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

• US 8,838,825 B2
• Filed: 06/27/2011
• Issued: 09/16/2014
• Est. Priority Date: 06/13/2003
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Agnoli, Giovanni M., Abt, John O., Bowman, Samuel R., Delwiche, James A., Dillon, Jeffrey C., Yanowitz, Andrew
• Primary Examiner(s): Nguyen, Quang N
• Application Number:
  US13/170,101
• Publication Number:
  US 20110258675A1
• Time in Patent Office: 1,177 Days
• Field of Search: 345/698, 345/99, 348/461, 348/537, 368/210, 368/241, 368/329, 709/203, 709/217, 709/218, 709/223, 709/224, 709/231, 709/246
• US Class Current: 709/231
• 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 an interface of a computerized device between a computer and a video client, a method of performing data transmission flow control, the method comprising:

receiving a stream of input data from the video client according to a first format;

converting the received input data to scanned lines of video data;

generating frames and vertical blanking intervals based on the scanned lines; and

for each generated vertical blanking interval, transmitting one of the frames from the interface of the computerized device to the computer, wherein the computer synchronizes with the video data by determining a vertical blanking frequency from a frequency of frames received from the interface,

wherein the computerized device and the computer share an external clock for synchronizing data transmission.

2. The method of claim 1, wherein the frame additionally comprises audio data.

3. The method of claim 1, wherein the frame of data is National Television System Committee (NTSC) compliant.

4. The method of claim 1, wherein the size of at least one frame of said plurality of frames varies to accommodate various data sizes.

5. The method of claim 1, wherein the frames of data are of a predetermined size.

6. The method of claim 1, wherein the first format comprises one or more analog signals.

7. The method of claim 6, wherein the first format comprises one or more digital signals.

8. The method of claim 7, wherein the digital signals are compressed.

9. A computer readable apparatus having a non-transitory computer readable storage medium containing instructions which, when executed by a computerized device:

responsive to receiving a stream of input data according to a first format, converting the received input data to scanned lines of video data;

generating frames and vertical blanking intervals based on the scanned lines; and

for each generated vertical blanking interval, transmitting one of the frames from an interface of the computerized device to a first device, wherein the first device synchronizes with the video data by determining a vertical blanking frequency from a frequency of frames received from the interface,

wherein the computerized device and the first device share an external clock for synchronizing data transmission.

10. The computer readable apparatus of claim 9, wherein the generated frames are associated with one or more audio data.

11. The computer readable apparatus of claim 9, wherein the first format is compressed.

12. A computer readable apparatus having a non-transitory computer readable storage medium containing instructions which, when executed by a computerized device:

responsive to receiving data frames from a peer device, according to a first format comprising one or more video data and one or more vertical blanking intervals, determine a frequency of receipt of vertical blanking intervals based on a frequency of the received data frames;

for each vertical blanking interval, display a corresponding video data; and

synchronize to the peer device, based at least in part on the determined frequency of vertical blanking intervals,

wherein the computerized device and the peer device share an external clock for synchronizing data transmission.

13. The apparatus of claim 12, wherein the first format comprises one or more video data and one or more audio data.

14. The apparatus of claim 12, wherein the data frames accommodate various video formats.

15. The apparatus of claim 12, wherein the data frames have a fixed size.

16. The apparatus of claim 12, wherein the first format comprises a plurality of scan lines.

17. The apparatus of claim 12, wherein the first format comprises a compressed digital signal.