JP2009105477A - Reproducing device and reproducing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To start decoding processing after storing a small amount of moving image data in a buffer memory within a range such that no buffer underflow arises after reproduction is started. <P>SOLUTION: A buffer control unit 114 acquires display time information and recording position information of clip information recorded on a disk 104 through a disk access unit 103. Further, the buffer control unit acquires information (reproduction stop time information) associated with a maximum seek time from a combination of moving image streams selected by a user. Then the size of data corresponding to the maximum seek time is calculated and instructions are sent to a decoder 105 so that the decoder starts decoding processing after data are stored in the buffer memory 102 by the calculated size. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a playback device, a playback method, a program, and a storage medium, and particularly to a technique suitable for use in intermittent playback processing.

  2. Description of the Related Art Conventionally, a video camera that records and reproduces video data and audio data on a disk medium such as a DVD is known. In this type of apparatus, video data and audio data are encoded according to an encoding method such as the MPEG method, and the data amount is compressed and recorded on a recording medium such as a disk. Therefore, at the time of reproduction, it is necessary to decode (decode) the reproduced video data and audio data.

  Therefore, at the time of reproduction, decoding is started after a certain amount of moving image data is stored in a memory (hereinafter referred to as a buffer memory) from a recording medium. When the moving image data is decoded and displayed, the decoded moving image data in the buffer memory becomes unnecessary, and the moving image data of that portion is discarded from the buffer memory. Accordingly, since the buffer memory becomes free for the amount discarded, the subsequent moving image data is continuously accumulated from the recording medium so that the moving image data to be decoded next always exists in the buffer memory.

  If control is performed so that moving image data always exists in the buffer memory in this way, decoding of moving image data can be performed continuously without interruption. Therefore, the moving image data in the buffer memory is accumulated by reading from the recording medium and consumed every time it is decoded. Therefore, in order to continuously display moving images, it is necessary to accumulate subsequent moving image data before the moving image data in the buffer memory runs out.

  However, the following phenomenon may occur when the moving image data stored in advance is small when starting the decoding of the moving image data. For example, when the subsequent moving image data is stored in the buffer memory, it takes time to store the data because the seek is generated because the moving image data is not continuously recorded on the recording medium. May not be stored in the buffer memory. The phenomenon in which the moving image data to be decoded is not stored in the buffer memory is generally called buffer underflow. As a result, the moving image stops and is displayed halfway.

  Conversely, if decoding is started after accumulating more moving image data than necessary, decoding cannot be started until a predetermined amount of moving image data is accumulated. The time will be longer. Therefore, it is desirable to start decoding after the necessary amount of moving image data is stored in the buffer memory.

  Therefore, there is a method of calculating the size of the moving image data that is displayed for the maximum seek time from the maximum bit rate of the moving image data recorded on the recording medium and storing it in the buffer memory. If this method is used, even if it takes the maximum seek time when moving image data recorded at the maximum bit rate, seek is performed in a state where the amount of moving image data for the seek time is accumulated in the buffer memory. . For this reason, it is possible to prevent the moving image data from disappearing from the buffer memory.

  In addition, as a method for quickly displaying a moving image after the user performs an operation for starting reproduction, a method for storing moving image data in a buffer memory in advance before the user performs an operation for starting reproduction is disclosed. (For example, refer to Patent Document 1). When this method is used, since the moving image data has already been stored in the buffer memory when the user performs an operation to start reproduction, decoding can be started immediately. Therefore, it is possible to display a moving image quickly.

Japanese Patent Laid-Open No. 11-11095

  However, with the technique described in Patent Document 1, the moving image data selected by the user is not necessarily included in the moving image data accumulated before the user performs an operation to start reproduction. Therefore, when the moving image data selected by the user is not accumulated in the buffer memory, the moving image display cannot be started quickly.

  Further, since the moving image data is accumulated in the buffer memory before the user performs an operation for starting reproduction, the moving image data is accumulated in the buffer memory even when the user does not perform an operation for starting reproduction. For this reason, there is a problem that the power consumption increases particularly in a device such as a digital video camera that operates on a battery. Therefore, it is desirable to start decoding after accumulating as much moving image data as necessary in the buffer memory after the user performs an operation to start reproduction.

  In view of the above-described problems, an object of the present invention is to make it possible to start decoding after accumulating a small amount of moving image data in a buffer memory within a range where buffer underflow does not occur after starting reproduction.

  The reproducing apparatus of the present invention includes a reproducing unit that reproduces encoded moving image data from a recording medium, a storage unit that accumulates moving image data reproduced by the reproducing unit in a memory, and a moving image that is accumulated in the memory. Decoding means for reading image data and performing decoding processing; acquisition means for acquiring a data amount for a predetermined time from the beginning of the moving image data to be reproduced from the recording medium; and starting reproduction of the moving image data In response to the instruction, the reproduction unit is controlled to start reproduction of the moving image data from the recording medium and start accumulation in the memory, and the data for the predetermined time acquired by the acquisition unit Control means for controlling the decoding means to start the decoding process in response to the amount of moving image data being stored in the memory. .

  The reproduction method of the present invention includes a reproduction step of reproducing encoded moving image data from a recording medium, an accumulation step of accumulating moving image data reproduced in the reproduction step in a memory, and a moving image accumulated in the memory A decoding step of reading data and performing a decoding process; an acquisition step of acquiring a data amount for a predetermined time from the beginning of the moving image data to be reproduced from the recording medium; and a reproduction start of the moving image data Controls the processing in the reproduction step so as to start reproduction of the moving image data from the recording medium in response to an instruction and starts accumulation in the memory, and data for the predetermined time acquired in the acquisition step And a control step of controlling to start the decoding process in response to the amount of moving image data being stored in the memory.

  The program of the present invention includes a reproduction step of reproducing encoded moving image data from a recording medium, an accumulation step of accumulating moving image data reproduced in the reproduction step in a memory, and moving image data accumulated in the memory A decoding step of reading out the video and performing a decoding process, an acquisition step of acquiring a data amount for a predetermined time from the beginning of the moving image data to be reproduced from the recording medium, and an instruction to start reproduction of the moving image data And controlling the processing in the reproduction step so as to start the reproduction of the moving image data from the recording medium and start accumulating in the memory, and the data amount for the predetermined time acquired in the acquisition step And causing the computer to execute a control step for controlling to start the decoding process in response to the moving image data being stored in the memory. It is characterized in.

  The storage medium of the present invention stores the program described above.

  According to the present invention, a data amount for a predetermined time from the beginning of moving image data is acquired, and the moving image data of the predetermined amount of data has been stored in the memory after starting reproduction. Control to start the decryption process. As a result, decoding can be started after a small amount of moving image data is accumulated in the buffer memory within a range in which buffer underflow does not occur after starting reproduction. Therefore, regardless of the type of moving image, it is possible to quickly display the moving image after the user performs an operation to start reproduction, and to prevent the moving image from being stopped and displayed.

(First embodiment)
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram illustrating a configuration example of a video recording / playback apparatus (digital video camera) according to the present embodiment. Hereinafter, a digital video camera that records moving image data and management information of the moving image data on a disk-shaped recording medium will be described.

  The digital video camera 10 according to the present embodiment includes a camera unit 100, an encoder 101, a buffer memory 102 used when accessing a disk, and a disk access unit 103 that performs writing to or reading from a recording disk 104 such as a DVD. ing. In addition, a decoder 105 for decoding moving image data recorded on the disk 104 is provided. Further, an LCD 108 that displays the decoded video and an LCD controller 107 that performs control to display on the LCD 108 are provided. At the same time, a video signal can be output to the external output terminal 106.

  Further, the CPU 110 is connected to the ROM 111, the RAM 112, the operation unit 113, the buffer control unit 114, and other blocks by the CPU bus 109, and can be controlled by the CPU 110. The operation unit 113 can send input signals input by user operations from various operation keys and knobs (not shown) to the CPU 110, and the CPU 110 can perform various processes in response to instructions from the user. Further, in the present embodiment, a buffer control unit 114 that controls the decoder 105 to control the amount of data stored in the buffer memory 102 is provided. Detailed processing contents of the buffer control unit 114 will be described later.

Next, a process for recording a captured moving image will be described.
When receiving an instruction to start recording from the operation unit 113, the camera unit 100 generates a video signal from the captured subject image and outputs the generated video signal to the encoder 101. The encoder 101 encodes the video signal according to a predetermined encoding method (for example, H.264 method) and outputs the encoded video signal to the buffer memory 102.

  The disk access unit 103 reads out moving image data from the buffer memory 102 and records it on the disk 104 in response to the accumulation of a predetermined amount of data in the buffer memory 102. When receiving a recording stop instruction from the operation unit 113, the disc access unit 103 stops recording moving image data on the disc 104.

  In this embodiment, the data rate that can be recorded on the disc 104 is higher than the data rate of the encoded moving image data. Therefore, the encoded moving image data is temporarily stored in the buffer memory 102, and the moving image data is read from the buffer memory 102 and recorded on the disk 104 when the predetermined amount of data is stored.

  In the present embodiment, the data rate of moving image data to be recorded can be changed. That is, in the present embodiment, three shooting modes are prepared: a high-quality shooting mode, a standard shooting mode, and a long-time shooting mode. The user operates the operation unit 113 to select and set one of these three shooting modes.

  The CPU 110 sets the target data rate of the encoded moving image data by controlling the encoder 101 according to the shooting mode set by the user. That is, the data rate of the moving image data in the high image quality mode is the highest, and the data rate is set to decrease in the order of the standard shooting mode and the long time shooting mode.

  On the other hand, when displaying the moving image captured by the camera unit 100 on the LCD 108, the decoder 105 reads the moving image data output from the encoder 101 and accumulated in the buffer memory 102. Then, the moving image data is decoded, and the moving image is displayed on the LCD 108 by the LCD controller 107.

  In the recording format used in the present embodiment, one moving image data unit is defined as a clip. A clip is composed of two types of data: a stream that is moving image data and clip information that is management information of the moving image stream. The moving image stream and clip information exist as independent files, and one file is composed of two files. In addition, the same clip number is assigned to each of the moving image stream and the clip information constituting one clip, and the association is possible.

  When recording moving image data, each time one moving image stream is recorded, one clip information is generated and sent to the disk access unit 103 and recorded on the disk 104 under the control of the CPU 110. The clip information includes information such as the size of the moving image stream, the aspect ratio, the display time of the I picture (intra picture), and the recording position of the I picture.

  As described above, in the present embodiment, the data rate of moving image data to be encoded differs according to the shooting mode set by the user. Therefore, the data amount per unit time of the moving image data to be recorded varies depending on the shooting mode.

  In this embodiment, when encoding moving image data, the encoder 101 generates representative image data using the first frame of each clip. Then, the disc access unit 103 records representative image data on the disc 104 together with the data of each clip.

Next, an operation when reproducing moving image data will be described.
When the playback mode is set by the operation unit 113, the disc access unit 103 reads representative image data of each clip recorded on the disc 104 and stores it in the buffer memory 102 under the control of the CPU 110. Then, the representative image data stored in the buffer memory 102 is decoded by the decoder 105, and the representative image is displayed on the LCD 108 by the LCD controller 107. Accordingly, the user can select a representative image of a clip to be reproduced from the representative images displayed on the LCD 108 and instruct the reproduction.

  When an instruction to start playback is input from the operation unit 113, the disk access unit 103 functions as a playback unit under the control of the CPU 110, and reads moving image data specified by the user from the disk 104. The disk access unit 103 functions as a storage unit, and temporarily stores the read moving image data in the buffer memory 102. Next, the decoder 105 functions as a decoding unit, and sequentially decodes the accumulated moving image data. Then, it is output to the external output terminal 106 or displayed on the LCD 108 through the LCD controller 107. Further, when moving image data is decoded by the decoder 105, the clip information is sent to the CPU 110. Accordingly, the CPU 110 can acquire information necessary for decoding from the clip information, and can control the decoder 105 to decode the moving image data. In this way, the digital video camera 10 can reproduce and display the moving image data recorded on the disc 104.

  In the present embodiment, reproduction is intermittently performed by alternately providing a period for reproducing from the disk 104 and a period for stopping reproduction. When moving image data is reproduced from the disk 104, the amount of data in the buffer memory 102 increases. On the other hand, when decoding is performed to display a moving image, the decoded moving image data in the buffer memory 102 becomes unnecessary and is discarded. Therefore, the amount of data in the buffer memory 102 decreases.

  In the present embodiment, the rate at which moving image data is reproduced from the disk 104 and accumulated in the buffer memory 102 (reproduction rate) is determined by reading out and decoding the moving image data accumulated in the buffer memory 102 and making the moving image unnecessary. It is higher than the rate at which image data is discarded. Therefore, the moving image data is temporarily stored in the buffer memory 102 until the predetermined amount of moving image data is satisfied. The accumulation of the moving image data is stopped until the moving image data in the buffer memory 102 is decoded and consumed to some extent. Further, when the amount of moving image data decreases, moving image data is stored again in the buffer memory 102 until the moving image data is filled with a predetermined amount. Thus, power consumption can be suppressed by performing intermittent reproduction.

  Next, a phenomenon that occurs when a seek occurs in the conventional reproduction process will be described with reference to FIGS. FIG. 2 is a diagram showing a transition of the amount of data accumulated in the buffer memory since the reproduction process is started. Hereinafter, the relationship between the data amount of the buffer memory, reading of moving image data, and decoding processing (decoding processing) of moving image data will be described with reference to FIG.

  In FIG. 2, the vertical axis represents the amount of data in the buffer memory, and the horizontal axis represents time. Periods a1 and a2 represent periods during which moving image data is being reproduced from the disc. During this period, the amount of data in the buffer memory increases. A period d represents a period in which the reproduction of moving image data is stopped. During this period, the amount of data in the buffer memory decreases due to the decoding process.

  In the period a1 and the period a2, when the amount of data in the buffer memory reaches the threshold value β, the accumulation is stopped by stopping the reproduction. In the period d, the data in the buffer memory is consumed by the decoding process of the moving image data, and the accumulation of the moving image data is resumed when the data amount in the buffer memory reaches the threshold value α.

  As described above, decoding of moving image data starts after a certain amount of moving image data is accumulated in the buffer memory. In the example shown in FIG. 2, the decoding process is started when the amount of moving image data in the buffer memory reaches the threshold value γ. That is, in FIG. 2, a period b represents a period during which moving image data is decoded and displayed. The period c represents a period during which the decoding process is stopped, and is a period from when an instruction to start reproduction is issued until a moving image is actually displayed on the screen. It is desirable to minimize this period c as much as possible.

  The reason why the decoding is not started until the amount of moving image data in the buffer memory reaches the threshold value γ is that data is continuously arranged on the disc when the moving image data is reproduced from the disc as described above. This is not always the case. That is, when data is discontinuously arranged, seeking occurs and it may take time to reproduce the data.

FIG. 3 is a diagram showing an example of recording positions of moving image streams from the inner circumference side to the outer circumference side of the disc.
In FIG. 3, the left side is the inner circumference side of the disc, and the right side is the outer circumference side of the disc. Stream A and stream B indicate moving image streams that are moving image data according to the recording format.

  When recording or deletion of moving image data is repeatedly performed, moving image streams may be arranged apart from each other on the disc as shown in FIG. In the example shown in FIG. 3, the stream A and the stream B are separated from each other by a distance A on the disc. In this case, after reading the stream A, in order to continue reading the stream B, it is necessary to seek the section of the distance A.

  Next, the transition state of the buffer memory when moving image data is reproduced from the disc in which the moving image stream is recorded in the state shown in FIG. 3 will be described with reference to FIG. FIG. 4 is a diagram illustrating an example when a seek occurs and a buffer underflow occurs.

  In FIG. 4, threshold values α, β, and γ are the same as those shown in FIG. 2, threshold value α is a threshold value for the amount of data for resuming the reproduction of moving image data, and threshold value β stops reproduction of the moving image data. This is a threshold for the amount of data to be processed. The threshold γ is a data amount threshold for starting decoding of moving image data.

  Periods a1 and a2 are periods during which moving image data is reproduced. The period c and the period b are the same as those in FIG. 2, and the period c is a period from the start of reproduction of moving image data to the start of decoding. The period b decodes and displays moving image data. It is a period. In the period a1, moving image data is accumulated in the buffer memory by the same operation as in FIG. Further, a period f represents a period in which seek occurs when switching from reading of stream A to reading of stream B shown in FIG. 3, and period e represents a period in which buffer underflow occurs. Yes.

  In the example shown in FIG. 4, in the period a2, during the period f in which seek is occurring, the moving image data is not reproduced and the moving image data is not stored in the buffer memory. On the other hand, since moving image data is consumed from the buffer memory by decoding, the moving image data stored in the buffer memory gradually decreases, and there is a period e in which there is no moving image data in the buffer memory. Yes.

  During this period e, moving image data to be decoded does not exist in the buffer memory, so that the moving image is stopped and displayed on the screen. In order to prevent such a phenomenon from occurring, it is only necessary to set the threshold value γ higher and accumulate a larger amount of moving image data before starting decoding. However, if a large amount of moving image data is accumulated before the decoding is started, the accumulation time is increased accordingly, so that the decoding is delayed correspondingly.

  Next, an example in which the decoding start operation is delayed due to the occurrence of seek will be described. FIG. 5 is a diagram illustrating an example of transition of the amount of data stored in the buffer memory when a seek occurs during reproduction of moving image data and the start of decoding is delayed by the seek. For example, such a phenomenon may occur when the data size of the stream A shown in FIG. 3 is very small.

  In FIG. 5, it is assumed that the amount of moving image data to start decoding is set to a threshold value δ higher than the threshold value γ shown in FIG. The period c and the period b are the same as those in FIG. 2, and the period c is a period from the start of reproduction of moving image data to the start of decoding. The period b decodes and displays moving image data. It is a period.

  In the example shown in FIG. 5, playback of the stream A ends in the period g before the amount of data in the buffer memory reaches the threshold δ and seeks occur, and moving image data is accumulated in the buffer memory during the period h. It has not been. Thus, it takes a lot of time to start decoding.

  However, if the time for decoding the moving image data accumulated in the period g is longer than the period h, the moving image as described in FIG. 4 is stopped and displayed without setting a large threshold. This phenomenon does not occur. Therefore, it may not be necessary to accumulate moving image data until the data amount reaches the threshold value δ. From the above, if the amount of data to be accumulated before starting decoding is determined in consideration of the time required for seeking and the time for decoding, the moving image is prevented from being stopped and displayed halfway. be able to.

  Next, the reproduction processing in the present embodiment will be described with reference to FIGS. FIG. 7 is a diagram showing a part of clip information of moving image data recorded based on the recording format in the present embodiment. In the recording format used in this embodiment, I picture display time information (Presentation Time Stamp, hereinafter referred to as PTS) is recorded for each I picture. Further, recording position information (Source Packet Number, hereinafter referred to as SPN) on the disk 104 is also recorded for each I picture.

  As shown in FIG. 7, the display time of the I picture is defined by a 90 kHz clock, and 90 kHz corresponds to 1 second. In this embodiment, the I picture is created with a display time interval of 0.5 seconds. In addition, ID numbers are assigned consecutively to I pictures. For example, the first I picture has an ID number of 1, a PTS of 98816, and an SPN of 4.

FIG. 8 is a flowchart illustrating an example of a processing procedure by the buffer control unit 114 of the present embodiment.
First, in step S801 in FIG. 8, the buffer control unit 114 functions as an acquisition unit, and among the clip information recorded on the disc 104, the display time information and the recording position information shown in FIG. Get. Further, information on the maximum seek time (reproduction stop time information) is also acquired from the combination of moving image streams selected by the user. Next, in step S802, the size of data corresponding to the maximum seek time is calculated.

  From the clip information shown in FIG. 7, the display time and recording position of each I picture from the beginning of the moving image data to be reproduced will be known. For this reason, it is possible to calculate the timing of starting decoding and the size of data necessary for accumulating moving image data corresponding to the seek time. For example, assuming that it takes up to 1 second to seek, it is only necessary to start decoding after moving the moving image data for one second in the buffer memory 102. Therefore, if the size of moving image data for one second is calculated. Good. Further, the timing (time) at which reproduction is started can be calculated from the size of the moving image data for one second and the reproduction rate.

In the example shown in FIG. 7, the moving image data for one second is a portion from ID1 to ID3 since the display time of ID1 is 98816 Hz and the display time of ID3 is 188928 Hz. Therefore, the moving image data may be accumulated before ID3 after the reproduction is started. In FIG. 7, the recording positions of ID1 and ID3 are 4 and 7979, respectively. Therefore, the size of the moving image data from ID1 to ID3 is 192 bytes in 1 SPN, and is calculated as follows. Can do.
(7979-4) × 192 = 1531200 bytes≈1.46 Mbytes (1 Mbyte = 1048576 bytes)

  Therefore, after starting reproduction, 1.46 Mbytes of moving image data is accumulated in the buffer memory 102, and then decoding is started. As a result, even when the seek takes a maximum of one second, since the moving image data for one second has already been accumulated, there is no moving image data in the buffer memory 102, and the moving image is stopped and displayed. Nothing happens.

  In the present embodiment, as described above, the data rate of moving image data recorded differs depending on the shooting mode. For this reason, the amount of moving image data for one second also differs for each moving image data. Therefore, by confirming the clip information of each moving image data, it is possible to calculate the amount of data to be accumulated in the buffer memory 102 at the start of reproduction for each moving image data.

  Next, in step S803, the buffer control unit 114 functions as a control unit, and sends an instruction to the decoder 105 to start decoding after the data size calculated in step S802 is accumulated in the buffer memory 102. The process is terminated.

FIG. 6 is a diagram illustrating a transition of the amount of data accumulated in the buffer memory 102 since the reproduction process is started in the present embodiment.
In FIG. 6, a period a represents a period during which moving image data is being reproduced from the disc 104. A period b ′ represents a period during which moving image data is decoded and displayed. The period c ′ represents a period during which the decoding process is stopped, and is also the time from when an instruction to start reproduction is given until the moving image is actually displayed on the LCD 108.

  Further, the period i represents a period until the reproduction of the stream A shown in FIG. 3 ends, and the period j represents a period during which seek occurs when switching from reading of the stream A to reading of the stream B shown in FIG. Represents.

  As shown in FIG. 6, the seek is completed before the amount of data stored in the buffer memory 102 becomes 0 in the period j, and the reproduction of the next moving image data can be started. Furthermore, since the decoding can be started after the necessary minimum amount of moving image data (data amount of the threshold value ε) is accumulated, the time from the start of reproduction to the display of the moving image on the screen is shortened. be able to.

  As described above, when the data amount corresponding to the maximum seek time is calculated from the maximum bit rate of the moving image data recorded on the disc, when the maximum bit rate of the moving image data is 24 Mbps, data for one second is obtained. The amount is 24/8 = 3 Mbytes. Therefore, when the seek time for one second is taken into account, if the amount of data to be accumulated is determined from the maximum bit rate, 3 Mbytes must be accumulated. That is, in this embodiment, it is sufficient to store about half the data amount as compared with the case where the data amount to be stored is calculated from the maximum bit rate.

  As described above, in the present embodiment, the size of moving image data to be accumulated before decoding is started can be reduced, and the accumulation time of moving image data can be shortened. Accordingly, it is possible to shorten the time from when the user performs an operation to start reproduction until the moving image is displayed on the screen. Therefore, regardless of the type of moving image, it is possible to quickly display the moving image after the user performs an operation to start reproduction, and to prevent the moving image from being stopped and displayed.

(Other embodiments according to the present invention)
Each means constituting the playback apparatus and each step of the playback method in the embodiment of the present invention described above can be realized by operating a program stored in a RAM or ROM of a computer. This program and a computer-readable storage medium storing the program are included in the present invention.

  In addition, the present invention can be implemented as, for example, a system, apparatus, method, program, storage medium, or the like. Specifically, the present invention may be applied to a system including a plurality of devices. The present invention may be applied to an apparatus composed of a single device.

  The present invention includes a case where a software program (in the embodiment, a program corresponding to the flowchart shown in FIG. 8) that realizes the functions of the above-described embodiments is directly or remotely supplied to the system or apparatus. This includes the case where the system or the computer of the apparatus is also achieved by reading and executing the supplied program code.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. In other words, the present invention includes a computer program itself for realizing the functional processing of the present invention.

  In that case, as long as it has the function of a program, it may be in the form of object code, a program executed by an interpreter, script data supplied to the OS, and the like.

  Examples of the storage medium for supplying the program include a flexible disk, a hard disk, an optical disk, and a magneto-optical disk. Further, there are MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card, ROM, DVD (DVD-ROM, DVD-R) and the like.

  As another program supply method, there is a method of connecting to a homepage on the Internet using a browser of a client computer. It can also be supplied by downloading the computer program itself of the present invention or a compressed file including an automatic installation function from a homepage to a storage medium such as a hard disk.

  It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the present invention.

  As another method, the program of the present invention is encrypted, stored in a recording medium such as a CD-ROM, distributed to users, and encrypted from a homepage via the Internet to users who have cleared predetermined conditions. Download the key information to be solved. It is also possible to execute the encrypted program by using the key information and install the program on a computer.

  Further, the functions of the above-described embodiments are realized by the computer executing the read program. Furthermore, based on the instructions of the program, an OS or the like running on the computer performs part or all of the actual processing, and the functions of the above-described embodiments can be realized by the processing.

  As another method, a program read from a storage medium is first written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Then, based on the instructions of the program, the CPU or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are also realized by the processing.

It is a block diagram which shows the structural example of the video recording / reproducing apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the transition of the data amount in a buffer memory. It is a figure which shows an example of the recording position of the stream on a disc. It is a figure which shows an example of the transition of the data amount in the buffer memory at the time of seek generation | occurrence | production. It is a figure which shows another example of transition of the data amount in the buffer memory at the time of seek generation | occurrence | production. In an embodiment of the present invention, it is a figure showing an example of transition of the amount of data in a buffer memory at the time of seek occurrence. It is a figure which shows an example of the display time information and recording position information in the clip information in the embodiment of the present invention. It is a flowchart which shows an example of the process sequence by the buffer control part of embodiment of this invention.

Explanation of symbols

100 Camera Unit 101 Encoder 102 Buffer Memory 103 Disk Access Unit 104 Disk 105 Decoder 106 External Output Terminal 107 LCD Controller 108 LCD
109 CPU bus 110 CPU
111 ROM
112 RAM
113 Operation unit 114 Buffer control unit

Claims (14)

Reproduction means for reproducing the encoded moving image data from the recording medium;
Storage means for storing the moving image data reproduced by the reproduction means in a memory;
Decoding means for reading out moving image data stored in the memory and performing decoding processing;
Obtaining means for obtaining a data amount for a predetermined time from the beginning of the moving image data to be reproduced from the recording medium;
In response to an instruction to start reproduction of the moving image data, the reproduction unit is controlled to start reproduction of the moving image data from the recording medium and start accumulation in the memory, and is acquired by the acquisition unit. And a control unit that controls the decoding unit to start the decoding process in response to the moving image data having a data amount for the predetermined time being stored in the memory. .   The acquisition means is configured to reproduce the moving image to be reproduced based on display times of a plurality of screens included in the moving image data and clip information indicating recording positions of data respectively corresponding to the plurality of screens on the recording medium. The playback apparatus according to claim 1, wherein a data amount for a predetermined time from the head of the data is acquired.   3. The playback apparatus according to claim 1, wherein the control unit controls the decoding unit to start the decoding process according to a storage amount of moving image data stored in the memory. .   The control means determines a time to start decoding by the decoding means based on a rate of reproduction by the reproducing means and display time information, recording position information and reproduction stop time information acquired by the acquiring means. The reproduction apparatus according to claim 1, wherein the reproduction apparatus is a reproduction apparatus.   2. The reproducing apparatus according to claim 1, wherein the predetermined time is a time required to seek the moving image data on the recording medium.   The playback apparatus according to claim 1, wherein the acquisition unit acquires display time information and recording position information of an intra picture of the moving image data. A reproduction step of reproducing the encoded moving image data from the recording medium;
An accumulation step of accumulating the moving image data reproduced in the reproduction step in a memory;
A decoding step of reading out the moving image data stored in the memory and performing a decoding process;
An acquisition step of acquiring a data amount for a predetermined time from the beginning of the moving image data to be reproduced from the recording medium;
In response to an instruction to start reproduction of the moving image data, the reproduction process is controlled so as to start reproduction of the moving image data from the recording medium and start accumulation in the memory. And a control step of controlling to start the decoding process in response to the acquired moving image data having a data amount for the predetermined time being stored in the memory.   In the acquisition step, the moving image to be reproduced based on display times of a plurality of screens included in the moving image data and clip information indicating recording positions of data respectively corresponding to the plurality of screens on the recording medium 8. The reproduction method according to claim 7, wherein a data amount for a predetermined time from the head of the image data is acquired.   The reproduction method according to claim 7 or 8, wherein in the control step, the decoding process is controlled in accordance with an accumulation amount of moving image data accumulated in the memory.   In the control step, the time for starting decoding in the decoding step is determined based on the reproduction rate in the reproduction step and the display time information, recording position information, and reproduction stop time information acquired in the acquisition step. The reproduction method according to any one of claims 7 to 9, wherein:   8. The reproducing method according to claim 7, wherein the predetermined time is a time required for seeking the moving image data on the recording medium.   12. The reproduction method according to claim 7, wherein in the acquisition step, display time information and recording position information of an intra picture of the moving image data are acquired. A reproduction step of reproducing the encoded moving image data from the recording medium;
An accumulation step of accumulating the moving image data reproduced in the reproduction step in a memory;
A decoding step of reading out the moving image data stored in the memory and performing a decoding process;
An acquisition step of acquiring a data amount for a predetermined time from the beginning of the moving image data to be reproduced from the recording medium;
In response to an instruction to start reproduction of the moving image data, the reproduction process is controlled so as to start reproduction of the moving image data from the recording medium and start accumulation in the memory. A program for causing a computer to execute a control step of controlling to start the decoding process in response to the acquired moving image data having a data amount for the predetermined time being stored in the memory.   A computer-readable storage medium storing the program according to claim 13.

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