Class: AVAssetReaderOutput

Inherits:
NSObject show all

Overview

AVAssetReaderOutput is an abstract class that defines an interface for reading a single collection of samples of a common media type from an AVAssetReader object.

Direct Known Subclasses

AVAssetReaderAudioMixOutput, AVAssetReaderTrackOutput, AVAssetReaderVideoCompositionOutput

Instance Attribute Summary (collapse)

Instance Method Summary (collapse)

Methods inherited from NSObject

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Constructor Details

This class inherits a constructor from NSObject

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class NSObject

Instance Attribute Details

- (Boolean) alwaysCopiesSampleData

Indicates whether the data in buffers gets copied before being vended. When the value of this property is YES, the output always vends a buffer with copied data—you can freely modify data in such buffers.When the value of this property is NO, the buffers vended may not be copied—such buffers may still be referenced by other entities. The result of modifying a buffer whose data hasn’t been copied is undefined.Requesting buffers whose data hasn’t been copied when possible can lead to performance improvements.The default value of this property is YES

Returns:

  • (Boolean)

- (String) mediaType (readonly)

A string representing the media type of the track (or tracks) represented by the output. (read-only) The value of this property is one of the media type strings defined in AVMediaFormat.h.

Returns:

Instance Method Details

- (CMSampleBufferRef) copyNextSampleBuffer

Synchronously copies the next sample buffer for the output. If this method returns NULL, you should check the value of the associated AVAssetReader object’s status property to determine why no more samples could be read.

Returns:

  • (CMSampleBufferRef)

    The output sample buffer, or NULL if there are no more sample buffers available for the output within the time range specified by the asset reader’s timeRange property. Ownership follows the “The Create Rule” in Memory Management Programming Guide for Core Foundation.