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Core Video Reference

Framework
QuartzCore/QuartzCore.h
Companion guide
Declared in
CVBase.h
CVBuffer.h
CVDisplayLink.h
CVHostTime.h
CVImageBuffer.h
CVOpenGLBuffer.h
CVOpenGLBufferPool.h
CVOpenGLTexture.h
CVOpenGLTextureCache.h
CVPixelBuffer.h
CVPixelBufferPool.h
CVPixelFormatDescription.h
CVReturn.h

Overview

Core Video is a new pipeline model for digital video in Mac OS X. Partitioning the processing into discrete steps makes it simpler for developers to access and manipulate individual frames without having to worry about translating between data types (QuickTime, OpenGL, and so on) or display synchronization issues.

Core Video is available in:

Functions by Task

CVBuffer Functions

Core Video buffer functions operate on all Core Video buffer types, including pixel buffers and OpenGL buffers, as well as OpenGL textures.

CVDisplayLink Functions

The main purpose of the CoreVideo display link to provide a separate high-priority thread to notify your application when a given display will need each frame. How often a frame is requested is based on the refresh rate of the display device currently associated with the display link. A CoreVideo display link is represented in code by the CVDisplayLinkRef type. The display link API uses the Core Foundation class system internally to provide reference counting behaviour and other useful properties.

CVHostTime Functions

CVImageBuffer Functions

The functions in this section operate on Core Video buffers derived from the CVImageBuffer abstract type (CVImageBufferRef ); specifically, pixel buffers, OpenGL buffers, and OpenGL textures.

CVOpenGLBuffer Functions

The Core Video OpenGL buffer (type CVOpenGLBufferRef is a wrapper around the standard OpenGL pbuffer.

CVOpenGLBufferPool Functions

An OpenGL buffer pool is a utility object for managing a set of OpenGL buffer objects for recycling.

CVOpenGLTexture Functions

The Core Video OpenGL texture is a wrapper around the standard OpenGL texture type.

CVOpenGLTextureCache Functions

CVPixelBuffer Functions

A pixel buffer stores an image in main memory

CVPixelBufferPool Functions

CVPixelFormatDescription Functions

Used only if you are defining a custom pixel format.

Functions

CVBufferGetAttachment

Returns a specific attachment of a Core Video buffer.

CFTypeRef CVBufferGetAttachment (
   CVBufferRef buffer,
   CFStringRef key,
   CVAttachmentMode *attachmentMode
);

Parameters
buffer

The Core Video buffer whose attachment you want to obtain.

key

A key in the form of a Core Foundation string identifying the desired attachment.

attachmentMode

On return, attachmentMode points to the mode of the attachment. See “CVBuffer Attachment Modes” for possible values. If the attachment mode is not defined, this parameter returns NULL.

Return Value

If found, the specified attachment.

Discussion

You can attach any Core Foundation object to a Core Video buffer to store additional information by calling CVBufferSetAttachment or CVBufferSetAttachments.

You can find predefined attachment keys in “CVBuffer Attachment Keys” and “Image Buffer Attachment Keys.”

Availability
Declared In
CVBuffer.h

CVBufferGetAttachments

Returns all attachments of a Core Video buffer. 

CFDictionaryRef CVBufferGetAttachments (
   CVBufferRef buffer,
   CVAttachmentMode attachmentMode
);

Parameters
buffer

The Core Video buffer whose attachments you want to obtain.

attachmentMode

The mode of the attachments you want to obtain. See “CVBuffer Attachment Modes” for possible values.

Return Value

A Core Foundation dictionary with all buffer attachments identified by keys. If no attachment is present, the dictionary is empty. Returns NULL for an invalid attachment mode.

Discussion

CVBufferGetAttachments is a convenience call that returns all attachments with their corresponding keys in a Core Foundation dictionary.

You can find predefined attachment keys in “CVBuffer Attachment Keys” and “Image Buffer Attachment Keys.”

Availability
Declared In
CVBuffer.h

CVBufferPropagateAttachments

Copies all propagatable attachments from one Core Video buffer to another.

void CVBufferPropagateAttachments (
   CVBufferRef sourceBuffer,
   CVBufferRef destinationBuffer
);

Parameters
sourceBuffer

The buffer to copy attachments from.

destinationBuffer

The buffer to copy attachments to.

Discussion

CVBufferPropagateAttachments is a convenience call that copies all attachments with a mode of kCVAttachmentMode_ShouldPropagate from one buffer to another.

Availability
Declared In
CVBuffer.h

CVBufferRelease

Releases a Core Video buffer. 

void CVBufferRelease (
   CVBufferRef buffer
);

Parameters
buffer

The Core Video buffer that you want to release.

Discussion

Like CFRelease CVBufferRelease decrements the retain count of a Core Video buffer. If that count consequently becomes zero the memory allocated to the object is deallocated and the object is destroyed. Unlike CFRelease, you can pass NULL to CVBufferRelease without causing a crash.

Availability
Related Sample Code
Declared In
CVBuffer.h

CVBufferRemoveAllAttachments

Removes all attachments of a Core Video buffer. 

void CVBufferRemoveAllAttachments (
   CVBufferRef buffer
);

Parameters
buffer

The Core Video buffer whose attachments you want to remove.

Discussion

CVBufferRemoveAllAttachments removes all attachments of a buffer and decrements their reference counts.

Availability
Declared In
CVBuffer.h

CVBufferRemoveAttachment

Removes a specific attachment of a Core Video buffer.

void CVBufferRemoveAttachment (
   CVBufferRef buffer,
   CFStringRef key
);

Parameters
buffer

The Core Video buffer containing the attachment to remove.

key

A key in the form of a Core Foundation string identifying the desired attachment.

Discussion

CVBufferRemoveAttachment removes an attachment identified by a key. If found the attachment is removed and the retain count decremented.

You can find predefined attachment keys in “CVBuffer Attachment Keys” and “Image Buffer Attachment Keys.”

Availability
Declared In
CVBuffer.h

CVBufferRetain

Retains a Core Video buffer.

CVBufferRef CVBufferRetain (
   CVBufferRef buffer
);

Parameters
buffer

The Core Video buffer that you want to retain.

Return Value

For convenience, the same Core Video buffer you wanted to retain.

Discussion

Like CFRetain, CVBufferRetain increments the retain count of a Core Video buffer. Unlike CFRetain, you can pass NULL to CVBufferRetain without causing a crash.

Availability
Related Sample Code
Declared In
CVBuffer.h

CVBufferSetAttachment

Sets or adds an attachment of a Core Video buffer.

void CVBufferSetAttachment (
   CVBufferRef buffer,
   CFStringRef key,
   CFTypeRef value,
   CVAttachmentMode attachmentMode
);

Parameters
buffer

The Core Video buffer to which to add or set the attachment.

key

The key, in the form of a Core Foundation string, identifying the desired attachment.

value

The attachment in the form of a Core Foundation object. If this parameter is NULL, the function returns an error.

attachmentMode

Specifies the attachment mode for this attachment. See “CVBuffer Attachment Modes” for possible values. Any given attachment key may exist in only one mode at a time.

Discussion

You can attach any Core Foundation object to a Core Video buffer to store additional information. If the key doesn't currently exist for the buffer object when you call this function, the new attachment will be added. If the key does exist, the existing attachment will be replaced. In both cases the retain count of the attachment will be incremented. The value can be any CFType. You can find predefined attachment keys in “CVBuffer Attachment Keys” and “Image Buffer Attachment Keys.”

You can also set attachments when creating a buffer by specifying them in the kCVBufferPropagatedAttachmentsKey or kkCVBufferNonpropagatedAttachmentsKey attributes when creating the buffer.

To retrieve attachments, use the CVBufferGetAttachment or CVBufferGetAttachments functions.

Availability
Declared In
CVBuffer.h

CVBufferSetAttachments

Sets a set of attachments for a Core Video buffer. 

void CVBufferSetAttachments (
   CVBufferRef buffer,
   CFDictionaryRef theAttachments,
   CVAttachmentMode attachmentMode
);

Parameters
buffer

The Core Video buffer to which to set the attachments.

theAttachments

The attachments to set, in the form of a Core Foundation dictionary array.

attachmentMode

Specifies which attachment mode is desired for this attachment. A particular attachment key may only exist in a single mode at a time.

Discussion

CVBufferSetAttachments is a convenience call that in turn calls CVBufferSetAttachment for each key and value in the given dictionary. All key-value pairs must be in the root level of the dictionary.

Availability
Declared In
CVBuffer.h

CVDisplayLinkCreateWithActiveCGDisplays

Creates a display link capable of being used with all active displays.

CVReturn CVDisplayLinkCreateWithActiveCGDisplays (
   CVDisplayLinkRef *displayLinkOut
);

Parameters
displayLinkOut

On return, displayLinkOut points to the newly created display link.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

CVDisplayLinkCreateWithActiveCGDisplays determines the displays actively used by the host computer and creates a display link compatible with all of them. For most applications, calling this function is the most convenient way to create a display link. After creation, you can assign the display link to any active display by calling CVDisplayLinkSetCurrentCGDisplay.

Availability
Related Sample Code
Declared In
CVDisplayLink.h

CVDisplayLinkCreateWithCGDisplay

Creates a display link for a single display.

CVReturn CVDisplayLinkCreateWithCGDisplay (
   CGDirectDisplayID displayID,
   CVDisplayLinkRef *displayLinkOut
);

Parameters
displayID

The Core Graphics ID of the target display.

displayLinkOut

On return, displayLinkOut points to the newly created display link.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

Use this call to create a display link for a single display.

Availability
Related Sample Code
Declared In
CVDisplayLink.h

CVDisplayLinkCreateWithCGDisplays

Creates a display link for an array of displays.

CVReturn CVDisplayLinkCreateWithCGDisplays (
   CGDirectDisplayID *displayArray,
   CFIndex count,
   CVDisplayLinkRef *displayLinkOut
);

Parameters
displayArray

A pointer to an array of Core Graphics display IDs representing all the active monitors you want to use with this display link.

count

The number of displays in the display array.

displayLisk

On return, displayLinkOut points to the newly created display link.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

Use this call to create a display link for a set of displays identified by the Core Graphics display IDs.

Availability
Declared In
CVDisplayLink.h

CVDisplayLinkCreateWithOpenGLDisplayMask

Creates a display link from an OpenGL display mask.

CVReturn CVDisplayLinkCreateWithOpenGLDisplayMask (
   CGOpenGLDisplayMask mask,
   CVDisplayLinkRef *displayLinkOut
);

Parameters
mask

The OpenGL display mask describing the available displays.

displayLinkOut

On return, displayLinkOut points to the newly created display link.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

Using this function avoids having to call the Core Graphics function CGOpenGLDisplayMaskToDisplayID.

Availability
Related Sample Code
Declared In
CVDisplayLink.h

CVDisplayLinkGetActualOutputVideoRefreshPeriod

Retrieves the actual output refresh period of a display as measured by the host time base.

double CVDisplayLinkGetActualOutputVideoRefreshPeriod (
   CVDisplayLinkRef displayLink
);

Parameters
displayLink

The display link to get the refresh period from.

Return Value

A double-precision floating-point value representing the actual refresh period. This value may be zero if the device is not running or is otherwise unavailable.

Discussion

This call returns the actual output refresh period (in seconds) as computed relative to the host time base.

Availability
Declared In
CVDisplayLink.h

CVDisplayLinkGetCurrentCGDisplay

Gets the current display associated with a display link.

CGDirectDisplayID CVDisplayLinkGetCurrentCGDisplay (
   CVDisplayLinkRef displayLink
);

Parameters
displayLink

The display link whose current display you want obtain.

Return Value

A CGDirectDisplayID representing the current display.

Availability
Declared In
CVDisplayLink.h

CVDisplayLinkGetCurrentTime

Retrieves the current (“now”) time of a given display link.

CVReturn CVDisplayLinkGetCurrentTime (
   CVDisplayLinkRef displayLink,
   CVTimeStamp *outTime
);

Parameters
displayLink

The display link whose current time you want to obtain.

outTime

A pointer to a CVTimeStamp structure. Note that yout must set the version in the structure (currently 0) before calling to indicate which version of the timestamp structure you want.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

You use this call to obtain the timestamp of the frame that is currently being displayed.

Availability
Declared In
CVDisplayLink.h

CVDisplayLinkGetNominalOutputVideoRefreshPeriod

Retrieves the nominal refresh period of a display link.

CVTime CVDisplayLinkGetNominalOutputVideoRefreshPeriod (
   CVDisplayLinkRef displayLink
);

Parameters
displayLink

The display link whose refresh period you want to obtain.

Return Value

A CVTime structure that holds the nominal refresh period. This value is indefinite if an invalid display link was specified.

Discussion

This call allows one to retrieve the device's ideal refresh period. For example, an NTSC output device might report 1001/60000 to represent the exact NTSC vertical refresh rate.

Availability
Declared In
CVDisplayLink.h

CVDisplayLinkGetOutputVideoLatency

Retrieves the nominal latency of a display link.

CVTime CVDisplayLinkGetOutputVideoLatency (
   CVDisplayLinkRef displayLink
);

Parameters
displayLink

The display link whose latency value you want to obtain.

Return Value

A CVTime structure that holds the latency value. This value may be indefinite.

Discussion

This call allows you to retrieve the device’s built-in output latency. For example, an NTSC device with one frame of latency might report back 1001/30000 or 2002/60000.

Availability
Declared In
CVDisplayLink.h

CVDisplayLinkGetTypeID

Obtains the Core Foundation ID for the display link data type. 

CFTypeID CVDisplayLinkGetTypeID (
   void
);

Return Value

The Core Foundation ID for this type.

Availability
Declared In
CVDisplayLink.h

CVDisplayLinkIsRunning

Indicates whether a given display link is running. 

Boolean CVDisplayLinkIsRunning (
   CVDisplayLinkRef displayLink
);

Parameters
displayLink

The display link whose run state you want to determine.

Return Value

Returns true if the display link is running, false otherwise.

Availability
Related Sample Code
Declared In
CVDisplayLink.h

CVDisplayLinkRelease

Releases a display link.

void CVDisplayLinkRelease (
   CVDisplayLinkRef displayLink
);

Parameters
displayLink

The display link to release. This function is NULL-safe.

Availability
Related Sample Code
Declared In
CVDisplayLink.h

CVDisplayLinkRetain

Retains a display link.

CVDisplayLinkRef CVDisplayLinkRetain (
   CVDisplayLinkRef displayLink
);

Parameters
displayLink

The display link to retain. This function is NULL-safe.

Return Value

For convenience, this function returns the retained display link if successful.

Availability
Declared In
CVDisplayLink.h

CVDisplayLinkSetCurrentCGDisplay

Sets the current display of a display link. 

CVReturn CVDisplayLinkSetCurrentCGDisplay (
   CVDisplayLinkRef displayLink,
   CGDirectDisplayID displayID
);

Parameters
displayLink

The display link whose display you want to set.

displayID

The ID of the display to be set.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

Although it is safe to call this function on a running display link, a discontinuity may appear in the video timestamp.

Availability
Related Sample Code
Declared In
CVDisplayLink.h

CVDisplayLinkSetCurrentCGDisplayFromOpenGLContext

Selects the display link most optimal for the current renderer of an OpenGL context.

CVReturn CVDisplayLinkSetCurrentCGDisplayFromOpenGLContext (
   CVDisplayLinkRef displayLink,
   CGLContextObj cglContext,
   CGLPixelFormatObj cglPixelFormat
);

Parameters
displayLink

The display link for which you want to set the current display.

cglContext

The OpenGL context to retrieve the current renderer from.

cglPixelFormat

The OpenGL pixel format used to create the passed-in OpenGL context.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

This function chooses the display with the lowest refresh rate.

Availability
Related Sample Code
Declared In
CVDisplayLink.h

CVDisplayLinkSetOutputCallback

Set the renderer output callback function.

CVReturn CVDisplayLinkSetOutputCallback (
   CVDisplayLinkRef displayLink,
   CVDisplayLinkOutputCallback callback,
   void *userInfo
);

Parameters
displayLink

The display link whose output callback you want to set.

callback

The callback function to set for this display link. See CVDisplayLinkOutputCallback for more information about implementing this function.

userInfo

A pointer to user data.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

The display link invokes this callback whenever it wants you to output a frame.

Availability
Related Sample Code
Declared In
CVDisplayLink.h

CVDisplayLinkStart

Activates a display link.

CVReturn CVDisplayLinkStart (
   CVDisplayLinkRef displayLink
);

Parameters
displayLink

The display link to activate.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

Calling this function starts the display link thread, which then periodically calls back to your application to request that you display frames. If the specified display link is already running, CVDisplayLinkStart returns an error.

Availability
Related Sample Code
Declared In
CVDisplayLink.h

CVDisplayLinkStop

Stops a display link.

CVReturn CVDisplayLinkStop (
   CVDisplayLinkRef displayLink
);

Parameters
displayLink

The display link to stop.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

If the specified display link is already stopped, CVDisplayLinkStop returns an error.

In Mac OS X v.10.4 and later, the display link thread is automatically stopped if the user employs Fast User Switching. The display link is restarted when switching back to the original user.

Availability
Related Sample Code
Declared In
CVDisplayLink.h

CVDisplayLinkTranslateTime

Translates the time in the display link’s time base from one representation to another. 

CVReturn CVDisplayLinkTranslateTime (
   CVDisplayLinkRef displayLink,
   const CVTimeStamp *inTime,
   CVTimeStamp *outTime
);

Parameters
displayLink

The display link whose time base should be used to do the translation.

inTime

A pointer to a CVTimeStamp structure containing the source time to translate.

outTime

A pointer to a CVTimeStamp structure into which the target time is written. Before calling, you must set the version field (currently 0) to indicate which version of the structure you want. You should also set the flags field to specify which representations to translate to.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

Note that the display link has to be running for this call to succeed.

Availability
Declared In
CVDisplayLink.h

CVGetCurrentHostTime

Retrieves the current value of the host time base.

uint64_t CVGetCurrentHostTime

Return Value

The current host time.

Discussion

In Mac OS X, the host time base for CoreVideo and CoreAudio are identical, so the values returned from either API can be used interchangeably.

Availability
Declared In
CVHostTime.h

CVGetHostClockFrequency

Retrieve the frequency of the host time base.

double CVGetHostClockFrequency

Return Value

The current host frequency.

Discussion

In Mac OS X, the host time base for CoreVideo and CoreAudio are identical, and the values returned from either API can be used interchangeably.

Availability
Declared In
CVHostTime.h

CVGetHostClockMinimumTimeDelta

Retrieve the smallest possible increment in the host time base.

uint32_t CVGetHostClockMinimumTimeDelta

Return Value

The smallest valid increment in the host time base.

Availability
Declared In
CVHostTime.h

CVImageBufferGetCleanRect

Returns the source rectangle of a Core Video image buffer that represents the clean aperture of the buffer in encoded pixels. 

CGRect CVImageBufferGetCleanRect (
   CVImageBufferRef imageBuffer
);

Parameters
imageBuffer

The image buffer that you want to retrieve the display size from.

Return Value

A CGRect structure returning the nominal display size of the buffer. Returns a rectangle of zero size if called with either a non-CVImageBufferRef type or NULL.

Discussion

The clean aperture size is smaller than the full size of the image. For example, an NTSC DV frame would return a CGRect structure with an origin of (8,0) and a size of (704,480). Note that the origin of this rectangle is always in the lower-left corner. This is the same coordinate system as that used by Quartz and Core Image.

Availability
Declared In
CVImageBuffer.h

CVImageBufferGetColorSpace

Returns the color space of a Core Video image buffer.

CGColorSpaceRef CVImageBufferGetColorSpace (
   CVImageBufferRef imageBuffer
);

Parameters
imageBuffer

The image buffer that you want to retrieve the color space from.

Return Value

The color space of the buffer. Returns NULL if called with either a non-CVImageBufferRef type or NULL.

Availability
Declared In
CVImageBuffer.h

CVImageBufferGetDisplaySize

Returns the nominal output display size, in square pixels, of a Core Video image buffer. 

CGSize CVImageBufferGetDisplaySize (
   CVImageBufferRef imageBuffer
);

Parameters
imageBuffer

The image buffer that you want to retrieve the display size from.

Return Value

A CGSize structure defining the nominal display size of the buffer Returns zero size if called with a non-CVImageBufferRef type or NULL.

Discussion

For example, for an NTSC DV frame this would be 640 x 480.

Availability
Declared In
CVImageBuffer.h

CVImageBufferGetEncodedSize

Returns the full encoded dimensions of a Core Video image buffer. 

CGSize CVImageBufferGetEncodedSize (
   CVImageBufferRef imageBuffer
);

Parameters
imageBuffer

The image buffer that you want to retrieve the encoded size from.

Return Value

A CGSize structure defining the full encoded size of the buffer. Returns zero size if called with either a non-CVImageBufferRef type or NULL.

Discussion

For example, for an NTSC DV frame, the encoded size would be 720 x 480. Note: When creating a Core Image image from a Core Video image buffer, you use this call to retrieve the image size.

Availability
Declared In
CVImageBuffer.h

CVOpenGLBufferAttach

Attaches an OpenGL context to a Core Video OpenGL buffer. 

CVReturn CVOpenGLBufferAttach (
   CVOpenGLBufferRef openGLBuffer,
   CGLContextObj cglContext,
   GLenum face,
   GLint level,
   GLint screen
);

Parameters
openGLBuffer

The buffer you want to attach an OpenGL context to.

cglContext

The OpenGL context you want to attach.

face

The OpenGL face enumeration (0 for noncube maps.)

level

The mipmap level for drawing in the OpenGL context. This value cannot exceed the maximum mipmap level for this buffer.

screen

The virtual screen number you want to use for this context.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Availability
Declared In
CVOpenGLBuffer.h

CVOpenGLBufferCreate

Create a new Core Video OpenGL buffer that can be used for OpenGL rendering purposes

CVReturn CVOpenGLBufferCreate (
   CFAllocatorRef allocator,
   size_t width,
   size_t height,
   CFDictionaryRef attributes,
   CVOpenGLBufferRef *bufferOut
);

Parameters
allocator

The allocator to use to create the Core Video OpenGL buffer. Pass NULL to specify the default allocator.

width

The width of the buffer in pixels.

height

The height of the buffer in pixels.

attributes

A Core Foundation dictionary containing other desired attributes of the buffer (texture target, internal format, max mipmap level, etc.). May be NULL. The following attribute values are assumed if you do not explicitly define them:

  • kCVOpenGLBufferTarget = GL_TEXTURE_RECTANGLE_EXT

  • kCVOpenGLBufferInternalFormat = GL_RGBA

  • kCVOpenGLBufferMaximumMipmapLevel = 0

bufferOut

On return, bufferOut points to the newly created OpenGL buffer.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

Availability
Declared In
CVOpenGLBuffer.h

CVOpenGLBufferGetAttributes

Obtains the attributes of a Core Video OpenGL buffer. 

CFDictionaryRef CVOpenGLBufferGetAttributes (
   CVOpenGLBufferRef openGLBuffer
);

Parameters
openGLBuffer

The OpenGL buffer whose attributes you want to obtain.

Return Value

A Core Foundation dictionary containing the OpenGL buffer attributes, or NULL if no attributes exist.

Availability
Declared In
CVOpenGLBuffer.h

CVOpenGLBufferGetTypeID

Obtains the Core Foundation type ID for the OpenGL buffer type. 

CFTypeID CVOpenGLBufferGetTypeID (
   void
);

Return Value

The Core Foundation ID for this data type.

Availability
Declared In
CVOpenGLBuffer.h

CVOpenGLBufferPoolCreate

Creates a new OpenGL buffer pool.

CVReturn CVOpenGLBufferPoolCreate (
   CFAllocatorRef allocator,
   CFDictionaryRef poolAttributes,
   CFDictionaryRef openGLBufferAttributes,
   CVOpenGLBufferPoolRef *poolOut
);

Parameters
allocator

The allocator to use for allocating this buffer pool. Pass NULL to specify the default allocator.

poolAttributes

A Core Foundation dictionary containing the attributes to be used for the pool itself.

openGLBufferAttributes

A Core Foundation dictionary containing the attributes to be used for creating new OpenGL buffers within the pool.

poolOut

On return, poolOut points to the new OpenGL buffer pool.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Availability
Declared In
CVOpenGLBufferPool.h

CVOpenGLBufferPoolCreateOpenGLBuffer

Creates a new OpenGL buffer from an OpenGL buffer pool.

CVReturn CVOpenGLBufferPoolCreateOpenGLBuffer (
   CFAllocatorRef allocator,
   CVOpenGLBufferPoolRef openGLBufferPool,
   CVOpenGLBufferRef *openGLBufferOut
);

Parameters
allocator

The allocator to use for creating the buffer. May be NULL to specify the default allocator.

openGLBufferPool

The OpenGL buffer pool that should create the new OpenGL buffer.

openGLBufferOut

On return, OpenGLBufferOut points to the new OpenGL buffer.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

The function creates a new OpenGL buffer using the OpenGL buffer attributes specified in the CVOpenGLBufferPoolCreate call. This buffer has default attachments as specified in the openGLBufferAttributes parameter of CVOpenGLBufferPoolCreate (using either the kCVBufferPropagatedAttachmentsKey or kCVBufferNonPropagatedAttachmentsKey attributes).

Availability
Declared In
CVOpenGLBufferPool.h

CVOpenGLBufferPoolGetAttributes

Returns the pool attributes dictionary for an Open GL buffer pool. 

CFDictionaryRef CVOpenGLBufferPoolGetAttributes (
   CVOpenGLBufferPoolRef pool
);

Parameters
pool

The OpenGL buffer pool to retrieve the attributes from.

Return Value

The buffer-pool attributes Core Foundation dictionary, or NULL on failure.

Availability
Declared In
CVOpenGLBufferPool.h

CVOpenGLBufferPoolGetOpenGLBufferAttributes

Returns the attributes of OpenGL buffers that will be created from a buffer pool. 

CFDictionaryRef CVOpenGLBufferPoolGetOpenGLBufferAttributes (
   CVOpenGLBufferPoolRef pool
);

Parameters
pool

The OpenGL buffer pool to retrieve the attributes from.

Return Value

The OpenGL buffer attributes Core Foundation dictionary, or NULL on failure.

Discussion

You can use this function to obtain information about the OpenGL buffers that will be created from the buffer pool.

Availability
Declared In
CVOpenGLBufferPool.h

CVOpenGLBufferPoolGetTypeID

Obtains the Core Foundation ID for the OpenGL buffer pool type. 

CFTypeID CVOpenGLBufferPoolGetTypeID (
   void
);

Return Value

The Core Foundation ID for this data type.

Availability
Declared In
CVOpenGLBufferPool.h

CVOpenGLBufferPoolRelease

Releases an OpenGL buffer pool. 

void CVOpenGLBufferPoolRelease (
   CVOpenGLBufferPoolRef openGLBufferPool
);

Parameters
openGLBufferPool

The OpenGL buffer pool that you want to release.

Discussion

This function is equivalent to CFRelease, but NULL safe.

Availability
Declared In
CVOpenGLBufferPool.h

CVOpenGLBufferPoolRetain

Retains an OpenGL buffer pool. 

CVOpenGLBufferPoolRef CVOpenGLBufferPoolRetain (
   CVOpenGLBufferPoolRef openGLBufferPool
);

Parameters
openGLBufferPool

The OpenGL buffer pool that you want to retain.

Return Value

For convenience, the same buffer pool object you wanted to retain.

Discussion

This function is equivalent to CFRetain, but NULL safe.

Availability
Declared In
CVOpenGLBufferPool.h

CVOpenGLBufferRelease

Releases a Core Video OpenGL buffer. 

void CVOpenGLBufferRelease (
   CVOpenGLBufferRef buffer
);

Parameters
buffer

The OpenGL buffer that you want to release.

Discussion

This function is equivalent to CFRelease, but NULL safe.

Availability
Declared In
CVOpenGLBuffer.h

CVOpenGLBufferRetain

Retains a Core Video OpenGL buffer. 

CVOpenGLBufferRef CVOpenGLBufferRetain (
   CVOpenGLBufferRef buffer
);

Parameters
buffer

The OpenGL Buffer that you want to retain.

Return Value

For convenience, the OpenGL buffer that was retained.

Discussion

This function is equivalent to CFRetain, but NULL safe.

Availability
Declared In
CVOpenGLBuffer.h

CVOpenGLTextureCacheCreate

Creates an OpenGL texture cache.

CVReturn CVOpenGLTextureCacheCreate (
   CFAllocatorRef allocator,
   CFDictionaryRef cacheAttributes,
   CGLContextObj cglContext,
   CGLPixelFormatObj cglPixelFormat,
   CFDictionaryRef textureAttributes,
   CVOpenGLTextureCacheRef *cacheOut
);

Parameters
allocator

The allocator to use for allocating the cache. Pass NULL to specify the default allocator.

cacheAttributes

A Core Foundation dictionary containing the attributes of the cache itself. Pass NULL to specify no attributes.

cglContext

The OpenGL context into which the texture objects will be created.

cglPixelFormat

The OpenGL pixel format used to create the OpenGL context specified in cglContext.

textureAttributes

A Core Foundation dictionary containing the attributes to be used for creating the OpenGL texture objects. Pass NULL to specify no attributes.

cacheOut

On return, cacheOut points to the newly created texture cache.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Availability
Declared In
CVOpenGLTextureCache.h

CVOpenGLTextureCacheCreateTextureFromImage

Creates an OpenGL texture object from an existing image buffer.

CVReturn CVOpenGLTextureCacheCreateTextureFromImage (
   CFAllocatorRef allocator,
   CVOpenGLTextureCacheRef textureCache,
   CVImageBufferRef sourceImage,
   CFDictionaryRef attributes,
   CVOpenGLTextureRef *textureOut
);

Parameters
allocator

The allocator to use for allocating the OpenGL texture object. May be NULL to specify the default allocator.

textureCache

The OpenGL texture cache to be used to manage the texture.

sourceImage

The image buffer from which you want to create an OpenGL texture.

attributes

The desired buffer attributes for the OpenGL texture.

textureOut

On return, textureOut points to the newly created texture object.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

This function copies all image buffer attachments designated as propagatable to the newly-created texture.

Availability
Declared In
CVOpenGLTextureCache.h

CVOpenGLTextureCacheFlush

Flushes the OpenGL texture cache.

void CVOpenGLTextureCacheFlush (
   CVOpenGLTextureCacheRef textureCache,
   CVOptionFlags options
);

Parameters
textureCache

The texture cache to flush.

options

Currently unused; pass 0.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

You must call this function periodically to allow the texture cache to perform housekeeping operations.

Availability
Declared In
CVOpenGLTextureCache.h

CVOpenGLTextureCacheGetTypeID

Returns the Core Foundation ID of the texture cache type. 

CFTypeID CVOpenGLTextureCacheGetTypeID (
   void
);

Return Value

The Core Foundation ID for this type.

Availability
Declared In
CVOpenGLTextureCache.h

CVOpenGLTextureCacheRelease

Releases an OpenGL texture cache.

void CVOpenGLTextureCacheRelease (
   CVOpenGLTextureCacheRef textureCache
);

Parameters
textureCache

The OpenGL texture cache that you want to release.

Discussion

This function is equivalent to CFRelease, but NULL safe.

Availability
Declared In
CVOpenGLTextureCache.h

CVOpenGLTextureCacheRetain

Retains an OpenGL texture cache. 

CVOpenGLTextureCacheRef CVOpenGLTextureCacheRetain (
   CVOpenGLTextureCacheRef textureCache
);

Parameters
textureCache

The OpenGL texture cache that you want to retain.

Return Value

For convenience, the return value is the buffer you wanted to retain.

Discussion

This function is equivalent to CFRetain, but NULL safe.

Availability
Declared In
CVOpenGLTextureCache.h

CVOpenGLTextureGetCleanTexCoords

Returns the texture coordinates for the part of the image that should be displayed.

void CVOpenGLTextureGetCleanTexCoords (
   CVOpenGLTextureRef image,
   GLfloat lowerLeft[2],
   GLfloat lowerRight[2],
   GLfloat upperRight[2],
   GLfloat upperLeft[2]
);

Parameters
image

The Core Video OpenGL texture whose clean tex coordinates you want to obtain.

lowerLeft

On return, the GLFloat array hold the s and t texture coordinates of the lower-left corner of the image.

lowerRight

On return, the GLFloat array hold the s and t texture coordinates of the lower-right corner of the image.

upperRight

On return, the GLFloat array hold the s and t texture coordinates of the upper-right corner of the image.

upperLeft

On return, the GLFloat array hold the s and t texture coordinates of the upper-left corner of the image.

Discussion

This function automatically takes into account whether or not the texture is flipped.

Availability
Related Sample Code
Declared In
CVOpenGLTexture.h

CVOpenGLTextureGetName

Returns the texture target name of a CoreVideo OpenGL texture. 

GLuint CVOpenGLTextureGetName (
   CVOpenGLTextureRef image
);

Parameters
image

The Core Video OpenGL texture whose texture target name you want to obtain.

Return Value

The target name of the texture.

Discussion

See the OpenGL specification for more information about texture targets.

Availability
Related Sample Code
Declared In
CVOpenGLTexture.h

CVOpenGLTextureGetTarget

Returns the texture target (for example, GL_TEXTURE_2D) of an OpenGL texture.

GLenum CVOpenGLTextureGetTarget (
   CVOpenGLTextureRef image
);

Parameters
image

The Core Video OpenGL texture whose target you want to obtain.

Return Value

The OpenGL texture target.

Discussion

See the OpenGL specification for more information about texture targets.

Availability
Related Sample Code
Declared In
CVOpenGLTexture.h

CVOpenGLTextureGetTypeID

Obtains the Core Foundation ID for the Core Video OpenGL texture type. 

CFTypeID CVOpenGLTextureGetTypeID (
   void
);

Return Value

The Core Foundation ID for this type.

Availability
Related Sample Code
Declared In
CVOpenGLTexture.h

CVOpenGLTextureIsFlipped

Determines whether or not an OpenGL texture is flipped vertically.

Boolean CVOpenGLTextureIsFlipped (
   CVOpenGLTextureRef image
);

Parameters
image

The Core Video OpenGL texture whose orientation you want to determine.

Return Value

Returns true if (0,0) in the texture is in the upper-left corner, false if (0,0) is in the lower left corner.

Discussion

Quartz assumes a lower-left origin.

Availability
Declared In
CVOpenGLTexture.h

CVOpenGLTextureRelease

Releases a Core Video OpenGL texture.

void CVOpenGLTextureRelease (
   CVOpenGLTextureRef texture
);

Parameters
texture

The Core Video OpenGL texture that you want to release.

Discussion

This function is equivalent to CFRelease, but NULL safe.

Availability
Related Sample Code
Declared In
CVOpenGLTexture.h

CVOpenGLTextureRetain

Retains a Core Video OpenGL texture.

CVOpenGLTextureRef CVOpenGLTextureRetain (
   CVOpenGLTextureRef texture
);

Parameters
texture

The Core Video OpenGL texture that you want to retain.

Return Value

For convenience, the Core Video OpenGL texture you want to retain.

Discussion

This function is equivalent to CFRetain, but NULL safe.

Availability
Declared In
CVOpenGLTexture.h

CVPixelBufferCreate

Creates a single pixel buffer for a given size and pixel format.

CVReturn CVPixelBufferCreate (
   CFAllocatorRef allocator,
   size_t width,
   size_t height,
   OSType pixelFormatType,
   CFDictionaryRef pixelBufferAttributes,
   CVPixelBufferRef *pixelBufferOut
);

Parameters
allocator

The allocator to use to create the pixel buffer. Pass NULL to specify the default allocator.

width

Width of the pixel buffer, in pixels.

height

Height of the pixel buffer, in pixels.

pixelFormatType

The pixel format identified by its respective four-character code (type OSType).

pixelBufferAttributes

A dictionary with additonal attributes for a pixel buffer. This parameter is optional. See “Pixel Buffer Attribute Keys” for more details.

pixelBufferOut

On return, pixelBufferOut points to the newly created pixel buffer.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

This function allocates the necessary memory based on the pixel dimensions, format, and extended pixels described in the pixel buffer’s attributes.

Some of the parameters specified in this call override equivalent pixel buffer attributes. For example, if you define the kCVPixelBufferWidth and kCVPixelBufferHeight keys in the pixel buffer attributes parameter (pixelBufferAttributes), these values are overriden by the width and height parameters.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferCreateResolvedAttributesDictionary

Takes an array of CFDictionary objects describing various pixel buffer attributes and tries to resolve them into a single dictionary.

CVReturn CVPixelBufferCreateResolvedAttributesDictionary (
   CFAllocatorRef allocator,
   CFArrayRef attributes,
   CFDictionaryRef *resolvedDictionaryOut
);

Parameters
allocator

The allocator to use to create the pixel buffer. Pass NULL to specify the default allocator.

attributes

An array of Core Foundation dictionaries containing pixel buffer attribute key-value pairs.

resolvedDictionaryOut

On return, resolvedDictionaryOut points to the consolidated dictionary.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

This call is useful when you need to resolve requirements between several potential clients of a buffer.

If two or more dictionaries contain the same key but different values, errors may occur. For example, the width and height attributes must match, but if the bytes-per-row (rowBytes) attributes differ, the least common multiple is taken. Mismatches in pixel format allocators or callbacks also cause an error.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferCreateWithBytes

Creates a pixel buffer for a given size and pixel format containing data specified by a memory location.

CVReturn CVPixelBufferCreateWithBytes (
   CFAllocatorRef allocator,
   size_t width,
   size_t height,
   OSType pixelFormatType,
   void *baseAddress,
   size_t bytesPerRow,
   CVPixelBufferReleaseBytesCallback releaseCallback,
   void *releaseRefCon,
   CFDictionaryRef pixelBufferAttributes,
   CVPixelBufferRef *pixelBufferOut
);

Parameters
allocator

The allocator to use to create this buffer. Pass NULL to specify the default allocator.

width

Width of the pixel buffer, in pixels.

height

Height of the pixel buffer, in pixels.

pixelFormatType

Pixel format indentified by its respective four character code (type OSType).

baseAddress

A pointer to the base address of the memory storing the pixels.

bytesPerRow

Row bytes of the pixel storage memory.

releaseCallback

The callback function to be called when the pixel buffer is destroyed. This callback allows the owner of the pixels to free the memory. See CVPixelBufferReleaseBytesCallback for more information.

releaseRefCon

User data identifying the pixel buffer. This value is passed to your pixel buffer release callback.

pixelBufferAttributes

A Core Foundation dictionary with additonal attributes for a a pixel buffer. This parameter is optional. See “Pixel Buffer Attribute Keys” for more details.

pixelBufferOut

On return, pixelBufferOut points to the newly created pixel buffer.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

Some of the parameters specified in this call override equivalent pixel buffer attributes. For example, if you define the kCVPixelBufferWidth and kCVPixelBufferHeight keys in the pixel buffer attributes parameter (pixelBufferAttributes), these values are overriden by the width and height parameters.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferCreateWithPlanarBytes

Creates a single pixel buffer in planar format for a given size and pixel format containing data specified by a memory location.

CVReturn CVPixelBufferCreateWithPlanarBytes (
   CFAllocatorRef allocator,
   size_t width,
   size_t height,
   OSType pixelFormatType,
   void *dataPtr,
   size_t dataSize,
   size_t numberOfPlanes,
   void *planeBaseAddress[],
   size_t planeWidth[],
   size_t planeHeight[],
   size_t planeBytesPerRow[],
   CVPixelBufferReleasePlanarBytesCallback releaseCallback,
   void *releaseRefCon,
   CFDictionaryRef pixelBufferAttributes,
   CVPixelBufferRef *pixelBufferOut
);

Parameters
allocator

The allocator to use to create this buffer. Pass NULL to specify the default allocator.

width

Width of the pixel buffer, in pixels.

height

Height of the pixel buffer, in pixels.

pixelFormatType

Pixel format indentified by its respective four-character code (type OSType).

dataPtr

A pointer to a plane descriptor block if applicable, or NULL if not.

dataSize

The size of the memory if the planes are contiguous, or NULL if not.

numberOfPlanes

The number of planes.

planeBaseAddress

The array of base addresses for the planes.

planeWidth

The array of plane widths.

planeHeight

The array of plane heights.

planeBytesPerRow

Thje array of plane bytes-per-row values.

releaseCallback

The callback function that gets called when the pixel buffer is destroyed. This callback allows the owner of the pixels to free the memory. See CVPixelBufferReleaseBytesCallback for more information.

releaseRefCon

A pointer to user data identifying the pixel buffer. This value is passed to your pixel buffer release callback.

pixelBufferAttributes

A dictionary with additonal attributes for a a pixel buffer. This parameter is optional. See “Pixel Buffer Attribute Keys” for more details.

pixelBufferOut

On return, pixelBufferOut points to the newly created pixel buffer.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

Some of the parameters specified in this call override equivalent pixel buffer attributes. For example, if you define the kCVPixelBufferWidth and kCVPixelBufferHeight keys in the pixel buffer attributes parameter (pixelBufferAttributes), these values are overriden by the width and height parameters.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferFillExtendedPixels

Fills the extended pixels of the pixel buffer. 

CVReturn CVPixelBufferFillExtendedPixels (
   CVPixelBufferRef pixelBuffer
);

Parameters
pixelBuffer

The pixel buffer whose extended pixels you want to fill.

Discussion

This function replicates edge pixels to fill the entire extended region of the image.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferGetBaseAddress

Returns the base address of the pixel buffer.

void * CVPixelBufferGetBaseAddress (
   CVPixelBufferRef pixelBuffer
);

Parameters
pixelBuffer

The pixel buffer whose base address you want to obtain.

Return Value

The base address of the pixels. For chunky buffers, this returns a pointer to the pixel at (0,0) in the buffer For planar buffers this returns a pointer to a PlanarComponentInfo structure (as defined by QuickTime in ImageCodec.h).

Discussion

Retrieving the base address for a pixel buffer requires that the buffer base address be locked via a successful call to CVPixelBufferLockBaseAddress.

Availability
Related Sample Code
Declared In
CVPixelBuffer.h

CVPixelBufferGetBaseAddressOfPlane

Returns the base address of the plane at the specified plane index.

void * CVPixelBufferGetBaseAddressOfPlane (
   CVPixelBufferRef pixelBuffer,
   size_t planeIndex
);

Parameters
pixelBuffer

The pixel buffer containing the plane whose base address you want to obtain.

planeIndex

The index of the plane.

Return Value

The base address of the plane, or NULL for nonplanar pixel buffers.

Discussion

Retrieving the base address for a pixel buffer requires that the buffer base address be locked by a successful call to CVPixelBufferLockBaseAddress.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferGetBytesPerRow

Returns the number of bytes per row of the pixel buffer.

size_t CVPixelBufferGetBytesPerRow (
   CVPixelBufferRef pixelBuffer
);

Parameters
pixelBuffer

The pixel buffer whose bytes-per-row value you want to obtain.

Return Value

The number of bytes per row of the image data. For planar buffers this function returns a rowBytes value such that bytesPerRow * height covers the entire image including all planes.

Availability
Related Sample Code
Declared In
CVPixelBuffer.h

CVPixelBufferGetBytesPerRowOfPlane

Returns the number of bytes per row for a plane at the specified index in the pixel buffer.

size_t CVPixelBufferGetBytesPerRowOfPlane (
   CVPixelBufferRef pixelBuffer,
   size_t planeIndex
);

Parameters
pixelBuffer

The pixel buffer containing the plane.

planeIndex

The index of the plane whose bytes-per-row value you want to obtain.

Return Value

The number of row bytes of the plane, or NULL for nonplanar pixel buffers.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferGetDataSize

Returns the data size for contiguous planes of the pixel buffer.

size_t CVPixelBufferGetDataSize (
   CVPixelBufferRef pixelBuffer
);

Parameters
pixelBuffer

The pixel buffer whose data size you want to obtain.

Return Value

The data size as specified in the call to CVPixelBufferCreateWithPlanarBytes.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferGetExtendedPixels

Returns the amount of extended pixel padding in the pixel buffer.

void CVPixelBufferGetExtendedPixels (
   CVPixelBufferRef pixelBuffer,
   size_t *extraColumnsOnLeft,
   size_t *extraColumnsOnRight,
   size_t *extraRowsOnTop,
   size_t *extraRowsOnBottom
);

Parameters
pixelBuffer

The pixel buffer whose extended pixel size you want to obtain.

extraColumnsOnLeft

Returns the pixel row padding to the left. May be NULL.

extraColumnsOnRight

Returns the pixel row padding to the right. May be NULL.

extraRowsOnTop

Returns the pixel row padding to the top. May be NULL.

extraRowsOnBottom

The pixel row padding to the bottom. May be NULL.

Discussion

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferGetHeight

Returns the height of the pixel buffer.

size_t CVPixelBufferGetHeight (
   CVPixelBufferRef pixelBuffer
);

Parameters
pixelBuffer

The pixel buffer whose height you want to obtain.

Return Value

The buffer height, in pixels.

Availability
Related Sample Code
Declared In
CVPixelBuffer.h

CVPixelBufferGetHeightOfPlane

Returns the height of the plane at planeIndex in the pixel buffer.

size_t CVPixelBufferGetHeightOfPlane (
   CVPixelBufferRef pixelBuffer,
   size_t planeIndex
);

Parameters
pixelBuffer

The pixel buffer whose plane height you want to obtain.

planeIndex

The index of the plane.

Return Value

The height of the buffer, in pixels, or 0 for nonplanar pixel buffers.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferGetPixelFormatType

Returns the pixel format type of the pixel buffer.

OSType CVPixelBufferGetPixelFormatType (
   CVPixelBufferRef pixelBuffer
);

Parameters
pixelBuffer

The pixel buffer whose format type you want to obtain.

Return Value

A four-character code OSType identifier for the pixel format.

Discussion

Availability
Related Sample Code
Declared In
CVPixelBuffer.h

CVPixelBufferGetPlaneCount

Returns number of planes of the pixel buffer.

size_t CVPixelBufferGetPlaneCount (
   CVPixelBufferRef pixelBuffer
);

Parameters
pixelBuffer

The pixel buffer whose plane count you want to obtain..

Return Value

The number of planes. Returns 0 for nonplanar pixel buffers.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferGetTypeID

Returns the Core Foundation ID of the pixel buffer type. 

CFTypeID CVPixelBufferGetTypeID (
   void
);

Return Value

The Core Foundation ID for this type.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferGetWidth

Returns the width of the pixel buffer.

size_t CVPixelBufferGetWidth (
   CVPixelBufferRef pixelBuffer
);

Parameters
pixelBuffer

The pixel buffer whose width you want to obtain.

Return Value

The width of the buffer, in pixels.

Availability
Related Sample Code
Declared In
CVPixelBuffer.h

CVPixelBufferGetWidthOfPlane

Returns the width of the plane at a given index in the pixel buffer.

size_t CVPixelBufferGetWidthOfPlane (
   CVPixelBufferRef pixelBuffer,
   size_t planeIndex
);

Parameters
pixelBuffer

The pixel buffer whose plane width you want to obtain.

planeIndex

The index of the plane at which to obtain the width.

Return Value

The width of the plane, in pixels, or 0 for nonplanar pixel buffers.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferIsPlanar

Determine if the pixel buffer is planar.

Boolean CVPixelBufferIsPlanar (
   CVPixelBufferRef pixelBuffer
);

Parameters
pixelBuffer

The pixel buffer to check.

Return Value

Returns true if the pixel buffer was created using CVPixelBufferCreateWithPlanarBytes, false otherwise.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferLockBaseAddress

Locks the base address of the pixel buffer. 

CVReturn CVPixelBufferLockBaseAddress (
   CVPixelBufferRef pixelBuffer,
   CVOptionFlags lockFlags
);

Parameters
pixelBuffer

The pixel buffer whose base address you want to lock.

lockFlags

No options currently defined; pass 0.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Availability
Related Sample Code
Declared In
CVPixelBuffer.h

CVPixelBufferPoolCreate

Creates a pixel buffer pool.

CVReturn CVPixelBufferPoolCreate (
   CFAllocatorRef allocator,
   CFDictionaryRef poolAttributes,
   CFDictionaryRef pixelBufferAttributes,
   CVPixelBufferPoolRef *poolOut
);

Parameters
allocator

The allocator to use for allocating this buffer pool. Pass NULL to specify the default allocator.

poolAttributes

A Core Foundation dictionary containing the attributes for this pixel buffer pool.

pixelBufferAttributes

A Core Foundation dictionary containing the attributes to be used for creating new pixel buffers within the pool.

poolOut

On return, poolOut points to the newly created pixel buffer pool.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Availability
Related Sample Code
Declared In
CVPixelBufferPool.h

CVPixelBufferPoolCreatePixelBuffer

Creates a pixel buffer from a pixel buffer pool.

CVReturn CVPixelBufferPoolCreatePixelBuffer (
   CFAllocatorRef allocator,
   CVPixelBufferPoolRef pixelBufferPool,
   CVPixelBufferRef *pixelBufferOut
);

Parameters
allocator

The allocator to use for creating the pixel buffer. Pass NULL to specify the default allocator.

pixelBufferPool

The pixel buffer pool for creating the new pixel buffer.

pixelBufferOut

On return, pixelBufferOut points to the newly created pixel buffer.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

This function creates a new pixel buffer using the pixel buffer attributes specifed during pool creation. This buffer has default attachments as specified in the pixelBufferAttributes parameter of CVPixelBufferPoolCreate (using either the kCVBufferPropagatedAttachmentsKey or kCVBufferNonPropagatedAttachmentsKey attributes).

Availability
Related Sample Code
Declared In
CVPixelBufferPool.h

CVPixelBufferPoolGetAttributes

Returns the pool attributes dictionary for a pixel buffer pool.

CFDictionaryRef CVPixelBufferPoolGetAttributes (
   CVPixelBufferPoolRef pool
);

Parameters
pool

The pixel buffer pool to retrieve the attributes from.

Return Value

A Core Foundation dictionary containing the pool attributes, or NULL on failure.

Discussion

Availability
Declared In
CVPixelBufferPool.h

CVPixelBufferPoolGetPixelBufferAttributes

Returns the attributes of pixel buffers that will be created from this pool.

CFDictionaryRef CVPixelBufferPoolGetPixelBufferAttributes (
   CVPixelBufferPoolRef pool
);

Parameters
pool

The pixel buffer pool to retrieve the attributes from.

Return Value

A Core Foundation dictionary containing the pixel buffer attributes, or NULL on failure.

Discussion

This function is provided for those cases where you may need to know some information about the buffers that will be created for you .

Availability
Declared In
CVPixelBufferPool.h

CVPixelBufferPoolGetTypeID

Returns the Core Foundation ID of the pixel buffer pool type. 

CFTypeID CVPixelBufferPoolGetTypeID (
   void
);

Return Value

The Core Foundation ID for this type.

Availability
Declared In
CVPixelBufferPool.h

CVPixelBufferPoolRelease

Releases a pixel buffer pool.

void CVPixelBufferPoolRelease (
   CVPixelBufferPoolRef pixelBufferPool
);

Parameters
pixelBufferPool

The pixel buffer pool that you want to release.

Discussion

This function is equivalent to CFRelease, but NULL safe.

Availability
Related Sample Code
Declared In
CVPixelBufferPool.h

CVPixelBufferPoolRetain

Retains a pixel buffer pool.

CVPixelBufferPoolRef CVPixelBufferPoolRetain (
   CVPixelBufferPoolRef pixelBufferPool
);

Parameters
buffer

The pixel buffer pool that you want to retain.

Return Value

For convenience, the same pixel buffer pool that you wanted to retain.

Discussion

This function is equivalent to CFRetain, but NULL safe.

Availability
Declared In
CVPixelBufferPool.h

CVPixelBufferRelease

Releases a pixel buffer.

void CVPixelBufferRelease (
   CVPixelBufferRef texture
);

Parameters
buffer

The pixel buffer that you want to release.

Discussion

This function is equivalent to CFRelease, but NULL safe.

Availability
Related Sample Code
Declared In
CVPixelBuffer.h

CVPixelBufferRetain

Retains a pixel buffer.

CVPixelBufferRef CVPixelBufferRetain (
   CVPixelBufferRef texture
);

Parameters
buffer

The pixel buffer that you want to retain.

Return Value

For convenience, the same pixel buffer you want to retain.

Discussion

This function is equivalent to CFRetain, but NULL safe.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferUnlockBaseAddress

Unlocks the base address of the pixel buffer. 

CVReturn CVPixelBufferUnlockBaseAddress (
   CVPixelBufferRef pixelBuffer,
   CVOptionFlags unlockFlags
);

Parameters
pixelBuffer

The pixel buffer whose base address you want to unlock.

unlockFlags

No options currently defined; pass 0.

Return Value

A Core Video result code. See “Result Codes” for possible values.

Discussion

Availability
Related Sample Code
Declared In
CVPixelBuffer.h

CVPixelFormatDescriptionArrayCreateWithAllPixelFormatTypes

Returns all the pixel format descriptions known to Core Video. 

CFArrayRef CVPixelFormatDescriptionArrayCreateWithAllPixelFormatTypes (
   CFAllocatorRef allocator
);

Parameters
allocator

The allocator to use when creating the description. Pass NULL to specify the default allocator.

Return Value

An array of Core Foundation dictionaries, each containing a pixel format description. See “Pixel Format Description Keys” for a list of keys relevant to the format description.

Availability
Declared In
CVPixelFormatDescription.h

CVPixelFormatDescriptionCreateWithPixelFormatType

Creates a pixel format description from a given OSType identifier. 

CFDictionaryRef CVPixelFormatDescriptionCreateWithPixelFormatType (
   CFAllocatorRef allocator,
   OSType pixelFormat
);

Parameters
allocator

The allocator to use when creating the description. Pass NULL to specify the default allocator.

pixelFormat

A four-character code that identifies the pixel format you want to obtain.

Return Value

A Core Foundation dictionary containing the pixel format description. See “Pixel Format Description Keys” for a list of keys relevant to the format description.

Availability
Declared In
CVPixelFormatDescription.h

CVPixelFormatDescriptionRegisterDescriptionWithPixelFormatType

Registers a pixel format description with Core Video.

void CVPixelFormatDescriptionRegisterDescriptionWithPixelFormatType (
   CFDictionaryRef description,
   OSType pixelFormat
);

Parameters
description

A Core Foundation dictionary containing the pixel format description. See “Pixel Format Description Keys” for a list of required and optional keys.

pixelFormat

The four-character code (type OSType) identifier for this pixel format.

Discussion

If you are using a custom pixel format, you must register the format with Core Video using this function. See Technical Q&A 1401: Registering Custom Pixel Formats with QuickTime and Core Video for more details.

Availability
Declared In
CVPixelFormatDescription.h

Callbacks

CVDisplayLinkOutputCallback

Defines a pointer to a display link output callback function, which is called whenever the display link wants the application to output a frame. 

typedef CVReturn (*CVDisplayLinkOutputCallback)(
   CVDisplayLinkRef displayLink,
   const CVTimeStamp *inNow,
   const CVTimeStamp *inOutputTime,
   CVOptionFlags flagsIn,
   CVOptionFlags *flagsOut,
   void *displayLinkContext
   );

You would declare a display link output callback function named MyDisplayLinkCallback like this: 

CVReturn MyDisplayLinkCallback (
   CVDisplayLinkRef displayLink,
   const CVTimeStamp *inNow,
   const CVTimeStamp *inOutputTime,
   CVOptionFlags flagsIn,
   CVOptionFlags *flagsOut,
   void *displayLinkContext
   );

Parameters
displayLink

The display link requesting the frame.

inNow

A pointer to the current time.

inOutputTime

A pointer to the time that the frame will be displayed.

flagsIn

Currently unused. Pass 0.

flagsOut

Currently unused. Pass 0.

displayLinkContext

A pointer to application-defined data. This is the pointer you passed into the CVDisplayLinkSetOutputCallback function when registering your callback.

Discussion

For a given display link, you must register a display link output callback using CVDisplayLinkSetOutputCallback so that you can process and output the requested frame.

You callback must retrieve the frame with the timestamp specified by the (inOutputTime parameter, manipulate it if desired (for example, apply color correction or map into onto a surface), and then output it to the display.

Availability
Declared In
CVDisplayLink.h

CVFillExtendedPixelsCallBack

Defines a pointer to a custom extended pixel-fill function, which is called whenever the system needs to pad a buffer holding your custom pixel format. 

typedef Boolean (*CVFillExtendedPixelsCallBack)(
   CVPixelBufferRef pixelBuffer,
   void *refCon
   );

Here is how you would declare a custom fill function named MyExtendedPixelFillFunc

Boolean MyExtendedPixelFillFunc (
   CVPixelBufferRef pixelBuffer,
   void *refCon
   );

Parameters
pixelBuffer

The pixel buffer to be padded.

refCon

A pointer to application-defined data. This is the same value you stored in the CVFillExtendedPixelsCallbackData structure.

Return Value

Return true if the padding was successful, false otherwise.

Discussion

For more information on implementing a custom extended pixel-fill callback, see Technical Q&A 1440: Implementing a CVFillExtendedPixelsCallback.

Availability
Declared In
CVPixelFormatDescription.h

CVPixelBufferReleaseBytesCallback

Defines a pointer to a pixel buffer release callback function, which is called when a pixel buffer created by CVPixelBufferCreateWithBytes is released. 

typedef void (*CVPixelBufferReleaseBytesCallback)(
   void *releaseRefCon,
   const void *baseAddress
   );

You would declare a pixel buffer release callback named MyPixelBufferReleaseCallback like this:

void MyPixelBufferReleaseCallback(
   void *releaseRefCon,
   const void *baseAddress
   );

Parameters
releaseRefCon

A pointer to application-defined data. This pointer is the same as that passed in the releaseRefCon parameter of CVPixelBufferCreateWithBytes.

baseAddress

A pointer to the base address of the memory holding the pixels. This pointer is the same as that passed in the baseAddress parameter of CVPixelBufferCreateWithBytes.

Discussion

You use this callback to release the pixels and perform any other cleanup when a pixel buffer is released.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferReleasePlanarBytesCallback

Defines a pointer to a pixel buffer release callback function, which is called when a pixel buffer created by CVPixelBufferCreateWithPlanarBytes is released. 

typedef void (*CVPixelBufferReleasePlanarBytesCallback)(
   void *releaseRefCon,
   const void *dataPtr,
   size_t dataSize,
   size_t numberOfPlanes,
   const void *planeAddresses[]
   );

You would declare a callback named MyPixelBufferReleasePlanarBytes like this:

void MyPixelBufferReleasePlanarBytes)(
   void *releaseRefCon,
   const void *dataPtr,
   size_t dataSize,
   size_t numberOfPlanes,
   const void *planeAddresses[]
   );

Parameters
releaseRefCon

A pointer to application-defined data. This pointer is the same as that passed in the releaseRefCon parameter of CVPixelBufferCreateWithPlanarBytes.

dataPtr

A pointer to a plane descriptor block. This is the same pointer you passed to CVPixelBufferCreateWithPlanarBytes in the dataPtr parameter.

dataSize

The size value you passed to CVPixelBufferCreateWithPlanarBytes in the dataSize parameter.

numberOfPlanes

The number of planes value you passed to CVPixelBufferCreateWithPlanarBytes in the numberOfPlanes parameter.

planeAddresses

A pointer to the base plane address you passed to CVPixelBufferCreateWithPlanarBytes in the basePlaneAddress parameter.

Discussion

You use this callback to release the pixels and perform any other cleanup when a pixel buffer is released.

Availability
Declared In
CVPixelBuffer.h

Data Types

CVBufferRef

Defines the base type for all Core Video buffers.

typedef struct __CVBuffer *CVBufferRef;

Discussion

CVBuffers represent an abstract type from which all Core Video buffers derive.

Availability
Declared In
CVBuffer.h

CVDisplayLinkRef

Defines a display link.

typedef struct __CVDisplayLink *CVDisplayLinkRef;

Availability
Declared In
CVDisplayLink.h

CVFillExtendedPixelsCallbackData

Holds information describing a custom extended pixel fill algorithm. 

typedef struct {
CFIndex version;
CVFillExtendedPixelsCallBack    fillCallBack;
void *refCon;
} CVFillExtendedPixelsCallBackData;

Fields
version

The version of this fill algorithm.

fillCallback

A pointer to a custom pixel fill function.

refCon

A pointer to application-defined data that is passed to your custom pixel fill function.

Discussion

You must fill out this structure and store it as part of your pixel format description Core Foundation dictionary (key: kCVPixelFormatFillExtendedPixelsCallback, type: CFData). However, if your custom pixel format never needs the functionality of CVPixelBufferFillExtendedPixels, you don’t need to add this key or implement the associated callback.

For more information about defining a custom pixel format, see “Pixel Format Description Keys.”

Availability
Declared In
CVPixelFormatDescription.h

CVImageBufferRef

Defines a Core Video image buffer. 

typedef CVBufferRef CVImageBufferRef;

Discussion

An image buffer is an abstract type representing Core Video buffers that hold images. In Core Video, pixel buffers, OpenGL buffers, and OpenGL textures all derive from the image buffer type.

Availability
Declared In
CVImageBuffer.h

CVOptionFlags

Define flags to be used for the display link output callback function.

typedef uint64_t CVOptionFlags;

Discussion

No flags are currently defined.

Availability
Declared In
CVBase.h

CVOpenGLBufferRef

Defines a Core Video OpenGL buffer. 

typedef CVImageBufferRef CVOpenGLBufferRef;

Discussion

The Core Video OpenGL buffer (type CVOpenGLBufferRef is a wrapper around the standard OpenGL pbuffer.

Availability
Declared In
CVOpenGLBuffer.h

CVOpenGLBufferPoolRef

Defines an OpenGL buffer pool.

typedef struct _CVOpenGLBufferPool *CVOpenGLBufferPoolRef;

Availability
Declared In
CVOpenGLBufferPool.h

CVOpenGLTextureRef

Defines an OpenGL texture-based image buffer.

typedef CVImageBufferRef CVOpenGLTextureRef;

Discussion

The Core Video OpenGL texture (type CVOpenGLTextureRef is a wrapper around the standard OpenGL texture.

Availability
Declared In
CVOpenGLTexture.h

CVOpenGLTextureCacheRef

Defines a CoreVideo OpenGL texture cache.

typedef struct __CVOpenGLTextureCache *CVOpenGLTextureCacheRef;

Availability
Declared In
CVOpenGLTextureCache.h

CVPixelBufferRef

Defines a Core Video pixel buffer. 

typedef CVImageBufferRef CVPixelBufferRef;

Discussion

The pixel buffer stores an image in main memory.

Availability
Declared In
CVPixelBuffer.h

CVPixelBufferPoolRef

Defines a pixel buffer pool.

typedef struct _CVPixelBufferPool *CVPixelBufferPoolRef;

Availability
Declared In
CVPixelBufferPool.h

CVReturn

Defines the return error code for Core Video functions.

typedef int32_t CVReturn;

Discussion

See “Result Codes” for possible values.

Availability
Declared In
CVReturn.h

CVSMPTETime

A structure for holding a SMPTE time.

struct CVSMPTETime    {
   SInt16  subframes;
   SInt16  subframeDivisor;
   UInt32  counter;
   UInt32  type;
   UInt32  flags;
   SInt16  hours;
   SInt16  minutes;
   SInt16  seconds;
   SInt16  frames;
;}
typedef struct CVSMPTETime CVSMPTETime;

Fields
subframes

The number of subframes in the full message.

subframeDivisor

The number of subframes per frame (typically, 80).

counter

The total number of messages received.

type

The kind of SMPTE time type. See “SMPTE Time Types” for a list of possible values.

flags

A set of flags that indicate the SMPTE state. See “SMPTE State Flags” for possible values.

hours

The number of hours in the full message.

minutes

The number of minutes in the full message.

seconds

The number of seconds in the full message.

frames

The number of frames in the full message.

Availability
Declared In
CVBase.h

CVTime

A structure for reporting Core Video time values.

typedef struct {
int64_t     timeValue;
int64_t     timeScale;
int32_t     flags;
} CVTime;

Fields
timeValue

The time value.

timeScale

The time scale for this value.

flags

Flags associated with the CVTime value. See “CVTime Constants” for possible values. If kCVTimeIsIndefinite is set, you should not use any of the other fields in this structure.

Discussion

This structure is equivalent to the QuickTime QTTime structure.

Availability
Declared In
CVBase.h

CVTimeStamp

A structure for defining a display timestamp.

typedef struct {
uint32_t    version;
int32_t     videoTimeScale;
int64_t     videoTime;
uint64_t    hostTime;
double      rateScalar;
int64_t     videoRefreshPeriod;
CVSMPTETime smpteTime;
uint64_t    flags;
uint64_t    reserved;
} CVTimeStamp;

Fields
version

The current CVTimeStamp structure is version 0. Some functions require you to specify a version when passing in a timestamp structure to be filled.

videoTimeScale

The scale (in units per second) of the videoTimeScale and videoRefreshPeriod fields.

videoTime

The start of a frame (or field for interlaced video).

hostTime

The host root time base time.

rateScalar

The current rate of the device as measured by the timestamps, divided by the nominal rate

videoPeriod

The nominal update period of the current output device.

smpteTime

The SMPTE time representation of the timestamp.

flags

A bit field containing additional information about the timestamp. See “CVTimeStamp Flags” for a list of possible values. .

reserved

Reserved. Do not use.

Discussion

This structure is designed to be very similar to the audio time stamp defined in the Core Audio framework. However, unlike the audio timestamps, floating-point values are not used to represent the video equivalent of sample times. This was done partly to avoid precision issues, and partly because QuickTime still uses integers for time values and time scales. In the actual implementation it has turned out to be very convenient to use integers, and we can represent frame rates like NTSC (30000/1001 fps) exactly. The mHostTime structure field uses the same Mach absolute time base used in Core Audio, so that clients of the Core Video API can synchronize between the two subsystems.

Availability
Declared In
CVBase.h

Constants

CVBuffer Attachment Keys

Specify an attachment type for a Core Video buffer. 

const CFStringRef kCVBufferMovieTimeKey;
const CFStringRef kCVBufferTimeValueKey;
const CFStringRef kCVBufferTimeScaleKey;

Constants
kCVBufferMovieTimeKey

The movie time associated with the buffer. Generally only available for frames emitted by QuickTime (type CFDictionary containing the kCVBufferTimeValueKey and kCVBufferTimeScaleKey keys).

Available in Mac OS X v10.3 and later.

Declared in CVBuffer.h.

kCVBufferTimeValueKey

The actual time value associated with the movie.

Available in Mac OS X v10.3 and later.

Declared in CVBuffer.h.

kCVBufferTimeScaleKey

The time scale associated with the movie.

Available in Mac OS X v10.3 and later.

Declared in CVBuffer.h.

CVBuffer Attachment Modes

Specify the propagation mode of a Core Video buffer attachment. 

enum {
   kCVAttachmentMode_ShouldNotPropagate    = 0,
   kCVAttachmentMode_ShouldPropagate       = 1,
};
typedef uint32_t CVAttachmentMode;

Constants
kCVAttachmentMode_ShouldNotPropagate

Do not propagate this attachment.

Available in Mac OS X v10.3 and later.

Declared in CVBuffer.h.

kCVAttachmentMode_ShouldPropagate

Copy this attachment when using the CVBufferPropagateAttachments function. For example, in most cases, you would want to propagate an attachment bearing a timestamp to each successive buffer.

Available in Mac OS X v10.3 and later.

Declared in CVBuffer.h.

Discussion

You set these attributes when adding attachments to a CVBuffer object.

CVBuffer Attribute Keys

Specify attributes associated with Core Video buffers. 

const CFStringRef kCVBufferPropagatedAttachmentsKey;
const CFStringRef kCVBufferNonPropagatedAttachmentsKey;

Constants
kCVBufferPropagatedAttachmentsKey

Attachments that should be copied when using the CVBufferPropagateAttachments function (type CFDictionary, containing a list of attachments as key-value pairs).

Available in Mac OS X v10.3 and later.

Declared in CVBuffer.h.

kCVBufferNonPropagatedAttachmentsKey

Attachments that should not be copied when using the CVBufferPropagateAttachments function (type CFDictionary, containing a list of attachments as key-value pairs).

Available in Mac OS X v10.3 and later.

Declared in CVBuffer.h.

Discussion

These attributes let you set multiple attachments at the time of buffer creation, rather than having to call CVBufferSetAttachment for each attachment.

CVTime Constants

Specify flags for the CVTime structure.

enum {
kCVTimeIsIndefinite = 1 << 0
};

Constants
kCVTimeIsIndefinite

The time value is unknown.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

CVTime Values

Indicate specific CVTime values. 

const CVTime kCVZeroTime;
const CVTime kCVIndefiniteTime;

Constants
kCVZeroTime

Zero time or duration. For example, CVDisplayLinkGetOutputVideoLatency returns kCVZeroTime for zero video latency.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVIndefiniteTime

An unknown or indefinite time. For example, CVDisplayLinkGetNominalOutputVideoRefreshPeriod returns kCVIndefiniteTime if the display link specified is not valid.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

CVTimeStamp Flags

Specify flags for the CVTimeStamp structure. 

enum
{
   kCVTimeStampVideoTimeValid              = (1L << 0),
   kCVTimeStampHostTimeValid               = (1L << 1),
   kCVTimeStampSMPTETimeValid              = (1L << 2),
   kCVTimeStampVideoRefreshPeriodValid     = (1L << 3),
   kCVTimeStampRateScalarValid             = (1L << 4),
   kCVTimeStampTopField                    = (1L << 16),
   kCVTimeStampBottomField                 = (1L << 17)
};
enum
{
   kCVTimeStampVideoHostTimeValid   =
   (kCVTimeStampVideoTimeValid | kCVTimeStampHostTimeValid),
   kCVTimeStampIsInterlaced             =
   (kCVTimeStampTopField | kCVTimeStampBottomField)
};

Constants
kCVTimeStampVideoTimeValid

The value in the video time field is valid.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVTimeStampHostTimeValid

The value in the host time field is valid.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVTimeStampSMPTETimeValid

The value in the SMPTE time field is valid.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVTimeStampVideoRefreshPeriodValid

The value in the video refresh period field is valid.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVTimeStampRateScalarValid

The value in the rate scalar field is valid.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVTimeStampTopField

The timestamp represents the top lines of an interlaced image.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVTimeStampBottomField

The timestamp represents the bottom lines of an interlaced image.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVTimeStampVideoHostTimeValid

A convenience constant indicating that both the video time and host time fields are valid.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVTimeStampIsInterlaced

A convenience constant indicating that the timestamp is for an interlaced image.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

Discussion

These flags indicate which fields in the CVTimeStamp structure contain valid information.

Image Buffer Attachment Keys

Specify attachment types associated with image buffers.

const CFStringRef kCVImageBufferCGColorSpaceKey;
const CFStringRef kCVImageBufferGammaLevelKey;
const CFStringRef kCVImageBufferCleanApertureKey;
const CFStringRef kCVImageBufferPreferredCleanApertureKey;
const CFStringRef kCVImageBufferCleanApertureWidthKey;
const CFStringRef kCVImageBufferCleanApertureHeightKey;
const CFStringRef kCVImageBufferCleanApertureHorizontalOffsetKey;
const CFStringRef kCVImageBufferCleanApertureVerticalOffsetKey;
const CFStringRef kCVImageBufferFieldCountKey;
const CFStringRef kCVImageBufferFieldDetailKey;
const CFStringRef kCVImageBufferFieldDetailTemporalTopFirst;
const CFStringRef kCVImageBufferFieldDetailTemporalBottomFirst;
const CFStringRef kCVImageBufferFieldDetailSpatialFirstLineEarly;
const CFStringRef kCVImageBufferFieldDetailSpatialFirstLineLate;
const CFStringRef kCVImageBufferPixelAspectRatioKey;
const CFStringRef kCVImageBufferPixelAspectRatioHorizontalSpacingKey;
const CFStringRef kCVImageBufferPixelAspectRatioVerticalSpacingKey;
const CFStringRef kCVImageBufferDisplayDimensionsKey;
const CFStringRef kCVImageBufferDisplayWidthKey;
const CFStringRef kCVImageBufferDisplayHeightKey;
const CFStringRef kCVImageBufferYCbCrMatrixKey;
const CFStringRef kCVImageBufferYCbCrMatrix_ITU_R_709_2;
const CFStringRef kCVImageBufferYCbCrMatrix_ITU_R_601_4;
const CFStringRef kCVImageBufferYCbCrMatrix_SMPTE_240M_1995;

Constants
kCVImageBufferCGColorSpaceKey

The color space for the buffer (type CGColorSpaceRef).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferGammaLevelKey

The gamma level for this buffer (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferCleanApertureKey

The clean aperture for the buffer (type CFDictionary , containing the clean aperture width, height, and horizontal and vertical offset key-value pairs).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferPreferredCleanApertureKey

The preferred clean aperture for the buffer (type CFDictionary , containing the clean aperture width, height, and horizontal and vertical offset key-value pairs).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferCleanApertureWidthKey

The clean aperture width (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferCleanApertureHeightKey

The clean aperture height (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferCleanApertureHorizontalOffsetKey

The clean aperture horizontal offset (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferCleanApertureVerticalOffsetKey

The clean aperture vertical offset (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferFieldCountKey

The field count for the buffer (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferFieldDetailKey

Specific information about the field of a video frame in the buffer (type CFDictionary, containing the temporal bottom first and top first and spacial first-line-early and first-line-late keys).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferFieldDetailTemporalTopFirst

(type CFString).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferFieldDetailTemporalBottomFirst

(type CFString).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferFieldDetailSpatialFirstLineEarly

(type CFString).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferFieldDetailSpatialFirstLineLate

(type CFString).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferPixelAspectRatioKey

The pixel aspect ratio of the buffer (type CFDictionary, containing the horizontal and vertical spacing keys).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferPixelAspectRatioHorizontalSpacingKey

The horizontal component of the buffer aspect ratio (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferPixelAspectRatioVerticalSpacingKey

The vertical component of the buffer aspect ratio (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferDisplayDimensionsKey

The buffer display dimensions (type CFDictionary containing the buffer display width and height keys).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferDisplayWidthKey

The buffer display width (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferDisplayHeightKey

The buffer display height (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferYCbCrMatrixKey

The type of conversion matrix used for this buffer when converting from YCbCr to RGB images (type CFString). The value for this key should be one of the following constants: kCVImageBufferYCbCrMatrix_ITU_R_709_2, kCVImageBufferYCbCrMatrix_ITU_R_601_4, or kCVImageBufferYCbCrMatrix_SMPTE_240M_1995.

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferYCbCrMatrix_ITU_R_709_2

Specifies the YCbCr to RGB conversion matrix for HDTV digital television (ITU R 709) images.

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferYCbCrMatrix_ITU_R_601_4

Specifies the YCbCr to RGB conversion matrix for standard digital television ( ITU R 601) images.

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

kCVImageBufferYCbCrMatrix_SMPTE_240M_1995

Specifies the YCbCR to RGB conversion matrix for 1920 x 1135 HDTV (SMPTE 240M 1995).

Available in Mac OS X v10.3 and later.

Declared in CVImageBuffer.h.

Discussion

Image buffer attachment keys are stored in a Core Foundation dictionary associated with an image buffer. Note that some of these keys are stored in subdictionaries keyed by a higher-level attribute. For example, the kCVImageBufferDisplayWidthKey and kCVImageBufferDisplayHeightKey attributes are stored in a Core Foundation dictionary keyed to the kCVImageBufferDisplayDimensionsKey attribute.

OpenGL Buffer Attribute Keys

Specify attributes of an OpenGL buffer.

const CFStringRef kCVOpenGLBufferWidth;
const CFStringRef kCVOpenGLBufferHeight;
const CFStringRef kCVOpenGLBufferTarget;
const CFStringRef kCVOpenGLBufferInternalFormat;
const CFStringRef kCVOpenGLBufferMaximumMipmapLevel;

Constants
kCVOpenGLBufferWidth

The width of the buffer.

Available in Mac OS X v10.3 and later.

Declared in CVOpenGLBuffer.h.

kCVOpenGLBufferHeight

The height of the buffer.

Available in Mac OS X v10.3 and later.

Declared in CVOpenGLBuffer.h.

kCVOpenGLBufferTarget

The OpenGL target for this buffer.

Available in Mac OS X v10.3 and later.

Declared in CVOpenGLBuffer.h.

kCVOpenGLBufferInternalFormat

The OpenGL internal format of this buffer.

Available in Mac OS X v10.3 and later.

Declared in CVOpenGLBuffer.h.

kCVOpenGLBufferMaximumMipmapLevel

The maximum mipmap level for this buffer.

Available in Mac OS X v10.3 and later.

Declared in CVOpenGLBuffer.h.

OpenGL Buffer Pool Attribute Keys

Specify attributes associated with an OpenGL buffer pool.

const CFStringRef kCVOpenGLBufferPoolMinimumBufferCountKey;
const CFStringRef kCVOpenGLBufferPoolMaximumBufferAgeKey;

Constants
kCVOpenGLBufferPoolMinimumBufferCountKey

Indicates the minimum number of buffers to keep in the pool (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVOpenGLBufferPool.h.

kCVOpenGLBufferPoolMaximumBufferAgeKey

Indicates how long unused buffers should be kept before they are deallocated (type CFAbsoluteTime).

Available in Mac OS X v10.3 and later.

Declared in CVOpenGLBufferPool.h.

Discussion

You specify these keys in a Core Foundation dictionary when calling functions such as CVOpenGLBufferPoolCreate.

Pixel Buffer Attribute Keys

Specify attributes associated with a pixel buffer. 

const CFStringRef kCVPixelBufferPixelFormatTypeKey;
   const CFStringRef kCVPixelBufferMemoryAllocatorKey;
   const CFStringRef kCVPixelBufferWidthKey;
   const CFStringRef kCVPixelBufferHeightKey;
   const CFStringRef kCVPixelBufferExtendedPixelsLeftKey;
   const CFStringRef kCVPixelBufferExtendedPixelsTopKey;
   const CFStringRef kCVPixelBufferExtendedPixelsRightKey;
   const CFStringRef kCVPixelBufferExtendedPixelsBottomKey;
   const CFStringRef kCVPixelBufferBytesPerRowAlignmentKey;
   const CFStringRef kCVPixelBufferCGBitmapContextCompatibilityKey;
   const CFStringRef kCVPixelBufferCGImageCompatibilityKey;
   const CFStringRef kCVPixelBufferOpenGLCompatibilityKey;

Constants
kCVPixelBufferPixelFormatTypeKey

The pixel format for this buffer (type CFNumber, or type CFArray containing an array of CFNumber types (actually type OSType)). For a listing of common pixel formats, see the QuickTime Ice Floe Dispatch 20.

Available in Mac OS X v10.3 and later.

Declared in CVPixelBuffer.h.

kCVPixelBufferMemoryAllocatorKey

The allocator used with this buffer (type CFAllocatorRef).

Available in Mac OS X v10.3 and later.

Declared in CVPixelBuffer.h.

kCVPixelBufferWidthKey

The width of the pixel buffer (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVPixelBuffer.h.

kCVPixelBufferHeightKey

The height of the pixel buffer (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVPixelBuffer.h.

kCVPixelBufferExtendedPixelsLeftKey

The number of pixels padding the left of the image (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVPixelBuffer.h.

kCVPixelBufferExtendedPixelsTopKey

The number of pixels padding the top of the image (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVPixelBuffer.h.

kCVPixelBufferExtendedPixelsRightKey

The number of pixels padding the right of the image (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVPixelBuffer.h.

kCVPixelBufferExtendedPixelsBottomKey

The number of pixels padding the bottom of the image (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVPixelBuffer.h.

kCVPixelBufferBytesPerRowAlignmentKey

Indicates the number of bytes per row in the pixel buffer (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVPixelBuffer.h.

kCVPixelBufferCGBitmapContextCompatibilityKey

Indicates whether the pixel buffer is compatible with Core Graphics bitmap contexts (type CFBoolean).

Available in Mac OS X v10.3 and later.

Declared in CVPixelBuffer.h.

kCVPixelBufferCGImageCompatibilityKey

Indicates whether the pixel buffer is compatible with CGImage types (type CFBoolean).

Available in Mac OS X v10.3 and later.

Declared in CVPixelBuffer.h.

kCVPixelBufferOpenGLCompatibilityKey

Indicates whether the pixel buffer is compatible with OpenGL contexts (type CFBoolean).

Available in Mac OS X v10.3 and later.

Declared in CVPixelBuffer.h.

Discussion

You specify these keys in a Core Foundation dictionary when calling functions such as CVPixelBufferCreate.

Pixel Buffer Pool Attribute Keys

Specify attributes associated with a pixel buffer pool.

const CFStringRef kCVPixelBufferPoolMinimumBufferCountKey;
const CFStringRef kCVPixelBufferPoolMaximumBufferAgeKey;

Constants
kCVPixelBufferPoolMinimumBufferCountKey

The minimum number of buffers allowed in the pixel buffer pool (type CFNumber).

Available in Mac OS X v10.3 and later.

Declared in CVPixelBufferPool.h.

kCVPixelBufferPoolMaximumBufferAgeKey

The maximum allowable age for a buffer in the pixel buffer pool (type CFAbsoluteTime).

Available in Mac OS X v10.3 and later.

Declared in CVPixelBufferPool.h.

Discussion

You specify these keys in a Core Foundation dictionary when calling functions such as CVPixelBufferPoolCreate.

Pixel Format Description Keys

Specify attributes of a pixel format. 

const CFStringRef kCVPixelFormatName;
const CFStringRef kCVPixelFormatConstant;
const CFStringRef kCVPixelFormatCodecType;
const CFStringRef kCVPixelFormatFourCC;
const CFStringRef kCVPixelFormatPlanes;
const CFStringRef kCVPixelFormatBlockWidth;
const CFStringRef kCVPixelFormatBlockHeight;
const CFStringRef kCVPixelFormatBitsPerBlock;
const CFStringRef kCVPixelFormatBlockHorizontalAlignment;
const CFStringRef kCVPixelFormatBlockVerticalAlignment;
const CFStringRef kCVPixelFormatHorizontalSubsampling;
const CFStringRef kCVPixelFormatVerticalSubsampling;
   
const CFStringRef kCVPixelFormatOpenGLFormat;
const CFStringRef kCVPixelFormatOpenGLType;
const CFStringRef kCVPixelFormatOpenGLInternalFormat;
   
const CFStringRef kCVPixelFormatCGBitmapInfo;
   
const CFStringRef kCVPixelFormatQDCompatibility;
const CFStringRef kCVPixelFormatCGBitmapContextCompatibility;
const CFStringRef kCVPixelFormatCGImageCompatibility;
const CFStringRef kCVPixelFormatOpenGLCompatibility;
   
const CFStringRef kCVPixelFormatFillExtendedPixelsCallback;

Constants
kCVPixelFormatName

The name of the pixel format (type CFString). This should be the same as the codec name you would use in QuickTime.

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatConstant

The pixel format constant for QuickTime.

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatCodecType

The codec type (type CFString). For example, '2vuy' or k422YpCbCr8CodecType.

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatFourCC

The Microsoft FourCC equivalent code for this pixel format (type CFString).

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatPlanes

The number of image planes associated with this format (type CFNumber. Each plane may contain a single component or an interleaved set of components. Note that if your pixel format is not planar, you can put the required format keys at the top-level dictionary.

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatBlockWidth

The width, in pixels, of the smallest byte-addressable group of pixels (type CFNumber. Used to assist with allocating memory for pixel formats that don't have an integer value for bytes per pixel. Assumed to be 1 if this key is not present. Here are some examples of block widths for standard pixel formats:

  • 8-bit luminance only, block width is 1, the bits per block value is 8.

  • 16-bit 1555 RGB, block width is 1, the bits per block value is 16.

  • 32-bit 8888 ARGB, block width is 1, the bits per block value is 32.

  • 2vuy (CbYCrY), block width is 2, the bits per block value is 32.

  • 1-bit bitmap, block width is 8, the bits per block value is 8.

  • v210, block width is 6, the bits per block value is 128 .

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatBlockHeight

The height, in pixels, of the smallest byte-addressable group of pixels (type CFNumber). Assumed to be one if this key is not present.

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatBitsPerBlock

The number of bits per block. For simple pixel formats, this value is the same as the traditional bits-per-pixel value. This key is mandatory in pixel format descriptions. See the description for kCVPixelFormatBlockWidth for examples of bits-per-block values.

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatBlockHorizontalAlignment

The horizontal alignment requirements of this format (type CFNumber). For example,the alignment for v210 would be '8' here for the horizontal case to match the standard v210 row alignment value of 48. Assumed to be 1 if this key is not present.

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatBlockVerticalAlignment

The vertical alignment requirements of this format (type CFNumber). Assumed to be 1 if this key is not present.

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatHorizontalSubsampling

Horizontal subsampling information for this plane (type CFNumber). Assumed to be 1 if this key is not present.

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatVerticalSubsampling

Vertical subsampling information for this plane (type CFNumber). Assumed to be 1 if this key is not present.

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatOpenGLFormat

The OpenGL format used to describe this image plane (if applicable). See the OpenGL specification for possible values.

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatOpenGLType

The OpenGL type to describe this image plane (if applicable). See the OpenGL specification for possible values.

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatOpenGLInternalFormat

The OpenGL internal format for this pixel format (if applicable). See the OpenGL specification for possible values.

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatCGBitmapInfo

The Core Graphics bitmap information for this pixel format (if applicable).

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatQDCompatibility

Indicates whether this format is compatible with QuickDraw (type CFBoolean).

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatCGBitmapContextCompatibility

Indicates whether this format is compatible with Core Graphics bitmap contexts(type CFBoolean).

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatCGImageCompatibility

Indicates whether this format is compatible with the CGImage type (type CFBoolean).

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatOpenGLCompatibility

Indicates whether this format is compatible with OpenGL (type CFBoolean).

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

kCVPixelFormatFillExtendedPixelsCallback

Specifies a custom extended pixel fill algorithm (type CFData). See CVFillExtendedPixelsCallBack and CVFillExtendedPixelsCallbackData for more information.

Available in Mac OS X v10.3 and later.

Declared in CVPixelFormatDescription.h.

Discussion

If you need to define a custom pixel format, you must specify these keys in a Core Foundation dictionary. For information about registering your pixel format, see Technical Q&A 1401: Registering Custom Pixel Formats with QuickTime and Core Video.

In most cases you do not need to specify your own pixel format.

SMPTE State Flags

Flags that describe the SMPTE time state.

enum{
   kCVSMPTETimeValid     = (1L << 0),
   kCVSMPTETimeRunning   = (1L << 1)
};

Constants
kCVSMPTETimeValid

The full time is valid.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVSMPTETimeRunning

Time is running.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

Discussion

You use these values in the CVSMPTETime structure.

SMPTE Time Types

Constants that describe the type of SMPTE time.

enum{
   kCVSMPTETimeType24        = 0,
   kCVSMPTETimeType25        = 1,
   kCVSMPTETimeType30Drop    = 2,
   kCVSMPTETimeType30        = 3,
   kCVSMPTETimeType2997      = 4,
   kCVSMPTETimeType2997Drop  = 5,
   kCVSMPTETimeType60        = 6,
   kCVSMPTETimeType5994      = 7
};

Constants
kCVSMPTETimeType24

24 frames per second (standard film).

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVSMPTETimeType25

25 frames per second (standard PAL).

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVSMPTETimeType30Drop

30 drop frame.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVSMPTETimeType30

30 frames per second.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVSMPTETimeType2997

29.97 frames per second (standard NTSC).

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVSMPTETimeType2997Drop

29.97 drop frame.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVSMPTETimeType60

60 frames per second.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

kCVSMPTETimeType5994

59.94 frames per second.

Available in Mac OS X v10.3 and later.

Declared in CVBase.h.

Discussion

You use these values in the CVSMPTETime structure.

Result Codes

The table below lists the result codes returned for Core Video. Note that these result codes are of type CVReturn, not type OSErr.

Result CodeValueDescription
kCVReturnSuccess 0

No error

Available in Mac OS X v10.3 and later.

kCVReturnFirst -6660

Placeholder to mark the beginning of Core Video result codes (not returned by any functions).

Available in Mac OS X v10.3 and later.

kCVReturnError -6660

An otherwise undefined error occurred.

Available in Mac OS X v10.3 and later.

kCVReturnInvalidArgument -6661

Invalid function parameter. For example, out of range or the wrong type.

Available in Mac OS X v10.3 and later.

kCVReturnAllocationFailed -6662

Memory allocation for a buffer or buffer pool failed.

Available in Mac OS X v10.3 and later.

kCVReturnInvalidDisplay -6670

The display specified when creating a display link is invalid.

Available in Mac OS X v10.3 and later.

kCVReturnDisplayLinkAlreadyRunning -6671

The specified display link is already running.

Available in Mac OS X v10.3 and later.

kCVReturnDisplayLinkNotRunning -6672

The specified display link is not running.

Available in Mac OS X v10.3 and later.

kCVReturnDisplayLinkCallbacksNotSet -6673

No callback registered for the specified display link. You must set either the output callback or both the render and display callbacks.

Available in Mac OS X v10.3 and later.

kCVReturnInvalidPixelFormat -6680

The buffer does not support the specified pixel format.

Available in Mac OS X v10.3 and later.

kCVReturnInvalidSize -6681

The buffer cannot support the requested buffer size (usually too big).

Available in Mac OS X v10.3 and later.

kCVReturnInvalidPixelBufferAttributes -6682

A buffer cannot be created with the specified attributes.

Available in Mac OS X v10.3 and later.

kCVReturnPixelBufferNotOpenGLCompatible -6683

The pixel buffer is not compatible with OpenGL due to an unsupported buffer size, pixel format, or attribute.

Available in Mac OS X v10.3 and later.

kCVReturnPoolAllocationFailed -6690

Allocation for a buffer pool failed, most likely due to a lack of resources. Check to make sure your parameters are in range.

Available in Mac OS X v10.3 and later.

kCVReturnInvalidPoolAttributes -6691

A buffer pool cannot be created with the specified attributes.

Available in Mac OS X v10.3 and later.

kCVReturnLast -6699

Placeholder to mark the end of Core Video result codes (not returned by any functions).

Available in Mac OS X v10.3 and later.



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© 2004, 2007 Apple Inc. All Rights Reserved. (Last updated: 2007-03-22)

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