Constants

Visual Context Constants

The following are values for kQTVisualContextTypeKey, a read-only CFStringRef that defines the type of the visual context:

Constants

kQTVisualContextExpectedReadAheadKey

A CFNumberRef that defines the number of seconds ahead of real time that the client expects to pull images out of a visual context. Applications using the Core Video display link should set this attribute according to the value returned by CVDisplayLinkGetOutputVideoLatency.

kQTVisualContextPixelBufferAttributesKey

A CFDictionaryRef that defines the dictionary containing pixel buffer attributes. See kICMCompressionSessionPropertyID_PixelBufferPool in ICM Compression Session Properties.

kQTVisualContextTargetDimensionsKey

A CFDictionaryRef that defines the dictionary containing kQTVisualContextTargetDimensions_WidthKey and kQTVisualContextTargetDimensions_HeightKey values. This key is used as a hint to optimize certain media types, such as text, that can be rendered at any resolution. If this attribute is not set, the movie will be rendered at its native resolution.

kQTVisualContextTargetDimensions_WidthKey

A CFNumberRef that defines the width, in pixels, of the rendering target.

kQTVisualContextTargetDimensions_HeightKey

A CFNumberRef that defines the height, in pixels, of the rendering target.

kQTVisualContextType_Direct3DTexture

The CFString value for use in dictionaries for identifying Direct3DTexture visual contexts.

Declared In

kQTPropertyClass_ImageDescription

The following are aperture mode properties of image descriptions in QuickTime 7.1.

enum {
   kQTPropertyClass_ImageDescription  = 'idsc',
   kICMImageDescriptionPropertyID_EncodedWidth = 'encw',
   kICMImageDescriptionPropertyID_EncodedHeight = 'ench',
   kICMImageDescriptionPropertyID_CleanAperture = 'clap',
   kICMImageDescriptionPropertyID_PixelAspectRatio = 'pasp',
   kICMImageDescriptionPropertyID_CleanApertureDisplayDimensions = 'cadi',
   kICMImageDescriptionPropertyID_ProductionApertureDisplayDimensions = 'prdi',
   kICMImageDescriptionPropertyID_EncodedPixelsDimensions = 'endi',
   kICMImageDescriptionPropertyID_DisplayWidth = 'disw',
   kICMImageDescriptionPropertyID_DisplayHeight = 'dish',
   kICMImageDescriptionPropertyID_ProductionDisplayWidth = 'pdsw',
   kICMImageDescriptionPropertyID_ProductionDisplayHeight = 'pdsh',
   kICMImageDescriptionPropertyID_NCLCColorInfo = 'nclc',
   kICMImageDescriptionPropertyID_FieldInfo = 'fiel',
   kICMImageDescriptionPropertyID_ClassicTrackWidth = 'claw',
   kICMImageDescriptionPropertyID_ClassicTrackHeight = 'clah',
   kICMImageDescriptionPropertyID_GammaLevel = 'gama',
   kICMImageDescriptionPropertyID_RowBytes = 'rowb',
   kICMImageDescriptionPropertyID_StepDuration = 'step',
   kICMImageDescriptionPropertyID_CleanApertureClipRect = 'cacr',
   kICMImageDescriptionPropertyID_CleanApertureMatrix = 'camx',
   kICMImageDescriptionPropertyID_ProductionApertureMatrix = 'pamx',
   kICMImageDescriptionPropertyID_SummaryString = 'isum',
};

Constants

kQTPropertyClass_ImageDescription

Class identifier for image description properties.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_EncodedWidth

The width of the encoded image. Usually, but not always, this is the ImageDescription's width field.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_EncodedHeight

The height of the encoded image. Usually, but not always, this is the ImageDescription's height field.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_CleanAperture

Describes the clean aperture of the buffer. If not specified explicitly in the image description, the default clean aperture (full encoded width and height) will be returned.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_PixelAspectRatio

Describes the pixel aspect ratio. If not specified explicitly in the image description, a square (1:1) pixel aspect ratio will be returned.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_CleanApertureDisplayDimensions

The dimensions at which the image can be displayed on a square-pixel display, generally calculated using the clean aperture and pixel aspect ratio. Note that this value is returned as a FixedPoint; the width and height can also be read separately as rounded SInt32s via kICMImageDescriptionPropertyID_CleanApertureDisplayWidth and kICMImageDescriptionPropertyID_CleanApertureDisplayHeight.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_ProductionApertureDisplayDimensions

The dimensions at which the image could be displayed on a square-pixel display, disregarding any clean aperture but honoring the pixel aspect ratio. This may be useful for authoring applications that want to expose the edge-processing region. For general viewing, use kICMImageDescriptionPropertyID_CleanApertureDimensions instead. Note that this value is returned as a FixedPoint; the width and height can also be read separately as rounded SInt32s via kICMImageDescriptionPropertyID_ProductionApertureDisplayWidth and kICMImageDescriptionPropertyID_ProductionApertureDisplayHeight.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_EncodedPixelsDimensions

Describes the dimensions of the encoded image. Note that this value is returned as a FixedPoint for convenience; the width and height can also be read separately as SInt32s via kICMImageDescriptionPropertyID_EncodedWidth and kICMImageDescriptionPropertyID_EncodedHeight.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_CleanApertureDisplayWidth

A width at which the buffer's image could be displayed on a square-pixel display, possibly calculated using the clean aperture and pixel aspect ratio.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_CleanApertureDisplayHeight

A height at which the buffer's image could be displayed on a square-pixel display, possibly calculated using the clean aperture and pixel aspect ratio.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_ProductionApertureDisplayWidth

A width at which the image could be displayed on a square-pixel display, disregarding any clean aperture but honoring the pixel aspect ratio. This may be useful for authoring applications that want to expose the edge processing region. For general viewing, use kICMImageDescriptionPropertyID_DisplayWidth instead.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_ProductionApertureDisplayHeight

A height at which the image could be displayed on a square-pixel display, disregarding any clean aperture but honoring the pixel aspect ratio. This may be useful for authoring applications that want to expose the edge processing region. For general viewing, use kICMImageDescriptionPropertyID_DisplayHeight instead.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_DisplayWidth

Synonym for kICMImageDescriptionPropertyID_CleanApertureDisplayHeight.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_DisplayHeight

Synonym for kICMImageDescriptionPropertyID_CleanApertureDisplayHeight.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_ProductionDisplayWidth

Synonym for kICMImageDescriptionPropertyID_ProductionApertureDisplayWidth.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_ProductionDisplayHeight

Synonym for kICMImageDescriptionPropertyID_ProductionApertureDisplayHeight.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_NCLCColorInfo

Color information, if available in the NCLCColorInfoImageDescriptionExtension format.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_CGColorSpace

A CGColorSpaceRef for the colorspace described by the image description, constructed from video color information or ICC Profile. It is important to note that the YCbCr matrix from the video color info is not represented in the CGColorSpaceRef. The caller of GetProperty is responsible for releasing this, for example, by calling CGColorSpaceRelease. Only supported on Mac OS X.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_ICCProfile

A CFDataRef containing the serialized ICC profile described by the image description. The caller of GetProperty is responsible for releasing this, for example, by calling CFRelease.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_FieldInfo

Information about the number and order of fields, if available.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_ClassicTrackWidth

A track width suitable for passing to NewMovieTrack when creating a new track to hold this image data.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_ClassicTrackHeight

A track height suitable for passing to NewMovieTrack when creating a new track to hold this image data.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_GammaLevel

A Fixed for the gammma level described by the image description.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_RowBytes

The offset in bytes from the start of one row to the next. Only valid if the codec type is a chunky pixel format.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_StepDuration

Defines a duration for quantizing time. This is applicable for cases where a single media sample generates visual output that varies continuously through its duration. By interpreting this property, such a sample may be considered to have internal "step points" at multiples of the stepping duration. This can be used to throttle frame generation during playback, and when stepping using InterestingTime APIs. Setting a step duration with value zero removes any current step duration.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_CleanApertureClipRect

The clean aperture as a FixedRect in source coordinates, within the rectangle defined by the image description width and height, suitable for use as a source rectangle in a decompression sequence. For historical reasons, the DVCPROHD codecs store the production aperture display dimensions in the image description width and height; the actual encoded dimensions are smaller. For DVCPROHD, the clip rect will be relative to the image description width and height, not the encoded dimensions.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_CleanApertureMatrix

A matrix transforming the clean aperture clip rect to the origin, scaled to the clean aperture display dimensions. For historical reasons, the DVCPROHD codecs store the production aperture display dimensions in the image description width and height; the actual encoded dimensions are smaller. For DVCPROHD, the matrix will be relative to the image description width and height, not the encoded dimensions.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_ProductionApertureMatrix

A matrix transforming the image to the origin, scaled to the production aperture display dimensions. For historical reasons, the DVCPROHD codecs store the production aperture display dimensions in the image description width and height; the actual encoded dimensions are smaller. For DVCPROHD, the matrix will be relative to the image description width and height, not the encoded dimensions.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMImageDescriptionPropertyID_SummaryString

A localized, human readable string summarizing the image as a CFString, that is, "Apple DV, 720 x 480 (640 x 480), Millions". The elements are: the codec name, the encoded pixels dimensions, then parenthetically the clean aperture mode dimensions, but only if they are different from the encoded pixels dimensions; then the depth. The codec name shall be from the localized decompressor component name string if exactly one decompressor with the correct cType is available; otherwise the string in the image description shall be used. The caller of GetProperty is responsible for releasing this CFString, for example, by calling CFRelease.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

Declared In

kQTPropertyClass_DVCompressor

The following are DV Compressor component properties in QuickTime 7.1.

enum {
   kQTPropertyClass_DVCompressor = 'dvco',
   kDVCompressorPropertyID_ProgressiveScan = 'prog',
   kDVCompressorPropertyID_AspectRatio16x9 = '16x9',
};

Constants

kQTPropertyClass_DVCompressor

The property class for DV compressors. (Applicable to DV25, DV50, NTSC, PAL, PROPAL.)

Available in Mac OS X v10.3 and later.

Declared in ImageCodec.h.

kDVCompressorPropertyID_ProgressiveScan

If set, indicates that the compressed frames should be marked as progressive-scan. By default, this flag is clear, meaning that frames should be marked as interlaced.

Available in Mac OS X v10.3 and later.

Declared in ImageCodec.h.

kDVCompressorPropertyID_AspectRatio16x9

If set, indicates that the compressor should use a 16:9 picture aspect ratio. If clear, the compressor will use the default 4:3 picture aspect ratio.

Available in Mac OS X v10.3 and later.

Declared in ImageCodec.h.

Declared In

kQTVisualPropertyID_ApertureMode

The following are visual properties of movies for aperture modes in QuickTime 7.1.

enum {
   kQTVisualPropertyID_ApertureMode = 'apmd',
};

Constants

kQTVisualPropertyID_ApertureMode

You can set the aperture mode property on a movie to indicate whether aspect ratio and clean aperture correction should be performed (kQTPropertyClass_Visual / kQTVisualPropertyID_ApertureMode). When a movie is in clean, production or encoded pixels aperture mode, each track's dimensions are overriden by special dimensions for that mode. The original track dimensions are preserved and can be restored by setting the movie into classic aperture mode. Aperture modes are not saved in movies. You can set the aperture mode property on a decompression session options object to indicate whether pixel buffers should be tagged to enable aspect ratio and clean aperture correction (kQTPropertyClass_ICMDecompressionSessionOptions / kICMDecompressionSessionOptionsPropertyID_ApertureMode).

Available in Mac OS X v10.3 and later.

Declared in Movies.h.

Declared In

Aperture Mode Properties

You can set the aperture mode property on a movie to indicate whether aspect ratio and clean aperture correction should be performed (kQTPropertyClass_Visual/kQTVisualPropertyID_ApertureMode). When a movie is in clean, production or encoded pixels aperture mode, each track’s dimensions are overriden by special dimensions for that mode. The original track dimensions are preserved and can be restored by setting the movie into classic aperture mode. Aperture modes are not saved in movies. You can set the aperture mode property on a decompression session options object to indicate whether pixel buffers should be tagged to enable aspect ratio and clean aperture correction (kQTPropertyClass_ICMDecompressionSessionOptions / kICMDecompressionSessionOptionsPropertyID_ApertureMode). The movie will be recalculated (laid out again) after one of the following happens: the movie’s aperture mode is changed; a track property corresponding to the current aperture mode is changed (that is, kQTVisualPropertyID_EncodedWidth for kQTApertureMode_EncodedPixels). Track and movie matrices will stay constant unless explicitly changed. The aperture mode of a movie can be set during NewMovieFromProperties, and set/get using SetMovieProperties and GetMovieProperties. NewMovieFromProperties defaults to kQTApertureMode_Classic. Decompression session options also support this property.

enum {
   kQTApertureMode_Classic = 'clas',
   kQTApertureMode_CleanAperture = 'clea',
   kQTApertureMode_ProductionAperture = 'prod',
   kQTApertureMode_EncodedPixels = 'enco'
};

Constants

kQTApertureMode_Classic

An aperture mode which gives compatibility with behavior in QuickTime 7.0.x and earlier. A movie in classic aperture mode uses track dimensions as set in NewMovieTrack and SetTrackDimensions. A decompression session in classic aperture mode does not set the clean aperture or pixel aspect ratio attachments on emitted pixel buffers. Movies default to classic aperture mode. If you call SetTrackDimensions on a track, the movie is automatically switched into classic aperture mode.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kQTApertureMode_CleanAperture

An aperture mode for general display. Where possible, video will be displayed at the correct pixel aspect ratio, trimmed to the clean aperture. A movie in clean aperture mode sets each track's dimensions to match its kQTVisualPropertyID_CleanApertureDimensions. A decompression session in clean aperture mode sets the clean aperture and pixel aspect ratio attachments on emitted pixel buffers based on the image description.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kQTApertureMode_ProductionAperture

An aperture mode for modal use in authoring applications. Where possible, video will be displayed at the correct pixel aspect ratio, but without trimming to the clean aperture so that the edge processing region can be viewed. A movie in production aperture mode sets each track's dimensions to match its kQTVisualPropertyID_ProductionApertureDimensions. A decompression session in production aperture mode sets the pixel aspect ratio attachments on emitted pixel buffers based on the image description.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kQTApertureMode_EncodedPixels

An aperture mode for technical use. Displays all encoded pixels with no aspect ratio or clean aperture compensation. A movie in encoded pixels aperture mode sets each track's dimensions to match its kQTVisualPropertyID_EncodedPixelsDimensions. A decompression session in encoded pixels aperture mode does not set the clean aperture or pixel aspect ratio attachments on emitted pixel buffers.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

Declared In

Track Aperture Mode Dimension Properties

The following are the vsual properties of tracks for aperture modes. A track's dimensions may vary depending on the movie's aperture mode. The dimensions for a given aperture mode may be accessed using these properties.

enum {
   kQTVisualPropertyID_ClassicDimensions = 'cldi',
   kQTVisualPropertyID_CleanApertureDimensions = 'cadi',
   kQTVisualPropertyID_ProductionApertureDimensions = 'prdi',
   kQTVisualPropertyID_EncodedPixelsDimensions = 'endi',
   kQTVisualPropertyID_HasApertureModeDimensions = 'hamd',
};

Constants

kQTVisualPropertyID_ClassicDimensions

The track dimensions used in QuickTime 7.0.x and earlier. Setting this property is equivalent to calling SetTrackDimensions, except that SetTrackDimensions also changes the aperture mode to kQTApertureMode_Classic, and setting this property does not.

Available in Mac OS X v10.3 and later.

Declared in Movies.h.

kQTVisualPropertyID_CleanApertureDimensions

The track dimensions to use in clean aperture mode.

Available in Mac OS X v10.3 and later.

Declared in Movies.h.

kQTVisualPropertyID_ProductionApertureDimensions

The track dimensions to use in production aperture mode.

Available in Mac OS X v10.3 and later.

Declared in Movies.h.

kQTVisualPropertyID_EncodedPixelsDimensions

The track dimensions to use in encoded pixels aperture mode.

Available in Mac OS X v10.3 and later.

Declared in Movies.h.

kQTVisualPropertyID_HasApertureModeDimensions

True if aperture mode dimensions have been set on this movie, even if they are all identical to the classic dimensions (as is the case for content with square pixels and no edge processing region). This property can also be tested on a movie, where it is true if any track has aperture mode dimensions.

Available in Mac OS X v10.3 and later.

Declared in Movies.h.

Declared In

kCharacteristicSupportsApertureModes

Defines media characteristics for aperture modes.

enum {
   kCharacteristicSupportsApertureModes = 'apmd',
}

Constants

kCharacteristicSupportsApertureModes

Indicates that a media handler supports aperture modes, which enable video to be automatically scaled and cropped to compensate for non-square pixel aspect ratios and to trim possibly-dirty edge processing regions. The dimensions of such a track may change when the movie’s aperture mode is changed.

Available in Mac OS X v10.3 and later.

Declared in Movies.h.

Declared In

kQTSpecialScalingMode_FitWithinDimensions

Defines scaling modes.

enum {
   kQTSpecialScalingMode_FitWithinDimensions = 'fit '
};

Constants

kQTSpecialScalingMode_FitWithinDimensions

Adjusts destination dimensions so that the source fits within the dimensions specified with kQTSettingsImageWidth and kQTSettingsImageHeight by fitting to the shortest side, and scales the source to the destination. Internally, the default scaling mode, which is based on the source aperture mode, is used for compression session, instead of this scaling mode..

Available in Mac OS X v10.3 and later.

Declared in QuickTimeComponents.h.

Declared In

QT Settings for Video, Image, Clean Aperture, and Pixel Aspect Ratio

Defines settings for video and image sizes, clean aperture and pixel aspect ratios.

enum {
   kQTSettingsVideoSize          = 'isiz'
   kQTSettingsImageWidth         = 'iwdt'
   QTSettingsImageHeight         = 'ihgt'
   kQTSettingsCleanAperture      = 'clap'
   kQTSettingsPixelAspectRatio   = 'pasp'
   kQTSettingsScalingMode        = 'scam'
   kQTSettingsUseCodecEnforcedDimensions = 'uenf'
   kQTSettingsDeinterlaceSource  = 'dint'
};

Constants

kQTSettingsVideoSize

The video size-related container.

Available in Mac OS X v10.3 and later.

Declared in QuickTimeComponents.h.

kQTSettingsImageWidth

The destination width. If this is zero, it means the source width.

Available in Mac OS X v10.3 and later.

Declared in QuickTimeComponents.h.

QTSettingsImageHeight

The destination height. If this is zero, it means the source height.

kQTSettingsCleanAperture

The clean aperture for compression sessions. If this is all zeros, it means no clean aperture (that is, full width and height).

Available in Mac OS X v10.3 and later.

Declared in QuickTimeComponents.h.

kQTSettingsPixelAspectRatio

The pixel aspect ratio for compression sessions. If this is all zeros, it means square pixels (that is, 1:1).

Available in Mac OS X v10.3 and later.

Declared in QuickTimeComponents.h.

kQTSettingsScalingMode

The scaling mode for compression sessions. If this is zero, it means scaling mode based on the source aperture mode.

Available in Mac OS X v10.3 and later.

Declared in QuickTimeComponents.h.

kQTSettingsUseCodecEnforcedDimensions

If TRUE, compressor’s enforced dimension overrides the image size settings.

Available in Mac OS X v10.3 and later.

Declared in QuickTimeComponents.h.

kQTSettingsDeinterlaceSource

If TRUE, deinterlacing is applied to source frames.

Available in Mac OS X v10.3 and later.

Declared in QuickTimeComponents.h.

Declared In

kICMDecompressionSessionOptionsPropertyID_ApertureMode

Defines properties of decompression session options objects.

enum {
   kICMDecompressionSessionOptionsPropertyID_ApertureMode = 'apmd', // OSType,
   Read/Write
};

Constants

kICMDecompressionSessionOptionsPropertyID_ApertureMode

You can set the aperture mode property on a decompression session options object to indicate whether pixel buffers should be tagged to enable aspect ratio and clean aperture correction. The default aperture mode for a decompression session is clean aperture mode.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

Declared In

kICMCompressionSessionOptionsPropertyID_ExtraAspectRatioStretchFactor

Defines properties of compression sessions options objects.

enum {
   kICMCompressionSessionOptionsPropertyID_ExtraAspectRatioStretchFactor =      'exsf', // Fixed,
   Default fixed1,
   Read/Write
};

Constants

kICMCompressionSessionOptionsPropertyID_ExtraAspectRatioStretchFactor

Requests additional distortion to be applied to the aspect ratio in the kICMScalingMode_Letterbox and kICMScalingMode_Trim scaling modes. Values greater than fixed1 mean wider, values less than fixed1 mean narrower. For example, a value of X2Fix(2.0) would make the picture aspect ratio twice as wide.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

Declared In

Aperture scaling modes

These constants indicate how source frames to a compression session should be scaled if the dimensions and/or display aspect ratio do not match.

enum {
   kICMScalingMode_StretchCleanAperture = 'sc2c',
   kICMScalingMode_StretchProductionAperture = 'sp2p',
   kICMScalingMode_Letterbox = 'lett',
   kICMScalingMode_Trim = 'trim'
};

Constants

kICMScalingMode_StretchCleanAperture

The clean aperture of the source frames is scaled to the clean aperture of the destination.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMScalingMode_StretchProductionAperture

The full width and height of source frames is scaled to the full width and height of the destination. This is the default if no other scaling mode is specified.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMScalingMode_Letterbox

The clean aperture of the source frames is scaled to fit inside the clean aperture of the destination, preserving the original display aspect ratio. If the display aspect ratios are different, the source frames are centered with black bars above and below, or to the left and right.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

kICMScalingMode_Trim

The clean aperture of the source frames is scaled to cover the clean aperture of the destination, preserving the original display aspect ratio. If the display aspect ratios are different, the source frames are centered and cropped.

Available in Mac OS X v10.3 and later.

Declared in ImageCompression.h.

Declared In

TrackApertureModeDimensionsAID

The type of atom that stores information for video correction in the movie resource. A child of the 'track' atom.

   enum {
   TrackApertureModeDimensionsAID          = 'tapt',
   TrackCleanApertureDimensionsAID         = 'clef',
   TrackProductionApertureDimensionsAID    = 'prof',
   TrackEncodedPixelsDimensionsAID         = 'enof',
};

Constants

TrackApertureModeDimensionsAID

The container atom.

Available in Mac OS X v10.3 and later.

Declared in MoviesFormat.h.

TrackCleanApertureDimensionsAID

The container atom.

Available in Mac OS X v10.3 and later.

Declared in MoviesFormat.h.

TrackProductionApertureDimensionsAID

The container atom.

Available in Mac OS X v10.3 and later.

Declared in MoviesFormat.h.

TrackEncodedPixelsDimensionsAID

The container atom.

Available in Mac OS X v10.3 and later.

Declared in MoviesFormat.h.

Declared In

kQTPropertyClass_ImageCompressor

The following is a property for image compressor components.

enum {
kQTPropertyClass_ImageCompressor = 'imco',
};

Constants

kQTPropertyClass_ImageCompressor

Property class for image compressor components.

Available in Mac OS X v10.3 and later.

Declared in ImageCodec.h.

Declared In

movieExportSourceApertureMode

The following sets the aperture mode on the decompression session.

enum {
   movieExportSourceApertureMode = 'srap',
};

Constants

movieExportSourceApertureMode

A pointer to an OSType. The source movie’s aperture mode.

Available in Mac OS X v10.3 and later.

Declared in QuickTimeComponents.h.

Declared In

kICMImageCompressorPropertyID_Enforced

The following are enforced properties (introduced in QuickTime 7.0.4) for image compressor components. Image compressors that sometimes or always restrict image dimensions, clean aperture and/or pixel aspect ratio should support these properties. If these properties can change dynamically for a compressor (for example, in response to user interaction) then the properties should be listenable, and the compressor should call the listeners whenever the properties change. (In this case, the component's GetComponentPropertyInfo function should set the kComponentPropertyFlagWillNotifyListeners flag.) If a compressor has a mode in which these properties are flexible, then when the component is in that mode, (a) the component's GetComponentProperty function should return kQTPropertyAskLaterErr for these properties, and (b) the component's GetComponentPropertyInfo function should set the kComponentPropertyFlagCanGetLater flag for these properties.

enum {
   kICMImageCompressorPropertyID_EnforcedEncodedWidth    = 'enwi',
   kICMImageCompressorPropertyID_EnforcedEncodedHeight   = 'enhe',
   kICMImageCompressorPropertyID_EnforcedCleanAperture   = 'encl',
   kICMImageCompressorPropertyID_EnforcedPixelAspectRatio = 'enpa',
   kICMImageCompressorPropertyID_EnforcedFieldInfo       = 'enfi',
};

Constants

kICMImageCompressorPropertyID_EnforcedEncodedWidth

The encoded width enforced for compressed frames.

Available in Mac OS X v10.3 and later.

Declared in ImageCodec.h.

kICMImageCompressorPropertyID_EnforcedEncodedHeight

The encoded height enforced for compressed frames.

Available in Mac OS X v10.3 and later.

Declared in ImageCodec.h.

kICMImageCompressorPropertyID_EnforcedCleanAperture

The clean aperture enforced for compressed frames.

Available in Mac OS X v10.3 and later.

Declared in ImageCodec.h.

kICMImageCompressorPropertyID_EnforcedPixelAspectRatio

The pixel aspect ratio enforced for compressed frames.

Available in Mac OS X v10.3 and later.

Declared in ImageCodec.h.

kICMImageCompressorPropertyID_EnforcedFieldInfo

The number and order of fields enforced for compressed frames.

Available in Mac OS X v10.3 and later.

Declared in ImageCodec.h.

Declared In

Audio Properties

The following is a list of the new audio properties available in QuickTime 7.1.

enum {
   kQTAudioRenderQuality_PlaybackDefault = 0x8000,
   kQTAudioPropertyID_RenderQuality = 'qual',
   kQTMovieAudioExtractionAudioPropertyID_RenderQuality = 'qual',
   kQTAudioPropertyID_DeviceASBD = 'dasd',
   kQTAudioPropertyID_SummaryASBD = 'sasd',
   kQTAudioPropertyID_RateChangesPreservePitch = 'aucp',
   kQTAudioPropertyID_Pitch  = 'pitc',
   kQTSCAudioPropertyID_RenderQuality = 'qlty',
};

Constants

kQTAudioPropertyID_DeviceASBD

This is a get-only property and returns the AudioStreamBasicDescription of the device the movie is playing to. The interesting fields are the sample rate, which reflects device’s current state, and the number of channels, which matches what is reported by kQTAudioPropertyID_DeviceChannelLayout.

kQTAudioPropertyID_SummaryASBD

Get-only. Returns the AudioStreamBasicDescription corresponding to the Summary Mix of a movie. This describes non-interleaved, Float32 linear PCM data, with a sample rate equal to the highest audio sample rate found among the sound tracks contributing to the AudioContext mix, and a number of channels that matches what is reported by kQTAudioPropertyID_SummaryChannelLayout.

kQTAudioPropertyID_RateChangesPreservePitch

This property was introduced in QuickTime 7 and must be set in order for pitch changes to take effect. When the playback rate is not unity, audio must be resampled in order to play at the new rate. The default resampling affects the pitch of the audio (for example, playing at 2x speed raises the pitch by an octave, 1/2x lowers an octave). If this property is set on the Movie, an alternative algorithm may be used, which alters the speed without changing the pitch. Because this is more computationally expensive, this property may be silently ignored on some slow CPUs. Media handlers may query this movie property and honor it when performing Scaled Edits. This property can be specified as a property to the NewMovieFromProperties API. Currently, it has no effect when set on an open movie.

kQTAudioPropertyID_Pitch

The movie pitch adjustment. This adjusts the pitch of all audio tracks that contribute to the AudioContext mix. Pitch control takes effect only if kQTAudioPropertyID_RateChangesPreservePitch is in effect; otherwise, returns kQTMessageNotHandledErr. The Float32 value is specified in cents: 0.0 == no change, 1.0 == one cent up, 100.0 == one semi-tone up, -1.0 == one cent down. The most useful ranges for pitch are +/- 1200, that is, one octave.

kQTAudioPropertyID_RenderQuality

Movie audio render quality takes effect for movie playback. UInt32 values are as defined in AudioUnit/AudioUnitProperties.h and vary from 0x00 (kRenderQuality_Min) to 0x7F (kRenderQuality_Max). A special value kQTAudioRenderQuality_PlaybackDefault) is also defined which resets the quality settings of the playback processing chain to values that are chosen to be an optimal balance of performance and quality.

kQTMovieAudioExtractionAudioPropertyID_RenderQuality

Sets the render quality to be used for this audio extraction session. UInt32 values are as defined in AudioUnit/AudioUnitProperties.h and vary from 0x00(kRenderQuality_Min) to 0x7F (kRenderQuality_Max). A special value (kQTAudioRenderQuality_PlaybackDefault) is also defined which resets the quality settings to the same values that were chosen by default for playback.

kQTSCAudioPropertyID_RenderQuality

Specifies the quality with which QuickTime should render the audio stream during the compression/decompression/transcode operation. Accepted constants are those used by AudioUnits (defined in AudioUnitProperties.h): kRenderQuality_Max, kRenderQuality_High, kRenderQuality_Medium, kRenderQuality_Low, kRenderQuality_Min. Available in QuickTimeComponents.h.

Declared In

Metadata Constants

The following is a list of new metadata constants available in QuickTime 7.1:

enum {
   kQTMetaDataCommonKeyAlbum     = 'albm',
   kQTMetaDataCommonKeyArtist    = 'arts',
   kQTMetaDataCommonKeyArtwork   = 'artw',
   kQTMetaDataCommonKeyChapterName = 'chap',
   kQTMetaDataCommonKeyComposer  = 'comp',
   kQTMetaDataCommonKeyDescription = 'desc',
   kQTMetaDataCommonKeyGenre     = 'genr',
   kQTMetaDataCommonKeyOriginalFormat = 'orif',
   kQTMetaDataCommonKeyOriginalSource = 'oris',
   kQTMetaDataCommonKeyPerformers = 'perf',
   kQTMetaDataCommonKeySoftware  = 'soft',
   kQTMetaDataCommonKeyWriter    = 'wrtr'
};

Constants

kQTMetaDataCommonKeyAlbum

Information to come.

Declared In