Automatic multi-camera video composition
First Claim
1. An automatic video switching system comprising:
- multiple audio inputs, each associated with at least one corresponding video source;
an audio scorer capable of calculating an audio score for each of the audio inputs, the audio score for a given audio input corresponding to an audio signal received at that input over an examination interval;
state memory to store at least a partial time-history of video source selection; and
switching logic to select a current video source for a given examination interval, based on a weighted comparison for that examination interval of the audio scores associated with each of the video sources, the comparison weighting based on the partial time-history of video source selection.
1 Assignment
0 Petitions
Accused Products
Abstract
Methods and apparatus are disclosed for automatically selecting a video output from among several video input sources. In one method, one or more audio sensors are associated with each video input source. Preferably, an audio sensor is positioned to receive audio signals from directions that receive favorable coverage in the field of view of the associated video source. An autoselector calculates audio scores for each of the audio sensors over short (e.g., 0.5 seconds) examination intervals. At each examination interval, the potential exists for a different video source to be selected as the video output. The autoselector selects a video source based on the audio scores for an examination interval, as well as the recent time-history of video source selection. For instance, if a new video source has just been selected, selection of a different source may be disabled for a few seconds. The time-history is also used to increase the probability that source selection varies in a seemingly-natural manner.
-
Citations
24 Claims
-
1. An automatic video switching system comprising:
-
multiple audio inputs, each associated with at least one corresponding video source;
an audio scorer capable of calculating an audio score for each of the audio inputs, the audio score for a given audio input corresponding to an audio signal received at that input over an examination interval;
state memory to store at least a partial time-history of video source selection; and
switching logic to select a current video source for a given examination interval, based on a weighted comparison for that examination interval of the audio scores associated with each of the video sources, the comparison weighting based on the partial time-history of video source selection. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
an analog video camera output signal, a video camera digital output signal, a digitally-compressed video signal, a recorded video signal, and a computer-generated video signal.
-
-
8. The system of claim 1, wherein the system comprises at least one network connection to receive one of the audio inputs from a remote location.
-
9. The system of claim 1, wherein the switching logic has the capability to select a different current video source for each of several remote locations.
-
10. A method of automatically selecting a video source from among multiple available video sources, the method comprising:
-
associating at least one audio source with each of the video sources;
evaluating, over an examination interval, an audio signal received from each audio source, thereby forming an audio score for each audio source that expresses the level of audio activity present at that audio source during the examination interval;
maintaining at least a partial time-history of video source selection;
performing a weighted comparison for the evaluation interval of the audio scores associated with each of the video sources, where the weighting is based on the partial time-history of video source selection; and
selecting a current video source based on the weighted comparison. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19)
determining the variation in each of the audio signals during that subwindow; and
incrementing the audio score for the audio source having the largest variation for that subwindow.
-
-
17. The method of claim 10, the method further comprising, when one of the audio sources and a corresponding video source are at a location remote from the location where the current video source is selected, receiving the audio signal over a communications network, and notifying the remote location to transmit video when its video source has been selected as the current video source.
-
18. The method of claim 10, wherein the selection of a current video source occurs in real-time at approximately the end of an examination interval.
-
19. The method of claim 10, comprising relating the selection of a current video source to a point in the video stream that corresponds to a time preceding the end of the examination interval.
-
20. An apparatus comprising a computer-readable medium containing computer instructions that, when executed, cause a processor or multiple communicating processors to perform a method of automatically selecting a video source from among multiple available video sources, the method comprising:
-
associating at least one audio source with each of the video sources;
evaluating, over an examination interval, an audio signal received from each audio source, thereby forming an audio score for each audio source that expresses the level of audio activity present at that audio source during the examination interval;
maintaining at least a partial time-history of video source selection;
performing a weighted comparison for the evaluation interval of the audio scores associated with each of the video sources, where the weighting is based on the partial time-history of video source selection; and
selecting a current video source based on the weighted comparison. - View Dependent Claims (21, 22, 23, 24)
determining the variation in each of the audio signals during that subwindow; and
incrementing the audio score for the audio source having the largest variation for that subwindow.
-
-
24. The apparatus of claim 20, the method further comprising, when one of the audio sources and a corresponding video source are at a location remote from the location where the current video source is selected, receiving that audio signal over a communications network, and notifying the remote location to transmit video when its video source has been selected as the current video source.
Specification