Method of manually fine tuning audio synchronization of a home network

• US 20030198257A1
• Filed: 04/23/2002
• Published: 10/23/2003
• Est. Priority Date: 04/23/2002
• Status: Active Grant

• Current Assignee: Gateway Incorporated (Acer, Inc.)
• Original Assignee: Gateway Incorporated (Acer, Inc.)
• Inventors: Rector, Dusty D., Sullivan, Gary E.
• Granted Patent: US 7,333,519 B2
• Time in Patent Office: Days
• US Class Current: 370/516
• CPC Class Codes: H04H 20/18 Arrangements for synchronising broadcast or distribution via plural systems
• CPC Class Codes: H04J 3/0644 External master-clock
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging

Abstract

A method is provided for manually synchronizing the playback of a digital audio broadcast on a plurality of network output devices. The method is applicable for use with methods such as those that use a time code, insert a control track pulse, or use an audio waveform sample for synchronization. The manual adjustment method relies on a graphical user interface for adjustment and audible pulses from the devices which are to be synchronized. The digital audio broadcast from multiple receivers does not present to a listener any audible delay or echo effect.

Claims

1. A method of manually fine tuning audio synchronization on a home network, comprising:

outputting audible signals from two or more devices on the home network;

displaying graphics which represent a control mechanism for adjusting the time delay between the two or more audible signals;

moving a graphics object of a graphics control mechanism so as to increase or decrease a timing delay in reference to the two or more audible signals; and

once the signals are determined to be simultaneous, recording the delay for the devices and correcting the timing of the audio output with the delay so as to make the two or more devices sound synchronized.

2. The method of claim 1, wherein moving the graphics object entails using a touch screen by an adjuster.

3. The method of claim 1, wherein moving the graphics object entails using a mouse by an adjuster.

4. The method of claim 1, wherein moving the graphics object entails using a track ball by an adjuster.

5. A method of synchronizing the playback of an audio broadcast on a plurality of network output devices, comprising:

initially synchronizing the audio playback of the plurality of network output devices by an automated process involving an audio stream; and

then manually synchronizing the audio playback of the plurality of network output devices,

the digital audio broadcast from multiple receiving devices not presenting to a listener any audible delay or echo effect.

6. The method of claim 5, wherein the automated process involves inserting a reference time value to an audio stream by a transmitting device.

7. The method of claim 6, wherein, in the automated process, the transmitting device sets its own clock and then sets the clocks on all the receiving devices.

8. The method of claim 7, wherein the receiving devices periodically adjust themselves for time drift.

9. The method of claim 8, wherein the transmitting device inserts a time code into the audio stream.

10. The method of claim 5, wherein the automated process involves inserting a control track pulse into the audio stream by a transmitting device.

11. The method of claim 10, wherein the transmitting device need not have its clock synchronized with the receivers.

12. The method of claim 11, wherein one of the receiving devices sets its own clock and then sets the clocks of all the other receiving devices.

13. The method of claim 12, wherein the one of the receiving devices inserts a control track pulse in its audio stream.

14. The method of claim 5, wherein the automated process involves using an audio waveform sample to synchronize audio playback.

15. The method of claim 14, wherein one of the receiving devices sets its own clock and then sets the clocks of the other receiving devices.

16. The method of claim 15, wherein the one of the receiving devices records latency values for the other receiving devices.

17. The method of claim 16, wherein the one of the receiving devices determines an arbitrary reference value.

18. The method of claim 5, wherein the latency is derived using each of first and second consecutive unique signals.

19. The method of claim 18, wherein a transmitting device sends out the first and second unique signals and is clocked at a base clock rate.

20. The method of claim 19, wherein the latency is derived by enabling a counter from the time one of the first and second unique signals is sent until the time of its return to the transmitting device, the counter being clocked at one half the base clock rate.

21. The method of claim 20, further comprising determining the time drift of a receiving device.

22. The method of claim 21, wherein the time drift includes the time for the operating system to respond to a command instruction after the unique signals have been received by the receiving device.

23. The method of claim 5, wherein the audio stream is buffered by the receiving devices.

24. The method of claim 5, wherein global positioning system data is used by at least one of the multiple receiving devices.

25. The method of claim 5, wherein the step of manually synchronizing involves using a graphical user interface.

26. The method of claim 25, wherein the graphical user interface includes sliding bars or scroll bars.

27. The method of claim 26, wherein a user chooses the display option on the graphical user interface.

28. The method of claim 27, wherein the offset value is determined in response to scrolling of the scroll bars or sliding of the sliding bars by the user.

29. The method of claim 28, wherein the speed of the scrolling or sliding is changeable.

30. The method of claim 29, wherein the offset value is added to or subtracted from a latency value for one of the receiving devices and stored.

31. The method of claim 5, wherein the step of manually synchronizing involves audible pulses emanating from each of the devices to be adjusted and a reference device.

32. A system for synchronizing audio playback of multiple receiving devices, comprising:

a transmitting device; and

two or more receiving devices, wherein the receiving devices are synchronized through at least two of the group consisting of a control track pulse, a time code, an audio waveform sample, communication latency, and processing latency,

wherein one of the devices allows a user to manually synchronize the audio playback of the devices.

33. The system of claim 32, wherein the system has a time drift detector.

34. The system of claim 32, wherein the system has a clock synchronizer.

35. The system of claim 32, wherein the system has a latency detector.

36. The system of claim 32, wherein the system has manual fine tune control.

37. The system of claim 32, wherein the system has a time drift detector, a clock synchronizer, a latency detector, and manual fine tune control.

38. The system of claim 32, wherein the receiving devices are synchronized through audio waveform samples and the communication latency is shorter than the time interval between consecutive audio waveform samples.

39. A system for synchronizing the audio playback of two or more receiving devices, comprising:

means for transmitting consecutive unique signals in an audio stream;

means for receiving the consecutive unique signals in the audio stream, the time the means for receiving the unique signal takes to act upon the unique signal being determined by a communications latency between the transmitting means and the receiving means and a processing latency determined by internal processing by the receiving means; and

means for manually synchronizing the audio playback of the devices.

40. The system of claim 39, further comprising means for synchronizing clocks located in the receiving means.

41. The system of claim 40, further comprising means for detecting time drift in the receiving means.

42. The system of claim 41, further comprising means for manual fine tune control of the receiving means.

43. The system of claim 42, further comprising means for comparing an audio waveform sample with an audio stream.