JP4016158B2 - Signal reproduction method and signal reproduction apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a signal reproduction method and a signal reproduction apparatus. Specifically, the signal read out from the recording medium at a predetermined cycle is stored in the storage means, and the storage means stores the signal read out from the recording medium for a predetermined amount from the current reproduction position. When the operation is switched from variable speed playback to a new playback speed, the signal stored in the storage means is read according to the new playback speed until the signal corresponding to the new playback speed is read from the recording medium. By obtaining the reproduction output signal, the feeling of response to the operation is improved.
[0002]
[Prior art]
In a conventional signal reproduction device, for example, a signal reproduction device that reproduces an image signal recorded on a disk-shaped recording medium such as a magnetic disk or an optical disk, a variable speed reproduction operation that can vary a reproduction speed is performed in addition to a normal reproduction operation. It has been made possible. Therefore, by switching the operation from normal reproduction to variable speed reproduction and performing high-speed reproduction or low-speed reproduction, the position where a desired image is recorded can be easily detected.
[0003]
When n system image signals are compressed and recorded on the disc-shaped recording medium, the predetermined time period TM is divided into “1 / n” as shown in FIG. 1 to TS-n are set. Here, by reading out one system of compressed image signals in one time slot, it is possible to read out n systems of compressed image signals in a predetermined period TM. Furthermore, the image signals read out in each time slot are decompressed, so that n system image signals can be reproduced simultaneously.
[0004]
[Problems to be solved by the invention]
By the way, in such a signal reproduction apparatus capable of reproducing n-system image signals, such as a video server, when the reproduction speed is changed by switching the operation to the variable speed reproduction operation during the normal reproduction operation, for example, as shown in FIG. 4A. Thus, at the time t11 after the time slot TS-aa, when the operation mode is switched from the normal playback to the variable speed playback as shown in FIG. 4B and the playback speed is changed, the image is displayed as shown in FIG. 4C. The signal is stopped at the time t11. Thereafter, when an image signal corresponding to the reproduction speed changed in the time slot TS-ab is read from the disc-shaped recording medium, output of the image signal corresponding to the reproduction speed changed at time t12 is started. FIG. 4C shows a case where the address is increased at the time of reproduction, and in the variable speed reproduction, the image is updated at the interval Tw according to the variable reproduction speed.
[0005]
As described above, during the period from the time point t11 to the time point t12, the image signal is stopped in the state at the time point t11, so that the reaction of the operation of the signal reproduction device to the operation is felt late.
[0006]
Therefore, the present invention provides a signal reproduction method and a signal reproduction apparatus that can obtain a good response when the operation is switched from normal reproduction to variable speed reproduction and the reproduction speed is varied.
[0007]
[Means for Solving the Problems]
In the signal reproduction method according to the present invention, when reproducing a signal recorded on a recording medium, the signal is read from the recording medium at a predetermined cycle according to the reproduction speed and stored in the storage means. The signal read from the recording medium is stored for a predetermined amount from the current playback position, the signal stored in the storage means is read to obtain the playback output signal, and the operation is switched from normal playback to variable speed playback. when a fast new reproduction speed than the reproduction speed at the time of reproduction, the new reproduction until a signal corresponding to the speed is read out at a predetermined period from the recording medium, fast and than the reproduction speed during the reproduction speed is the normal reproduction The reproduction output signal is obtained by controlling the reading of the signal stored in the storage means so as to be slower than the new reproduction speed .
[0008]
The signal reproducing apparatus according to the present invention comprises a signal reading means for reading a signal recorded on a recording medium, a storage means for storing a signal read by the signal reading means for a predetermined amount from the current reproduction position, and an operation. An operation means for switching to normal reproduction or variable speed reproduction and setting a reproduction speed at the time of variable speed reproduction, and a signal reading means for controlling a signal reading means so as to read a signal from the recording medium at a predetermined cycle according to the reproduction speed and a storage means Control means for controlling the signal writing / reading operation in the control means. In the control means, the operation is switched from the normal reproduction to the variable speed reproduction by the operation means, and a new speed higher than the reproduction speed at the normal reproduction is obtained. when the playback speed, the until a new signal corresponding to the playback speed is read out at a predetermined period from the recording medium, fast and a new playback speed than the reproduction speed of the normal reproduction reproduction Such that the slower than degrees, and controls the readout of the stored signals in the storage means.
[0009]
In the present invention, signals of each system are read out in different time slot periods from a disc-shaped recording medium on which a plurality of systems of signals are compressed and recorded. A signal read at a predetermined cycle based on the time slot is stored in the storage means. The storage means stores signals for a predetermined period, for example, before and after the current reproduction position. The signal stored in the storage means is read out and output as a reproduction output signal. Since the signal is compressed and recorded on the disk-shaped recording medium, the signal read from the disk-shaped recording medium is expanded before being output as a reproduction output signal.
[0010]
Here, when the operation is switched from normal playback to variable speed playback and the playback speed is set to a new playback speed, for example, when the playback speed is increased, a signal corresponding to the new playback speed is sent to the next time slot. In the period until the data is read out from the disk-shaped recording medium, the signal stored in the storage means is read out so that the reproduction speed is higher than the reproduction speed during normal reproduction and lower than the new reproduction speed .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of a signal recording / reproducing system capable of recording signals of a plurality of systems and reproducing the recorded signals. The server 10 is supplied with image signals Vin-1 to Vin-n of images such as programs and commercials from the outside, and the image signal Vin-1 is compression-encoded by the encoder unit 12-1, The amount is compressed to “1 / n”. The image signal Vin-1 compression-encoded by the encoder unit 12-1 is temporarily stored in the buffer memory 14-1.
[0012]
Similarly to the image signal Vin-1, the image signals Vin-2 to Vin-n of the other systems are compressed to “1 / n” by the encoder units 12-2 to 12-n and the buffer memory 14-2. It is temporarily stored in ~ 14-n.
[0013]
The time slot signal generator 16 sets n time slots by dividing the predetermined period TM into “1 / n”, and generates time slot signals SL-1 to SL-n indicating the respective time slots. Is done. The generated time slot signal SL-1 is supplied to the buffer memory 14-1 and a buffer memory 32-1 described later. Based on the time slot signal SL-1, the compressed image signal Vin-1 held in the buffer memory 14-1 is transmitted via the data bus 42 using a hard disk drive or a RAID disk array. The data is supplied to and recorded on the configured data recording unit 20.
[0014]
Similarly, the time slot signals SL-2 to SL-n are supplied to the buffer memories 14-2 to 14-n and the buffer memories 32-2 to 32-n. Based on the time slot signals SL-2 to SL-n, the compressed image signals Vin-2 to Vin-n held in the buffer memories 14-2 to 14-n are respectively transmitted at different time slot timings. The data is recorded in the data recording unit 20 via the data bus 42.
[0015]
The image signal recorded in the data recording unit 20 is read based on the control signal CT supplied from the control unit 40 via the control bus 44. Here, since a hard disk drive or a RAID disk array uses a disk-shaped recording medium that can be randomly accessed, a desired image signal can be quickly read based on the control signal CT. . Further, a desired image signal is read from the recorded image signal in units of time slots and written in any of the buffer memories 32-1 to 32-n. Here, the buffer memory to which the read image signal is written is designated by the time slot signals SL-1 to SLn.
[0016]
The image signal written in the buffer memory 32-1 is supplied to the decoder unit 34-1 and decoded. The image signal decoded by the decoder unit 34-1 is written in a memory for JOG operation (hereinafter referred to as “JOG memory”) 36-1. The image signal written in the JOG memory 36-1 is reproduced. The reproduction output signal Vout-1 is read according to the speed and output as a reproduction output signal Vout-1.By supplying the reproduction output signal Vout-1 to the monitor television 51-1, for example, a program or program is displayed on the screen of the monitor television 51-1. Commercials etc. are displayed.
[0017]
Similarly, the image signals written in the buffer memories 32-2 to 3-n are respectively supplied to the decoder units 34-2 to 34-n and decoded. The image signals decoded by the decoder units 34-2 to 34-n are written in the JOG memories 36-2 to 36-n. The image signals written in the JOG memories 36-2 to 36-n are read and output as reproduction output signals Vout-2 to Vout-n.
[0018]
The buffer memory 32 and the JOG memory 36 store a predetermined amount of image signals from the current reproduction position, for example, image signals for a predetermined number of consecutive frames before and after normal reproduction, and image signals in units of frames at variable speed reproduction. They are stored at frame intervals according to the variable playback speed.
[0019]
An operation device 50 is connected to the control unit 40, and an operation signal PS is supplied from the operation device 50 to the control unit 40. In the control unit 40, a control signal CT based on the operation signal PS is generated. The operation of the data recording unit 20, the buffer memory 32, the decoder unit 34, the JOG memory 36, etc. is controlled by this control signal CT, and the operation mode is switched to normal reproduction or variable speed reproduction, and the reproduction speed for variable speed reproduction is set. Etc. are performed.
[0020]
Next, the operation will be described with reference to FIG. FIG. 2A shows an operation mode set based on the operation signal PS from the operation device 50. In normal playback, the playback position address increases sequentially as shown in FIG. 2B. In addition, as shown in FIG. 2C, the image signal recorded in the data recording unit 20 in a predetermined time slot is read and written in the buffer memory 32. The image signal written in the buffer memory 32 is read out and supplied to the decoder unit 34. In the decoder unit 34, the read image signal is decompressed and written in the JOG memory 36. The image signal written in the JOG memory 36 is read out to be a reproduction output signal Vout shown in FIG. 2D. 2D indicates the amount of signal stored in the buffer memory 32 and the JOG memory 36, and FIG. 2E indicates the operating state of the signal recording / reproducing system.
[0021]
Since the JOG memory 36 stores the previous and next image signals for the current reproduction position, when the reproduction operation is started based on the operation signal PS from the operation device 50, the image signal is received from the JOG memory 36. Images can be displayed promptly by simply reading them out. Further, since the buffer memory 32 and the JOG memory 36 store image signals for a predetermined number of consecutive frames before and after the current playback position, the decoder unit 34 decompresses the image signals stored in the buffer memory 32. Then, by writing to the JOG memory 36 and reading the image signal from the JOG memory 36, the reproduction operation can be started even before the image signal is read from the data recording unit 20 in a predetermined time slot.
[0022]
Here, when the operation mode is set to the variable speed reproduction based on the operation signal PS from the operation device 50 at the time t1, and the reproduction speed is varied by operating the operation device 50 as shown in FIG. 2B, For example, the image is updated at the interval Tw according to the variable reproduction speed. That is, an image is displayed based on the image signals at addresses M1, M2, M3, M4. An image signal corresponding to the changed reproduction speed is read from the data recording unit 20 in the time slot TS-b and written in the buffer memory 32. The image signal written in the buffer memory 32 is decompressed by the decoder unit 34 and written in the JOG memory 36. The signal written in the JOG memory 36 is read at time t2, and an image corresponding to the variable reproduction speed, that is, an image based on the image signal at addresses M1, M2, M3, M4. Each one is displayed sequentially.
[0023]
In addition, a period from when the image signal corresponding to the variable reproduction speed is read from the data recording unit 20 to when it is read from the JOG memory, that is, a period from time t1 to time t2 (hereinafter referred to as “pseudo variable speed reproduction period”). ) Generates a reproduction output signal Vout from the image signals stored in the buffer memory 32 and the JOG memory 36, and displays the image.
[0024]
When the playback speed Rp during the pseudo variable speed playback period is higher than the normal speed Rs when the operation mode is normal playback, the initial speed Rr when the variable speed playback is set is faster. The playback speed Rp is set so as to satisfy the condition of Expression (1).
Variable speed playback initial speed Rr> playback speed Rp> normal playback speed Rs (1)
Furthermore, since the timing of the time point t2 is known as the predetermined period TM which is the time slot period and the time slot position, the operation mode is switched to the variable speed playback and the playback speed is changed at the time t1. Timing can be determined. For this reason, the time Tp from the time point t1 to the time point t2 is obtained, and the playback speed during the pseudo variable speed playback period is determined from the time Tp and the signal amount of the image signal stored in the buffer memory 32 or the JOG memory 36. Is done.
[0025]
Here, the reproduction speed Rp satisfies the condition of the expression (1), and all the image signals stored in the buffer memory 32 and the JOG memory 36 are read during the period from the time point t1 to the time point t2. By setting so that there is no image, it is possible to smoothly switch images when the operation mode is switched from normal playback to variable speed playback. For example, as shown in FIG. 2D, in the pseudo variable speed reproduction period, the slope of the line segment indicating the address position is larger than that in the normal reproduction period. That is, in the pseudo-variable speed reproduction period, the address change amount increases in interval T w as compared with the normal playback period, a faster than playback speed during playback speed normal playback. Also, in the pseudo variable speed reproduction period, the address change amount in the interval T w is less than the address change amount in the new playback speed. That is, in the pseudo variable speed playback period, the playback speed is lower than the new playback speed. As described above, during the pseudo variable speed playback period, the image signal is read out so that the playback speed is higher than the playback speed during normal playback and lower than the new playback speed. When the operation mode is switched, the image can be switched smoothly.
[0026]
Further, by adjusting the playback speed Rp to be the normal playback speed Rs at the time t1 and to be the initial speed Rr of the variable speed playback at the time t2, the playback image having the running period from the time t1 to the time t2 is obtained. Can be displayed.
[0027]
When the initial speed Rr of variable speed playback is lower than the normal playback speed Rs, the playback speed Rp during the pseudo variable speed playback period is set so as to satisfy the expression (2).
Variable speed playback initial speed Rr = playback speed Rp (2)
As described above, when the playback speed Rp is set so as to satisfy the expression (2), the variable speed playback is started immediately from the time t1 when the operation mode is switched to the variable speed playback and the playback speed is changed. It is possible to display an image equivalent to.
[0028]
As described above, according to the above-described embodiment, when the operation is switched from the normal reproduction to the variable speed reproduction, the image signal corresponding to the variable speed reproduction is read from the data recording unit 20 and output. During the pseudo variable speed playback period, an image signal stored in the buffer memory 32 or the JOG memory 36 is read out and a playback output signal is generated and output according to the initial speed of the variable speed playback. The image signal is not stopped in the state at the time of being received, and the feeling of use can be improved with a good response feeling.
[0029]
In the above-described embodiment, the case where the image signal recorded in the data recording unit 20 of the server 10 is reproduced has been described. However, the reproduced image signal is limited to the image signal recorded in the server 10. is not. Further, the signal is not limited to the image signal, but may be an audio signal or the like.
[0030]
【The invention's effect】
According to the present invention, the signal read from the recording medium at a predetermined cycle is stored in the storage means, and the signal read from the recording medium is stored in the storage means for a predetermined amount from the current reproduction position. . Here, the operation is switched to the variable speed reproduction from the normal reproduction, when a fast new reproduction speed than the reproduction speed of the normal reproduction, a predetermined period from a signal corresponding to said new reproduction speed recording medium The signal stored in the storage means is read so that the playback speed is higher than the playback speed at the time of normal playback and lower than the new playback speed. For this reason, when the operation mode is switched from the normal playback to the variable speed playback, the playback is not stopped during the period until the signal corresponding to the new playback speed is read out from the recording medium in a predetermined cycle, In addition, during the period until the signal corresponding to the new playback speed is read out from the recording medium at a predetermined cycle, the playback speed is set to be higher than the playback speed during normal playback and lower than the new playback speed. It can be used like a switching run-up period to switch images smoothly.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a signal recording / reproducing system.
FIG. 2 is a diagram for explaining a signal reproduction method;
FIG. 3 is a diagram showing time slots.
FIG. 4 is a diagram for explaining a conventional signal reproduction method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Server, 16 ... Time slot signal generation part, 20 ... Data recording part, 32-1 to 32-n ... Buffer memory, 34-1 to 34-n ... Decoder part, 36 ... JOG memory, 40 ... control unit, 42 ... data bus, 44 ... control bus, 50 ... operating device, 51-1 ... monitor TV

Claims (2)

When playing back the signal recorded on the recording medium,
The signal is read out from the recording medium at a predetermined cycle according to the reproduction speed and stored in the storage means,
The storage means stores a signal read from the recording medium for a predetermined amount from the current reproduction position,
Reading the signal stored in the storage means to obtain a reproduction output signal,
By switching the operation to the variable speed reproduction from the normal reproduction, when said normally was fast new reproduction speed than the reproduction speed at the time of reproduction, the signal corresponding to the new playback speed read at the predetermined period from said recording medium Until the playback speed is higher than the playback speed during normal playback and lower than the new playback speed until a playback output signal is obtained by controlling reading of the signal stored in the storage means. A signal reproduction method characterized by the above. Signal reading means for reading a signal recorded on the recording medium;
Storage means for storing a predetermined amount of the signal read by the signal reading means from the current reproduction position;
Operation means for switching the operation to normal playback or variable speed playback and setting the playback speed during variable speed playback;
Control means for controlling the signal reading means so as to read a signal from the recording medium in a predetermined cycle according to a reproduction speed, and for controlling a signal writing / reading operation in the storage means,
In the control unit, is switched to operate in the variable speed reproduction from the normal reproduction by said operating means, when said normally is a reproduction of the playback speed faster new playback speed than, according to the new reproduction speed Until the signal is read out from the recording medium at the predetermined period, the reproduction speed of the signal stored in the storage means is set so that the reproduction speed is higher than the reproduction speed during the normal reproduction and lower than the new reproduction speed. A signal reproducing apparatus characterized by controlling reading .

Images