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QTKit Functions Reference

Overview

This chapter describes the functions that are available in the QuickTime Kit framework.

Functions by Task

Creating QTTime Structures

The following functions are used to create QTTime structures.

• QTMakeTime
• QTMakeTimeScaled
• QTTimeFromString
• QTMakeTimeWithTimeRecord
• QTMakeTimeWithTimeInterval

Getting and Setting Times

The following functions are used to get and set times.

• QTGetTimeRecord
• QTGetTimeInterval

Comparing QTTime Structures

The following function is used to compare QTTime structures.

• QTTimeCompare
• QTSMPTETimeCompare
• QTStringFromSMPTETime

Adding and Subtracting Times

The following functions are used to add and subtract times:

• QTTimeIncrement
• QTTimeDecrement

Getting a Time Description

The following function is used to get a time description:

• QTStringFromTime

Time Range Functions

• QTEqualTimeRanges
• QTIntersectionTimeRange
• QTMakeTimeRange
• QTStringFromTimeRange
• QTTimeInTimeRange
• QTTimeRangeEnd
• QTTimeRangeFromString
• QTUnionTimeRange

QuickTime Helper Functions

• QTStringForOSType
• QTOSTypeForString

Functions

QTEqualTimeRanges

Returns YES if the specified time ranges are identical.

BOOL QTEqualTimeRanges (
   QTTimeRange range,
   QTTimeRange range2
);

Discussion

This function returns YES if the specified time ranges are identical.

Availability

• Available in Mac OS X v10.3 and later.

Declared In

QTTimeRange.h

QTGetTimeInterval

Returns the value of a QTTime structure expressed as an NSTimeInterval.

BOOL QTGetTimeInterval (
   QTTime time,
   NSTimeInterval *timeInterval
);

Discussion

This function returns, in the location to by timeInterval, the value of a QTTime structure expressed as a NSTimeInterval. Returns YES if the method succeeded.

Availability

• Available in Mac OS X v10.3 and later.

Declared In

QTTime.h

QTGetTimeRecord

Returns the value of a QTTime structure expressed as a TimeRecord.

BOOL QTGetTimeRecord (
   QTTime time,
   TimeRecord *timeRecord
);

Discussion

This function returns, in the location pointed to by timeRecord, the value of a QTTime structure expressed as a TimeRecord. Returns YES if the method succeeded.

Availability

• Available in Mac OS X v10.3 and later.

Related Sample Code

• QTAudioExtractionPanel

Declared In

QTTime.h

QTIntersectionTimeRange

Returns a QTTimeRange structure that represents the intersection of the two ranges.

QTTimeRange QTIntersectionTimeRange (
   QTTimeRange range1,
   QTTimeRange range2
);

Discussion

This function returns a QTTimeRange structure that represents the intersection of the two ranges. The intersection of two ranges is the largest range that includes all times that are in both ranges.

Availability

• Available in Mac OS X v10.3 and later.

Declared In

QTTimeRange.h

QTMakeTime

Creates a QTTime structure.

QTTime QTMakeTime (
   long long timeValue,
   long timeScale
);

Discussion

This function creates a QTTime structure initialized using the scalar value timeValue and the time scale scale.

Availability

• Available in Mac OS X v10.3 and later.

Related Sample Code

• QTAudioExtractionPanel
• QTKitCommandLine
• QTKitCreateMovie
• QTKitMovieShuffler

Declared In

QTTime.h

QTMakeTimeRange

Returns a QTTimeRange structure initialized using the QTTime structures time and duration.

QTTimeRange QTMakeTimeRange (
   QTTime time,
   QTTime duration
);

Discussion

This function returns a QTTimeRange structure initialized using the QTTime structures time and duration. Those structures may have different time scales. In all cases, the time scale used in the new QTTimeRange structure is that of time.

Availability

• Available in Mac OS X v10.3 and later.

Related Sample Code

• QTKitCommandLine
• QTKitMovieShuffler

Declared In

QTTimeRange.h

QTMakeTimeScaled

Returns a QTTime structure.

QTTime QTMakeTimeScaled (
   QTTime time,
   long timeScale
);

Discussion

This function returns a QTTime structure whose time is set to the time of a QTTime structure interpreted using the time scale scale.

Availability

• Available in Mac OS X v10.3 and later.

Declared In

QTTime.h

QTMakeTimeWithTimeInterval

Creates a QTTime structure.

QTKIT_EXTERN QTTime QTMakeTimeWithTimeInterval (
   NSTimeInterval timeInterval
);

Discussion

Creates a QTTime structure initialized using the NSTimeInterval value timeInterval.

Availability

• Available in Mac OS X v10.3 and later.

Declared In

QTTime.h

QTMakeTimeWithTimeRecord

Creates a QTTime structure.

QTKIT_EXTERN QTTime QTMakeTimeWithTimeRecord (
   TimeRecord timeRecord
);

Discussion

This function creates a QTTime structure initialized using the values in the time record timeRecord.

Availability

• Available in Mac OS X v10.3 and later.

Related Sample Code

• QTAudioExtractionPanel

Declared In

QTTime.h

QTOSTypeForString

Returns a four-character code representing the specified NSString.

OSType QTOSTypeForString (
   NSString *string
);

Discussion

This function returns a four-character code representing the specified NSString.

Availability

• Available in Mac OS X v10.3 and later.

Declared In

QTUtilities.h

QTSMPTETimeCompare

Compares two SMPTETime structures.

NSComparisonResult QTSMPTETimeCompare(SMPTETime time, SMPTETIme otherTime)

QTStringForOSType

Returns an NSString representing the specified four-character code type.

NSString * QTStringForOSType (
   OSType type
);

Discussion

This function returns an NSString representing the specified four-character code type.

Availability

• Available in Mac OS X v10.3 and later.

Declared In

QTUtilities.h

QTStringFromSMPTETime

Returns a human-readable string from the SMPTETime. The returned string is of the form hh:mm:ss.ff.

NSString* QTStringFromSMPTETime(SMPTETime time)

Availability

• Available in Mac OS X v10.5 and later.

Declared In

QTTime.h

QTStringFromTime

Returns a description of a QTTime structure.

NSString * QTStringFromTime (
   QTTime time
);

Discussion

This function returns a description of a QTTime structure. The string is in the form "sign:days:hours:minutes:seconds:timevalue:timescale", where sign is empty or “-”. Note that this is not for user input, but for archiving and debugging purposes.

Availability

• Available in Mac OS X v10.3 and later.

Related Sample Code

• CIVideoDemoGL
• QTAudioExtractionPanel
• QTKitPlayer
• QTRecorder

Declared In

QTTime.h

QTStringFromTimeRange

Returns a description of a QTTimeRange structure.

NSString * QTStringFromTimeRange (
   QTTimeRange range
);

Discussion

This function returns a description of a QTTimeRange structure. The string is in the form "hours:minutes:seconds.frames:: hours:minutes:seconds.frames". Note that this is for archiving and debugging purposes, not for user display.

Availability

• Available in Mac OS X v10.3 and later.

Declared In

QTTimeRange.h

QTTimeCompare

Returns a value of type NSComparisonResult.

NSComparisonResult QTTimeCompare (
   QTTime time,
   QTTime otherTime
);

Discussion

This function returns a value of type NSComparisonResult that indicates the result of comparing a QTTime structure with the specified QTTime structure otherTime.

Availability

• Available in Mac OS X v10.3 and later.

Related Sample Code

• QTAudioExtractionPanel
• QTKitMovieShuffler

Declared In

QTTime.h

QTTimeDecrement

Subtracks one QTTime from another.

QTTime QTTimeDecrement (
   QTTime time,
   QTTime decrement
);

Discussion

This function returns a QTTime structure whose time is set to the time of a QTTime structure minus that of the structure decrement.

Availability

• Available in Mac OS X v10.3 and later.

Related Sample Code

• QTAudioExtractionPanel

Declared In

QTTime.h

QTTimeFromString

Returns a QTTime structure.

QTKIT_EXTERN QTTime QTTimeFromString (
   NSString *string
);

Discussion

This function returns a QTTime structure whose time is set to the time expressed by the string; the string is assumed to be in the form "days:hours:minutes:seconds:frames/timescale".

Availability

• Available in Mac OS X v10.3 and later.

Related Sample Code

• QTAudioExtractionPanel

Declared In

QTTime.h

QTTimeIncrement

Adds two QTTime structures.

QTTime QTTimeIncrement (
   QTTime time,
   QTTime increment
);

Discussion

This function returns a QTTime structure whose time is set to the time of a QTTime structure plus that of the structure increment.

Availability

• Available in Mac OS X v10.3 and later.

Declared In

QTTime.h

QTTimeInTimeRange

Returns YES if the specified time time lies in the time range range.

BOOL QTTimeInTimeRange (
   QTTime time,
   QTTimeRange range
);

Discussion

This function returns YES if the specified time time lies in the time range range.

Availability

• Available in Mac OS X v10.3 and later.

Declared In

QTTimeRange.h

QTTimeRangeEnd

Returns a QTTime structure representing the end of the specified time range.

QTTime QTTimeRangeEnd (
   QTTimeRange range
);

Discussion

This function returns a QTTime structure representing the end of the specified time range.

Availability

• Available in Mac OS X v10.3 and later.

Declared In

QTTimeRange.h

QTTimeRangeFromString

Returns a QTTimeRange structure

QTTimeRange QTTimeRangeFromString (
   NSString *string
);

Discussion

This function returns a QTTimeRange structure whose range is set to the range expressed by string; the string is assumed to be in the form "days:hours:minutes:seconds.frames/timescale~days:hours:minutes:seconds.frames/timescale".

Availability

• Available in Mac OS X v10.3 and later.

Declared In

QTTimeRange.h

QTUnionTimeRange

Returns a QTTimeRange structure.

QTTimeRange QTUnionTimeRange (
   QTTimeRange range1,
   QTTimeRange range2
);

Discussion

This function returns a QTTimeRange structure that represents the union of the two ranges. The union of two ranges is the smallest range that includes all times that are in either range.

Availability

• Available in Mac OS X v10.3 and later.

Declared In

QTTimeRange.h

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