Media-Editing Application with Video Segmentation and Caching Capabilities

Abstract

For a media-editing application that creates a composite media presentation, some embodiments of the invention provide a method for reducing rendering operations by dividing the composite presentation into several segments and rendering the segments in a manner that allows for these segments to move with respect to each other without losing the rendered results. The media-editing application defines portions of a media presentation as segments. When the media-editing application renders a segment of the media presentation, the application computes an identifier that uniquely identifies the segment and then uses this identifier to store and later retrieve the rendered result for the segment. The application in some embodiments computes the identifier based on a set of attributes of the segment, and stores the results of rendering the segment at a location that is uniquely identifiable in a storage structure by the identifier.

Description

BACKGROUND[0001]Digital graphic design, image editing, audio editing, and video editing applications (hereafter collectively referred to as media content editing applications or media-editing applications) provide graphical designers, media artists, and other users with the necessary tools to create a variety of media content. Examples of such applications include Final Cut Pro® and iMovie®, both sold by Apple Inc. These applications give users the ability to edit, combine, transition, overlay, and piece together different media content in a variety of manners to create a resulting media project. The resulting media project specifies a particular sequenced composition of any number of text, audio, image, and / or video content elements that is used to create a media presentation.[0002]Typically, a user previews portions of a media presentation while creating the presentation in order to see if the media content of the media presentation would be presented as the user desires. However,...

AI Technical Summary

Benefits of technology

[0005]For a media-editing application that creates a composite media presentation, some embodiments of the invention provide a novel method for reducing rendering operations by dividing the composite presentation into several segments and rendering the segments in a manner that allows for these segments to move with respect to each other without losing the rendered results. The media-editing application of some embodiments includes a composite display area for displaying media clips that are part of the composite media presentation. In some embodiments, the composite display area includes a timeline and one or more tracks that span the timeline for holding one or more media clips.

[0007]When the media-editing application renders a segment of the media presentation, the application computes an identifier that uniquely identifies the segment and then uses this identifier to store and later retrieve the rendered result for the segment. The application in some embodiments computes the identifier based on a set of attributes of the segment, and stores the results of rendering the segment at a location that is uniquely identifiable in a storage structure by the identifier. When a segment is moved within the composite presentation (e.g., moved along the timeline, moved from one track to another, moved within the composite graph, etc.) without changing its set of attributes, the media-editing application can use the rendered result for the segment without re-rendering the segment. This is because the identifier for this moved segment did not change as its set of attributes did not change, and this identifier can be used to retrieve the rendered results from the storage structure. Similarly, the media-editing application is able to use the same rendered result for any other segment that has the identical attributes, without having to render the other segment.

[0011]In some embodiments, the media-editing application includes several background-rendering modules. These modules automatically render segments of a media presentation in the background of a system on which the media-editing application is being executed. By performing rendering in the background, the background-rendering modules produce rendered results for the segments. That is, the modules pre-generate playable media output data (e.g., composite video frames or audio samples) of the media presentation without interrupting other operations (e.g., editing operations, etc.) of the media-editing application. As such, the users can continue on interacting with the media presentation using the media-editing application without being interrupted.

[0017]The background-rendering modules of some embodiments minimize their impact on the editing modules' operations by allowing the editing modules to access a portion of the media presentation simultaneously while the background-rendering modules are accessing the same portion. That is, the background-rendering modules do not block the editing modules from accessing the media project while the background-rendering modules are accessing the media project. In some embodiments, the background-rendering modules allow the simultaneous access by using a readers / writer lock when the background-rendering modules access a portion of the media project. A readers / writer lock allows multiple modules or processes to access the same piece of data simultaneously. In some embodiments, a separate lock is used to control access to the rendered result for a segment.

Problems solved by technology

However, some portions of the media presentation require a lot of processing capability for a media-editing application to playback in real-time for previewing.

When the required processing capability exceeds that of a system on which the media-editing application is executed, the media-editing application must playback the portions of the presentation in low quality or the application may not playback the portions in real-time.

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