1 /*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg 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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 /**
20 * @file
21 * @ingroup lavu_frame
22 * reference-counted frame API
23 */
24
25 #ifndef AVUTIL_FRAME_H
26 #define AVUTIL_FRAME_H
27
28 #include <stddef.h>
29 #include <stdint.h>
30
38
39
40 /**
41 * @defgroup lavu_frame AVFrame
42 * @ingroup lavu_data
43 *
44 * @{
45 * AVFrame is an abstraction for reference-counted raw multimedia data.
46 */
47
49 /**
50 * The data is the AVPanScan struct defined in libavcodec.
51 */
53 /**
54 * ATSC A53 Part 4 Closed Captions.
55 * A53 CC bitstream is stored as uint8_t in AVFrameSideData.data.
56 * The number of bytes of CC data is AVFrameSideData.size.
57 */
59 /**
60 * Stereoscopic 3d metadata.
61 * The data is the AVStereo3D struct defined in libavutil/stereo3d.h.
62 */
64 /**
65 * The data is the AVMatrixEncoding enum defined in libavutil/channel_layout.h.
66 */
68 /**
69 * Metadata relevant to a downmix procedure.
70 * The data is the AVDownmixInfo struct defined in libavutil/downmix_info.h.
71 */
73 /**
74 * ReplayGain information in the form of the AVReplayGain struct.
75 */
77 /**
78 * This side data contains a 3x3 transformation matrix describing an affine
79 * transformation that needs to be applied to the frame for correct
80 * presentation.
81 *
82 * See libavutil/display.h for a detailed description of the data.
83 */
85 /**
86 * Active Format Description data consisting of a single byte as specified
87 * in ETSI TS 101 154 using AVActiveFormatDescription enum.
88 */
90 /**
91 * Motion vectors exported by some codecs (on demand through the export_mvs
92 * flag set in the libavcodec AVCodecContext flags2 option).
93 * The data is the AVMotionVector struct defined in
94 * libavutil/motion_vector.h.
95 */
97 /**
98 * Recommmends skipping the specified number of samples. This is exported
99 * only if the "skip_manual" AVOption is set in libavcodec.
100 * This has the same format as AV_PKT_DATA_SKIP_SAMPLES.
101 * @code
102 * u32le number of samples to skip from start of this packet
103 * u32le number of samples to skip from end of this packet
104 * u8 reason for start skip
105 * u8 reason for end skip (0=padding silence, 1=convergence)
106 * @endcode
107 */
109 /**
110 * This side data must be associated with an audio frame and corresponds to
111 * enum AVAudioServiceType defined in avcodec.h.
112 */
114 /**
115 * Mastering display metadata associated with a video frame. The payload is
116 * an AVMasteringDisplayMetadata type and contains information about the
117 * mastering display color volume.
118 */
120 /**
121 * The GOP timecode in 25 bit timecode format. Data format is 64-bit integer.
122 * This is set on the first frame of a GOP that has a temporal reference of 0.
123 */
125
126 /**
127 * The data represents the AVSphericalMapping structure defined in
128 * libavutil/spherical.h.
129 */
131
132 /**
133 * Content light level (based on CTA-861.3). This payload contains data in
134 * the form of the AVContentLightMetadata struct.
135 */
137
138 /**
139 * The data contains an ICC profile as an opaque octet buffer following the
140 * format described by ISO 15076-1 with an optional name defined in the
141 * metadata key entry "name".
142 */
144
145 /**
146 * Timecode which conforms to SMPTE ST 12-1. The data is an array of 4 uint32_t
147 * where the first uint32_t describes how many (1-3) of the other timecodes are used.
148 * The timecode format is described in the documentation of av_timecode_get_smpte_from_framenum()
149 * function in libavutil/timecode.h.
150 */
152
153 /**
154 * HDR dynamic metadata associated with a video frame. The payload is
155 * an AVDynamicHDRPlus type and contains information for color
156 * volume transform - application 4 of SMPTE 2094-40:2016 standard.
157 */
159
160 /**
161 * Regions Of Interest, the data is an array of AVRegionOfInterest type, the number of
162 * array element is implied by AVFrameSideData.size / AVRegionOfInterest.self_size.
163 */
165
166 /**
167 * Encoding parameters for a video frame, as described by AVVideoEncParams.
168 */
170
171 /**
172 * User data unregistered metadata associated with a video frame.
173 * This is the H.26[45] UDU SEI message, and shouldn't be used for any other purpose
174 * The data is stored as uint8_t in AVFrameSideData.data which is 16 bytes of
175 * uuid_iso_iec_11578 followed by AVFrameSideData.size - 16 bytes of user_data_payload_byte.
176 */
178
179 /**
180 * Film grain parameters for a frame, described by AVFilmGrainParams.
181 * Must be present for every frame which should have film grain applied.
182 */
184
185 /**
186 * Bounding boxes for object detection and classification,
187 * as described by AVDetectionBBoxHeader.
188 */
190
191 /**
192 * Dolby Vision RPU raw data, suitable for passing to x265
193 * or other libraries. Array of uint8_t, with NAL emulation
194 * bytes intact.
195 */
197
198 /**
199 * Parsed Dolby Vision metadata, suitable for passing to a software
200 * implementation. The payload is the AVDOVIMetadata struct defined in
201 * libavutil/dovi_meta.h.
202 */
204 };
205
214 };
215
216
217 /**
218 * Structure to hold side data for an AVFrame.
219 *
220 * sizeof(AVFrameSideData) is not a part of the public ABI, so new fields may be added
221 * to the end with a minor bump.
222 */
230
231 /**
232 * Structure describing a single Region Of Interest.
233 *
234 * When multiple regions are defined in a single side-data block, they
235 * should be ordered from most to least important - some encoders are only
236 * capable of supporting a limited number of distinct regions, so will have
237 * to truncate the list.
238 *
239 * When overlapping regions are defined, the first region containing a given
240 * area of the frame applies.
241 */
243 /**
244 * Must be set to the size of this data structure (that is,
245 * sizeof(AVRegionOfInterest)).
246 */
248 /**
249 * Distance in pixels from the top edge of the frame to the top and
250 * bottom edges and from the left edge of the frame to the left and
251 * right edges of the rectangle defining this region of interest.
252 *
253 * The constraints on a region are encoder dependent, so the region
254 * actually affected may be slightly larger for alignment or other
255 * reasons.
256 */
261 /**
262 * Quantisation offset.
263 *
264 * Must be in the range -1 to +1. A value of zero indicates no quality
265 * change. A negative value asks for better quality (less quantisation),
266 * while a positive value asks for worse quality (greater quantisation).
267 *
268 * The range is calibrated so that the extreme values indicate the
269 * largest possible offset - if the rest of the frame is encoded with the
270 * worst possible quality, an offset of -1 indicates that this region
271 * should be encoded with the best possible quality anyway. Intermediate
272 * values are then interpolated in some codec-dependent way.
273 *
274 * For example, in 10-bit H.264 the quantisation parameter varies between
275 * -12 and 51. A typical qoffset value of -1/10 therefore indicates that
276 * this region should be encoded with a QP around one-tenth of the full
277 * range better than the rest of the frame. So, if most of the frame
278 * were to be encoded with a QP of around 30, this region would get a QP
279 * of around 24 (an offset of approximately -1/10 * (51 - -12) = -6.3).
280 * An extreme value of -1 would indicate that this region should be
281 * encoded with the best possible quality regardless of the treatment of
282 * the rest of the frame - that is, should be encoded at a QP of -12.
283 */
286
287 /**
288 * This structure describes decoded (raw) audio or video data.
289 *
290 * AVFrame must be allocated using av_frame_alloc(). Note that this only
291 * allocates the AVFrame itself, the buffers for the data must be managed
292 * through other means (see below).
293 * AVFrame must be freed with av_frame_free().
294 *
295 * AVFrame is typically allocated once and then reused multiple times to hold
296 * different data (e.g. a single AVFrame to hold frames received from a
297 * decoder). In such a case, av_frame_unref() will free any references held by
298 * the frame and reset it to its original clean state before it
299 * is reused again.
300 *
301 * The data described by an AVFrame is usually reference counted through the
302 * AVBuffer API. The underlying buffer references are stored in AVFrame.buf /
303 * AVFrame.extended_buf. An AVFrame is considered to be reference counted if at
304 * least one reference is set, i.e. if AVFrame.buf[0] != NULL. In such a case,
305 * every single data plane must be contained in one of the buffers in
306 * AVFrame.buf or AVFrame.extended_buf.
307 * There may be a single buffer for all the data, or one separate buffer for
308 * each plane, or anything in between.
309 *
310 * sizeof(AVFrame) is not a part of the public ABI, so new fields may be added
311 * to the end with a minor bump.
312 *
313 * Fields can be accessed through AVOptions, the name string used, matches the
314 * C structure field name for fields accessible through AVOptions. The AVClass
315 * for AVFrame can be obtained from avcodec_get_frame_class()
316 */
318 #define AV_NUM_DATA_POINTERS 8
319 /**
320 * pointer to the picture/channel planes.
321 * This might be different from the first allocated byte. For video,
322 * it could even point to the end of the image data.
323 *
324 * All pointers in data and extended_data must point into one of the
325 * AVBufferRef in buf or extended_buf.
326 *
327 * Some decoders access areas outside 0,0 - width,height, please
328 * see avcodec_align_dimensions2(). Some filters and swscale can read
329 * up to 16 bytes beyond the planes, if these filters are to be used,
330 * then 16 extra bytes must be allocated.
331 *
332 * NOTE: Pointers not needed by the format MUST be set to NULL.
333 *
334 * @attention In case of video, the data[] pointers can point to the
335 * end of image data in order to reverse line order, when used in
336 * combination with negative values in the linesize[] array.
337 */
339
340 /**
341 * For video, a positive or negative value, which is typically indicating
342 * the size in bytes of each picture line, but it can also be:
343 * - the negative byte size of lines for vertical flipping
344 * (with data[n] pointing to the end of the data
345 * - a positive or negative multiple of the byte size as for accessing
346 * even and odd fields of a frame (possibly flipped)
347 *
348 * For audio, only linesize[0] may be set. For planar audio, each channel
349 * plane must be the same size.
350 *
351 * For video the linesizes should be multiples of the CPUs alignment
352 * preference, this is 16 or 32 for modern desktop CPUs.
353 * Some code requires such alignment other code can be slower without
354 * correct alignment, for yet other it makes no difference.
355 *
356 * @note The linesize may be larger than the size of usable data -- there
357 * may be extra padding present for performance reasons.
358 *
359 * @attention In case of video, line size values can be negative to achieve
360 * a vertically inverted iteration over image lines.
361 */
363
364 /**
365 * pointers to the data planes/channels.
366 *
367 * For video, this should simply point to data[].
368 *
369 * For planar audio, each channel has a separate data pointer, and
370 * linesize[0] contains the size of each channel buffer.
371 * For packed audio, there is just one data pointer, and linesize[0]
372 * contains the total size of the buffer for all channels.
373 *
374 * Note: Both data and extended_data should always be set in a valid frame,
375 * but for planar audio with more channels that can fit in data,
376 * extended_data must be used in order to access all channels.
377 */
379
380 /**
381 * @name Video dimensions
382 * Video frames only. The coded dimensions (in pixels) of the video frame,
383 * i.e. the size of the rectangle that contains some well-defined values.
384 *
385 * @note The part of the frame intended for display/presentation is further
386 * restricted by the @ref cropping "Cropping rectangle".
387 * @{
388 */
390 /**
391 * @}
392 */
393
394 /**
395 * number of audio samples (per channel) described by this frame
396 */
398
399 /**
400 * format of the frame, -1 if unknown or unset
401 * Values correspond to enum AVPixelFormat for video frames,
402 * enum AVSampleFormat for audio)
403 */
405
406 /**
407 * 1 -> keyframe, 0-> not
408 */
410
411 /**
412 * Picture type of the frame.
413 */
415
416 /**
417 * Sample aspect ratio for the video frame, 0/1 if unknown/unspecified.
418 */
420
421 /**
422 * Presentation timestamp in time_base units (time when frame should be shown to user).
423 */
425
426 /**
427 * DTS copied from the AVPacket that triggered returning this frame. (if frame threading isn't used)
428 * This is also the Presentation time of this AVFrame calculated from
429 * only AVPacket.dts values without pts values.
430 */
432
433 /**
434 * Time base for the timestamps in this frame.
435 * In the future, this field may be set on frames output by decoders or
436 * filters, but its value will be by default ignored on input to encoders
437 * or filters.
438 */
440
441 /**
442 * picture number in bitstream order
443 */
445 /**
446 * picture number in display order
447 */
449
450 /**
451 * quality (between 1 (good) and FF_LAMBDA_MAX (bad))
452 */
454
455 /**
456 * for some private data of the user
457 */
459
460 /**
461 * When decoding, this signals how much the picture must be delayed.
462 * extra_delay = repeat_pict / (2*fps)
463 */
465
466 /**
467 * The content of the picture is interlaced.
468 */
470
471 /**
472 * If the content is interlaced, is top field displayed first.
473 */
475
476 /**
477 * Tell user application that palette has changed from previous frame.
478 */
480
481 /**
482 * reordered opaque 64 bits (generally an integer or a double precision float
483 * PTS but can be anything).
484 * The user sets AVCodecContext.reordered_opaque to represent the input at
485 * that time,
486 * the decoder reorders values as needed and sets AVFrame.reordered_opaque
487 * to exactly one of the values provided by the user through AVCodecContext.reordered_opaque
488 */
490
491 /**
492 * Sample rate of the audio data.
493 */
495
496 /**
497 * Channel layout of the audio data.
498 */
500
501 /**
502 * AVBuffer references backing the data for this frame. All the pointers in
503 * data and extended_data must point inside one of the buffers in buf or
504 * extended_buf. This array must be filled contiguously -- if buf[i] is
505 * non-NULL then buf[j] must also be non-NULL for all j < i.
506 *
507 * There may be at most one AVBuffer per data plane, so for video this array
508 * always contains all the references. For planar audio with more than
509 * AV_NUM_DATA_POINTERS channels, there may be more buffers than can fit in
510 * this array. Then the extra AVBufferRef pointers are stored in the
511 * extended_buf array.
512 */
514
515 /**
516 * For planar audio which requires more than AV_NUM_DATA_POINTERS
517 * AVBufferRef pointers, this array will hold all the references which
518 * cannot fit into AVFrame.buf.
519 *
520 * Note that this is different from AVFrame.extended_data, which always
521 * contains all the pointers. This array only contains the extra pointers,
522 * which cannot fit into AVFrame.buf.
523 *
524 * This array is always allocated using av_malloc() by whoever constructs
525 * the frame. It is freed in av_frame_unref().
526 */
528 /**
529 * Number of elements in extended_buf.
530 */
532
535
536 /**
537 * @defgroup lavu_frame_flags AV_FRAME_FLAGS
538 * @ingroup lavu_frame
539 * Flags describing additional frame properties.
540 *
541 * @{
542 */
543
544 /**
545 * The frame data may be corrupted, e.g. due to decoding errors.
546 */
547 #define AV_FRAME_FLAG_CORRUPT (1 << 0)
548 /**
549 * A flag to mark the frames which need to be decoded, but shouldn't be output.
550 */
551 #define AV_FRAME_FLAG_DISCARD (1 << 2)
552 /**
553 * @}
554 */
555
556 /**
557 * Frame flags, a combination of @ref lavu_frame_flags
558 */
560
561 /**
562 * MPEG vs JPEG YUV range.
563 * - encoding: Set by user
564 * - decoding: Set by libavcodec
565 */
567
569
571
572 /**
573 * YUV colorspace type.
574 * - encoding: Set by user
575 * - decoding: Set by libavcodec
576 */
578
580
581 /**
582 * frame timestamp estimated using various heuristics, in stream time base
583 * - encoding: unused
584 * - decoding: set by libavcodec, read by user.
585 */
587
588 /**
589 * reordered pos from the last AVPacket that has been input into the decoder
590 * - encoding: unused
591 * - decoding: Read by user.
592 */
594
595 /**
596 * duration of the corresponding packet, expressed in
597 * AVStream->time_base units, 0 if unknown.
598 * - encoding: unused
599 * - decoding: Read by user.
600 */
602
603 /**
604 * metadata.
605 * - encoding: Set by user.
606 * - decoding: Set by libavcodec.
607 */
609
610 /**
611 * decode error flags of the frame, set to a combination of
612 * FF_DECODE_ERROR_xxx flags if the decoder produced a frame, but there
613 * were errors during the decoding.
614 * - encoding: unused
615 * - decoding: set by libavcodec, read by user.
616 */
618 #define FF_DECODE_ERROR_INVALID_BITSTREAM 1
619 #define FF_DECODE_ERROR_MISSING_REFERENCE 2
620 #define FF_DECODE_ERROR_CONCEALMENT_ACTIVE 4
621 #define FF_DECODE_ERROR_DECODE_SLICES 8
622
623 /**
624 * number of audio channels, only used for audio.
625 * - encoding: unused
626 * - decoding: Read by user.
627 */
629
630 /**
631 * size of the corresponding packet containing the compressed
632 * frame.
633 * It is set to a negative value if unknown.
634 * - encoding: unused
635 * - decoding: set by libavcodec, read by user.
636 */
638
639 /**
640 * For hwaccel-format frames, this should be a reference to the
641 * AVHWFramesContext describing the frame.
642 */
644
645 /**
646 * AVBufferRef for free use by the API user. FFmpeg will never check the
647 * contents of the buffer ref. FFmpeg calls av_buffer_unref() on it when
648 * the frame is unreferenced. av_frame_copy_props() calls create a new
649 * reference with av_buffer_ref() for the target frame's opaque_ref field.
650 *
651 * This is unrelated to the opaque field, although it serves a similar
652 * purpose.
653 */
655
656 /**
657 * @anchor cropping
658 * @name Cropping
659 * Video frames only. The number of pixels to discard from the the
660 * top/bottom/left/right border of the frame to obtain the sub-rectangle of
661 * the frame intended for presentation.
662 * @{
663 */
668 /**
669 * @}
670 */
671
672 /**
673 * AVBufferRef for internal use by a single libav* library.
674 * Must not be used to transfer data between libraries.
675 * Has to be NULL when ownership of the frame leaves the respective library.
676 *
677 * Code outside the FFmpeg libs should never check or change the contents of the buffer ref.
678 *
679 * FFmpeg calls av_buffer_unref() on it when the frame is unreferenced.
680 * av_frame_copy_props() calls create a new reference with av_buffer_ref()
681 * for the target frame's private_ref field.
682 */
685
686
687 #if FF_API_COLORSPACE_NAME
688 /**
689 * Get the name of a colorspace.
690 * @return a static string identifying the colorspace; can be NULL.
691 * @deprecated use av_color_space_name()
692 */
695 #endif
696 /**
697 * Allocate an AVFrame and set its fields to default values. The resulting
698 * struct must be freed using av_frame_free().
699 *
700 * @return An AVFrame filled with default values or NULL on failure.
701 *
702 * @note this only allocates the AVFrame itself, not the data buffers. Those
703 * must be allocated through other means, e.g. with av_frame_get_buffer() or
704 * manually.
705 */
707
708 /**
709 * Free the frame and any dynamically allocated objects in it,
710 * e.g. extended_data. If the frame is reference counted, it will be
711 * unreferenced first.
712 *
713 * @param frame frame to be freed. The pointer will be set to NULL.
714 */
716
717 /**
718 * Set up a new reference to the data described by the source frame.
719 *
720 * Copy frame properties from src to dst and create a new reference for each
721 * AVBufferRef from src.
722 *
723 * If src is not reference counted, new buffers are allocated and the data is
724 * copied.
725 *
726 * @warning: dst MUST have been either unreferenced with av_frame_unref(dst),
727 * or newly allocated with av_frame_alloc() before calling this
728 * function, or undefined behavior will occur.
729 *
730 * @return 0 on success, a negative AVERROR on error
731 */
733
734 /**
735 * Create a new frame that references the same data as src.
736 *
737 * This is a shortcut for av_frame_alloc()+av_frame_ref().
738 *
739 * @return newly created AVFrame on success, NULL on error.
740 */
742
743 /**
744 * Unreference all the buffers referenced by frame and reset the frame fields.
745 */
747
748 /**
749 * Move everything contained in src to dst and reset src.
750 *
751 * @warning: dst is not unreferenced, but directly overwritten without reading
752 * or deallocating its contents. Call av_frame_unref(dst) manually
753 * before calling this function to ensure that no memory is leaked.
754 */
756
757 /**
758 * Allocate new buffer(s) for audio or video data.
759 *
760 * The following fields must be set on frame before calling this function:
761 * - format (pixel format for video, sample format for audio)
762 * - width and height for video
763 * - nb_samples and channel_layout for audio
764 *
765 * This function will fill AVFrame.data and AVFrame.buf arrays and, if
766 * necessary, allocate and fill AVFrame.extended_data and AVFrame.extended_buf.
767 * For planar formats, one buffer will be allocated for each plane.
768 *
769 * @warning: if frame already has been allocated, calling this function will
770 * leak memory. In addition, undefined behavior can occur in certain
771 * cases.
772 *
773 * @param frame frame in which to store the new buffers.
774 * @param align Required buffer size alignment. If equal to 0, alignment will be
775 * chosen automatically for the current CPU. It is highly
776 * recommended to pass 0 here unless you know what you are doing.
777 *
778 * @return 0 on success, a negative AVERROR on error.
779 */
781
782 /**
783 * Check if the frame data is writable.
784 *
785 * @return A positive value if the frame data is writable (which is true if and
786 * only if each of the underlying buffers has only one reference, namely the one
787 * stored in this frame). Return 0 otherwise.
788 *
789 * If 1 is returned the answer is valid until av_buffer_ref() is called on any
790 * of the underlying AVBufferRefs (e.g. through av_frame_ref() or directly).
791 *
792 * @see av_frame_make_writable(), av_buffer_is_writable()
793 */
795
796 /**
797 * Ensure that the frame data is writable, avoiding data copy if possible.
798 *
799 * Do nothing if the frame is writable, allocate new buffers and copy the data
800 * if it is not.
801 *
802 * @return 0 on success, a negative AVERROR on error.
803 *
804 * @see av_frame_is_writable(), av_buffer_is_writable(),
805 * av_buffer_make_writable()
806 */
808
809 /**
810 * Copy the frame data from src to dst.
811 *
812 * This function does not allocate anything, dst must be already initialized and
813 * allocated with the same parameters as src.
814 *
815 * This function only copies the frame data (i.e. the contents of the data /
816 * extended data arrays), not any other properties.
817 *
818 * @return >= 0 on success, a negative AVERROR on error.
819 */
821
822 /**
823 * Copy only "metadata" fields from src to dst.
824 *
825 * Metadata for the purpose of this function are those fields that do not affect
826 * the data layout in the buffers. E.g. pts, sample rate (for audio) or sample
827 * aspect ratio (for video), but not width/height or channel layout.
828 * Side data is also copied.
829 */
831
832 /**
833 * Get the buffer reference a given data plane is stored in.
834 *
835 * @param plane index of the data plane of interest in frame->extended_data.
836 *
837 * @return the buffer reference that contains the plane or NULL if the input
838 * frame is not valid.
839 */
841
842 /**
843 * Add a new side data to a frame.
844 *
845 * @param frame a frame to which the side data should be added
846 * @param type type of the added side data
847 * @param size size of the side data
848 *
849 * @return newly added side data on success, NULL on error
850 */
854
855 /**
856 * Add a new side data to a frame from an existing AVBufferRef
857 *
858 * @param frame a frame to which the side data should be added
859 * @param type the type of the added side data
860 * @param buf an AVBufferRef to add as side data. The ownership of
861 * the reference is transferred to the frame.
862 *
863 * @return newly added side data on success, NULL on error. On failure
864 * the frame is unchanged and the AVBufferRef remains owned by
865 * the caller.
866 */
870
871 /**
872 * @return a pointer to the side data of a given type on success, NULL if there
873 * is no side data with such type in this frame.
874 */
877
878 /**
879 * Remove and free all side data instances of the given type.
880 */
882
883
884 /**
885 * Flags for frame cropping.
886 */
887 enum {
888 /**
889 * Apply the maximum possible cropping, even if it requires setting the
890 * AVFrame.data[] entries to unaligned pointers. Passing unaligned data
891 * to FFmpeg API is generally not allowed, and causes undefined behavior
892 * (such as crashes). You can pass unaligned data only to FFmpeg APIs that
893 * are explicitly documented to accept it. Use this flag only if you
894 * absolutely know what you are doing.
895 */
897 };
898
899 /**
900 * Crop the given video AVFrame according to its crop_left/crop_top/crop_right/
901 * crop_bottom fields. If cropping is successful, the function will adjust the
902 * data pointers and the width/height fields, and set the crop fields to 0.
903 *
904 * In all cases, the cropping boundaries will be rounded to the inherent
905 * alignment of the pixel format. In some cases, such as for opaque hwaccel
906 * formats, the left/top cropping is ignored. The crop fields are set to 0 even
907 * if the cropping was rounded or ignored.
908 *
909 * @param frame the frame which should be cropped
910 * @param flags Some combination of AV_FRAME_CROP_* flags, or 0.
911 *
912 * @return >= 0 on success, a negative AVERROR on error. If the cropping fields
913 * were invalid, AVERROR(ERANGE) is returned, and nothing is changed.
914 */
916
917 /**
918 * @return a string identifying the side data type
919 */
921
922 /**
923 * @}
924 */
925
926 #endif /* AVUTIL_FRAME_H */