6.12. EGL Interoperability

This section describes the EGL interoperability functions of the CUDA runtime application programming interface.

Functions

__host__ cudaError_t cudaEGLStreamConsumerAcquireFrame(cudaEglStreamConnection *conn, cudaGraphicsResource_t *pCudaResource, cudaStream_t *pStream, unsigned int timeout): Acquire an image frame from the EGLStream with CUDA as a consumer.
__host__ cudaError_t cudaEGLStreamConsumerConnect(cudaEglStreamConnection *conn, EGLStreamKHR eglStream): Connect CUDA to EGLStream as a consumer.
__host__ cudaError_t cudaEGLStreamConsumerConnectWithFlags(cudaEglStreamConnection *conn, EGLStreamKHR eglStream, unsigned int flags): Connect CUDA to EGLStream as a consumer with given flags.
__host__ cudaError_t cudaEGLStreamConsumerDisconnect(cudaEglStreamConnection *conn): Disconnect CUDA as a consumer to EGLStream .
__host__ cudaError_t cudaEGLStreamConsumerReleaseFrame(cudaEglStreamConnection *conn, cudaGraphicsResource_t pCudaResource, cudaStream_t *pStream): Releases the last frame acquired from the EGLStream.
__host__ cudaError_t cudaEGLStreamProducerConnect(cudaEglStreamConnection *conn, EGLStreamKHR eglStream, EGLint width, EGLint height): Connect CUDA to EGLStream as a producer.
__host__ cudaError_t cudaEGLStreamProducerDisconnect(cudaEglStreamConnection *conn): Disconnect CUDA as a producer to EGLStream .
__host__ cudaError_t cudaEGLStreamProducerPresentFrame(cudaEglStreamConnection *conn, cudaEglFrame eglframe, cudaStream_t *pStream): Present a CUDA eglFrame to the EGLStream with CUDA as a producer.
__host__ cudaError_t cudaEGLStreamProducerReturnFrame(cudaEglStreamConnection *conn, cudaEglFrame *eglframe, cudaStream_t *pStream): Return the CUDA eglFrame to the EGLStream last released by the consumer.
__host__ cudaError_t cudaEventCreateFromEGLSync(cudaEvent_t *phEvent, EGLSyncKHR eglSync, unsigned int flags): Creates an event from EGLSync object.
__host__ cudaError_t cudaGraphicsEGLRegisterImage(struct cudaGraphicsResource **pCudaResource, EGLImageKHR image, unsigned int flags): Registers an EGL image.
__host__ cudaError_t cudaGraphicsResourceGetMappedEglFrame(cudaEglFrame *eglFrame, cudaGraphicsResource_t resource, unsigned int index, unsigned int mipLevel): Get an eglFrame through which to access a registered EGL graphics resource.

6.12.1. Functions

__host__ cudaError_t cudaEGLStreamConsumerAcquireFrame(cudaEglStreamConnection *conn, cudaGraphicsResource_t *pCudaResource, cudaStream_t *pStream, unsigned int timeout)

Acquire an image frame from the EGLStream with CUDA as a consumer.

Acquire an image frame from EGLStreamKHR. cudaGraphicsResourceGetMappedEglFrame can be called on pCudaResource to get cudaEglFrame.

Parameters

conn – - Connection on which to acquire
pCudaResource – - CUDA resource on which the EGLStream frame will be mapped for use.
pStream – - CUDA stream for synchronization and any data migrations implied by cudaEglResourceLocationFlags.
timeout – - Desired timeout in usec.

Returns

cudaSuccess, cudaErrorInvalidValue, cudaErrorUnknown, cudaErrorLaunchTimeout

__host__ cudaError_t cudaEGLStreamConsumerConnect(cudaEglStreamConnection *conn, EGLStreamKHR eglStream)

Connect CUDA to EGLStream as a consumer.

Connect CUDA as a consumer to EGLStreamKHR specified by eglStream.

The EGLStreamKHR is an EGL object that transfers a sequence of image frames from one API to another.

Parameters

conn – - Pointer to the returned connection handle
eglStream – - EGLStreamKHR handle

Returns

cudaSuccess, cudaErrorInvalidValue, cudaErrorUnknown

__host__ cudaError_t cudaEGLStreamConsumerConnectWithFlags(cudaEglStreamConnection *conn, EGLStreamKHR eglStream, unsigned int flags)

Connect CUDA to EGLStream as a consumer with given flags.

Connect CUDA as a consumer to EGLStreamKHR specified by stream with specified flags defined by cudaEglResourceLocationFlags.

The flags specify whether the consumer wants to access frames from system memory or video memory. Default is cudaEglResourceLocationVidmem.

See also

cudaEGLStreamConsumerDisconnect, cudaEGLStreamConsumerAcquireFrame, cudaEGLStreamConsumerReleaseFrame, ::cuEGLStreamConsumerConnectWithFlags

Parameters

conn – - Pointer to the returned connection handle
eglStream – - EGLStreamKHR handle
flags – - Flags denote intended location - system or video.

Returns

cudaSuccess, cudaErrorInvalidValue, cudaErrorUnknown

__host__ cudaError_t cudaEGLStreamConsumerDisconnect(cudaEglStreamConnection *conn)

Disconnect CUDA as a consumer to EGLStream .

Disconnect CUDA as a consumer to EGLStreamKHR.

Parameters: conn – - Conection to disconnect.
Returns: cudaSuccess, cudaErrorInvalidValue, cudaErrorUnknown

__host__ cudaError_t cudaEGLStreamConsumerReleaseFrame(cudaEglStreamConnection *conn, cudaGraphicsResource_t pCudaResource, cudaStream_t *pStream)

Releases the last frame acquired from the EGLStream.

Release the acquired image frame specified by pCudaResource to EGLStreamKHR.

Parameters

conn – - Connection on which to release
pCudaResource – - CUDA resource whose corresponding frame is to be released
pStream – - CUDA stream on which release will be done.

Returns

cudaSuccess, cudaErrorInvalidValue, cudaErrorUnknown

__host__ cudaError_t cudaEGLStreamProducerConnect(cudaEglStreamConnection *conn, EGLStreamKHR eglStream, EGLint width, EGLint height)

Connect CUDA to EGLStream as a producer.

Connect CUDA as a producer to EGLStreamKHR specified by stream.

The EGLStreamKHR is an EGL object that transfers a sequence of image frames from one API to another.

Parameters

conn – - Pointer to the returned connection handle
eglStream – - EGLStreamKHR handle
width – - width of the image to be submitted to the stream
height – - height of the image to be submitted to the stream

Returns

cudaSuccess, cudaErrorInvalidValue, cudaErrorUnknown

__host__ cudaError_t cudaEGLStreamProducerDisconnect(cudaEglStreamConnection *conn)

Disconnect CUDA as a producer to EGLStream .

Disconnect CUDA as a producer to EGLStreamKHR.

Parameters: conn – - Conection to disconnect.
Returns: cudaSuccess, cudaErrorInvalidValue, cudaErrorUnknown

__host__ cudaError_t cudaEGLStreamProducerPresentFrame(cudaEglStreamConnection *conn, cudaEglFrame eglframe, cudaStream_t *pStream)

Present a CUDA eglFrame to the EGLStream with CUDA as a producer.

The cudaEglFrame is defined as:

typedef struct cudaEglFrame_st {
    union {
        cudaArray_t            pArray[CUDA_EGL_MAX_PLANES];
        struct cudaPitchedPtr  pPitch[CUDA_EGL_MAX_PLANES];
    } frame;
    cudaEglPlaneDesc planeDesc[CUDA_EGL_MAX_PLANES];
    unsigned int planeCount;
    cudaEglFrameType frameType;
    cudaEglColorFormat eglColorFormat;
} cudaEglFrame;

For cudaEglFrame of type cudaEglFrameTypePitch, the application may present sub-region of a memory allocation. In that case, cudaPitchedPtr::ptr will specify the start address of the sub-region in the allocation and cudaEglPlaneDesc will specify the dimensions of the sub-region.

Parameters

conn – - Connection on which to present the CUDA array
eglframe – - CUDA Eglstream Proucer Frame handle to be sent to the consumer over EglStream.
pStream – - CUDA stream on which to present the frame.

Returns

cudaSuccess, cudaErrorInvalidValue, cudaErrorUnknown

__host__ cudaError_t cudaEGLStreamProducerReturnFrame(cudaEglStreamConnection *conn, cudaEglFrame *eglframe, cudaStream_t *pStream)

Return the CUDA eglFrame to the EGLStream last released by the consumer.

This API can potentially return cudaErrorLaunchTimeout if the consumer has not returned a frame to EGL stream. If timeout is returned the application can retry.

Parameters

conn – - Connection on which to present the CUDA array
eglframe – - CUDA Eglstream Proucer Frame handle returned from the consumer over EglStream.
pStream – - CUDA stream on which to return the frame.

Returns

cudaSuccess, cudaErrorLaunchTimeout, cudaErrorInvalidValue, cudaErrorUnknown

__host__ cudaError_t cudaEventCreateFromEGLSync(cudaEvent_t *phEvent, EGLSyncKHR eglSync, unsigned int flags)

Creates an event from EGLSync object.

Creates an event *phEvent from an EGLSyncKHR eglSync with the flages specified via flags. Valid flags include:

cudaEventDefault: Default event creation flag.
cudaEventBlockingSync: Specifies that the created event should use blocking synchronization. A CPU thread that uses cudaEventSynchronize() to wait on an event created with this flag will block until the event has actually been completed.

cudaEventRecord and TimingData are not supported for events created from EGLSync.

The EGLSyncKHR is an opaque handle to an EGL sync object. typedef void* EGLSyncKHR

Parameters

phEvent – - Returns newly created event
eglSync – - Opaque handle to EGLSync object
flags – - Event creation flags

Returns

cudaSuccess, cudaErrorInitializationError, cudaErrorInvalidValue, cudaErrorLaunchFailure, cudaErrorMemoryAllocation

__host__ cudaError_t cudaGraphicsEGLRegisterImage(struct cudaGraphicsResource **pCudaResource, EGLImageKHR image, unsigned int flags)

Registers an EGL image.

Registers the EGLImageKHR specified by image for access by CUDA. A handle to the registered object is returned as pCudaResource. Additional Mapping/Unmapping is not required for the registered resource and cudaGraphicsResourceGetMappedEglFrame can be directly called on the pCudaResource.

The application will be responsible for synchronizing access to shared objects. The application must ensure that any pending operation which access the objects have completed before passing control to CUDA. This may be accomplished by issuing and waiting for glFinish command on all GLcontexts (for OpenGL and likewise for other APIs). The application will be also responsible for ensuring that any pending operation on the registered CUDA resource has completed prior to executing subsequent commands in other APIs accesing the same memory objects. This can be accomplished by calling cuCtxSynchronize or cuEventSynchronize (preferably).

The surface’s intended usage is specified using flags, as follows:

cudaGraphicsRegisterFlagsNone: Specifies no hints about how this resource will be used. It is therefore assumed that this resource will be read from and written to by CUDA. This is the default value.
cudaGraphicsRegisterFlagsReadOnly: Specifies that CUDA will not write to this resource.
cudaGraphicsRegisterFlagsWriteDiscard: Specifies that CUDA will not read from this resource and will write over the entire contents of the resource, so none of the data previously stored in the resource will be preserved.

The EGLImageKHR is an object which can be used to create EGLImage target resource. It is defined as a void pointer. typedef void* EGLImageKHR

See also

cudaGraphicsUnregisterResource, cudaGraphicsResourceGetMappedEglFrame, ::cuGraphicsEGLRegisterImage

Parameters

pCudaResource – - Pointer to the returned object handle
image – - An EGLImageKHR image which can be used to create target resource.
flags – - Map flags

Returns

cudaSuccess, cudaErrorInvalidResourceHandle, cudaErrorInvalidValue, cudaErrorUnknown

__host__ cudaError_t cudaGraphicsResourceGetMappedEglFrame(cudaEglFrame *eglFrame, cudaGraphicsResource_t resource, unsigned int index, unsigned int mipLevel)

Get an eglFrame through which to access a registered EGL graphics resource.

Returns in *eglFrame an eglFrame pointer through which the registered graphics resource resource may be accessed. This API can only be called for EGL graphics resources.

The cudaEglFrame is defined as

typedef struct cudaEglFrame_st {
    union {
        cudaArray_t             pArray[CUDA_EGL_MAX_PLANES];
        struct cudaPitchedPtr   pPitch[CUDA_EGL_MAX_PLANES];
    } frame;
    cudaEglPlaneDesc planeDesc[CUDA_EGL_MAX_PLANES];
    unsigned int planeCount;
    cudaEglFrameType frameType;
    cudaEglColorFormat eglColorFormat;
} cudaEglFrame;

See also

cudaGraphicsSubResourceGetMappedArray, cudaGraphicsResourceGetMappedPointer, ::cuGraphicsResourceGetMappedEglFrame

Note

Note that in case of multiplanar *eglFrame, pitch of only first plane (unsigned int cudaEglPlaneDesc::pitch) is to be considered by the application.

Parameters

eglFrame – - Returned eglFrame.
resource – - Registered resource to access.
index – - Index for cubemap surfaces.
mipLevel – - Mipmap level for the subresource to access.

Returns

cudaSuccess, cudaErrorInvalidValue, cudaErrorUnknown