Apparatus and method for synchronizing audio and video frames in an MPEG presentation system
First Claim
1. An apparatus for synchronizing audio and video presentation signals in a multiprocessor multimedia system comprising:
- a data source for supplying a video data bitstream and an audio data bitstream;
a video signal interface coupled to the data source for receiving the video data bitstream, converting the video data bitstream into video performance signals, and transmitting the video performance signals to a video display, the video signal interface having a first timing signal source;
an audio signal interface coupled to the data source for receiving the audio data bitstream, converting the audio data bitstream into audio performance signals, and transmitting the audio performance signals to an audio speaker, the audio signal interface having a second timing signal source having a timing independent from the first timing signal source;
a controller coupled to the video signal interface, the audio signal interface, and the data source, the controller having a program code including;
an audio/video synchrony monitoring routine for determining whether the audio performance signals are asynchronous to the video performance signals; and
an audio/video synchrony restoring routine operative when the audio performance signals are asynchronous to the video performance signals.
2 Assignments
0 Petitions
Accused Products
Abstract
Synchronization of MPEG audio and video presentations is attained by detecting a lack of synchrony between the data presentations and modifying the audio data stream based on the detected lack of synchrony. Synchrony of the MPEG audio and video presentations is monitored by tracking the amount of data transferred to audio and video interfaces over time. Synchronization of MPEG audio and video presentations is achieved in a system in which audio and video interfaces are controlled by separate and independent timing signal generators by tracking the amount of audio and video data output by the respective audio and video interfaces. The amount of audio and video data output by the interfaces is compared and, as a result of the comparison, the audio data stream is modified to restore synchrony. Alternatively, presentation of the video data stream is modified to achieve synchrony.
-
Citations
22 Claims
-
1. An apparatus for synchronizing audio and video presentation signals in a multiprocessor multimedia system comprising:
-
a data source for supplying a video data bitstream and an audio data bitstream; a video signal interface coupled to the data source for receiving the video data bitstream, converting the video data bitstream into video performance signals, and transmitting the video performance signals to a video display, the video signal interface having a first timing signal source; an audio signal interface coupled to the data source for receiving the audio data bitstream, converting the audio data bitstream into audio performance signals, and transmitting the audio performance signals to an audio speaker, the audio signal interface having a second timing signal source having a timing independent from the first timing signal source; a controller coupled to the video signal interface, the audio signal interface, and the data source, the controller having a program code including; an audio/video synchrony monitoring routine for determining whether the audio performance signals are asynchronous to the video performance signals; and an audio/video synchrony restoring routine operative when the audio performance signals are asynchronous to the video performance signals. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method of synchronizing audio and video presentation signals in a multiprocessor multimedia system comprising:
-
supplying a video data bitstream and an audio data bitstream; formatting the video data bitstream for display including; supplying a first timing signal for formatting the video data bitstream; receiving the video data bitstream; converting the video data bitstream into video performance signals; and transmitting the video performance signals to a video display; formatting the audio data bitstream for performance including; supplying a second timing signal for formatting the audio data bitstream, the second timing signal being supplied having a timing independent from the first timing signal; receiving the audio data bitstream; converting the audio data bitstream into audio performance signals, and transmitting the audio performance signals to an audio speaker; determining whether the audio performance signals are asynchronous to the video performance signals; and restoring audio/video synchrony when the audio performance signals are asynchronous to the video performance signals. - View Dependent Claims (9, 10, 11, 12, 13, 14)
-
-
15. A multimedia system comprising:
-
a data source for supplying a video data bitstream and an audio data bitstream; a video signal interface coupled to the data source for receiving the video data bitstream, converting the video data bitstream into video performance signals, and transmitting the video performance signals to a video display, the video signal interface having a first timing signal source; an audio signal interface coupled to the data source for receiving the audio data bitstream, converting the audio data bitstream into audio performance signals, and transmitting the audio performance signals to an audio speaker, the audio signal interface having a second timing signal source having a timing independent from the first timing signal source; a controller coupled to the video signal interface, the audio signal interface, and the data source, the controller including a means for synchronizing audio and video presentation signals, the synchronizing means including; means for monitoring audio/video synchrony; means for determining whether the audio performance signals are asynchronous to the video performance signals; and means for restoring audio/video synchrony operative when the audio performance signals are asynchronous to the video performance signals. - View Dependent Claims (16, 17, 18, 19, 20, 21)
-
-
22. A method of providing an apparatus for synchronizing audio and video presentation signals in a multiprocessor multimedia system comprising:
-
providing a data source for supplying a video data bitstream and an audio data bitstream; providing a video signal interface coupled to the data source for receiving the video data bitstream, converting the video data bitstream into video performance signals, and transmitting the video performance signals to a video display, the video signal interface having a first timing signal source; providing an audio signal interface coupled to the data source for receiving the audio data bitstream, converting the audio data bitstream into audio performance signals, and transmitting the audio performance signals to an audio speaker, the audio signal interface having a second timing signal source having a timing independent from the first timing signal source; providing a controller coupled to the video signal interface, the audio signal interface, and the data source, the controller having a program code including; an audio/video synchrony monitoring routine for determining whether the audio performance signals are asynchronous to the video performance signals; and an audio/video synchrony restoring routine operative when the audio performance signals are asynchronous to the video performance signals.
-
Specification