JP2000101985A - Stream data fast forwarding mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stream data fast forwarding mechanism, capable of performing fast forwarding faster or slower by providing plural kinds of fast forwarding speeds and manually or automatically performing switching. SOLUTION: First and 2nd fast forwarding data are prepared. A time stamp controller 7 reads the time stamp in transmission stored in a register 5, in response to a fast-forwarding request r1 from a client and gives to a read transmission controller 3 an instruction as to which fast-forwarding data is to be read from which time stamp. The read transmission controller 3 reads fast-forwarding data designated by a storage device 1 from a designated time stamp and transmits it to the client in response to this instruction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trick play control system for digital image / audio stream data.
In particular, it relates to a fast-forward mechanism for stream data.

[0002]

2. Description of the Related Art Some video server systems for providing digital image and audio data have a trick play function for realizing video on demand. Trick play is a general term for operations other than normal reproduction and stop, such as pause (pause), fast forward (wind), and fast rewind (rewind) of stream data being reproduced.

[0003] The stream data additionally has a numerical value defining a time called a time stamp at every predetermined time as data, and various trick plays are realized using this value. The following two methods are typical methods for achieving fast-forward in trick play.

(1) A method in which stream data for fast forward is prepared in advance separately from stream data for normal reproduction, and the stream data to be serviced is switched by a fast forward command / fast forward command release. When generating the stream data, the time stamp position of the fast-forward data and the time stamp position of the normal reproduction data are matched. At the time of normal reproduction, upon receiving a fast-forward command from the client, the server reads the time stamp value of the data being serviced, and starts the service of the fast-forward data from the position of the same time stamp. In this way, the client side looks as if the data being reproduced has been fast-forwarded, even though other data (fast-forward stream data prepared in advance) is actually being sent. Hereinafter, this will be described in detail with reference to FIG.

In FIG. 6, data d (tn) of normal reproduction data is stream data (where n = 1, 2, 3,...) Including a time stamp tn. The data f (tn) of the fast-forward data is stream data (n = 1, 2, 3,...) Including the time stamp tn, and the data obtained by fast-forwarding the data d (tn) is f
Fast forward data is created to correspond to (tn). When a fast-forward command is received from a client while d (tn) is being serviced in normal playback, the server returns f (tn + 1)
Starts transmission of fast-forward data.

Contrary to the above, the fast-forward cancellation switches from fast-forward data to normal data. The advantage of this method is that smooth fast-forward data can be reproduced. (2) A method of repeating jump reproduction using only normal reproduction data. Upon receiving a fast-forward command from the client during normal playback, as shown in FIG. 7, the server reads the timestamp value of the data being serviced, adds a certain amount of the timestamp value to the value, and stores the data for normal playback. After the short time reproduction, the operation of skipping the stream data until the next time stamp value, then adding a certain amount to the time stamp value and reproducing the normal reproduction data for a short time is repeated. On the client side, it appears that the stream data being played back is skipped and played back (skip playback). The fast-forward is canceled by canceling this operation routine and performing normal reproduction. The advantage of this method is that it is not necessary to prepare data for fast forward.

[0007]

However, the above-mentioned 2)
In the two methods, there is only one fast-forward reproduction speed, so that there is a problem that it is not possible to cope with a case where fast-forward or slow-forward is desired.

The present invention has been made in view of the above-mentioned circumstances, and provides a stream data fast-forward mechanism capable of performing faster or slower fast-forward by providing a plurality of types of fast-forward speeds and switching manually or automatically. The purpose is to.

[0009]

In order to solve the above-mentioned problems, a stream data fast-forward mechanism according to the present invention includes a storage device for storing a plurality of types of fast-forward video streams corresponding to a plurality of types of fast-forward speeds; Means for specifying which of the fast-forward video streams to transmit, a register for storing a time stamp during transmission, and, in response to the specifying means, reading the time stamp stored in the register, A time stamp control device for outputting control data indicating which video stream of the fast-forward video stream is transmitted from which time stamp; and the storage device in response to the control data output from the time stamp control device. From the stream data having the time stamp read from the register. Characterized by comprising a read transmission control apparatus for transmitting read the data.

According to the present invention, a plurality of types of fast-forward data are prepared in advance, and the server can transmit fast-forward data at a designated speed in response to a request for fast-forward data from a client. The stream data fast-forward mechanism of the present invention further comprises a first fast-forward video stream having at least a first fast-forward speed and the first fast-forward video stream.
Storage means for storing a second fast-forward video stream having a second fast-forward speed different from the fast-forward speed of the first and second fast-forward video streams; means for specifying which of the first and second fast-forward video streams is to be transmitted; A register for storing a time stamp of, a timer for outputting a timeout signal after counting a predetermined time, and in response to the designation means,
Reading the time stamp stored in the register,
A first indicating the first video stream and indicating which timestamp of the first video stream to transmit from.
Outputting control data, starting the timer, outputting a second control data indicating a time stamp of the second video stream from a time stamp of the second video stream in response to a timeout signal from the timer; A time stamp control device, and reads and transmits stream data specified by the first control data output from the time stamp control device, and, after counting a predetermined time by the timer, outputs the stream data from the time stamp control device. And a read transmission control device for reading and transmitting the stream data specified by the second control data.

According to the present invention, a plurality of types of fast-forward data are prepared in advance, and the server automatically switches between a plurality of types of fast-forward data and transmits to the client in response to a request for fast-forward data from the client. be able to.

Further, the stream data fast-forward mechanism of the present invention further comprises a first fast-forward video stream having at least a first fast-forward speed and a second fast-forward video stream having a second fast-forward speed different from the first fast-forward speed. Storage means for storing the first and second fast-forward video streams; a first register for storing a timestamp during transmission; and a first fast-forward video stream. The second value that stores the increment value of the time stamp when playing back
A register, a third register for storing an increment value of a time stamp when the second fast-forward video stream is reproduced, a timer for outputting a timeout signal after counting a predetermined time, and reading the time stamp stored in the register Obtaining a time stamp value obtained by adding an increment value stored in one of the second register and the third register, and obtaining the time stamp value by the addition of the video stream designated by the designation means. And outputting control data indicating transmission from the received time stamp, starting the timer, reading a time stamp from the first register again in response to a timeout signal from the timer, and reading the second register or Stored in one of the third registers A timestamp value obtained by adding the increment value obtained from the timestamp, and outputting the control data indicating that the video stream specified by the specifying means is transmitted from the timestamp obtained by the addition of the video stream. A stamp control device, and a read control device that reads and transmits stream data specified by the control data from the storage device in response to control data output from the time stamp control device. I do.

According to the present invention, in response to a fast-forward request from a client, the server can skip and reproduce the normal reproduction data at the designated speed. Further, the stream data fast forward mechanism of the present invention stores at least a first fast forward video stream having a first fast forward speed and a second fast forward video stream having a second fast forward speed different from the first fast forward speed. Storage means for transmitting, a means for designating which of the first and second fast-forward video streams is to be transmitted, a first register for storing a time stamp during transmission,
A second register for storing an increment value of a time stamp when reproducing the fast-forward video stream, a third register for storing an increment value of the time stamp for reproducing the second fast-forward video stream, and a predetermined time count. After that, a timer for outputting a time-out signal and a time stamp stored in the register are read, and a time stamp value obtained by adding an increment value stored in the second register is obtained. And outputting first control data indicating that the video stream is transmitted from the time stamp obtained by the addition, starts the timer, and responds to a time-out signal from the timer to output the first control data. Read the time stamp from the register again To obtain a timestamp value obtained by adding the increment value stored in the third register,
A time stamp control device for outputting second control data indicating a video stream specified by the specifying means and transmitting the video stream from the time stamp obtained by the addition, and the time stamp control Reading the stream data specified by the first control data output from the device from the storage device and transmitting the data; reading the stream data specified by the second control data after counting a predetermined time by the timer; And a transmission control device.

According to the present invention, in response to a fast-forward request from a client, the server automatically switches between a plurality of types of speeds (by automatically switching the playback time of normal playback data). It is possible to realize fast-forward skip reproduction in which the speed gradually increases.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows an embodiment of the present invention.
For example, a block diagram of a stream data fast-forward mechanism in a video server system is shown. In FIG. 1, a storage device 1 is constituted by, for example, a disk array, and stores stream data to be transmitted and a plurality of types of fast-forward data (for example, MPEG data). The read transmission control device 3 reads out specified stream data (fast-forward data) from the specified time stamp among the stream data (fast-forward data) stored in the storage device 1 and outputs the read data as read transmission data. The register 5 holds a time stamp of the stream data (fast-forward data) being transmitted. The time stamp control device 7 receives the fast-forward request (r1, r2) from the client,
With reference to, which stream data (fast-forward data) is transmitted from which time stamp is read out and given to the transmission control device 3.

In the first embodiment, two types of fast-forward data are prepared in advance. That is, the data for normal reproduction shown in FIG. 2A is compared with the first data shown in FIG.
Two types of fast-forward data, ie, fast-forward data 1 and second fast-forward data 2 shown in FIG. 2C, which is faster than the first fast-forward data, are prepared. In FIG. 2, tn represents a time stamp, and s represents a start time stamp.

The operation of the fast-forward mechanism for stream data according to the first embodiment configured as described above will be described. Upon receiving the fast-forward request r1 from the client, the time stamp control device 7 reads the value of the register 5 at that time and starts the service of the fast-forward data 1. That is,
The time stamp control device 7 reads the time stamp of the stream data currently being transmitted from the register 5 and gives the read transmission control device 3 an instruction on which stream data (fast-forward data) to read from which time stamp. In response to this command, the read transmission control device 3 reads the stream data (fast-forward data 1) having the specified time stamp of the specified stream data (fast-forward data 1) from the storage device 1, and transmits the read stream data to the client. As a result, the client can see the fast-forward reproduction based on the fast-forward data 1. If the client desires a faster fast-forward, it sends a fast-forward request r2 to the server. In response to the fast-forward request r2, the time stamp control device 7 reads the time stamp held in the register 5, reads an instruction of which stream data (fast-forward data) to read from which time stamp, and sends the command to the transmission control device 3. give. In response to this command, the read transmission control device 3 reads the fast-forward data 1 having the specified time stamp of the specified stream data (fast-forward data 2) from the storage device 1 and transmits the read fast-forward data 1 to the client. As a result, the client will see faster fast-forward playback. (Second Embodiment) FIG. 3 is a block diagram of a stream data fast-forward mechanism according to a second embodiment of the present invention.
The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In the first embodiment, the switching of the fast-forward data is performed manually, but in the second embodiment, the switching is performed automatically. In the second embodiment, a timer 9 is further provided in the first embodiment. The timer 9 performs a predetermined time counting operation in response to a start signal from the time stamp control device 7, and outputs a timer request signal Tr to the time stamp control device 7.

When a fast-forward request r1 is received from a client during normal reproduction of stream data, the time stamp control device 7 reads the value of the register 5 at that time, and
The service of the fast-forward data r1 is started by the same control as described in the first embodiment. As a result, the client can see the fast-forward reproduction based on the fast-forward data 1. At the same time, the time stamp control device 7 requests the timer 9 to start the timer. After counting a predetermined time, the timer 9 outputs a timer request signal Tr to the time stamp control device 7. In response to the timer request signal Tr, the time stamp controller 7 reads the value of the register 5 at that time,
Start the service. The control at this time is the same as that in the case of the fast-forward data 1, and the description thereof is omitted. As a result, fast-forward reproduction in which the fast-forward speed gradually increases can be realized. (Third Embodiment) FIG. 4 is a block diagram of a stream data fast-forward mechanism according to a third embodiment of the present invention. The same parts as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof will be omitted. In the third embodiment, a plurality of types of fast forward are realized using only the normal reproduction data. FIG.
In, the register 11 stores an increment value of the time stamp when the fast forward 1 is realized. Also,
The register 13 stores an increment value of the time stamp when the fast forward 2 is realized.

When a fast-forward request r1 is received from the client during normal reproduction of stream data, the value of the register 5 at that time is read, and the service of the stream data is provided by the time stamp obtained by adding the increment value 1 stored in the register 11. Start. That is, a read command indicating which stream data is to be read is output to the transmission controller 3 together with the time stamp obtained by the addition and the data indicating which fast-forward speed. In response to this command, the read / transmission control device reads the designated stream data from the designated time stamp and transmits it.

At the same time as the start of the service, the time stamp control device 7 requests the timer 9 to start the timer. In response to this request, the timer 9 outputs a timer request signal Tr after counting a predetermined time. In response to the timer request signal Tr, the time stamp control device 7 reads the value of the register 5 again, and starts the service of the stream data with the time stamp obtained by adding the value of the register 11. This operation is performed for each cycle. Therefore, when the client requests a faster fast-forward, a fast-forward request r2 is transmitted to the time stamp controller 7. In response to the fast forward request r2, the time stamp control device 7 reads the value of the register 5 at that time, adds the increment value of the register 13, and starts the service of the stream data with the obtained time stamp. . As a result, the client will see faster fast-forward skip playback. (Fourth Embodiment) In the third embodiment, a plurality of fast-forward speeds are switched in response to a fast-forward request from the client side. In the fourth embodiment, the fast-forward speed is automatically switched on the server side.

In FIG. 4, when the fast forward request r1 is received from the client during the normal reproduction of the stream data, the time stamp control device 7 sets the register 5 at that time.
Is read out, and the service of the stream data is started with a time stamp obtained by adding the value of the register 11 to the value. At the same time, the timer stamp control device 7
Request the timer start. After counting the predetermined time, the timer 9 outputs a timer request signal Tr to the time stamp control device 7. In response to the timer request signal Tr, the time stamp control device 7 reads the value of the register 5 again, reads and increments the increment value of the register 13, and uses the time stamp obtained as a result to provide stream data service. Move to the cycle to be performed.

It appears to the client that normal reproduction → skip reproduction with the time stamp increment value 11 → skip reproduction with the time stamp increment value 13 is continuously reproduced. This makes it possible to realize fast-forward skip reproduction in which the speed gradually increases. (Fifth Embodiment) In the fifth embodiment, there is provided a stream data fast-forward mechanism capable of arbitrarily setting the timing of shifting from fast-forward 1 to fast-forward 2. The same parts as those in the fourth embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The manual operation circuit 15 variably sets a time stamp increment value 1 for realizing fast-forward 1 and a time stamp increment value 2 for realizing fast-forward 2 based on the input switching timing value Tn. I do. Thereby, it is possible to switch from the fast forward 1 to the fast forward 2 at an arbitrary timing. With such a configuration, it is possible to select a desired fast forward while actually watching the reproduction of the fast forward data on the client side.

In the above-described embodiment, the fast-forward mechanism for stream data has been described. However, the present invention is not limited to the fast-forward mechanism for stream data, and can be applied to fast rewind of stream data by the same control. is there.

Further, in the above-described embodiment, two types of fast-forward data and two types of fast-forward speed have been described. However, two or more types of fast-forward data may be used.

[0026]

As described above, according to the present invention,
Multiple types of fast forward can be realized manually or automatically.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a stream data fast-forward mechanism according to a first embodiment of the present invention.

FIG. 2 shows normal reproduction data used in the embodiment;
FIG. 3 is a conceptual diagram showing fast-forward data 1 and fast-forward data 2.

FIG. 3 is a block diagram showing a fast-forward mechanism for stream data according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a fast-forward mechanism for stream data according to third and fourth embodiments of the present invention.

FIG. 5 is a block diagram showing a stream data fast-forward mechanism according to a fifth embodiment of the present invention.

FIG. 6 is a conceptual diagram showing normal reproduction data and fast-forward data for explaining a first fast-forward method in the prior art.

FIG. 7 is a conceptual diagram for explaining a second fast-forward method in the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Storage device 3 ... Read transmission control device 5 ... Register 7 ... Time stamp control device 9 ... Timer 11 ... Register (increment value 1) 13 ... Register (increment value 2) 15 ... Manual operation circuit

Claims (5)

[Claims] 1. A storage device for storing a plurality of types of fast-forward video streams corresponding to a plurality of types of fast-forward speeds, means for specifying which of the plurality of types of fast-forward video streams to transmit, and a time stamp during transmission A register for storing a time stamp stored in the register in response to the specifying means, and control data indicating which video stream of the plurality of types of fast-forward video streams is transmitted from which time stamp. And a read transmission control device for reading and transmitting stream data having a time stamp read from the register from the storage device in response to control data output from the time stamp control device. A stream comprising: Data fast forward mechanism. 2. A storage device for storing at least a first fast-forward video stream having a first fast-forward speed and a second fast-forward video stream having a second fast-forward speed different from the first fast-forward speed. Means for designating which of the first and second fast-forward video streams is to be transmitted, a register for storing a time stamp during transmission, a timer for outputting a timeout signal after counting a predetermined time, and a response to the designating means Reading the time stamp stored in the register, indicating the first video stream, and outputting first control data indicating which time stamp of the first video stream to transmit, starting the timer, Indicating a second video stream in response to a timeout signal from the timer;
A time stamp control device that outputs second control data indicating from which time stamp of the video stream to transmit, and reads and transmits the stream data specified by the first control data output from the time stamp control device And a read transmission control device for reading and transmitting the stream data specified by the second control data output from the time stamp control device after counting a predetermined time by the timer. mechanism. 3. A storage device for storing at least a first fast-forward video stream having a first fast-forward speed and a second fast-forward video stream having a second fast-forward speed different from the first fast-forward speed; Means for specifying which of the first and second fast-forward video streams is to be transmitted, a first register for storing a time stamp during transmission, and an increment value for the time stamp when the first fast-forward video stream is reproduced. A second register for storing an increment value of a time stamp when the second fast-forward video stream is reproduced; a timer for outputting a timeout signal after counting a predetermined time; and a timer for storing a timeout signal. Read the time stamp
A timestamp value obtained by adding an increment value stored in one of the second register and the third register is obtained, and a video stream specified by the specifying means and obtained by the addition of the video stream is obtained. Control data indicating that transmission is to be performed from the time stamp, and starts the timer, and in response to a timeout signal from the timer,
The time stamp is read again from the register, and the second
Obtaining a timestamp value obtained by adding the increment value stored in either the register or the third register; and obtaining a timestamp value from the timestamp obtained by the addition of the video stream specified by the specifying means. A time stamp control device for outputting control data indicating transmission, and reading and transmitting stream data specified by the control data from the storage device in response to the control data output from the time stamp control device A stream data fast-forward mechanism, comprising: a read control device. 4. A storage device for storing at least a first fast-forward video stream having a first fast-forward speed and a second fast-forward video stream having a second fast-forward speed different from the first fast-forward speed. Means for specifying which of the first and second fast-forward video streams is to be transmitted, a first register for storing a time stamp during transmission, and an increment value for the time stamp when the first fast-forward video stream is reproduced. A second register for storing an increment value of a time stamp when the second fast-forward video stream is reproduced; a timer for outputting a timeout signal after counting a predetermined time; and a timer for storing a timeout signal. Read the time stamp
Obtaining a timestamp value obtained by adding the increment value stored in the second register, and transmitting the video stream specified by the specifying means from the timestamp obtained by the addition of the video stream. Output the first control data, start the timer, read the time stamp from the first register again in response to a timeout signal from the timer, and add the increment value stored in the third register. A time stamp control device that obtains the time stamp value, and outputs second control data that is a video stream specified by the specifying means and that is transmitted from the time stamp obtained by the addition of the video stream. And output from the time stamp control device. A read / transmission control device for reading and transmitting the stream data specified by the first control data from the storage device, reading the stream data specified by the second control data after counting a predetermined time by the timer, and A fast forward mechanism for stream data, comprising: 5. The apparatus according to claim 1, further comprising means for variably setting an increment value stored in said second register and an increment value stored in said third register, whereby said second fast-forward video stream is read from said second fast-forward video stream. The stream data fast-forward mechanism according to claim 4, wherein the timing for switching to the fast-forward video stream is set arbitrarily.