Multimedia server

• US 6,301,604 B1
• Filed: 11/30/1998
• Issued: 10/09/2001
• Est. Priority Date: 12/01/1997
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Nojima, Shinji
• Primary Examiner(s): Banankhah, Majid A.
• Application Number:
  US09/201,123
• Time in Patent Office: 1,044 Days
• Field of Search: 709/104, 709/108, 709/231, 709/101, 709/102, 709/106, 710/7, 710/20, 710/52, 710/56, 710/129, 710/8, 710/13, 710/101, 710/124, 710/128, 710/107, 710/117, 707/10, 707/30, 707/520, 712/38, 711/212
• US Class Current: 718/108
• CPC Class Codes: H04N 21/233 Processing of audio elementary streams monitoring, identification or recognition of audio in broadcast systems H04H60/58
• CPC Class Codes: H04N 21/2385 Channel allocation H04N21/266 takes precedence; Bandwidth allocation H04N21/24 takes precedence ; allocation of channels according to the instantaneous demands of the users in time-division multiplex systems H04J3/1682; admission control, resource allocation in open networks H04L12/5692; arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896; negotiating bandwidth in wireless networks H04W28/16
• CPC Class Codes: H04N 21/2405 Monitoring of the internal components or processes of the server, e.g. server load allocation of resources in multiprogramming arrangements G06F9/50; performance measurement of computer activity G06F11/34
• CPC Class Codes: H04N 21/2662 Controlling the complexity of the video stream, e.g. by scaling the resolution or bitrate of the video stream based on the client capabilities
• CPC Class Codes: H04N 7/17336 Handling of requests in head-ends

Abstract

Multimedia applications including a video and an audio are transmitted at respective adapted transfer rates in a server connected with a networks. The server operates on an operating system which permits a multithreading by allocating time slices to thread. For each application, data on a required transfer rate indicative of a permitted lowest transfer rate for the application is prepared. Threads are generated for respective applications. An initial number of slices are allocated to each thread to let said threads transmit said respective applications. A transfer rate of each thread is measured at a time interval. A number of slices to be allocated to each thread is calculated such that the measured transfer rate of each thread (i.e., each application) becomes equal to the required transfer rate of the application transmitted by the thread.

Claims

1. A method for transmitting multimedia applications including a video and an audio at respective adapted transfer rates in a server connected with a network wherein the server operates on an operating system which permits a multithreading by allocating time slices to thread, the method comprising the steps of;

for each application, preparing data on a required transfer rate indicative of a permitted lowest transfer rate for the application;

generating threads for respective applications;

allocating an initial number of slices to each thread to let said treads transmit said respective applications;

measuring a transfer rate of each thread at a time interval;

calculating a number of slices to be allocated to each thread such that the measured transfer rate of each thread (i.e., each application) becomes equal to said required transfer rate of the application transmitted by the thread; and

allocating said calculated number of slices to each thread.

2. A method as defined in claim 1, wherein said calculating step comprises the step of calculating a number of slices by multiplying a current number of slices allocated to each thread by a ratio of said required transfer rate to said measured transfer rate.

3. A method as defined in claim 1, further comprising the step of, in response to a detection of a synchronism among said applications, temporarily allocating a corrected number of slices to each thread such that said applications have been synchronized by the end of a subsequent time interval.

4. A method as defined in claim 1, further comprising the steps of, in response to a detection of a decrease in a total of said measured transfer rates, allocating less slices to applications of lower priorities and more slices to an application of a higher priority.

5. A method as defined in claim 4, wherein said step of allocating less slices to applications of lower priorities comprises the steps of;

calculating an amount of reduction in said less slices by using a coefficient; and

in response to a result of said step of allocating less slices to applications of lower priorities, changing a value of said coefficient so that a difference between said required transfer rate and said measured transfer rate of said application of said higher priority becomes zero.

6. A method as defined in claim 1, further comprising the step of, in response to a detection that a total of said measured transfer rates exceeds a predetermined value, reducing said total of said measured transfer rates to a percentage associated with said total of said measured transfer rates.

9. A method as defined in claim 1, further comprising the steps, executed by a client connected with the network, of:

receiving and storing a unit of data addressed to said client;

storing a unit ID of said received unit and a received time; and

displaying a stored unit of data of said unit ID according to said received time.

7. A method for transmitting data to a plurality of destinations in a server connected with a network wherein the server operates on an operating system which permits a multithreading by allocating time slices to thread, the method comprising the steps of;

creating a thread to each destination; and

in response to a request from one of said thread, returning a unit of data to be preferably transmitted at a time of said request, wherein said step of returning a unit of data includes the step of;

in response to a detection that a difference between said time of said request and a time of last request from a thread different from the requesting thread is smaller than a value associated with an unoccupied period of a central processing unit of the server, returning a same unit of data as returned at said time of last request.

8. A method as defined in claim 7, further comprising the step of selecting a predetermined constant value for said value.

10. A server for transmitting multimedia applications including a video and an audio at respective adapted transfer rates in a server connected with a network wherein the server operates on an operating system which permits a multithreading by allocating time slices to thread, the server comprising:

means for preparing data on a required transfer rate indicative of a permitted lowest transfer rate for the application;

means for generating threads for respective applications;

means for allocating an initial number of slices to each thread to let said threads transmit said respective applications;

means for measuring a transfer rate of each thread at a time, interval;

means for calculating a number of slices to be allocated to each tread such that the measured transfer rate of each thread (i.e., each application) becomes equal to said required transfer rate of the application transmitted by the thread; and

means for allocating said calculated number of slices to each thread.