provided;
A storage control step of controlling storage of the generated second moving image;
When a frame transmission request is received from the receiving side, transmission for controlling transmission of the last stored one frame of the stored second moving image to the receiving side via the network. A control step;
An erasing step of erasing a frame stored before the transmitted frame. Transmission control means for controlling transmission of a transmission request for one frame of the moving image to an information providing apparatus for providing the moving image via a network;
Via the network, transmitted from the information providing apparatus, reception control means for controlling the reception of one of the frames of the moving image,
An information processing apparatus comprising: a reproducing unit configured to reproduce the moving image based on the received frame of the moving image. A transmission control step of controlling transmission of a transmission request for one frame of the moving image to an information providing apparatus for providing a moving image via a network;
Via the network, transmitted from the information providing device, a reception control step of controlling the reception of one of the frames of the moving image,
A reproducing step of reproducing the moving image based on the received frame of the moving image. A transmission control step of controlling transmission of a transmission request for one frame of the moving image to an information providing apparatus for providing a moving image via a network;
Via the network, transmitted from the information providing device, a reception control step of controlling the reception of one of the frames of the moving image,
A reproducing step of reproducing the moving image based on the received frame of the moving image. A recording medium storing a program for causing a computer to execute information processing. A transmission control step of controlling transmission of a transmission request for one frame of the moving image to an information providing apparatus for providing a moving image via a network;
Via the network, transmitted from the information providing device, a reception control step of controlling the reception of one of the frames of the moving image,
And a reproducing step of reproducing the moving image based on the received frame of the moving image.

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