Synchronized transmission of audio and video data from a computer to a client via an interface

• US 20040255339A1
• Filed: 12/23/2003
• Published: 12/16/2004
• Est. Priority Date: 06/13/2003
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Computer Incorporated (Apple Inc.)
• Inventors: Dillon, Jeffery C., Delwiche, James A,, Bowman, Samuel R,, Agnoli, Giovanni M., Abt, John O., Yanowitz, Andrew
• Granted Patent: US 7,353,284 B2
• Time in Patent Office: Days
• US Class Current: 725/143
• CPC Class Codes: G06F 3/14 Digital output to display device ; Cooperation and interconnection of the display device with other functional units
• CPC Class Codes: G09G 2350/00 Solving problems of bandwidth in display systems
• CPC Class Codes: G09G 2370/025 LAN communication management
• CPC Class Codes: G09G 2370/10 Use of a protocol of communication by packets in interfaces along the display data pipeline
• CPC Class Codes: H04L 47/30 in combination with information about buffer occupancy at either end or at transit nodes
• CPC Class Codes: H04N 19/152 by measuring the fullness of the transmission buffer
• CPC Class Codes: H04N 21/4113 PC
• CPC Class Codes: H04N 21/43632 involving a wired protocol, e.g. IEEE 1394 high-speed IEEE 1394 serial bus H04L12/40052
• CPC Class Codes: H04N 21/64707 for transferring content from a first network to a second network, e.g. between IP and wireless

Abstract

A method for controlling data transmission between a computer and a video client via an interface, the method comprising: the computer polling the interface a first time to determine the size of the buffer on the interface; receiving a first buffer size value from the interface; sending a plurality of frames of video and audio data to the buffer on the interface such that a delay period exists between the sending of each frame; the computer polling the interface a second time to determine buffer size after the frames are sent to the interface; receiving a second buffer size value from the interface; and modifying the amount of time between the transmission of frames.

Claims

1. In a system having a computer, a video client, and an interface between the computer and video client that facilitates data transmission between the computer and the video client, the interface having a buffer for storing data frames received from the computer to be sent to the video client, the buffer having a size that varies with the amount of data it stores, the interface having an optimal buffer size, a method of performing data transmission flow control, the method comprising:

the computer polling the interface a first time to determine the size of the buffer on the interface;

receiving a first buffer size value from the interface;

sending a plurality of frames of video and audio data to the buffer on the interface such that a delay period exists between the sending of each frame;

the computer polling the interface a second time to determine buffer size after the frames are sent to the interface;

receiving a second buffer size value from the interface; and

if the second buffer size value is larger than the optimal size, and larger than the first buffer size value, then increasing the delay period between transmission of frames from the computer to the interface.

2. The method of claim 1, wherein buffer size refers to fullness of meaningful data in a fixed-sized buffer.

3. In a system having a computer, a video client, and an interface between the computer and video client that facilitates data transmission between the computer and the video client, the interface having a buffer for storing data frames received from the computer to be sent to the video client, the buffer having a size that varies with the amount of data it stores, the interface having an optimal buffer size, a method of performing data transmission flow control, the method comprising:

the computer polling the interface a first time to determine the size of the buffer on the interface;

receiving a first buffer size value from the interface;

sending a plurality of frames of video and audio data to the buffer on the interface such that a delay period exists between the sending of each frame;

the computer polling the interface a second time to determine buffer size after the frames are sent to the interface;

receiving a second buffer size value from the interface; and

if the second buffer size value is smaller than optimal size, and smaller than the first buffer size value, decreasing the delay period between transmission of frames from the computer to the interface.

4. The method of claim 3, wherein buffer size refers to fullness of meaningful data in a fixed-sized buffer.

5. A computer program product containing instructions which, when executed by a computer, performs data transmission flow control by performing the acts of:

polling for a first time an interface in communication with the computer, the interface having a buffer for storing data frames received from the computer, the frames to be sent to the video client, the buffer having a size that varies with the amount of data contained in the buffer, the buffer having an optimal size;

receiving a first buffer size value from the interface;

sending a plurality of frames of video and audio data to the buffer on the interface such that a delay period exists between the sending of each frame;

polling the interface a second time to determine buffer size after the frames are sent to the interface;

receiving a second buffer size value from the interface; and

if the second buffer size value is larger than the optimal size, and larger than the first buffer size value, then increasing the delay period between transmission of frames from the computer to the interface.

6. The computer program product of claim 5, wherein buffer size refers to fullness of meaningful data in a fixed-sized buffer.

7. A computer program product containing instructions which, when executed by a computer, performs data transmission flow control by performing the acts of:

polling for a first time an interface in communication with the computer, the interface having a buffer for storing data frames received from the computer, the frames to be sent to the video client, the buffer having a size that varies with the amount of data contained in the buffer, the buffer having an optimal size;

receiving a first buffer size value from the interface;

sending a plurality of frames of video and audio data to the buffer on the interface such that a delay period exists between the sending of each frame;

polling the interface a second time to determine buffer size after the frames are sent to the interface;

receiving a second buffer size value from the interface; and

if the second buffer size value is smaller than the optimal size, and smaller than the first buffer size value, then decreasing the delay period between transmission of frames from the computer to the interface.

8. The computer program product of claim 7, wherein buffer size refers to fullness of meaningful data in a fixed-sized buffer.

9. In a system having a computer, a video client, and an interface between the computer and video client that facilitates data transmission between the computer and the video client, the interface having a buffer for storing data frames received from the computer to be sent to the video client, the buffer having a size that varies with the amount of data it stores, the interface having an optimal buffer size, apparatus for performing data transmission flow control, the method comprising:

means for polling the interface a first time to determine the size of the buffer on the interface;

means for receiving a first buffer size value from the interface;

means for sending a plurality of frames of video and audio data to the buffer on the interface such that a delay period exists between the sending of each frame;

means for polling the interface a second time to determine buffer size after the frames are sent to the interface;

means for receiving a second buffer size value from the interface; and

means for, if the second buffer size value is larger than the optimal size, and larger than the first buffer size value, increasing the delay period between transmission of frames from the computer to the interface.

10. The method of claim 9, wherein buffer size refers to fullness of meaningful data in a fixed-sized buffer.

11. In a system having a computer, a video client, and an interface between the computer and video client that facilitates data transmission between the computer and the video client, the interface having a buffer for storing data frames received from the computer to be sent to the video client, the buffer having a size that varies with the amount of data it stores, the interface having an optimal buffer size, apparatus for performing data transmission flow control, the apparatus comprising:

means for polling the interface a first time to determine the size of the buffer on the interface;

means for receiving a first buffer size value from the interface;

means for sending a plurality of frames of video and audio data to the buffer on the interface such that a delay period exists between the sending of each frame;

means for polling the interface a second time to determine buffer size after the frames are sent to the interface;

means for receiving a second buffer size value from the interface; and

means for, if the second buffer size value is smaller than optimal size, and smaller than the first buffer size value, decreasing the delay period between transmission of frames from the computer to the interface.

12. The apparatus of claim 11, wherein buffer size refers to fullness of meaningful data in a fixed-sized buffer.