Type Method

videoCompositionWithPropertiesOfAsset:

Creates a video composition object configured to present the video tracks of the specified asset.

Declaration

+ (AVVideoComposition *)videoCompositionWithPropertiesOfAsset:(AVAsset *)asset;

Parameters

asset

The asset whose configuration matches the intended use of the video composition.

Return Value

A new video composition object.

Discussion

This method creates the video composition object and configures it with the values and instructions suitable for presenting the video tracks of the specified asset. The returned object contains instructions that respect the spatial properties and time ranges of the specified asset’s video tracks. It also configures the object properties in the following way:

  • The value of the frameDuration property is set to a value short enough to accommodate the greatest nominal frame rate value among the asset’s video tracks, as indicated by the nominalFrameRate property of each track. If all of the asset tracks have a nominal frame rate of 0, a frame rate of 30 frames per second is used, with the frame duration set accordingly.

  • The value assigned to the renderSize property depends on whether the asset is an AVComposition object. If it is, the value is set to the value of the naturalSize property of the composition. If it is not, the value is set to a value that encompasses all of the asset’s video tracks.

  • The value of the renderScale property is set to 1.0.

  • The value of the animationTool property is set to nil.

See Also

Creating a Video Composition Object

+ videoCompositionWithAsset:applyingCIFiltersWithHandler:

Creates a video composition configured to apply Core Image filters to each video frame of the specified asset.