Detailed Description

Defines a helper class for V4L2 Video Decoder.

The video decoder device node is /dev/nvhost-nvdec. The category name for the decoder is "NVDEC".

Refer to V4L2 Video Decoder for more information on the decoder.

Definition at line 58 of file NvVideoDecoder.h.

Inheritance diagram for NvVideoDecoder:

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Collaboration diagram for NvVideoDecoder:

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Public Member Functions
	~NvVideoDecoder ()

int	setCapturePlaneFormat (uint32_t pixfmt, uint32_t width, uint32_t height)
	Sets the format on the decoder output plane. More...

int	setOutputPlaneFormat (uint32_t pixfmt, uint32_t sizeimage)
	Sets the format on the decoder output plane. More...

int	disableCompleteFrameInputBuffer ()
	Informs the decoder that input buffers may not contain complete frames. More...

int	setFrameInputMode (unsigned int ctrl_value)
	Informs the decoder that input buffers may not contain complete frames. More...

int	disableDPB ()
	Disables the display picture buffer. More...

int	getMinimumCapturePlaneBuffers (int &num)
	Gets the minimum number of buffers to be requested on the decoder capture plane. More...

int	setSkipFrames (enum v4l2_skip_frames_type skip_frames)
	Sets the skip-frames parameter of the decoder. More...

int	setMaxPerfMode (int flag)
	Sets the decoder for maximum performance. More...

int	enableMetadataReporting ()
	Enables video decoder output metadata reporting. More...

int	checkifMasteringDisplayDataPresent (v4l2_ctrl_video_displaydata &displaydata)

int	MasteringDisplayData (v4l2_ctrl_video_hdrmasteringdisplaydata *hdrmasteringdisplaydata)

int	getMetadata (uint32_t buffer_index, v4l2_ctrl_videodec_outputbuf_metadata &metadata)
	Gets metadata for the decoded capture plane buffer. More...

int	getInputMetadata (uint32_t buffer_index, v4l2_ctrl_videodec_inputbuf_metadata &input_metadata)
	Gets metadata for the decoder output plane buffer. More...

int	getSAR (uint32_t &sar_width, uint32_t &sar_height)
	Gets Sample Aspect Ratio (SAR) width and height for decoder. More...

int	DevicePoll (v4l2_ctrl_video_device_poll *devicepoll)
	Issues Poll on the device which blocks until : a) Either there is something to dequeue from capture or output plane or any events. More...

int	SetPollInterrupt ()
	Sets the polling interrupt, now if the application calls Poll, the device should not block, in other words polling is disabled. More...

int	ClearPollInterrupt ()
	Clears the polling interrupt, now if the application calls Poll, the device should block until the event is triggered, in other words polling is enabled. More...

int	subscribeEvent (uint32_t type, uint32_t id, uint32_t flags)
	Subscribes to an V4L2 event. More...

int	dqEvent (struct v4l2_event &event, uint32_t max_wait_ms)
	Dequeues an event from the element. More...

int	setControl (uint32_t id, int32_t value)
	Sets the value of a control. More...

int	getControl (uint32_t id, int32_t &value)
	Gets the value of a control. More...

int	setExtControls (struct v4l2_ext_controls &ctl)
	Sets the value of several controls. More...

int	getExtControls (struct v4l2_ext_controls &ctl)
	Gets the value of several controls. More...

virtual int	isInError ()

int	abort ()
	Terminates processing of queued buffers immediately. More...

virtual int	waitForIdle (uint32_t max_wait_ms)
	Waits until the element processes all the output plane buffers. More...

void	enableProfiling ()
	Enables profiling for the V4l2Element. More...

void	getProfilingData (NvElementProfiler::NvElementProfilerData &data)
	Gets profiling data for the element. More...

void	printProfilingStats (std::ostream &out_stream=std::cout)
	Prints profiling data for the element to an output stream. More...

bool	isProfilingEnabled ()
	Checks whether profiling is enabled for the element. More...

Static Public Member Functions
static NvVideoDecoder *	createVideoDecoder (const char *name, int flags=0)
	Creates a new V4L2 Video Decoder object named name. More...

Data Fields
NvV4l2ElementPlane	output_plane
	Sets the output plane. More...

NvV4l2ElementPlane	capture_plane
	Sets the capture plane. More...

void *	app_data
	A pointer to the application-specific data. More...

Protected Attributes
int	fd
	Specifies the FD of the device opened using `v4l2_open`. More...

uint32_t	output_plane_pixfmt
	Pixel format of output plane buffers. More...

uint32_t	capture_plane_pixfmt
	Pixel format of capture plane buffers. More...

int	is_in_error
	Indicates if an error was encountered during the operation of the element. More...

const char *	comp_name
	Specifies the name of the component, for debugging. More...

NvElementProfiler	profiler
	Profiler for the element. More...

Constructor & Destructor Documentation

◆ ~NvVideoDecoder()

NvVideoDecoder::~NvVideoDecoder ( )

Member Function Documentation

◆ abort()

int NvV4l2Element::abort ( )

inherited

Terminates processing of queued buffers immediately.

All the buffers are returned to the application.

Calls VIDIOC_STREAMOFF IOCTL on both of the planes internally.

Returns: 0 for success, -1 otherwise.

◆ checkifMasteringDisplayDataPresent()

int NvVideoDecoder::checkifMasteringDisplayDataPresent ( v4l2_ctrl_video_displaydata & displaydata )

◆ ClearPollInterrupt()

int NvVideoDecoder::ClearPollInterrupt ( )

Clears the polling interrupt, now if the application calls Poll, the device should block until the event is triggered, in other words polling is enabled.

◆ createVideoDecoder()

static NvVideoDecoder* NvVideoDecoder::createVideoDecoder	(	const char *	name,
		int	flags = `0`
	)

static

Creates a new V4L2 Video Decoder object named name.

This method internally calls v4l2_open on the decoder dev node "/dev/nvhost-nvdec" and checks for V4L2_CAP_VIDEO_M2M_MPLANE capability on the device. This method allows the caller to specify additional flags with which the device should be opened.

The device is opened in blocking mode, which can be modified by passing the O_NONBLOCK flag to this method.

Returns: Reference to the newly created decoder object else NULL in case of failure during initialization.

◆ DevicePoll()

int NvVideoDecoder::DevicePoll ( v4l2_ctrl_video_device_poll * devicepoll )

Issues Poll on the device which blocks until : a) Either there is something to dequeue from capture or output plane or any events.

b) Poll was interrupted by a call to the device using V4L2_CID_SET_POLL_INTERRUPT c) Application has already interrupted polling by V4L2_CID_SET_POLL_INTERRUPT

◆ disableCompleteFrameInputBuffer()

int NvVideoDecoder::disableCompleteFrameInputBuffer ( )

Informs the decoder that input buffers may not contain complete frames.

Deprecated interface, Use setFrameInputMode instead.

Calls the VIDIOC_S_EXT_CTRLS IOCTL internally with Control ID V4L2_CID_MPEG_VIDEO_DISABLE_COMPLETE_FRAME_INPUT.

Returns: 0 for success, -1 otherwise.

◆ disableDPB()

int NvVideoDecoder::disableDPB ( )

Disables the display picture buffer.

Calls the VIDIOC_S_EXT_CTRLS IOCTL internally with Control ID V4L2_CID_MPEG_VIDEO_DISABLE_DPB. Must be called after setFormat on both the planes and before requestBuffers on any of the planes.

Returns: 0 for success, -1 otherwise.

◆ dqEvent()

int NvV4l2Element::dqEvent	(	struct v4l2_event &	event,
		uint32_t	max_wait_ms
	)

inherited

Dequeues an event from the element.

Calls VIDIOC_DQEVENT IOCTL internally. The caller can specify the maximum time to wait for dequeuing the event. The call blocks until an event is dequeued successfully or timeout is reached.

Parameters

[in,out]	event	A reference to the `v4l2_event` structure to fill.
[in]	max_wait_ms	Specifies the max wait time for dequeuing an event, in milliseconds.

Returns: 0 for success, -1 otherwise.

◆ enableMetadataReporting()

int NvVideoDecoder::enableMetadataReporting ( )

Enables video decoder output metadata reporting.

Calls the VIDIOC_S_EXT_CTRLS IOCTL internally with Control ID V4L2_CID_MPEG_VIDEO_ERROR_REPORTING. Must be called after setFormat on both the planes and before requestBuffers on any of the planes.

Returns: 0 for success, -1 otherwise.

◆ enableProfiling()

void NvV4l2Element::enableProfiling ( )

virtualinherited

Enables profiling for the V4l2Element.

Must be called before setting either plane formats.

Reimplemented from NvElement.

◆ getControl()

int NvV4l2Element::getControl	(	uint32_t	id,
		int32_t &	value
	)

inherited

Gets the value of a control.

Calls VIDIOC_G_CTRL IOCTL internally.

Parameters

[in]	id	ID of the control to get.
[out]	value	A reference to the variable into which the control value is read.

Returns: 0 for success, -1 otherwise.

◆ getExtControls()

int NvV4l2Element::getExtControls ( struct v4l2_ext_controls & ctl )

inherited

Gets the value of several controls.

Calls VIDIOC_G_EXT_CTRLS IOCTL internally.

Parameters

[in,out] ctl A pointer to the controls to get.

Returns: 0 for success, -1 otherwise.

◆ getInputMetadata()

int NvVideoDecoder::getInputMetadata	(	uint32_t	buffer_index,
		v4l2_ctrl_videodec_inputbuf_metadata &	input_metadata
	)

Gets metadata for the decoder output plane buffer.

Calls the VIDIOC_G_EXT_CTRLS IOCTL internally with Control ID V4L2_CID_MPEG_VIDEODEC_INPUT_METADATA. Must be called for a buffer that has been dequeued from the output plane. The returned metadata corresponds to the last dequeued buffer with index buffer_index.

Parameters

[in]	buffer_index	Index of the output plane buffer whose metadata is required.
[in,out]	input_metadata	Reference to the metadata structure v4l2_ctrl_videodec_inputbuf_metadata to be filled.

Returns: 0 for success, -1 otherwise.

◆ getMetadata()

int NvVideoDecoder::getMetadata	(	uint32_t	buffer_index,
		v4l2_ctrl_videodec_outputbuf_metadata &	metadata
	)

Gets metadata for the decoded capture plane buffer.

Calls the VIDIOC_G_EXT_CTRLS IOCTL internally with Control ID V4L2_CID_MPEG_VIDEODEC_METADATA. Must be called for a buffer that has been dequeued from the capture plane. The returned metadata corresponds to the last dequeued buffer with index buffer_index.

Parameters

[in]	buffer_index	Index of the capture plane buffer whose metadata is required.
[in,out]	metadata	Reference to the metadata structure v4l2_ctrl_videodec_outputbuf_metadata to be filled.

Returns: 0 for success, -1 otherwise.

◆ getMinimumCapturePlaneBuffers()

int NvVideoDecoder::getMinimumCapturePlaneBuffers ( int & num )

Gets the minimum number of buffers to be requested on the decoder capture plane.

Calls the VIDIOC_G_CTRL IOCTL internally with Control ID V4L2_CID_MIN_BUFFERS_FOR_CAPTURE. It is valid after the first V4L2_RESOLUTION_CHANGE_EVENT and may change after each subsequent event.

Parameters

[out] num A reference to the integer to return the number of buffers.

Returns: 0 for success, -1 otherwise.

◆ getProfilingData()

void NvElement::getProfilingData ( NvElementProfiler::NvElementProfilerData & data )

inherited

Gets profiling data for the element.

Returns: A constant reference to the element's profiling data.

◆ getSAR()

int NvVideoDecoder::getSAR	(	uint32_t &	sar_width,
		uint32_t &	sar_height
	)

Gets Sample Aspect Ratio (SAR) width and height for decoder.

Calls the VIDIOC_G_EXT_CTRLS IOCTL internally with Control ID V4L2_CID_MPEG_VIDEODEC_SAR_WIDTH and V4L2_CID_MPEG_VIDEODEC_SAR_HEIGHT. Must be called after V4L2_EVENT_RESOLUTION_CHANGE is dequeued.

Parameters

[in,out]	sar_width	Reference to the SAR width to be filled.
[in,out]	sar_height	Reference to the SAR height to be filled.

Returns: 0 for success, -1 otherwise.

◆ isInError()

virtual int NvV4l2Element::isInError ( )

virtualinherited

Reimplemented from NvElement.

◆ isProfilingEnabled()

bool NvElement::isProfilingEnabled ( )

inherited

Checks whether profiling is enabled for the element.

Returns: Boolean value indicating if profiling is enabled.

◆ MasteringDisplayData()

int NvVideoDecoder::MasteringDisplayData ( v4l2_ctrl_video_hdrmasteringdisplaydata * hdrmasteringdisplaydata )

◆ printProfilingStats()

void NvElement::printProfilingStats ( std::ostream & out_stream = std::cout )

inherited

Prints profiling data for the element to an output stream.

Parameters

[in] out_stream Output stream of type std::ostream to print the data to. It takes the default value std::cout if not specified.

◆ setCapturePlaneFormat()

int NvVideoDecoder::setCapturePlaneFormat	(	uint32_t	pixfmt,
		uint32_t	width,
		uint32_t	height
	)

Sets the format on the decoder output plane.

Calls VIDIOC_S_FMT IOCTL internally on the capture plane.

Parameters

[in]	pixfmt	One of the raw V4L2 pixel formats.
[in]	width	Width of the output buffers in pixels.
[in]	height	Height of the output buffers in pixels.

Returns: 0 for success, -1 otherwise.

◆ setControl()

int NvV4l2Element::setControl	(	uint32_t	id,
		int32_t	value
	)

inherited

Sets the value of a control.

Calls VIDIOC_S_CTRL IOCTL internally.

Parameters

[in]	id	ID of the control to be set.
[in]	value	Value to be set on the control.

Returns: 0 for success, -1 otherwise.

◆ setExtControls()

int NvV4l2Element::setExtControls ( struct v4l2_ext_controls & ctl )

inherited

Sets the value of several controls.

Calls VIDIOC_S_EXT_CTRLS IOCTL internally.

Parameters

[in] ctl A pointer to the controls to set.

Returns: 0 for success, -1 otherwise.

◆ setFrameInputMode()

int NvVideoDecoder::setFrameInputMode ( unsigned int ctrl_value )

Informs the decoder that input buffers may not contain complete frames.

Calls the VIDIOC_S_EXT_CTRLS IOCTL internally with Control ID V4L2_CID_MPEG_VIDEO_DISABLE_COMPLETE_FRAME_INPUT.

Parameters

[in] ctrl_value control value to disable complete frame input buffer.

Returns: 0 for success, -1 otherwise.

◆ setMaxPerfMode()

int NvVideoDecoder::setMaxPerfMode ( int flag )

Sets the decoder for maximum performance.

Calls the VIDIOC_S_EXT_CTRLS IOCTL internally with Control ID V4L2_CID_MPEG_VIDEO_MAX_PERFORMANCE. Must be called after setFormat on both the planes and before requestBuffers on any of the planes.

Parameters

[in] flag Integer variable to indicate whether max performance is to be enabled/disabled.

Returns: 0 for success, -1 otherwise.

◆ setOutputPlaneFormat()

int NvVideoDecoder::setOutputPlaneFormat	(	uint32_t	pixfmt,
		uint32_t	sizeimage
	)

Sets the format on the decoder output plane.

Calls the VIDIOC_S_FMT IOCTL internally on the output plane.

Parameters

[in]	pixfmt	One of the coded V4L2 pixel formats.
[in]	sizeimage	Maximum size of the buffers on the output plane. containing encoded data in bytes.

Returns: 0 for success, -1 otherwise.

◆ SetPollInterrupt()

int NvVideoDecoder::SetPollInterrupt ( )

Sets the polling interrupt, now if the application calls Poll, the device should not block, in other words polling is disabled.

◆ setSkipFrames()

int NvVideoDecoder::setSkipFrames ( enum v4l2_skip_frames_type skip_frames )

Sets the skip-frames parameter of the decoder.

Calls the VIDIOC_S_EXT_CTRLS IOCTL internally with Control ID V4L2_CID_MPEG_VIDEO_SKIP_FRAMES. Must be called after setFormat on both the planes and before requestBuffers on any of the planes.

Parameters

[in] skip_frames Type of frames to skip decoding, one of enum v4l2_skip_frames_type.

Returns: 0 for success, -1 otherwise.

◆ subscribeEvent()

int NvV4l2Element::subscribeEvent	(	uint32_t	type,
		uint32_t	id,
		uint32_t	flags
	)

inherited

Subscribes to an V4L2 event.

Calls VIDIOC_SUBSCRIBE_EVENT IOCTL internally.

Parameters

[in]	type	Type of the event.
[in]	id	ID of the event source.
[in]	flags	Event flags.

Returns: 0 for success, -1 otherwise.

◆ waitForIdle()

virtual int NvV4l2Element::waitForIdle ( uint32_t max_wait_ms )

virtualinherited

Waits until the element processes all the output plane buffers.

Objects extending V4l2Element must implement this because the idle condition is component-specific.

Parameters

[in] max_wait_ms Max time to wait in milliseconds.

Returns: 0 for success, -1 otherwise.

Reimplemented in NvVideoConverter.

Field Documentation

◆ app_data

void* NvV4l2Element::app_data

inherited

A pointer to the application-specific data.

Definition at line 169 of file NvV4l2Element.h.

◆ capture_plane

NvV4l2ElementPlane NvV4l2Element::capture_plane

inherited

Sets the capture plane.

Capture plane of the element

Definition at line 145 of file NvV4l2Element.h.

◆ capture_plane_pixfmt

uint32_t NvV4l2Element::capture_plane_pixfmt

protectedinherited

Pixel format of capture plane buffers.

Definition at line 182 of file NvV4l2Element.h.

◆ comp_name

const char* NvElement::comp_name

protectedinherited

Specifies the name of the component, for debugging.

Definition at line 122 of file NvElement.h.

◆ fd

int NvV4l2Element::fd

protectedinherited

Specifies the FD of the device opened using v4l2_open.

Definition at line 179 of file NvV4l2Element.h.

◆ is_in_error

int NvElement::is_in_error

protectedinherited

Indicates if an error was encountered during the operation of the element.

Definition at line 120 of file NvElement.h.

Referenced by NvElement::isInError().

◆ output_plane

NvV4l2ElementPlane NvV4l2Element::output_plane

inherited

Sets the output plane.

Output plane of the element

Definition at line 141 of file NvV4l2Element.h.

◆ output_plane_pixfmt

uint32_t NvV4l2Element::output_plane_pixfmt

protectedinherited

Pixel format of output plane buffers.

Definition at line 181 of file NvV4l2Element.h.

◆ profiler

NvElementProfiler NvElement::profiler

protectedinherited

Profiler for the element.

Definition at line 124 of file NvElement.h.

The documentation for this class was generated from the following file:

multimedia_api/ll_samples/include/NvVideoDecoder.h


Jetson Linux API Reference	32.7.5 Release

Jetson Linux API Reference

32.7.5 Release

Detailed Description

Public Member Functions

Static Public Member Functions

Data Fields

Protected Attributes

Constructor & Destructor Documentation

◆ ~NvVideoDecoder()

Member Function Documentation

◆ abort()

◆ checkifMasteringDisplayDataPresent()

◆ ClearPollInterrupt()

◆ createVideoDecoder()

◆ DevicePoll()

◆ disableCompleteFrameInputBuffer()

◆ disableDPB()

◆ dqEvent()

◆ enableMetadataReporting()

◆ enableProfiling()

◆ getControl()

◆ getExtControls()

◆ getInputMetadata()

◆ getMetadata()

◆ getMinimumCapturePlaneBuffers()

◆ getProfilingData()

◆ getSAR()

◆ isInError()

◆ isProfilingEnabled()

◆ MasteringDisplayData()

◆ printProfilingStats()

◆ setCapturePlaneFormat()

◆ setControl()

◆ setExtControls()

◆ setFrameInputMode()

◆ setMaxPerfMode()

◆ setOutputPlaneFormat()

◆ SetPollInterrupt()

◆ setSkipFrames()

◆ subscribeEvent()

◆ waitForIdle()

Field Documentation

◆ app_data

◆ capture_plane

◆ capture_plane_pixfmt

◆ comp_name

◆ fd

◆ is_in_error

◆ output_plane

◆ output_plane_pixfmt

◆ profiler