tor-browser

hwcontext.h (23588B)

---

/*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/

#ifndef AVUTIL_HWCONTEXT_H
#define AVUTIL_HWCONTEXT_H

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

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,
 AV_HWDEVICE_TYPE_D3D12VA,
};

/**
* This struct aggregates all the (hardware/vendor-specific) "high-level" state,
* i.e. state that is not tied to a concrete processing configuration.
* E.g., in an API that supports hardware-accelerated encoding and decoding,
* this struct will (if possible) wrap the state that is common to both encoding
* and decoding and from which specific instances of encoders or decoders can be
* derived.
*
* This struct is reference-counted with the AVBuffer mechanism. The
* av_hwdevice_ctx_alloc() constructor yields a reference, whose data field
* points to the actual AVHWDeviceContext. Further objects derived from
* AVHWDeviceContext (such as AVHWFramesContext, describing a frame pool with
* specific properties) will hold an internal reference to it. After all the
* references are released, the AVHWDeviceContext itself will be freed,
* optionally invoking a user-specified callback for uninitializing the hardware
* state.
*/
typedef struct AVHWDeviceContext {
 /**
  * A class for logging. Set by av_hwdevice_ctx_alloc().
  */
 const AVClass* av_class;

 /**
  * This field identifies the underlying API used for hardware access.
  *
  * This field is set when this struct is allocated and never changed
  * afterwards.
  */
 enum AVHWDeviceType type;

 /**
  * The format-specific data, allocated and freed by libavutil along with
  * this context.
  *
  * Should be cast by the user to the format-specific context defined in the
  * corresponding header (hwcontext_*.h) and filled as described in the
  * documentation before calling av_hwdevice_ctx_init().
  *
  * After calling av_hwdevice_ctx_init() this struct should not be modified
  * by the caller.
  */
 void* hwctx;

 /**
  * This field may be set by the caller before calling av_hwdevice_ctx_init().
  *
  * If non-NULL, this callback will be called when the last reference to
  * this context is unreferenced, immediately before it is freed.
  *
  * @note when other objects (e.g an AVHWFramesContext) are derived from this
  *       struct, this callback will be invoked after all such child objects
  *       are fully uninitialized and their respective destructors invoked.
  */
 void (*free)(struct AVHWDeviceContext* ctx);

 /**
  * Arbitrary user data, to be used e.g. by the free() callback.
  */
 void* user_opaque;
} AVHWDeviceContext;

/**
* This struct describes a set or pool of "hardware" frames (i.e. those with
* data not located in normal system memory). All the frames in the pool are
* assumed to be allocated in the same way and interchangeable.
*
* This struct is reference-counted with the AVBuffer mechanism and tied to a
* given AVHWDeviceContext instance. The av_hwframe_ctx_alloc() constructor
* yields a reference, whose data field points to the actual AVHWFramesContext
* struct.
*/
typedef struct AVHWFramesContext {
 /**
  * A class for logging.
  */
 const AVClass* av_class;

 /**
  * A reference to the parent AVHWDeviceContext. This reference is owned and
  * managed by the enclosing AVHWFramesContext, but the caller may derive
  * additional references from it.
  */
 AVBufferRef* device_ref;

 /**
  * The parent AVHWDeviceContext. This is simply a pointer to
  * device_ref->data provided for convenience.
  *
  * Set by libavutil in av_hwframe_ctx_init().
  */
 AVHWDeviceContext* device_ctx;

 /**
  * The format-specific data, allocated and freed automatically along with
  * this context.
  *
  * The user shall ignore this field if the corresponding format-specific
  * header (hwcontext_*.h) does not define a context to be used as
  * AVHWFramesContext.hwctx.
  *
  * Otherwise, it should be cast by the user to said context and filled
  * as described in the documentation before calling av_hwframe_ctx_init().
  *
  * After any frames using this context are created, the contents of this
  * struct should not be modified by the caller.
  */
 void* hwctx;

 /**
  * This field may be set by the caller before calling av_hwframe_ctx_init().
  *
  * If non-NULL, this callback will be called when the last reference to
  * this context is unreferenced, immediately before it is freed.
  */
 void (*free)(struct AVHWFramesContext* ctx);

 /**
  * Arbitrary user data, to be used e.g. by the free() callback.
  */
 void* user_opaque;

 /**
  * A pool from which the frames are allocated by av_hwframe_get_buffer().
  * This field may be set by the caller before calling av_hwframe_ctx_init().
  * The buffers returned by calling av_buffer_pool_get() on this pool must
  * have the properties described in the documentation in the corresponding hw
  * type's header (hwcontext_*.h). The pool will be freed strictly before
  * this struct's free() callback is invoked.
  *
  * This field may be NULL, then libavutil will attempt to allocate a pool
  * internally. Note that certain device types enforce pools allocated at
  * fixed size (frame count), which cannot be extended dynamically. In such a
  * case, initial_pool_size must be set appropriately.
  */
 AVBufferPool* pool;

 /**
  * Initial size of the frame pool. If a device type does not support
  * dynamically resizing the pool, then this is also the maximum pool size.
  *
  * May be set by the caller before calling av_hwframe_ctx_init(). Must be
  * set if pool is NULL and the device type does not support dynamic pools.
  */
 int initial_pool_size;

 /**
  * The pixel format identifying the underlying HW surface type.
  *
  * Must be a hwaccel format, i.e. the corresponding descriptor must have the
  * AV_PIX_FMT_FLAG_HWACCEL flag set.
  *
  * Must be set by the user before calling av_hwframe_ctx_init().
  */
 enum AVPixelFormat format;

 /**
  * The pixel format identifying the actual data layout of the hardware
  * frames.
  *
  * Must be set by the caller before calling av_hwframe_ctx_init().
  *
  * @note when the underlying API does not provide the exact data layout, but
  * only the colorspace/bit depth, this field should be set to the fully
  * planar version of that format (e.g. for 8-bit 420 YUV it should be
  * AV_PIX_FMT_YUV420P, not AV_PIX_FMT_NV12 or anything else).
  */
 enum AVPixelFormat sw_format;

 /**
  * The allocated dimensions of the frames in this pool.
  *
  * Must be set by the user before calling av_hwframe_ctx_init().
  */
 int width, height;
} AVHWFramesContext;

/**
* Look up an AVHWDeviceType by name.
*
* @param name String name of the device type (case-insensitive).
* @return The type from enum AVHWDeviceType, or AV_HWDEVICE_TYPE_NONE if
*         not found.
*/
enum AVHWDeviceType av_hwdevice_find_type_by_name(const char* name);

/** Get the string name of an AVHWDeviceType.
*
* @param type Type from enum AVHWDeviceType.
* @return Pointer to a static string containing the name, or NULL if the type
*         is not valid.
*/
const char* av_hwdevice_get_type_name(enum AVHWDeviceType type);

/**
* Iterate over supported device types.
*
* @param prev AV_HWDEVICE_TYPE_NONE initially, then the previous type
*             returned by this function in subsequent iterations.
* @return The next usable device type from enum AVHWDeviceType, or
*         AV_HWDEVICE_TYPE_NONE if there are no more.
*/
enum AVHWDeviceType av_hwdevice_iterate_types(enum AVHWDeviceType prev);

/**
* Allocate an AVHWDeviceContext for a given hardware type.
*
* @param type the type of the hardware device to allocate.
* @return a reference to the newly created AVHWDeviceContext on success or NULL
*         on failure.
*/
AVBufferRef* av_hwdevice_ctx_alloc(enum AVHWDeviceType type);

/**
* 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.
*
* @param ref a reference to the AVHWDeviceContext
* @return 0 on success, a negative AVERROR code on failure
*/
int av_hwdevice_ctx_init(AVBufferRef* ref);

/**
* 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.
*
* @param 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.
* @param type The type of the device to create.
* @param device A type-specific string identifying the device to open.
* @param opts A dictionary of additional (type-specific) options to use in
*             opening the device. The dictionary remains owned by the caller.
* @param flags currently unused
*
* @return 0 on success, a negative AVERROR code on failure.
*/
int av_hwdevice_ctx_create(AVBufferRef** device_ctx, enum AVHWDeviceType type,
                          const char* device, AVDictionary* opts, 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.
*
* @param dst_ctx On success, a reference to the newly-created
*                AVHWDeviceContext.
* @param type    The type of the new device to create.
* @param src_ctx A reference to an existing AVHWDeviceContext which will be
*                used to create the new device.
* @param flags   Currently unused; should be set to zero.
* @return        Zero on success, a negative AVERROR code on failure.
*/
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.
*
* 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.
*
* @param dst_ctx On success, a reference to the newly-created
*                AVHWDeviceContext.
* @param type    The type of the new device to create.
* @param src_ctx A reference to an existing AVHWDeviceContext which will be
*                used to create the new device.
* @param options Options for the new device to create, same format as in
*                av_hwdevice_ctx_create.
* @param flags   Currently unused; should be set to zero.
* @return        Zero on success, a negative AVERROR code on failure.
*/
int av_hwdevice_ctx_create_derived_opts(AVBufferRef** dst_ctx,
                                       enum AVHWDeviceType type,
                                       AVBufferRef* src_ctx,
                                       AVDictionary* options, int flags);

/**
* Allocate an AVHWFramesContext tied to a given device context.
*
* @param 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.
* @return a reference to the newly created AVHWFramesContext on success or NULL
*         on failure.
*/
AVBufferRef* av_hwframe_ctx_alloc(AVBufferRef* device_ctx);

/**
* 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.
*
* @param ref a reference to the AVHWFramesContext
* @return 0 on success, a negative AVERROR code on failure
*/
int av_hwframe_ctx_init(AVBufferRef* ref);

/**
* Allocate a new frame attached to the given AVHWFramesContext.
*
* @param hwframe_ctx a reference to an AVHWFramesContext
* @param frame an empty (freshly allocated or unreffed) frame to be filled with
*              newly allocated buffers.
* @param flags currently unused, should be set to zero
* @return 0 on success, a negative AVERROR code on failure
*/
int av_hwframe_get_buffer(AVBufferRef* hwframe_ctx, AVFrame* frame, 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.
*
* @param dst the destination frame. dst is not touched on failure.
* @param src the source frame.
* @param flags currently unused, should be set to zero
* @return 0 on success, a negative AVERROR error code on failure.
*/
int av_hwframe_transfer_data(AVFrame* dst, const AVFrame* src, int flags);

enum AVHWFrameTransferDirection {
 /**
  * Transfer the data from the queried hw frame.
  */
 AV_HWFRAME_TRANSFER_DIRECTION_FROM,

 /**
  * Transfer the data to the queried hw frame.
  */
 AV_HWFRAME_TRANSFER_DIRECTION_TO,
};

/**
* Get a list of possible source or target formats usable in
* av_hwframe_transfer_data().
*
* @param hwframe_ctx the frame context to obtain the information for
* @param dir the direction of the transfer
* @param 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.
* @param flags currently unused, should be set to zero
* @return 0 on success, a negative AVERROR code on failure.
*/
int av_hwframe_transfer_get_formats(AVBufferRef* hwframe_ctx,
                                   enum AVHWFrameTransferDirection dir,
                                   enum AVPixelFormat** formats, int flags);

/**
* This struct describes the constraints on hardware frames attached to
* a given device with a hardware-specific configuration.  This is returned
* by av_hwdevice_get_hwframe_constraints() and must be freed by
* av_hwframe_constraints_free() after use.
*/
typedef struct AVHWFramesConstraints {
 /**
  * A list of possible values for format in the hw_frames_ctx,
  * terminated by AV_PIX_FMT_NONE.  This member will always be filled.
  */
 enum AVPixelFormat* valid_hw_formats;

 /**
  * A list of possible values for sw_format in the hw_frames_ctx,
  * terminated by AV_PIX_FMT_NONE.  Can be NULL if this information is
  * not known.
  */
 enum AVPixelFormat* valid_sw_formats;

 /**
  * The minimum size of frames in this hw_frames_ctx.
  * (Zero if not known.)
  */
 int min_width;
 int min_height;

 /**
  * The maximum size of frames in this hw_frames_ctx.
  * (INT_MAX if not known / no limit.)
  */
 int max_width;
 int max_height;
} AVHWFramesConstraints;

/**
* 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().
*
* @param device_ctx a reference to the associated AVHWDeviceContext.
* @return The newly created HW-specific configuration structure on
*         success or NULL on failure.
*/
void* av_hwdevice_hwconfig_alloc(AVBufferRef* device_ctx);

/**
* 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.
*
* @param ref a reference to the associated AVHWDeviceContext.
* @param hwconfig a filled HW-specific configuration structure, or NULL
*        to return the maximum possible capabilities of the device.
* @return AVHWFramesConstraints structure describing the constraints
*         on the device, or NULL if not available.
*/
AVHWFramesConstraints* av_hwdevice_get_hwframe_constraints(
   AVBufferRef* ref, const void* hwconfig);

/**
* Free an AVHWFrameConstraints structure.
*
* @param constraints The (filled or unfilled) AVHWFrameConstraints structure.
*/
void av_hwframe_constraints_free(AVHWFramesConstraints** constraints);

/**
* Flags to apply to frame mappings.
*/
enum {
 /**
  * The mapping must be readable.
  */
 AV_HWFRAME_MAP_READ = 1 << 0,
 /**
  * The mapping must be writeable.
  */
 AV_HWFRAME_MAP_WRITE = 1 << 1,
 /**
  * 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_OVERWRITE = 1 << 2,
 /**
  * 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.
  */
 AV_HWFRAME_MAP_DIRECT = 1 << 3,
};

/**
* 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.
*
* @param dst Destination frame, to contain the mapping.
* @param src Source frame, to be mapped.
* @param flags Some combination of AV_HWFRAME_MAP_* flags.
* @return Zero on success, negative AVERROR code on failure.
*/
int av_hwframe_map(AVFrame* dst, const AVFrame* src, 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.
*
* @param derived_frame_ctx  On success, a reference to the newly created
*                           AVHWFramesContext.
* @param format             The AVPixelFormat for the derived context.
* @param derived_device_ctx A reference to the device to create the new
*                           AVHWFramesContext on.
* @param source_frame_ctx   A reference to an existing AVHWFramesContext
*                           which will be mapped to the derived context.
* @param flags  Some combination of AV_HWFRAME_MAP_* flags, defining the
*               mapping parameters to apply to frames which are allocated
*               in the derived device.
* @return       Zero on success, negative AVERROR code on failure.
*/
int av_hwframe_ctx_create_derived(AVBufferRef** derived_frame_ctx,
                                 enum AVPixelFormat format,
                                 AVBufferRef* derived_device_ctx,
                                 AVBufferRef* source_frame_ctx, int flags);

#endif /* AVUTIL_HWCONTEXT_H */