FIELD
This disclosure is related generally to video generation and more particularly to multi-source composite video generation using linked mobile devices.
BACKGROUND
It is often desirable to capture video of a person giving a presentation. For example, it is common to videotape a presenter giving a slide presentation at a conference so that those who were not able to attend the conference are able to view the presentation at a later time. Such videotaping can be sub-optimal for a number of reasons. For example, when a presenter and slides are videotaped in the same frame, it is often difficult to view the slides. Further, use of dedicated videotaping equipment for performing such videotaping can be expensive.
SUMMARY
Systems and methods are provided for generating a multi-stream composite video. A first mobile device is linked with a second mobile device so that the first mobile device and the second mobile device are time synchronized. A video stream is captured using the first mobile device. Interactions with a user interface are captured using the second mobile device. A composite video is generated based on the captured video stream and the captured interactions based on the time synchronization of the first mobile device and the second mobile device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram depicting a multi-device system for generating a composite video.
FIG. 2 depicts an example composite video display generated using the system of FIG. 1.
FIG. 3 is a block diagram depicting a second example configuration for synchronizing devices for capturing components for a composite video.
FIG. 4 is a diagram depicting example synchronization timelines generated by the first and second devices.
FIG. 5 depicts a composite video timeline generated based on a received captured video stream with first timeline data and captured interactions/displayed objects with second timeline data.
FIG. 6 is a block diagram depicting a system for generating a composite video.
FIG. 7 is a diagram depicting example frame configurations for a composite video.
FIG. 8 depicts example object displays on the second device and corresponding interactions for capture.
FIG. 9 depicts a first video stream 902 and a second video stream 904 overlaid on an object 906 displayed on the second device along with annotations thereto.
DETAILED DESCRIPTION
FIG. 1 is a block diagram depicting a multi-device system for generating a composite video. The system includes a first device 102 that is configured to capture a video stream 104 for incorporation into a composite video 106 via a camera 107. A second device 108 captures objects 110 displayed on a display 112 of the second device 108 as well as user interactions 114 with those objects 110. The captured interactions and/or record of displayed objects 116 are further transmitted for incorporation into the composite video 106. The first device 102 and the second device 108 are time synchronized at 118, such that the composite video 106 can be generated while maintaining context between the captured video stream 104 and the captured interactions and displayed objects 116 easily.
The devices 102, 108 can be time synchronized via a variety of mechanisms. For example, the devices can be time synchronized via communication with one another. For example, each of the devices can be equipped with a software application that is configured to communicate with another device via near field communications (e.g., a device tap operation). The devices 102, 108 can further be synchronized via independent communications with an external computing system, such as an external server. In the example of FIG. 1, the devices 102, 108 are paired and synchronized with one another based on bringing the devices 102, 108 within close proximity with each other (e.g., via automatic detection of such proximity, via a user proximity scan request). For example, one of the device's clocks can be selected as the master clock, and both devices 102, 108 can calculate the difference between their clock and the master clock. That device's associated captured data 104 or 116 can then have timing data appended based on the master clock time, such as via a master clock synchronized timeline.
The system of FIG. 1 can be utilized in a variety of contexts. For example, the system of FIG. 1 can be used to generate a composite video that can support simultaneous display of video of a presenter as well as presentation materials associated with the presentation. The system can further capture interactions with the presentation materials, including user annotations to the presentation materials during the presentation, transitions from one slide to another, as well as other interactions. Such an implementation has several advantages over traditional videotaping of a presenter and a projection screen displaying presentation materials. First, the system of FIG. 1 includes a device that is dedicated to recording the presentation materials and interactions therewith. The system of FIG. 1 can avoid one cycle of digital-to-audio-transmission-audio-to-digital conversion that often greatly diminishes traditional recording quality.
Further, the system of FIG. 1 can provide a low cost option for generating a composite video, where the components 104, 116 can be captured via widely distributed multi-purpose devices. For example, each of the first device 102 and the second device 108 can be implemented using mobile user devices such as smart phones (e.g., iPhones, Droid-based phones) or tablet computers (e.g., iPad). Many of such devices include cameras 107 capable of capturing reasonably high quality video. Further, the operations of such devices are highly customizable through the use of downloadable applications (apps) that can facilitate synchronization of the first and second devices, capture of video 104, display of objects 110, and capture of interactions 114 with the displayed objects 110.
Additionally, the system of FIG. 1 can simultaneously capture the displayed objects and captured interactions 116 along with the captured video stream 104 using the first device 102 as a video capture mechanism that is dedicated to capturing the presenter, without the need to capture the presentation materials using the first device camera 107. Such a configuration enables capture of the presenter from a best angle while still capturing the full scope of the content.
FIG. 2 depicts an example composite video display generated using the system of FIG. 1. The composite video includes presentation materials 202 and interactions therewith captured by the second device along with a captured video stream overlay 204 captured by the first device. In the example of FIG. 2, the presenter, depicted in the video stream 202 is discussing physics associated with bowling as part of a college curriculum. The presentation materials 202 at some points of the composite video display a video of a ball rolling down a bowling lane. At the point depicted in FIG. 2, the video at 202 is paused, and user annotations 206, captured from the second device, are displayed which describe how the spin of the ball guides it into the pocket of the pins for best results. The displayed objects that are capturable from the second device can take a variety of forms including Power Point presentation slides, images, video, web browser contents, and documents. Interactions can include transitions from one displayed object to another (e.g., Power Point slide transitions), movement of displayed objects around the display of the second device (e.g., movement of graphic objects of a flow diagram), and annotation on top of displayed objects (e.g., annotations to a still frame or playing video). The captured interactions and/or displayed objects are displayed in one region of the composite video, while the captured video stream from the first device is displayed in a second region of the video simultaneously for at least a portion of the composite video.
FIG. 3 is a block diagram depicting a second example configuration for synchronizing devices for capturing components for a composite video. A first device 302 includes a camera 304 for capturing a video stream 306 that includes timing data that is based on synchronization with a second device 308. The second device 308 is configured to capture objects displayed on its interface display 310 as well as interactions with those displayed objects, which are transmitted from the second device 308 along with timing information that is based on the synchronization at 312. The captured video stream 306 and the captured interactions and displayed objects 312 and their associated timing information are used to generate a composite video 314. In the example of FIG. 3, the first device 302 and the second device 308 are synchronized via communications with an external server computer 316, such as via applications 318 running on each of the devices 302, 308. For example, the server 316 can provide a current master time to each of the devices 302, 308. The devices can calculate a difference between their clocks and the master clock. Each device's associated captured data 312, 314 can then have timing data appended based on the master clock time, such as via a master clock synchronized timeline.
FIG. 4 is a diagram depicting example synchronization timelines generated by the first and second devices. The top timeline is generated by the first mobile device that is capturing a video stream, and the bottom timeline is generated by the second mobile device that is capturing displayed objects and user interactions. The devices are synchronized at T=0:00, such that the two timelines are time aligned. At T=1:24, video capture begins at the first device, and interaction and display object capture begins at the second device at T=1:45. At T=7:15, a change to the objects being displayed on the second device is captured. At T=12:24, the video capture is paused at the first device. At T=22:07, video capture at the first device resumes. A first annotation to the displayed objects is captured at the second device at T=28:15, and a second annotation is captured at T=30:15. Interaction and display object capture is halted at T=36:45 on the second device, and the video stream capture on the first device is halted at T=46:07. The captured video stream, along with first timeline data is transmitted from the first mobile device to a server or other device that will generate the composite video. The captured displayed objects and interactions therewith are also transmitted along with second timeline data. In one example, one of either the first or second devices is used to generate the composite video.
Using the timeline data received from the first and second devices, an entity generating the composite video is able to generate that composite video having synchronized display of video, objects, and/or annotations with ease. FIG. 5 depicts a composite video timeline generated based on a received captured video stream with first timeline data and captured interactions/displayed objects with second timeline data. The composite video begins at V=0:00, which corresponds to T=1:24, where the first device began capturing video, indicating the beginning of the presentation. At V=0:00, the composite video displays video from the first device of the presenter speaking At V=0:21, corresponding to T=1:45 on the device timelines, object 1 is displayed as part of the composite video. At V=5:51, object 2 is displayed as part of the composite video, based on the capture of object 2 being displayed on the second device at T=7:15. At V=11:00, the composite video is adjusted to show only object 2 without the speaker video based on the pause of video capture at T=12:24. The speaker video is again incorporated into the composite video at V=20:43 based on the corresponding resumption of video capture at T=22:07. Annotations are added over the display of object 2 in the composite video at V=26:51 and V=28:51 based on captures of corresponding annotations at T=28:15 and T=30:15, respectively, at the second device. At V=35:21, the composite video is adjusted to show only video based on the halting of object and interaction capture at the second device at T=36:45, and the composite video is ended at V=44:43 in accordance with video stream capture ending at T=46:07.
FIG. 6 is a block diagram depicting a system for generating a composite video. A first mobile device 602 captures a video stream 604. A second mobile device 606 captures objects displayed on an interface of the second mobile device along with interactions with and annotations to such objects at 608. The first mobile device 602 and the second mobile device 606 are synchronized such that the captured video stream 604 and the object/interaction data 608 are transmitted with timing info that is based on the synchronization to a server 610. The server 610 generates a composite video 612 based on the received content data 604, 608, where that composite video includes at least a portion having simultaneous display of video from the captured video stream 604 and objects/interactions from 608 that are time aligned based on the synchronized timing info. The composite video 612 may also utilize certain manual edits 614 in generation.
FIG. 7 is a diagram depicting example frame configurations for a composite video. At 702, a portion of the composite video is shown where the video stream is depicted alone. Such a configuration could correspond to V=0:00-V=0:21 of the composite video timeline of FIG. 5, where the presenter provided an introduction to the presentation. At 704, the video stream captured from the first device is depicted at one portion of the screen, while an object that was displayed on the second device is depicted at a second portion of the screen of the composite video. Such a configuration could correspond to V=0:21-V=11:00 of the FIG. 5 timeline. At 706, the video stream from the first device is displayed in a first portion of the composite video display while an object with overlaid captured annotations is depicted in a second region of the composite video. Such a configuration could correspond to V=26:51-V=35:21 of the FIG. 5 timeline. At 708, the object with annotations, as depicted on and captured by the second device is displayed without corresponding video from the first device.
FIG. 8 depicts example object displays on the second device and corresponding interactions for capture. At 802, a video of a bowling ball rolling down a lane is depicted on the second device. The second device captures the display of video and annotates its timeline accordingly. At 804, the video is paused, and the second device captures that interaction with the second device display. The second device further captures the user interacting with the display of the second device to add an arrow annotation 806 showing the desired direction of the ball. At 808, the second device captures a second user annotation 810 to the displayed object in the form of a second arrow indicating a direction of spin of the bowling ball. The second device stores an indication of that second annotation and updates its synchronized timeline accordingly. At 812, the second device captures an interaction with the display where the user commands display of a different object, a display of a bowling score sheet.
This application uses examples to illustrate the invention. The patentable scope of the invention includes other examples. For example, the systems described herein can generate a composite video that includes multiple video streams simultaneously, as depicted in FIG. 9, where a first video stream 902 and a second video stream 904 are overlaid on an object 906 displayed on the second device along with annotations thereto. Such a composite video configuration could be generated using the hardware described herein, such as by utilizing the camera 107 of the first device as well as a camera 120 of the second device, depicted in FIG. 1, to capture synchronized video for video stream 1902 and video stream 2904, respectively, where the camera 120 of the second device captures video from a different vantage point than the camera 107 of the first device.
Patent Application
20150264272
