#include "buffer.h"
#include "frame.h"
#include "log.h"
#include "pixfmt.h"

Data Structures
struct	AVHWDeviceContext
	This struct aggregates all the (hardware/vendor-specific) "high-level" state, i.e. More...

struct	AVHWFramesContext
	This struct describes a set or pool of "hardware" frames (i.e. More...

struct	AVHWFramesConstraints
	This struct describes the constraints on hardware frames attached to a given device with a hardware-specific configuration. More...

Typedefs
typedef struct AVHWDeviceInternal	AVHWDeviceInternal

typedef struct AVHWFramesInternal	AVHWFramesInternal

Enumerations
enum	AVHWDeviceType { AV_HWDEVICE_TYPE_NONE , AV_HWDEVICE_TYPE_VDPAU , AV_HWDEVICE_TYPE_CUDA , AV_HWDEVICE_TYPE_VAAPI , AV_HWDEVICE_TYPE_DXVA2 , AV_HWDEVICE_TYPE_QSV , AV_HWDEVICE_TYPE_VIDEOTOOLBOX , AV_HWDEVICE_TYPE_D3D11VA , AV_HWDEVICE_TYPE_DRM , AV_HWDEVICE_TYPE_OPENCL , AV_HWDEVICE_TYPE_MEDIACODEC , AV_HWDEVICE_TYPE_VULKAN }

enum	AVHWFrameTransferDirection { AV_HWFRAME_TRANSFER_DIRECTION_FROM , AV_HWFRAME_TRANSFER_DIRECTION_TO }

enum	{ AV_HWFRAME_MAP_READ = 1 << 0 , AV_HWFRAME_MAP_WRITE = 1 << 1 , AV_HWFRAME_MAP_OVERWRITE = 1 << 2 , AV_HWFRAME_MAP_DIRECT = 1 << 3 }
	Flags to apply to frame mappings. More...

Functions
enum AVHWDeviceType	av_hwdevice_find_type_by_name (const char *name)
	Look up an AVHWDeviceType by name. More...

const char *	av_hwdevice_get_type_name (enum AVHWDeviceType type)
	Get the string name of an AVHWDeviceType. More...

enum AVHWDeviceType	av_hwdevice_iterate_types (enum AVHWDeviceType prev)
	Iterate over supported device types. More...

AVBufferRef *	av_hwdevice_ctx_alloc (enum AVHWDeviceType type)
	Allocate an AVHWDeviceContext for a given hardware type. More...

int	av_hwdevice_ctx_init (AVBufferRef *ref)
	Finalize the device context before use. More...

int	av_hwdevice_ctx_create (AVBufferRef *device_ctx, enum AVHWDeviceType type, const char device, AVDictionary *opts, int flags)
	Open a device of the specified type and create an AVHWDeviceContext for it. More...

int	av_hwdevice_ctx_create_derived (AVBufferRef *dst_ctx, enum AVHWDeviceType type, AVBufferRef src_ctx, int flags)
	Create a new device of the specified type from an existing device. More...

int	av_hwdevice_ctx_create_derived_opts (AVBufferRef *dst_ctx, enum AVHWDeviceType type, AVBufferRef src_ctx, AVDictionary *options, int flags)
	Create a new device of the specified type from an existing device. More...

AVBufferRef *	av_hwframe_ctx_alloc (AVBufferRef *device_ctx)
	Allocate an AVHWFramesContext tied to a given device context. More...

int	av_hwframe_ctx_init (AVBufferRef *ref)
	Finalize the context before use. More...

int	av_hwframe_get_buffer (AVBufferRef hwframe_ctx, AVFrame frame, int flags)
	Allocate a new frame attached to the given AVHWFramesContext. More...

int	av_hwframe_transfer_data (AVFrame dst, const AVFrame src, int flags)
	Copy data to or from a hw surface. More...

int	av_hwframe_transfer_get_formats (AVBufferRef hwframe_ctx, enum AVHWFrameTransferDirection dir, enum AVPixelFormat *formats, int flags)
	Get a list of possible source or target formats usable in av_hwframe_transfer_data(). More...

void *	av_hwdevice_hwconfig_alloc (AVBufferRef *device_ctx)
	Allocate a HW-specific configuration structure for a given HW device. More...

AVHWFramesConstraints *	av_hwdevice_get_hwframe_constraints (AVBufferRef ref, const void hwconfig)
	Get the constraints on HW frames given a device and the HW-specific configuration to be used with that device. More...

void	av_hwframe_constraints_free (AVHWFramesConstraints **constraints)
	Free an AVHWFrameConstraints structure. More...

int	av_hwframe_map (AVFrame dst, const AVFrame src, int flags)
	Map a hardware frame. More...

int	av_hwframe_ctx_create_derived (AVBufferRef *derived_frame_ctx, enum AVPixelFormat format, AVBufferRef derived_device_ctx, AVBufferRef *source_frame_ctx, int flags)
	Create and initialise an AVHWFramesContext as a mapping of another existing AVHWFramesContext on a different device. More...

Typedef Documentation

◆ AVHWDeviceInternal

typedef struct AVHWDeviceInternal AVHWDeviceInternal

Definition at line 42 of file hwcontext.h.

◆ AVHWFramesInternal

typedef struct AVHWFramesInternal AVHWFramesInternal

Definition at line 112 of file hwcontext.h.

Enumeration Type Documentation

◆ AVHWDeviceType

enum AVHWDeviceType

Enumerator
AV_HWDEVICE_TYPE_NONE
AV_HWDEVICE_TYPE_VDPAU
AV_HWDEVICE_TYPE_CUDA
AV_HWDEVICE_TYPE_VAAPI
AV_HWDEVICE_TYPE_DXVA2
AV_HWDEVICE_TYPE_QSV
AV_HWDEVICE_TYPE_VIDEOTOOLBOX
AV_HWDEVICE_TYPE_D3D11VA
AV_HWDEVICE_TYPE_DRM
AV_HWDEVICE_TYPE_OPENCL
AV_HWDEVICE_TYPE_MEDIACODEC
AV_HWDEVICE_TYPE_VULKAN

Definition at line 27 of file hwcontext.h.

◆ AVHWFrameTransferDirection

enum AVHWFrameTransferDirection

Enumerator
AV_HWFRAME_TRANSFER_DIRECTION_FROM	Transfer the data from the queried hw frame.
AV_HWFRAME_TRANSFER_DIRECTION_TO	Transfer the data to the queried hw frame.

Definition at line 415 of file hwcontext.h.

◆ anonymous enum

anonymous enum

Flags to apply to frame mappings.

Enumerator
AV_HWFRAME_MAP_READ	The mapping must be readable.
AV_HWFRAME_MAP_WRITE	The mapping must be writeable.
AV_HWFRAME_MAP_OVERWRITE	The mapped frame will be overwritten completely in subsequent operations, so the current frame data need not be loaded. Any values which are not overwritten are unspecified.
AV_HWFRAME_MAP_DIRECT	The mapping must be direct. That is, there must not be any copying in the map or unmap steps. Note that performance of direct mappings may be much lower than normal memory.

Definition at line 520 of file hwcontext.h.

Function Documentation

◆ av_hwdevice_find_type_by_name()

enum AVHWDeviceType av_hwdevice_find_type_by_name ( const char * name )

Look up an AVHWDeviceType by name.

Parameters

name	String name of the device type (case-insensitive).

Returns: The type from enum AVHWDeviceType, or AV_HWDEVICE_TYPE_NONE if not found.

Examples: hw_decode.c.

Referenced by main().

◆ av_hwdevice_get_type_name()

const char * av_hwdevice_get_type_name ( enum AVHWDeviceType type )

Get the string name of an AVHWDeviceType.

Parameters

type	Type from enum AVHWDeviceType.

Returns: Pointer to a static string containing the name, or NULL if the type is not valid.

Examples: hw_decode.c.

Referenced by main().

◆ av_hwdevice_iterate_types()

enum AVHWDeviceType av_hwdevice_iterate_types ( enum AVHWDeviceType prev )

Iterate over supported device types.

Parameters

type	AV_HWDEVICE_TYPE_NONE initially, then the previous type returned by this function in subsequent iterations.

Returns: The next usable device type from enum AVHWDeviceType, or AV_HWDEVICE_TYPE_NONE if there are no more.

Examples: hw_decode.c.

Referenced by main().

◆ av_hwdevice_ctx_alloc()

AVBufferRef * av_hwdevice_ctx_alloc ( enum AVHWDeviceType type )

Allocate an AVHWDeviceContext for a given hardware type.

Parameters

type	the type of the hardware device to allocate.

Returns: a reference to the newly created AVHWDeviceContext on success or NULL on failure.

◆ av_hwdevice_ctx_init()

int av_hwdevice_ctx_init ( AVBufferRef * ref )

Finalize the device context before use.

This function must be called after the context is filled with all the required information and before it is used in any way.

Parameters

ref	a reference to the AVHWDeviceContext

Returns: 0 on success, a negative AVERROR code on failure

◆ av_hwdevice_ctx_create()

int av_hwdevice_ctx_create	(	AVBufferRef **	device_ctx,
		enum AVHWDeviceType	type,
		const char *	device,
		AVDictionary *	opts,
		int	flags
	)

Open a device of the specified type and create an AVHWDeviceContext for it.

This is a convenience function intended to cover the simple cases. Callers who need to fine-tune device creation/management should open the device manually and then wrap it in an AVHWDeviceContext using av_hwdevice_ctx_alloc()/av_hwdevice_ctx_init().

The returned context is already initialized and ready for use, the caller should not call av_hwdevice_ctx_init() on it. The user_opaque/free fields of the created AVHWDeviceContext are set by this function and should not be touched by the caller.

Parameters

device_ctx	On success, a reference to the newly-created device context will be written here. The reference is owned by the caller and must be released with av_buffer_unref() when no longer needed. On failure, NULL will be written to this pointer.
type	The type of the device to create.
device	A type-specific string identifying the device to open.
opts	A dictionary of additional (type-specific) options to use in opening the device. The dictionary remains owned by the caller.
flags	currently unused

Returns: 0 on success, a negative AVERROR code on failure.

Examples: hw_decode.c, qsvdec.c, vaapi_encode.c, and vaapi_transcode.c.

Referenced by hw_decoder_init(), and main().

◆ av_hwdevice_ctx_create_derived()

int av_hwdevice_ctx_create_derived	(	AVBufferRef **	dst_ctx,
		enum AVHWDeviceType	type,
		AVBufferRef *	src_ctx,
		int	flags
	)

Create a new device of the specified type from an existing device.

If the source device is a device of the target type or was originally derived from such a device (possibly through one or more intermediate devices of other types), then this will return a reference to the existing device of the same type as is requested.

Otherwise, it will attempt to derive a new device from the given source device. If direct derivation to the new type is not implemented, it will attempt the same derivation from each ancestor of the source device in turn looking for an implemented derivation method.

Parameters

dst_ctx	On success, a reference to the newly-created AVHWDeviceContext.
type	The type of the new device to create.
src_ctx	A reference to an existing AVHWDeviceContext which will be used to create the new device.
flags	Currently unused; should be set to zero.

Returns: Zero on success, a negative AVERROR code on failure.

◆ av_hwdevice_ctx_create_derived_opts()

int av_hwdevice_ctx_create_derived_opts	(	AVBufferRef **	dst_ctx,
		enum AVHWDeviceType	type,
		AVBufferRef *	src_ctx,
		AVDictionary *	options,
		int	flags
	)

Create a new device of the specified type from an existing device.

This function performs the same action as av_hwdevice_ctx_create_derived, however, it is able to set options for the new device to be derived.

Parameters

dst_ctx	On success, a reference to the newly-created AVHWDeviceContext.
type	The type of the new device to create.
src_ctx	A reference to an existing AVHWDeviceContext which will be used to create the new device.
options	Options for the new device to create, same format as in av_hwdevice_ctx_create.
flags	Currently unused; should be set to zero.

Returns: Zero on success, a negative AVERROR code on failure.

◆ av_hwframe_ctx_alloc()

AVBufferRef * av_hwframe_ctx_alloc ( AVBufferRef * device_ctx )

Allocate an AVHWFramesContext tied to a given device context.

Parameters

device_ctx a reference to a AVHWDeviceContext. This function will make a new reference for internal use, the one passed to the function remains owned by the caller.

Returns: a reference to the newly created AVHWFramesContext on success or NULL on failure.

Examples: vaapi_encode.c.

Referenced by set_hwframe_ctx().

◆ av_hwframe_ctx_init()

int av_hwframe_ctx_init ( AVBufferRef * ref )

Finalize the context before use.

This function must be called after the context is filled with all the required information and before it is attached to any frames.

Parameters

ref	a reference to the AVHWFramesContext

Returns: 0 on success, a negative AVERROR code on failure

Examples: vaapi_encode.c.

Referenced by set_hwframe_ctx().

◆ av_hwframe_get_buffer()

int av_hwframe_get_buffer	(	AVBufferRef *	hwframe_ctx,
		AVFrame *	frame,
		int	flags
	)

Allocate a new frame attached to the given AVHWFramesContext.

Parameters

hwframe_ctx	a reference to an AVHWFramesContext
frame	an empty (freshly allocated or unreffed) frame to be filled with newly allocated buffers.
flags	currently unused, should be set to zero

Returns: 0 on success, a negative AVERROR code on failure

Examples: vaapi_encode.c.

Referenced by main().

◆ av_hwframe_transfer_data()

int av_hwframe_transfer_data	(	AVFrame *	dst,
		const AVFrame *	src,
		int	flags
	)

Copy data to or from a hw surface.

At least one of dst/src must have an AVHWFramesContext attached.

If src has an AVHWFramesContext attached, then the format of dst (if set) must use one of the formats returned by av_hwframe_transfer_get_formats(src, AV_HWFRAME_TRANSFER_DIRECTION_FROM). If dst has an AVHWFramesContext attached, then the format of src must use one of the formats returned by av_hwframe_transfer_get_formats(dst, AV_HWFRAME_TRANSFER_DIRECTION_TO)

dst may be "clean" (i.e. with data/buf pointers unset), in which case the data buffers will be allocated by this function using av_frame_get_buffer(). If dst->format is set, then this format will be used, otherwise (when dst->format is AV_PIX_FMT_NONE) the first acceptable format will be chosen.

The two frames must have matching allocated dimensions (i.e. equal to AVHWFramesContext.width/height), since not all device types support transferring a sub-rectangle of the whole surface. The display dimensions (i.e. AVFrame.width/height) may be smaller than the allocated dimensions, but also have to be equal for both frames. When the display dimensions are smaller than the allocated dimensions, the content of the padding in the destination frame is unspecified.

Parameters

dst	the destination frame. dst is not touched on failure.
src	the source frame.
flags	currently unused, should be set to zero

Returns: 0 on success, a negative AVERROR error code on failure.

Examples: hw_decode.c, qsvdec.c, and vaapi_encode.c.

Referenced by decode_packet(), decode_write(), and main().

◆ av_hwframe_transfer_get_formats()

int av_hwframe_transfer_get_formats	(	AVBufferRef *	hwframe_ctx,
		enum AVHWFrameTransferDirection	dir,
		enum AVPixelFormat **	formats,
		int	flags
	)

Get a list of possible source or target formats usable in av_hwframe_transfer_data().

Parameters

hwframe_ctx	the frame context to obtain the information for
dir	the direction of the transfer
formats	the pointer to the output format list will be written here. The list is terminated with AV_PIX_FMT_NONE and must be freed by the caller when no longer needed using av_free(). If this function returns successfully, the format list will have at least one item (not counting the terminator). On failure, the contents of this pointer are unspecified.
flags	currently unused, should be set to zero

Returns: 0 on success, a negative AVERROR code on failure.

◆ av_hwdevice_hwconfig_alloc()

void * av_hwdevice_hwconfig_alloc ( AVBufferRef * device_ctx )

Allocate a HW-specific configuration structure for a given HW device.

After use, the user must free all members as required by the specific hardware structure being used, then free the structure itself with av_free().

Parameters

device_ctx a reference to the associated AVHWDeviceContext.

Returns: The newly created HW-specific configuration structure on success or NULL on failure.

◆ av_hwdevice_get_hwframe_constraints()

AVHWFramesConstraints * av_hwdevice_get_hwframe_constraints	(	AVBufferRef *	ref,
		const void *	hwconfig
	)

Get the constraints on HW frames given a device and the HW-specific configuration to be used with that device.

If no HW-specific configuration is provided, returns the maximum possible capabilities of the device.

Parameters

ref	a reference to the associated AVHWDeviceContext.
hwconfig	a filled HW-specific configuration structure, or NULL to return the maximum possible capabilities of the device.

Returns: AVHWFramesConstraints structure describing the constraints on the device, or NULL if not available.

◆ av_hwframe_constraints_free()

void av_hwframe_constraints_free ( AVHWFramesConstraints ** constraints )

Free an AVHWFrameConstraints structure.

Parameters

constraints The (filled or unfilled) AVHWFrameConstraints structure.

◆ av_hwframe_map()

int av_hwframe_map	(	AVFrame *	dst,
		const AVFrame *	src,
		int	flags
	)

Map a hardware frame.

This has a number of different possible effects, depending on the format and origin of the src and dst frames. On input, src should be a usable frame with valid buffers and dst should be blank (typically as just created by av_frame_alloc()). src should have an associated hwframe context, and dst may optionally have a format and associated hwframe context.

If src was created by mapping a frame from the hwframe context of dst, then this function undoes the mapping - dst is replaced by a reference to the frame that src was originally mapped from.

If both src and dst have an associated hwframe context, then this function attempts to map the src frame from its hardware context to that of dst and then fill dst with appropriate data to be usable there. This will only be possible if the hwframe contexts and associated devices are compatible - given compatible devices, av_hwframe_ctx_create_derived() can be used to create a hwframe context for dst in which mapping should be possible.

If src has a hwframe context but dst does not, then the src frame is mapped to normal memory and should thereafter be usable as a normal frame. If the format is set on dst, then the mapping will attempt to create dst with that format and fail if it is not possible. If format is unset (is AV_PIX_FMT_NONE) then dst will be mapped with whatever the most appropriate format to use is (probably the sw_format of the src hwframe context).

A return value of AVERROR(ENOSYS) indicates that the mapping is not possible with the given arguments and hwframe setup, while other return values indicate that it failed somehow.

On failure, the destination frame will be left blank, except for the hw_frames_ctx/format fields thay may have been set by the caller - those will be preserved as they were.

Parameters

dst	Destination frame, to contain the mapping.
src	Source frame, to be mapped.
flags	Some combination of AV_HWFRAME_MAP_* flags.

Returns: Zero on success, negative AVERROR code on failure.

◆ av_hwframe_ctx_create_derived()

int av_hwframe_ctx_create_derived	(	AVBufferRef **	derived_frame_ctx,
		enum AVPixelFormat	format,
		AVBufferRef *	derived_device_ctx,
		AVBufferRef *	source_frame_ctx,
		int	flags
	)

Create and initialise an AVHWFramesContext as a mapping of another existing AVHWFramesContext on a different device.

av_hwframe_ctx_init() should not be called after this.

Parameters

derived_frame_ctx	On success, a reference to the newly created AVHWFramesContext.
derived_device_ctx	A reference to the device to create the new AVHWFramesContext on.
source_frame_ctx	A reference to an existing AVHWFramesContext which will be mapped to the derived context.
flags	Some combination of AV_HWFRAME_MAP_* flags, defining the mapping parameters to apply to frames which are allocated in the derived device.

Returns: Zero on success, negative AVERROR code on failure.

Data Structures

Typedefs

Enumerations

Functions

Typedef Documentation

◆ AVHWDeviceInternal

◆ AVHWFramesInternal

Enumeration Type Documentation

◆ AVHWDeviceType

◆ AVHWFrameTransferDirection

◆ anonymous enum

Function Documentation

◆ av_hwdevice_find_type_by_name()

◆ av_hwdevice_get_type_name()

◆ av_hwdevice_iterate_types()

◆ av_hwdevice_ctx_alloc()

◆ av_hwdevice_ctx_init()

◆ av_hwdevice_ctx_create()

◆ av_hwdevice_ctx_create_derived()

◆ av_hwdevice_ctx_create_derived_opts()

◆ av_hwframe_ctx_alloc()

◆ av_hwframe_ctx_init()

◆ av_hwframe_get_buffer()

◆ av_hwframe_transfer_data()

◆ av_hwframe_transfer_get_formats()

◆ av_hwdevice_hwconfig_alloc()

◆ av_hwdevice_get_hwframe_constraints()

◆ av_hwframe_constraints_free()

◆ av_hwframe_map()

◆ av_hwframe_ctx_create_derived()