JPH1092087A - Random access reproducing method for disk recording data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To limit the range of a memory to be used for reproducing operation as occasion demands and to effectively utilize the range not used for the reproducing operation of a memory for another function. SOLUTION: This random access reproducing method is to store a series of reproducing outputs in the memory by accessing recording data in arbitrary positions on a disk and to output the stored reproducing outputs without interruption. In this case, an input command is interpreted (BK1) to detect a reproducing position on the disk to be reproduced, a reproducing speed, a reproducing speed range and a reproducing method, and according to the detected reproducing speed range and reproducing method, a means for obtaining a division of the memory and data to be accumulated in the memory is selected, and the data to be accumulated in the memory is obtained (BK3), and the disk is reproduced in accordance with the detected reproducing position and reproducing speed by utilizing the divided memory (BK4, 5 and 6), and then the continuous reproducing outputs are outputted (BK2 and BK7).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a random access method for accessing recorded data at an arbitrary position on a disk, storing a reproduced output by the access in a memory, and continuously outputting the stored reproduced output without interruption. Reproduction method.

[0002]

2. Description of the Related Art Video and audio playback devices using a random access device as a playback device have been put to practical use. The characteristics of the random access device, such as a high-speed seek and a high data transfer rate, are utilized in a technology (for example, virtual editing) for continuously reproducing data recorded at a distant position on a disk. For this technology,
Even when the playback device is performing a seek operation, the playback output must be continuously output. However, there is a problem in that the playback device itself cannot read data from the disc when the playback device is performing a seek operation. Therefore, even when the playback device is performing a seek operation, the playback output can be output continuously,
This problem is solved by reading data to be output during a seek operation from a disk in advance and storing the read data in a memory.

In this case, data that may be output as a reproduction output within a seek time is data that needs to be stored in a memory. Therefore, the required data amount is (reproduction speed x seek time x standard reproduction data rate)
Can be determined by: For example, if the seek time is T
When the memory amount M required for the following two cases C1 and C2 is obtained, C1. Reproduction speed range: from -1 × to + 2 × M = (2 − (− (− 1)) × D × T = 3 × T C2. Reproduction speed range: From stop to + 1 × speed M = (1− 0) × D × T = T.

[0004]

The above two cases C
As can be seen from 1, C2, the reproduction speed range has a great influence on the amount of data to be stored (necessary memory amount).
That is, if the reproduction speed range is tripled, the required amount of accumulated data is also tripled. This increase in the amount of stored data increases the product cost. In the case of a device in which the maximum reproduction speed range is from (-1 × speed to + 2 × speed) as in C1 above, the accumulated data amount M required for this device is
Becomes M = 3 × T. However, when this device is used in the speed range from (stop to + 1 × speed) as in the above C2, the accumulated data amount M requires only M = T, 2
The data storage capacity of × T is not used.

In view of the above problems, the present invention limits the range of the memory used for the reproducing operation as necessary and effectively utilizes the range of the memory not used for the reproducing operation for other purposes. It is an object of the present invention to provide a method for random access reproduction of data recorded on a disk, which can improve the cost performance of the entire arranged memory.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention accesses recorded data at an arbitrary position on a disk, stores a reproduced output by the access in a memory, and interrupts the stored reproduced output. This is a random access playback method that outputs data continuously without detecting the playback position, playback speed, playback speed range, and playback method of the disc to be played by interpreting the input command, and detects the playback speed range and playback. According to a method, a means for obtaining the data divided in the memory and the data stored in the memory is selected, and the reproduction is performed according to the disk reproduction position and the reproduction speed.

According to the random access reproducing method of the present invention, recorded data at an arbitrary position on a disk is accessed, a reproduced output is stored in a memory, and the stored reproduced output is continuously output without interruption. In this case, the method of the invention comprises:
The input command is interpreted to detect a reproduction position, a reproduction speed, a reproduction speed range, and a reproduction method of a disc to be reproduced, and the memory is divided according to the detected reproduction speed range and the reproduction method, and is stored in the memory. A means for obtaining data is selected to perform reproduction in accordance with the detected reproduction position and reproduction speed, and a continuous reproduction output is output.

[0008]

Next, an embodiment of the present invention will be described. FIG. 1 is a functional block diagram illustrating basic functions of a random access reproduction method according to an embodiment of the present invention, FIG. 2 is a time chart illustrating operations of the functional blocks in FIG. 1, and FIG. 6 is a time chart showing an operation in the case of reproduction.

First, the normal reproduction data rate Dout [Mbps]
, The playback speed range N [double speed], the data rate Dread [Mbps] of the read data of the playback device, and the seek time Tseek.
The relationship between [s] and the rate S [times / s] at which a seek operation is required when reading from the playback device will be described.
Since the maximum data input amount must be larger than the data output amount, the following equations (1) and (2) are used.
Holds, and the memory is used to satisfy this. Dout × N ≦ Dread × (1- (S × Tseek)) (1) Dread ≧ (Dout × N) / (1- (S × Tseek) (2)

As shown in FIG. 1, in the reproducing apparatus of this embodiment, a function block BK1 interprets an input command, gives a reproduction speed and a stop position for starting reproduction to a block BK2. A reproduction method specification including a speed range specification and an on-air reproduction (reproduction in which stop of reproduction output is a serious problem) instruction is given to the functional block BK3.
The block BK2 determines a reproduction output designation indicating a position to be reproduced from the reproduction position or the reproduction speed, and gives the designation to the blocks BK3 and BK7.

The block BK3 selects a means for obtaining data stored in the memory according to the reproduction speed range and the reproduction method from the block BK1, and based on the seek time of the reproduction device and the reproduction output designation from the block BK2, The amount of data that needs to be stored in the memory is determined, and the memory storage data list is passed to the block BK4. Block BK4
Determines the data that needs to be stored in the memory from the memory accumulation data list and the accumulation reproduction data list passed from the block BK3, and performs reproduction based on the determination in the block BK3.
5, while comparing the instructed data with the stored and reproduced data list indicating the reproduced and written data in the memory, all the data corresponding to the data that needs to be stored in the memory is written into the memory. Until the above, the reproduction from the disk is requested to the block BK5.

The block BK5 reproduces a corresponding portion of the disk in response to a disk reproduction request from the block BK4, and passes the reproduced disk reproduction data and a disk reproduction data list indicating the reproduced data to the block BK6. The block BK6 writes the disk reproduction data and the disk reproduction data list passed from the block BK5 to the memory as stored reproduction data and a stored reproduction data list, respectively. According to the reproduction output instruction given from the block BK2, the block BK7 outputs the corresponding stored reproduction data as the reproduction output based on the stored reproduction data list written in the memory by the block BK.

Next, the operation of the reproducing apparatus shown in FIG. 1 will be described with reference to FIG. In this case, the playback device is N
The disc is played at double speed. That is, the time t
The playback is performed from time 1 to time t2, and from time t2 to time t2.
3 (S on the time axis in FIG. 3 is the above-mentioned ratio S [times / s])
Until time t3, reproduction is performed again from time t3 to time t4, and seek is performed from time t4 to time t5.
The operation up to is repeated.

More specifically, from time t1 to time t2, reproduced data is stored in the memory in proportion to time with a slope of (Dread-N × Dout), and the amount of the stored data is calculated at time t1.
2 reaches the required accumulated reproduction data amount (M = N × Dout × Tseek). Since seek is performed from time t2 to time t3,
The amount of storage in the memory decreases in proportion to time with a slope of (−N × Dout) and becomes 0 at time t3, but by starting reproduction again, a reproduction output is output without interruption. be able to.

Next, a more specific reproduction apparatus of the above example will be described. If the memory amount (2 × Dout × Tseek [bit]) is prepared so that the reproduction speed range can correspond to 0 to +1.0 times speed and −1.0 to +1.0 times speed,
The following four usage methods can be switched and selected. (1) In the case where the reproduction speed range is 0 to +1.0 times speed: the function shown in FIG.
A set of reproduction outputs 12 is output using only k [bits].
In this case, since it is a conventional method, half of the memory is left.

(2) In the case where the reproduction speed range is 0 to +1.0 times speed and two reproduction outputs: Two sets of the functions shown in FIG. 1 can be operated by using half of the memory. That is, as the amount of memory for one set, Dout × Tseek [bit] is used before the reproduction output instruction position, so that if there is (2 × Dout × Tseek) (bit) memory, two sets can be reproduced. It is.

(3) The reproduction speed range is from -1.0 to +1.0.
In case of double speed: Dout × Ts before and after the playback output instruction position
eek [bit], the total (2 x Dout x Tseek) [bit] of memory is used, so there is no surplus. (4) In the case where the reproduction speed range is 0 to +1.0 times speed and on-air reproduction: Only one set of reproduction output is used, but the entire memory uses 2 × Dout × Tseek bits and stores reproduction data therein. Therefore, in the normal operation, every time the seek operation is completed, the accumulated reproduction data for another set of reproduction outputs remains in the memory as a margin, and even if some trouble occurs during the operation, the margin is maintained. By using the accumulated reproduction data, the reproduction output can be continuously output.

The case (4) will be further described with reference to FIG. At time t1, the amount of stored and reproduced data is N × Dout × Tseek. From time t1 to time t2, (Dread-
The reproduction data is stored in the memory in proportion to time with a gradient of (N × Dout), and the storage amount reaches a required storage reproduction data amount (2N × Dout × Tseek) at time t2. Since the seek is performed from the time t2 to the time t3, the storage amount of the memory becomes (−
It decreases in proportion to time with a slope of (N × Dout), and reaches (N × Dout × Tseek) at time t3.

After time t3, normally, at time t1
From time t3 are repeated. However, if
Even if a trouble occurs between the time t31 and the time 32 during the reproducing operation between the time t3 and the time t4 and the reproduction is not performed, the accumulated reproduction data is not reproduced between the time t31 and the time 32. However, since there is accumulated reproduction data for the margin, the reproduction output is not lost even after the seek operation between time t4 and time t5, which is advantageous for on-air reproduction. That is, the trouble during reproduction is automatically eliminated.

[0020]

As described above, according to the random access reproduction method of the present invention, a series of reproduction outputs are stored in a memory by accessing recording data at an arbitrary position on a disk, and the stored reproduction outputs are not interrupted. Output. In this case, according to the method of the present invention, the input command is interpreted to detect a reproduction position, a reproduction speed, a reproduction speed range, and a reproduction method of a disc to be reproduced, and the memory corresponds to the detected reproduction speed range and reproduction method. Dividing, selecting a means for obtaining data to be stored in the memory, the detected reproduction position,
Since the playback is performed according to the playback speed and the continuous playback output is output, the memory use efficiency can be improved, more functions can be executed with a small amount of memory, and the cost performance can be improved.

[Brief description of the drawings]

FIG. 1 is a functional block diagram illustrating basic functions of a random access reproduction method according to an embodiment of the present invention.

FIG. 2 is a time chart for explaining the operation of the functional block in FIG. 1;

FIG. 3 is a time chart showing an operation in the case of on-air reproduction.

[Explanation of symbols]

 BK1 to BK7 ... functional blocks.

Claims (3)

[Claims] 1. A random access reproduction method for accessing recorded data at an arbitrary position on a disc, storing a reproduced output by the access in a memory, and continuously outputting the stored reproduced output without interruption. Interpret the input command to detect the playback position and playback speed of the disk to be played back, the playback speed range and the playback method, and divide the memory according to the detected playback speed range and playback method and accumulate in the memory. A method for random access reproduction of recorded data on a disk, wherein a method for obtaining data is selected and reproduction is performed according to a disk reproduction position and a reproduction speed. 2. When a narrow range is instructed as a two-system output reproduction speed range as a reproduction method, the memory is divided into two parts, an area corresponding to two-system output is secured, and reproduction is performed for two systems. 2. The method according to claim 1, wherein the method is performed. 3. When only a standard speed is instructed as an on-air reproduction reproduction speed range as a reproduction method, a memory area exceeding a memory area necessary for one system of reproduction output is set.
2. The random access reproduction method for disk recording data according to claim 1, wherein the method is used as a margin for the reproduction output for one system.