Gst-nvunixfd

The Gst-nvunixfd plugin performs the hardware video buffers sharing between different processes and pipelines via IPC (inter-process communication). Gst-nvunixfd provides the Gst-nvunixfdsink and Gst-nvunixfdsrc for sending and receiving the hardware video buffers between pipelines to avoid unnecessary memory copy. Gst-nvunixfdsink acts as a server, the NvBufSurfaceMapParams which contains the video buffer information and the IPC sharable FD(File Descriptor) of the video buffer are sent to the Gst-nvunixfdsrc. Gst-nvunixfdsrc then creates a new NvBufSurface with the received data. On Jetson, FD is the bufferDesc in the NvBufSurface structure. On DGPU, FD is a cudaIpcMemHandle_t handle derived from the CUDA memory.

The Gst-nvunixfdsink pipeline can send hardware video buffers to multiple Gst-nvunixfdsrc pipelines, the Gst-nvunixfdsrc pipeline can receive hardware video buffers from multiple Gst-nvunixfdsink pipelines. All the pipelines should work in the same device and the same system. The batched NvBufSurface is not supported.

Gst-nvunixfdsink

Gst-nvunixfdsink is a Unix file descriptor sink derived from OSS unixfdsink element, which is used on server side.

Gst-nvunixfd

Inputs and Outputs

Inputs
- Gst no-batched buffer
Control parameters
- gpu-id: selects the GPU ID
- buffer-copy: copy buffer for every client
- buffer-timestamp-copy: copy timestamp of the received Gst buffers
- compute-hw: Compute HW for copy operation
- meta-serialization-lib: Set meta serialization library name to be used
- socket-type: The type of underlying socket
- socket-path: The path to the control socket used to control the shared memory
Output
- After client connects, server passes the NvBufSurface handle, timestamp and other data to client through IPC.

Features

The following table summarizes the features of the Gst-nvunixfdsink plugin.

Gst-nvunixfdsink plugin features

Feature	Description	Release
Configure GPU selection	Sets the GPU ID to be used for optical flow visualization operations (valid only for dGPU platforms)	DS 8.0
buffer copy	copy buffer for every client	DS 8.0
buffer timestamp copy	copy timestamp of received buffer	DS 8.0
compute HW	Compute HW for copy operation	DS 8.0
meta serialization lib	Set meta serialization library name to be used	DS 8.0
socket type	The type of underlying socket	DS 8.0
socket path	The path to the control socket used to control the shared memory	DS 8.0

Gst-nvunixfdsrc

Gst-nvunixfdsrc is a Unix file descriptor source derived from OSS unixfdsrc element, which is used on client side.

Gst-nvunixfd

Inputs and Outputs

Inputs
- The NvBufSurface handle, timestamp and other data received from server.
Control parameters
- gpu-id: selects the GPU ID
- buffer-copy: copy buffer for every client
- buffer-timestamp-copy: copy timestamp of received buffer
- compute-hw: Compute HW for copy operation
- meta-deserialization-lib: Set meta deserialization library name to be used
- socket-type: The type of underlying socket
- socket-path: The path to the control socket used to control the shared memory
- connection-attempts: Max number of attempts for connection (-1 = unlimited)
- connection-interval: Connection interval between connection attempts in micro seconds
Output
- Gst no-batched buffer

Features

The following table summarizes the features of the Gst-nvunixfdsrc plugin.

Gst-nvunixfdsrc plugin features

Feature	Description	Release
Configure GPU selection	Sets the GPU ID to be used for optical flow visualization operations (valid only for dGPU platforms)	DS 8.0
buffer copy	copy buffer for every client	DS 8.0
buffer timestamp copy	copy timestamp of received buffer	DS 8.0
compute HW	Compute HW for copy operation	DS 8.0
meta deserialization lib	Set meta deserialization library name to be used	DS 8.0
socket type	The type of underlying socket	DS 8.0
socket path	The path to the control socket used to control the shared memory	DS 8.0
connection attempts	Max number of attempts for connection	DS 8.0
connection interval	connection interval	DS 8.0

Gst Properties

The following table describes the Gst properties of the Gst-nvunixfdsrc plugin.

Gst-nvunixfdsrc plugin gst properties

Property	Meaning	Type and Range	Example Notes
gpu-id	Device ID of the GPU to be used(dGPU only)	Integer,0 to 4,294,967,295	gpu-id=0
buffer-copy	Buffer copy	Boolean. Default: false	buffer-copy=0
buffer-timestamp-copy	Buffer copy	Boolean. Default: false	buffer-copy=0
compute-hw	Type of computing hardware: 0: Default (GPU for gDPU, CPU for Jetson) 1: VLC( only for Jetson) 2: GPU	enum GstComputeHW	compute-hw=0 Default value is 0.
buffer-timestamp-copy	Buffer copy	Boolean. Default: false	buffer-copy=0
meta-serialization-lib	Meta serialization library name	String	./lib/serialization.so
socket-type	socket type	enum GUnixSocketAddressType	socket-type=G_UNIX_SOCKET_ADDRESS_PATH,Default value is G_UNIX_SOCKET_ADDRESS_PATH
socket-path	Path to the control socket	String	socket-path=/tmp/test1
connection-attempts	Max number of attempts for connection (-1 = unlimited)	int	connection-attempts=3,Default: -1
connection-interval	Path to the control socket	int	connection-interval=3000000,Default: 1000000