JP3025341B2 - Multimedia scheduling method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multimedia scheduling method , and more particularly , to a multimedia scheduling method for scheduling a multimedia application in an operating system of a computer.

In recent years, demands for developing and executing multimedia applications on existing operating systems have increased due to improvements in human interfaces. For example, sound and music, which are a type of media, are realized by sending data and instructions to the device at precise time intervals. Applications need to guarantee media continuity, unlike existing applications.

[0003]

2. Description of the Related Art Conventionally, scheduling of an operating system is performed on the basis of priority, and the scheduling is performed in order from the one with the highest priority.

[0004]

When a multimedia application is scheduled by a conventional priority-based scheduling method, the priority of a media application having a large time constraint is taken as the highest priority.

[0005] However, even if the number of media is small, it is possible, but if the number of media is large, the computing power of the computer is limited. Was.

[0006] The present invention has been made in view of the above points,
Dynamic scheduling can be performed according to the quality and importance according to the characteristics of each media, and even when the time constraints of the media cannot be satisfied, the quality of each media is hardly noticeable to humans and is highly reliable. An object of the present invention is to provide a multimedia scheduling method capable of constructing an application.

[0007]

SUMMARY OF THE INVENTION A multimedia scheduling method according to the present invention is a multimedia scheduling method of an operating system for scheduling a multimedia application.
The execution order of the media is determined based on the time constraints of each medium , and if the media is within the range that satisfies the time constraints on the end of processing , the processing delay will cause the media delay.
The first type, which does not affect the quality, and the processing delay is within the range that satisfies the time constraint on the processing end.
Media of the second type, which is separated from the media of the second type which affects the quality of the media, if the extracted media of the second type is not at the head position, the execution order is higher than that of the media of the extracted second type. Compares the importance of the previous first type of media with the extracted second type of media, and executes the extracted second type of media if the importance of the extracted second type of media is greater Advance the order.

[0008]

[0009]

In the present invention, the extracted second type of media is
If the media is not the first position, the extracted second type media
Extraction with the first type media whose execution order is earlier than the media
The importance of the second type of media is compared and extracted.
Extraction when the importance of the second type of media is high
The execution order of the second type of media
Because, even if not optimum scheduling in time constraints, by lowering the lower media, or importance low media priority of quality, as the media quality degradation for humans rarely a problem Dynamic scheduling becomes possible.

[0010]

FIG. 1 is a block diagram showing one embodiment of the method of the present invention. In the figure, 10 is a thread management apparatus manages the threads 11 ₁ to 11 _n that are currently requesting a schedule. The thread is a request of each media of the multimedia application. Each thread Thi has a deadline Di indicating that the processing must be completed by this time, an evaluation time Ci indicating the maximum estimated calculation time required for the processing, and a time regarding the processing completion.
Processing delays within the range that
Or media of D type that does not affect the quality of and breakfasts (the first type), or satisfy the time constraints of the processing end
Processing delays affect media quality even within the
The thread management device 10 manages the media property Fi, the importance Wi, and the quality Qi, which is an E-type (second type) media having an effect.

Here, since the multimedia application is for humans, a certain delay is allowed for each medium. For example human can not determine the delay of about 10msec for sound, reduced quality more you delay shall-out <br/> at acceptable if the delay of this extent, visual there is 10msec or more delay for Is acceptable. Although having such a delay tolerance, the delay affects the quality.
The type of media is E-type media, and the tolerance of the delay from the requested time of each E-type media is determined by the quality Q.
i. In other words, a medium with high quality Qi is a medium scheduled with a small delay from the requested time.

Further, some media periodically perform batch processing, and if preparation is delayed before the start of processing, the processing will not be performed. When scheduling becomes impossible using the importance level Wi for such a medium, the scheduling is performed by lowering the priority of the medium having the lowest importance level Wi.

[0013] thread sorter 12 shown in Figure 1 permutes management thread 11 ₁ to 11 _n a temporal high order of constraint thread management device 10, i.e. in ascending order of the deadline Di.

[0014] For pre Lee amplifier Te I Bed scheduler 13 threads 11 ₁ to 11 _n which is reordered, thread D type give priority to the thread of the E-type when there is a temporal margin in time for deadline Di If the E-type thread is given priority because there is no time to spare and a thread that cannot meet the deadline Di is generated, the priority of the E-type thread is lowered to delay the D-type thread. Either the deadline constraint of the thread is adhered to, or the deadline constraint of the D-type thread is broken and the E-type thread is prioritized for scheduling.

FIG. 2 shows a pre-inductive scheduler 13.
2 is a flowchart of a first embodiment of a schedule process executed by the first embodiment.

[0016] In the figure, look for thread E type from among threads 11 ₁ to 11 _n which is managed in the thread management apparatus 10 in step 18. In step 19, it is determined whether or not there is an E type thread. If there is no E type thread, the process is terminated. If there is, a set of positions of each E type thread found in step 20 is set as P and the process proceeds to step 21. .

In step 21, the thread Thα having the highest quality Qi is found from the threads specified at each position of the set P as shown by the following equation.

[0018]

(Equation 1)

In step 22, it is determined whether or not the above-mentioned thread Thα is located at the head position of the thread management device 10. If the thread Thα is at the head position, the processing is terminated.

In step 23, the thread management device 10
The evaluation time Cα of the thread Thα is expressed by the following expression for the D-type thread Thk located before (at the position on the head side) the thread Thα managed by the thread Tα.
A thread whose hk is larger than the margin up to the deadline Dk is searched, and a set of the thread positions is set as R. The margin is a value obtained by subtracting the sum of the evaluation times Ci of all the threads located before the thread Thk and the current time from the deadline DK of the thread Thk.

[0021]

(Equation 2)

In step 24, it is determined whether or not the set R exists. If so, the process is terminated. If not, the thread Thα is stored in step 25 in the thread management device 10.
And the process ends.

Here, as shown in FIG. 3, four threads (graphic display, MIDI1, MIDI2, PC
When M) is managed by the thread management device 10, M
If the evaluation time of the IDI (musical instrument digital interface) 1 is 5 msec, the current time is set to 0 and FIG.
The scheduling is performed so that the processing of each thread is performed in the order shown in FIG.

Further, if the evaluation time of MIDI1 is 10 msec as shown in parentheses, the thread of the graphic display will not be able to keep up, so that the priority of MIDI1, which is a low-quality medium, is lowered, as shown in FIG. Scheduling for processing each thread in order is performed.

FIG. 5 shows a flowchart of a second embodiment of the scheduling process. 3, the same parts as those in FIG. 3 are denoted by the same reference numerals, and the description thereof will be omitted.

In step 30 in FIG. 5, it is determined whether or not there is a thread whose importance Wi is smaller than the importance Wa of the thread Thα among the threads designated at each position of the set R as shown by the following equation.

[0027]

(Equation 3)

Here, if step 30 is satisfied, the thread Thα is moved to the head position of the thread management device 10 in step 31 and the processing is terminated.

Here, if the evaluation time of MIDI 1 is 10 msec in the state shown in FIG. 3, the thread of the graphic display will not be able to keep up, but since the importance of MIDI 1 is high, MIDI 1 has priority and each of them is given priority in the order shown in FIG. Scheduling to process threads is performed. In this case, the thread of the graphic display is not processed, but even if one field of the image is not displayed, it is hardly perceived by a human, and the image quality does not deteriorate. On the other hand, if the voice is out of synchronization, it can be often perceived by humans.

[0030]

As described above, according to the multimedia scheduling method of the present invention, it is possible to perform dynamic scheduling according to the quality and importance according to the characteristics of each medium, and to restrict the time of media. Even if the above is not satisfied, it is possible for a human to construct a highly reliable application with almost no deterioration in the quality of each medium, which is extremely useful in practical use.

[Brief description of the drawings]

FIG. 1 is a block diagram of the method of the present invention.

FIG. 2 is a flowchart of a first embodiment of a schedule process.

FIG. 3 is a diagram for explaining the present invention.

FIG. 4 is a diagram for explaining the present invention.

FIG. 5 is a flowchart of a second embodiment of the schedule process.

FIG. 6 is a diagram for explaining the present invention.

[Explanation of symbols]

10 thread management device 11 ₁ to 11 _n thread 12 thread sorter 13 Puriin flop Restorative scheduler

Continuation of the front page (56) References JP-A-63-68934 (JP, A) JP-A-62-284437 (JP, A) JP-A-2-87747 (JP, A) JP-A-4-235627 (JP) , A) Information Processing Society of Japan Research Report, VOL. 90, NO. 67 (90-OS-48); 17-24 (September 7, 1990). Proc. Of the 39th National Convention of Information Processing Society of Japan (▲ II ▼), p. 757-758 (accepted by the JPO archives in November 1989). (58) Field surveyed (Int.Cl. ⁷ , DB name) G06F 9/46 G06F 17/00 G06F 17/30 G06F 3/16 G06F 12/00 G06F 13/00 G06F 3/14 G06T 1/00 H04M 3 / 56 H04L 12/56 H04L 7/15 H04Q 11/04 G09G 5/00

Claims (2)

(57) [Claims] 1. A multimedia scheduling method of an operating system for scheduling a multimedia application, comprising: determining an execution order of media according to a time constraint of each medium; Satisfy
Processing delays affect media quality
The first type, which does not provide the processing, and the processing delay is within
The medium of the second type is extracted separately from the second type that affects the quality. If the extracted medium of the second type is not the head position,
The importance of the extracted second type media is compared with the extracted first type media whose execution order is earlier than the extracted second type media, and the extracted second type media becomes more important. In the case, the multimedia scheduling method is characterized in that the execution order of the extracted second type media is advanced. 2. The multimedia scheduling method according to claim 1, wherein the first type of media performs image processing, and the second type of media performs audio processing. Multimedia scheduling method.