hwcontext: Add device derivation
[libav.git] / libavutil / hwcontext.h
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1/*
2 * This file is part of Libav.
3 *
4 * Libav is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * Libav is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with Libav; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19#ifndef AVUTIL_HWCONTEXT_H
20#define AVUTIL_HWCONTEXT_H
21
22#include "buffer.h"
23#include "frame.h"
24#include "log.h"
25#include "pixfmt.h"
26
27enum AVHWDeviceType {
28 AV_HWDEVICE_TYPE_VDPAU,
ad884d10 29 AV_HWDEVICE_TYPE_CUDA,
551c6775 30 AV_HWDEVICE_TYPE_VAAPI,
c46db38c 31 AV_HWDEVICE_TYPE_DXVA2,
59e7361c 32 AV_HWDEVICE_TYPE_QSV,
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33};
34
35typedef struct AVHWDeviceInternal AVHWDeviceInternal;
36
37/**
38 * This struct aggregates all the (hardware/vendor-specific) "high-level" state,
39 * i.e. state that is not tied to a concrete processing configuration.
40 * E.g., in an API that supports hardware-accelerated encoding and decoding,
41 * this struct will (if possible) wrap the state that is common to both encoding
42 * and decoding and from which specific instances of encoders or decoders can be
43 * derived.
44 *
45 * This struct is reference-counted with the AVBuffer mechanism. The
46 * av_hwdevice_ctx_alloc() constructor yields a reference, whose data field
47 * points to the actual AVHWDeviceContext. Further objects derived from
48 * AVHWDeviceContext (such as AVHWFramesContext, describing a frame pool with
49 * specific properties) will hold an internal reference to it. After all the
50 * references are released, the AVHWDeviceContext itself will be freed,
51 * optionally invoking a user-specified callback for uninitializing the hardware
52 * state.
53 */
54typedef struct AVHWDeviceContext {
55 /**
56 * A class for logging. Set by av_hwdevice_ctx_alloc().
57 */
58 const AVClass *av_class;
59
60 /**
61 * Private data used internally by libavutil. Must not be accessed in any
62 * way by the caller.
63 */
64 AVHWDeviceInternal *internal;
65
66 /**
67 * This field identifies the underlying API used for hardware access.
68 *
69 * This field is set when this struct is allocated and never changed
70 * afterwards.
71 */
72 enum AVHWDeviceType type;
73
74 /**
75 * The format-specific data, allocated and freed by libavutil along with
76 * this context.
77 *
78 * Should be cast by the user to the format-specific context defined in the
79 * corresponding header (hwcontext_*.h) and filled as described in the
80 * documentation before calling av_hwdevice_ctx_init().
81 *
82 * After calling av_hwdevice_ctx_init() this struct should not be modified
83 * by the caller.
84 */
85 void *hwctx;
86
87 /**
88 * This field may be set by the caller before calling av_hwdevice_ctx_init().
89 *
90 * If non-NULL, this callback will be called when the last reference to
91 * this context is unreferenced, immediately before it is freed.
92 *
93 * @note when other objects (e.g an AVHWFramesContext) are derived from this
94 * struct, this callback will be invoked after all such child objects
95 * are fully uninitialized and their respective destructors invoked.
96 */
97 void (*free)(struct AVHWDeviceContext *ctx);
98
99 /**
100 * Arbitrary user data, to be used e.g. by the free() callback.
101 */
102 void *user_opaque;
103} AVHWDeviceContext;
104
105typedef struct AVHWFramesInternal AVHWFramesInternal;
106
107/**
108 * This struct describes a set or pool of "hardware" frames (i.e. those with
109 * data not located in normal system memory). All the frames in the pool are
110 * assumed to be allocated in the same way and interchangeable.
111 *
112 * This struct is reference-counted with the AVBuffer mechanism and tied to a
113 * given AVHWDeviceContext instance. The av_hwframe_ctx_alloc() constructor
114 * yields a reference, whose data field points to the actual AVHWFramesContext
115 * struct.
116 */
117typedef struct AVHWFramesContext {
118 /**
119 * A class for logging.
120 */
121 const AVClass *av_class;
122
123 /**
124 * Private data used internally by libavutil. Must not be accessed in any
125 * way by the caller.
126 */
127 AVHWFramesInternal *internal;
128
129 /**
130 * A reference to the parent AVHWDeviceContext. This reference is owned and
131 * managed by the enclosing AVHWFramesContext, but the caller may derive
132 * additional references from it.
133 */
134 AVBufferRef *device_ref;
135
136 /**
137 * The parent AVHWDeviceContext. This is simply a pointer to
138 * device_ref->data provided for convenience.
139 *
140 * Set by libavutil in av_hwframe_ctx_init().
141 */
142 AVHWDeviceContext *device_ctx;
143
144 /**
145 * The format-specific data, allocated and freed automatically along with
146 * this context.
147 *
148 * Should be cast by the user to the format-specific context defined in the
149 * corresponding header (hwframe_*.h) and filled as described in the
150 * documentation before calling av_hwframe_ctx_init().
151 *
152 * After any frames using this context are created, the contents of this
153 * struct should not be modified by the caller.
154 */
155 void *hwctx;
156
157 /**
158 * This field may be set by the caller before calling av_hwframe_ctx_init().
159 *
160 * If non-NULL, this callback will be called when the last reference to
161 * this context is unreferenced, immediately before it is freed.
162 */
163 void (*free)(struct AVHWFramesContext *ctx);
164
165 /**
166 * Arbitrary user data, to be used e.g. by the free() callback.
167 */
168 void *user_opaque;
169
170 /**
171 * A pool from which the frames are allocated by av_hwframe_get_buffer().
172 * This field may be set by the caller before calling av_hwframe_ctx_init().
173 * The buffers returned by calling av_buffer_pool_get() on this pool must
41ed7ab4 174 * have the properties described in the documentation in the corresponding hw
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175 * type's header (hwcontext_*.h). The pool will be freed strictly before
176 * this struct's free() callback is invoked.
177 *
178 * This field may be NULL, then libavutil will attempt to allocate a pool
179 * internally. Note that certain device types enforce pools allocated at
180 * fixed size (frame count), which cannot be extended dynamically. In such a
181 * case, initial_pool_size must be set appropriately.
182 */
183 AVBufferPool *pool;
184
185 /**
186 * Initial size of the frame pool. If a device type does not support
187 * dynamically resizing the pool, then this is also the maximum pool size.
188 *
189 * May be set by the caller before calling av_hwframe_ctx_init(). Must be
190 * set if pool is NULL and the device type does not support dynamic pools.
191 */
192 int initial_pool_size;
193
194 /**
195 * The pixel format identifying the underlying HW surface type.
196 *
197 * Must be a hwaccel format, i.e. the corresponding descriptor must have the
198 * AV_PIX_FMT_FLAG_HWACCEL flag set.
199 *
200 * Must be set by the user before calling av_hwframe_ctx_init().
201 */
202 enum AVPixelFormat format;
203
204 /**
205 * The pixel format identifying the actual data layout of the hardware
206 * frames.
207 *
208 * Must be set by the caller before calling av_hwframe_ctx_init().
209 *
210 * @note when the underlying API does not provide the exact data layout, but
211 * only the colorspace/bit depth, this field should be set to the fully
212 * planar version of that format (e.g. for 8-bit 420 YUV it should be
213 * AV_PIX_FMT_YUV420P, not AV_PIX_FMT_NV12 or anything else).
214 */
215 enum AVPixelFormat sw_format;
216
217 /**
218 * The allocated dimensions of the frames in this pool.
219 *
220 * Must be set by the user before calling av_hwframe_ctx_init().
221 */
222 int width, height;
223} AVHWFramesContext;
224
225/**
226 * Allocate an AVHWDeviceContext for a given pixel format.
227 *
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228 * @return a reference to the newly created AVHWDeviceContext on success or NULL
229 * on failure.
230 */
231AVBufferRef *av_hwdevice_ctx_alloc(enum AVHWDeviceType type);
232
233/**
234 * Finalize the device context before use. This function must be called after
235 * the context is filled with all the required information and before it is
236 * used in any way.
237 *
238 * @param ref a reference to the AVHWDeviceContext
239 * @return 0 on success, a negative AVERROR code on failure
240 */
241int av_hwdevice_ctx_init(AVBufferRef *ref);
242
243/**
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244 * Open a device of the specified type and create an AVHWDeviceContext for it.
245 *
246 * This is a convenience function intended to cover the simple cases. Callers
247 * who need to fine-tune device creation/management should open the device
248 * manually and then wrap it in an AVHWDeviceContext using
249 * av_hwdevice_ctx_alloc()/av_hwdevice_ctx_init().
250 *
251 * The returned context is already initialized and ready for use, the caller
252 * should not call av_hwdevice_ctx_init() on it. The user_opaque/free fields of
253 * the created AVHWDeviceContext are set by this function and should not be
254 * touched by the caller.
255 *
256 * @param device_ctx On success, a reference to the newly-created device context
257 * will be written here. The reference is owned by the caller
258 * and must be released with av_buffer_unref() when no longer
259 * needed. On failure, NULL will be written to this pointer.
260 * @param type The type of the device to create.
261 * @param device A type-specific string identifying the device to open.
262 * @param opts A dictionary of additional (type-specific) options to use in
263 * opening the device. The dictionary remains owned by the caller.
264 * @param flags currently unused
265 *
266 * @return 0 on success, a negative AVERROR code on failure.
267 */
268int av_hwdevice_ctx_create(AVBufferRef **device_ctx, enum AVHWDeviceType type,
269 const char *device, AVDictionary *opts, int flags);
270
271/**
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272 * Create a new device of the specified type from an existing device.
273 *
274 * If the source device is a device of the target type or was originally
275 * derived from such a device (possibly through one or more intermediate
276 * devices of other types), then this will return a reference to the
277 * existing device of the same type as is requested.
278 *
279 * Otherwise, it will attempt to derive a new device from the given source
280 * device. If direct derivation to the new type is not implemented, it will
281 * attempt the same derivation from each ancestor of the source device in
282 * turn looking for an implemented derivation method.
283 *
284 * @param dst_ctx On success, a reference to the newly-created
285 * AVHWDeviceContext.
286 * @param type The type of the new device to create.
287 * @param src_ctx A reference to an existing AVHWDeviceContext which will be
288 * used to create the new device.
289 * @param flags Currently unused; should be set to zero.
290 * @return Zero on success, a negative AVERROR code on failure.
291 */
292int av_hwdevice_ctx_create_derived(AVBufferRef **dst_ctx,
293 enum AVHWDeviceType type,
294 AVBufferRef *src_ctx, int flags);
295
296
297/**
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298 * Allocate an AVHWFramesContext tied to a given device context.
299 *
300 * @param device_ctx a reference to a AVHWDeviceContext. This function will make
301 * a new reference for internal use, the one passed to the
302 * function remains owned by the caller.
303 * @return a reference to the newly created AVHWFramesContext on success or NULL
304 * on failure.
305 */
306AVBufferRef *av_hwframe_ctx_alloc(AVBufferRef *device_ctx);
307
308/**
309 * Finalize the context before use. This function must be called after the
310 * context is filled with all the required information and before it is attached
311 * to any frames.
312 *
313 * @param ref a reference to the AVHWFramesContext
314 * @return 0 on success, a negative AVERROR code on failure
315 */
316int av_hwframe_ctx_init(AVBufferRef *ref);
317
318/**
319 * Allocate a new frame attached to the given AVHWFramesContext.
320 *
321 * @param hwframe_ctx a reference to an AVHWFramesContext
322 * @param frame an empty (freshly allocated or unreffed) frame to be filled with
323 * newly allocated buffers.
324 * @param flags currently unused, should be set to zero
325 * @return 0 on success, a negative AVERROR code on failure
326 */
327int av_hwframe_get_buffer(AVBufferRef *hwframe_ctx, AVFrame *frame, int flags);
328
329/**
330 * Copy data to or from a hw surface. At least one of dst/src must have an
331 * AVHWFramesContext attached.
332 *
333 * If src has an AVHWFramesContext attached, then the format of dst (if set)
334 * must use one of the formats returned by av_hwframe_transfer_get_formats(src,
335 * AV_HWFRAME_TRANSFER_DIRECTION_FROM).
336 * If dst has an AVHWFramesContext attached, then the format of src must use one
337 * of the formats returned by av_hwframe_transfer_get_formats(dst,
338 * AV_HWFRAME_TRANSFER_DIRECTION_TO)
339 *
340 * dst may be "clean" (i.e. with data/buf pointers unset), in which case the
341 * data buffers will be allocated by this function using av_frame_get_buffer().
342 * If dst->format is set, then this format will be used, otherwise (when
343 * dst->format is AV_PIX_FMT_NONE) the first acceptable format will be chosen.
344 *
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345 * The two frames must have matching allocated dimensions (i.e. equal to
346 * AVHWFramesContext.width/height), since not all device types support
347 * transferring a sub-rectangle of the whole surface. The display dimensions
348 * (i.e. AVFrame.width/height) may be smaller than the allocated dimensions, but
349 * also have to be equal for both frames. When the display dimensions are
350 * smaller than the allocated dimensions, the content of the padding in the
351 * destination frame is unspecified.
352 *
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353 * @param dst the destination frame. dst is not touched on failure.
354 * @param src the source frame.
355 * @param flags currently unused, should be set to zero
356 * @return 0 on success, a negative AVERROR error code on failure.
357 */
358int av_hwframe_transfer_data(AVFrame *dst, const AVFrame *src, int flags);
359
360enum AVHWFrameTransferDirection {
361 /**
362 * Transfer the data from the queried hw frame.
363 */
364 AV_HWFRAME_TRANSFER_DIRECTION_FROM,
365
366 /**
367 * Transfer the data to the queried hw frame.
368 */
369 AV_HWFRAME_TRANSFER_DIRECTION_TO,
370};
371
372/**
373 * Get a list of possible source or target formats usable in
374 * av_hwframe_transfer_data().
375 *
376 * @param hwframe_ctx the frame context to obtain the information for
377 * @param dir the direction of the transfer
378 * @param formats the pointer to the output format list will be written here.
379 * The list is terminated with AV_PIX_FMT_NONE and must be freed
380 * by the caller when no longer needed using av_free().
381 * If this function returns successfully, the format list will
382 * have at least one item (not counting the terminator).
383 * On failure, the contents of this pointer are unspecified.
384 * @param flags currently unused, should be set to zero
385 * @return 0 on success, a negative AVERROR code on failure.
386 */
387int av_hwframe_transfer_get_formats(AVBufferRef *hwframe_ctx,
388 enum AVHWFrameTransferDirection dir,
389 enum AVPixelFormat **formats, int flags);
390
391
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392/**
393 * This struct describes the constraints on hardware frames attached to
394 * a given device with a hardware-specific configuration. This is returned
395 * by av_hwdevice_get_hwframe_constraints() and must be freed by
396 * av_hwframe_constraints_free() after use.
397 */
398typedef struct AVHWFramesConstraints {
399 /**
400 * A list of possible values for format in the hw_frames_ctx,
401 * terminated by AV_PIX_FMT_NONE. This member will always be filled.
402 */
403 enum AVPixelFormat *valid_hw_formats;
404
405 /**
406 * A list of possible values for sw_format in the hw_frames_ctx,
407 * terminated by AV_PIX_FMT_NONE. Can be NULL if this information is
408 * not known.
409 */
410 enum AVPixelFormat *valid_sw_formats;
411
412 /**
413 * The minimum size of frames in this hw_frames_ctx.
414 * (Zero if not known.)
415 */
416 int min_width;
417 int min_height;
418
419 /**
420 * The maximum size of frames in this hw_frames_ctx.
421 * (INT_MAX if not known / no limit.)
422 */
423 int max_width;
424 int max_height;
425} AVHWFramesConstraints;
426
427/**
428 * Allocate a HW-specific configuration structure for a given HW device.
429 * After use, the user must free all members as required by the specific
430 * hardware structure being used, then free the structure itself with
431 * av_free().
432 *
433 * @param device_ctx a reference to the associated AVHWDeviceContext.
434 * @return The newly created HW-specific configuration structure on
435 * success or NULL on failure.
436 */
437void *av_hwdevice_hwconfig_alloc(AVBufferRef *device_ctx);
438
439/**
440 * Get the constraints on HW frames given a device and the HW-specific
441 * configuration to be used with that device. If no HW-specific
41ed7ab4 442 * configuration is provided, returns the maximum possible capabilities
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443 * of the device.
444 *
a1d9de30 445 * @param ref a reference to the associated AVHWDeviceContext.
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446 * @param hwconfig a filled HW-specific configuration structure, or NULL
447 * to return the maximum possible capabilities of the device.
448 * @return AVHWFramesConstraints structure describing the constraints
449 * on the device, or NULL if not available.
450 */
451AVHWFramesConstraints *av_hwdevice_get_hwframe_constraints(AVBufferRef *ref,
452 const void *hwconfig);
453
454/**
455 * Free an AVHWFrameConstraints structure.
456 *
457 * @param constraints The (filled or unfilled) AVHWFrameConstraints structure.
458 */
459void av_hwframe_constraints_free(AVHWFramesConstraints **constraints);
460
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461
462/**
463 * Flags to apply to frame mappings.
464 */
465enum {
466 /**
467 * The mapping must be readable.
468 */
469 AV_HWFRAME_MAP_READ = 1 << 0,
470 /**
471 * The mapping must be writeable.
472 */
473 AV_HWFRAME_MAP_WRITE = 1 << 1,
474 /**
475 * The mapped frame will be overwritten completely in subsequent
476 * operations, so the current frame data need not be loaded. Any values
477 * which are not overwritten are unspecified.
478 */
479 AV_HWFRAME_MAP_OVERWRITE = 1 << 2,
480 /**
481 * The mapping must be direct. That is, there must not be any copying in
482 * the map or unmap steps. Note that performance of direct mappings may
483 * be much lower than normal memory.
484 */
485 AV_HWFRAME_MAP_DIRECT = 1 << 3,
486};
487
488/**
489 * Map a hardware frame.
490 *
491 * This has a number of different possible effects, depending on the format
492 * and origin of the src and dst frames. On input, src should be a usable
493 * frame with valid buffers and dst should be blank (typically as just created
494 * by av_frame_alloc()). src should have an associated hwframe context, and
495 * dst may optionally have a format and associated hwframe context.
496 *
497 * If src was created by mapping a frame from the hwframe context of dst,
498 * then this function undoes the mapping - dst is replaced by a reference to
499 * the frame that src was originally mapped from.
500 *
501 * If both src and dst have an associated hwframe context, then this function
502 * attempts to map the src frame from its hardware context to that of dst and
503 * then fill dst with appropriate data to be usable there. This will only be
504 * possible if the hwframe contexts and associated devices are compatible -
505 * given compatible devices, av_hwframe_ctx_create_derived() can be used to
506 * create a hwframe context for dst in which mapping should be possible.
507 *
508 * If src has a hwframe context but dst does not, then the src frame is
509 * mapped to normal memory and should thereafter be usable as a normal frame.
510 * If the format is set on dst, then the mapping will attempt to create dst
511 * with that format and fail if it is not possible. If format is unset (is
512 * AV_PIX_FMT_NONE) then dst will be mapped with whatever the most appropriate
513 * format to use is (probably the sw_format of the src hwframe context).
514 *
515 * A return value of AVERROR(ENOSYS) indicates that the mapping is not
516 * possible with the given arguments and hwframe setup, while other return
517 * values indicate that it failed somehow.
518 *
519 * @param dst Destination frame, to contain the mapping.
520 * @param src Source frame, to be mapped.
521 * @param flags Some combination of AV_HWFRAME_MAP_* flags.
522 * @return Zero on success, negative AVERROR code on failure.
523 */
524int av_hwframe_map(AVFrame *dst, const AVFrame *src, int flags);
525
526
527/**
528 * Create and initialise an AVHWFramesContext as a mapping of another existing
529 * AVHWFramesContext on a different device.
530 *
531 * av_hwframe_ctx_init() should not be called after this.
532 *
533 * @param derived_frame_ctx On success, a reference to the newly created
534 * AVHWFramesContext.
535 * @param derived_device_ctx A reference to the device to create the new
536 * AVHWFramesContext on.
537 * @param source_frame_ctx A reference to an existing AVHWFramesContext
538 * which will be mapped to the derived context.
539 * @param flags Currently unused; should be set to zero.
540 * @return Zero on success, negative AVERROR code on failure.
541 */
542int av_hwframe_ctx_create_derived(AVBufferRef **derived_frame_ctx,
543 enum AVPixelFormat format,
544 AVBufferRef *derived_device_ctx,
545 AVBufferRef *source_frame_ctx,
546 int flags);
547
89923e41 548#endif /* AVUTIL_HWCONTEXT_H */