FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
frame.h
Go to the documentation of this file.
1 /*
2  *
3  * This file is part of FFmpeg.
4  *
5  * FFmpeg is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * FFmpeg is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with FFmpeg; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18  */
19 
20 /**
21  * @file
22  * @ingroup lavu_frame
23  * reference-counted frame API
24  */
25 
26 #ifndef AVUTIL_FRAME_H
27 #define AVUTIL_FRAME_H
28 
29 #include <stdint.h>
30 
31 #include "avutil.h"
32 #include "buffer.h"
33 #include "dict.h"
34 #include "rational.h"
35 #include "samplefmt.h"
36 #include "pixfmt.h"
37 #include "version.h"
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  /**
111  * This side data must be associated with an audio frame and corresponds to
112  * enum AVAudioServiceType defined in avcodec.h.
113  */
115 };
116 
125 };
126 
127 typedef struct AVFrameSideData {
130  int size;
133 
134 /**
135  * This structure describes decoded (raw) audio or video data.
136  *
137  * AVFrame must be allocated using av_frame_alloc(). Note that this only
138  * allocates the AVFrame itself, the buffers for the data must be managed
139  * through other means (see below).
140  * AVFrame must be freed with av_frame_free().
141  *
142  * AVFrame is typically allocated once and then reused multiple times to hold
143  * different data (e.g. a single AVFrame to hold frames received from a
144  * decoder). In such a case, av_frame_unref() will free any references held by
145  * the frame and reset it to its original clean state before it
146  * is reused again.
147  *
148  * The data described by an AVFrame is usually reference counted through the
149  * AVBuffer API. The underlying buffer references are stored in AVFrame.buf /
150  * AVFrame.extended_buf. An AVFrame is considered to be reference counted if at
151  * least one reference is set, i.e. if AVFrame.buf[0] != NULL. In such a case,
152  * every single data plane must be contained in one of the buffers in
153  * AVFrame.buf or AVFrame.extended_buf.
154  * There may be a single buffer for all the data, or one separate buffer for
155  * each plane, or anything in between.
156  *
157  * sizeof(AVFrame) is not a part of the public ABI, so new fields may be added
158  * to the end with a minor bump.
159  * Similarly fields that are marked as to be only accessed by
160  * av_opt_ptr() can be reordered. This allows 2 forks to add fields
161  * without breaking compatibility with each other.
162  */
163 typedef struct AVFrame {
164 #define AV_NUM_DATA_POINTERS 8
165  /**
166  * pointer to the picture/channel planes.
167  * This might be different from the first allocated byte
168  *
169  * Some decoders access areas outside 0,0 - width,height, please
170  * see avcodec_align_dimensions2(). Some filters and swscale can read
171  * up to 16 bytes beyond the planes, if these filters are to be used,
172  * then 16 extra bytes must be allocated.
173  */
175 
176  /**
177  * For video, size in bytes of each picture line.
178  * For audio, size in bytes of each plane.
179  *
180  * For audio, only linesize[0] may be set. For planar audio, each channel
181  * plane must be the same size.
182  *
183  * For video the linesizes should be multiples of the CPUs alignment
184  * preference, this is 16 or 32 for modern desktop CPUs.
185  * Some code requires such alignment other code can be slower without
186  * correct alignment, for yet other it makes no difference.
187  *
188  * @note The linesize may be larger than the size of usable data -- there
189  * may be extra padding present for performance reasons.
190  */
192 
193  /**
194  * pointers to the data planes/channels.
195  *
196  * For video, this should simply point to data[].
197  *
198  * For planar audio, each channel has a separate data pointer, and
199  * linesize[0] contains the size of each channel buffer.
200  * For packed audio, there is just one data pointer, and linesize[0]
201  * contains the total size of the buffer for all channels.
202  *
203  * Note: Both data and extended_data should always be set in a valid frame,
204  * but for planar audio with more channels that can fit in data,
205  * extended_data must be used in order to access all channels.
206  */
208 
209  /**
210  * width and height of the video frame
211  */
212  int width, height;
213 
214  /**
215  * number of audio samples (per channel) described by this frame
216  */
218 
219  /**
220  * format of the frame, -1 if unknown or unset
221  * Values correspond to enum AVPixelFormat for video frames,
222  * enum AVSampleFormat for audio)
223  */
224  int format;
225 
226  /**
227  * 1 -> keyframe, 0-> not
228  */
230 
231  /**
232  * Picture type of the frame.
233  */
235 
236 #if FF_API_AVFRAME_LAVC
239 #endif
240 
241  /**
242  * Sample aspect ratio for the video frame, 0/1 if unknown/unspecified.
243  */
245 
246  /**
247  * Presentation timestamp in time_base units (time when frame should be shown to user).
248  */
249  int64_t pts;
250 
251  /**
252  * PTS copied from the AVPacket that was decoded to produce this frame.
253  */
254  int64_t pkt_pts;
255 
256  /**
257  * DTS copied from the AVPacket that triggered returning this frame. (if frame threading isn't used)
258  * This is also the Presentation time of this AVFrame calculated from
259  * only AVPacket.dts values without pts values.
260  */
261  int64_t pkt_dts;
262 
263  /**
264  * picture number in bitstream order
265  */
267  /**
268  * picture number in display order
269  */
271 
272  /**
273  * quality (between 1 (good) and FF_LAMBDA_MAX (bad))
274  */
275  int quality;
276 
277 #if FF_API_AVFRAME_LAVC
280 
281  /**
282  * QP table
283  */
285  int8_t *qscale_table;
286  /**
287  * QP store stride
288  */
290  int qstride;
291 
294 
295  /**
296  * mbskip_table[mb]>=1 if MB didn't change
297  * stride= mb_width = (width+15)>>4
298  */
301 
302  /**
303  * motion vector table
304  * @code
305  * example:
306  * int mv_sample_log2= 4 - motion_subsample_log2;
307  * int mb_width= (width+15)>>4;
308  * int mv_stride= (mb_width << mv_sample_log2) + 1;
309  * motion_val[direction][x + y*mv_stride][0->mv_x, 1->mv_y];
310  * @endcode
311  */
312  int16_t (*motion_val[2])[2];
313 
314  /**
315  * macroblock type table
316  * mb_type_base + mb_width + 2
317  */
319  uint32_t *mb_type;
320 
321  /**
322  * DCT coefficients
323  */
325  short *dct_coeff;
326 
327  /**
328  * motion reference frame index
329  * the order in which these are stored can depend on the codec.
330  */
332  int8_t *ref_index[2];
333 #endif
334 
335  /**
336  * for some private data of the user
337  */
338  void *opaque;
339 
340  /**
341  * error
342  */
344 
345 #if FF_API_AVFRAME_LAVC
347  int type;
348 #endif
349 
350  /**
351  * When decoding, this signals how much the picture must be delayed.
352  * extra_delay = repeat_pict / (2*fps)
353  */
355 
356  /**
357  * The content of the picture is interlaced.
358  */
360 
361  /**
362  * If the content is interlaced, is top field displayed first.
363  */
365 
366  /**
367  * Tell user application that palette has changed from previous frame.
368  */
370 
371 #if FF_API_AVFRAME_LAVC
374 
375  /**
376  * Pan scan.
377  */
380 #endif
381 
382  /**
383  * reordered opaque 64bit (generally an integer or a double precision float
384  * PTS but can be anything).
385  * The user sets AVCodecContext.reordered_opaque to represent the input at
386  * that time,
387  * the decoder reorders values as needed and sets AVFrame.reordered_opaque
388  * to exactly one of the values provided by the user through AVCodecContext.reordered_opaque
389  * @deprecated in favor of pkt_pts
390  */
392 
393 #if FF_API_AVFRAME_LAVC
394  /**
395  * @deprecated this field is unused
396  */
398 
403 
404  /**
405  * log2 of the size of the block which a single vector in motion_val represents:
406  * (4->16x16, 3->8x8, 2-> 4x4, 1-> 2x2)
407  */
409 #endif
410 
411  /**
412  * Sample rate of the audio data.
413  */
415 
416  /**
417  * Channel layout of the audio data.
418  */
419  uint64_t channel_layout;
420 
421  /**
422  * AVBuffer references backing the data for this frame. If all elements of
423  * this array are NULL, then this frame is not reference counted. This array
424  * must be filled contiguously -- if buf[i] is non-NULL then buf[j] must
425  * also be non-NULL for all j < i.
426  *
427  * There may be at most one AVBuffer per data plane, so for video this array
428  * always contains all the references. For planar audio with more than
429  * AV_NUM_DATA_POINTERS channels, there may be more buffers than can fit in
430  * this array. Then the extra AVBufferRef pointers are stored in the
431  * extended_buf array.
432  */
434 
435  /**
436  * For planar audio which requires more than AV_NUM_DATA_POINTERS
437  * AVBufferRef pointers, this array will hold all the references which
438  * cannot fit into AVFrame.buf.
439  *
440  * Note that this is different from AVFrame.extended_data, which always
441  * contains all the pointers. This array only contains the extra pointers,
442  * which cannot fit into AVFrame.buf.
443  *
444  * This array is always allocated using av_malloc() by whoever constructs
445  * the frame. It is freed in av_frame_unref().
446  */
448  /**
449  * Number of elements in extended_buf.
450  */
452 
455 
456 /**
457  * @defgroup lavu_frame_flags AV_FRAME_FLAGS
458  * Flags describing additional frame properties.
459  *
460  * @{
461  */
462 
463 /**
464  * The frame data may be corrupted, e.g. due to decoding errors.
465  */
466 #define AV_FRAME_FLAG_CORRUPT (1 << 0)
467 /**
468  * @}
469  */
470 
471  /**
472  * Frame flags, a combination of @ref lavu_frame_flags
473  */
474  int flags;
475 
476  /**
477  * MPEG vs JPEG YUV range.
478  * It must be accessed using av_frame_get_color_range() and
479  * av_frame_set_color_range().
480  * - encoding: Set by user
481  * - decoding: Set by libavcodec
482  */
484 
486 
488 
489  /**
490  * YUV colorspace type.
491  * It must be accessed using av_frame_get_colorspace() and
492  * av_frame_set_colorspace().
493  * - encoding: Set by user
494  * - decoding: Set by libavcodec
495  */
497 
499 
500  /**
501  * frame timestamp estimated using various heuristics, in stream time base
502  * Code outside libavcodec should access this field using:
503  * av_frame_get_best_effort_timestamp(frame)
504  * - encoding: unused
505  * - decoding: set by libavcodec, read by user.
506  */
508 
509  /**
510  * reordered pos from the last AVPacket that has been input into the decoder
511  * Code outside libavcodec should access this field using:
512  * av_frame_get_pkt_pos(frame)
513  * - encoding: unused
514  * - decoding: Read by user.
515  */
516  int64_t pkt_pos;
517 
518  /**
519  * duration of the corresponding packet, expressed in
520  * AVStream->time_base units, 0 if unknown.
521  * Code outside libavcodec should access this field using:
522  * av_frame_get_pkt_duration(frame)
523  * - encoding: unused
524  * - decoding: Read by user.
525  */
526  int64_t pkt_duration;
527 
528  /**
529  * metadata.
530  * Code outside libavcodec should access this field using:
531  * av_frame_get_metadata(frame)
532  * - encoding: Set by user.
533  * - decoding: Set by libavcodec.
534  */
536 
537  /**
538  * decode error flags of the frame, set to a combination of
539  * FF_DECODE_ERROR_xxx flags if the decoder produced a frame, but there
540  * were errors during the decoding.
541  * Code outside libavcodec should access this field using:
542  * av_frame_get_decode_error_flags(frame)
543  * - encoding: unused
544  * - decoding: set by libavcodec, read by user.
545  */
547 #define FF_DECODE_ERROR_INVALID_BITSTREAM 1
548 #define FF_DECODE_ERROR_MISSING_REFERENCE 2
549 
550  /**
551  * number of audio channels, only used for audio.
552  * Code outside libavcodec should access this field using:
553  * av_frame_get_channels(frame)
554  * - encoding: unused
555  * - decoding: Read by user.
556  */
557  int channels;
558 
559  /**
560  * size of the corresponding packet containing the compressed
561  * frame. It must be accessed using av_frame_get_pkt_size() and
562  * av_frame_set_pkt_size().
563  * It is set to a negative value if unknown.
564  * - encoding: unused
565  * - decoding: set by libavcodec, read by user.
566  */
567  int pkt_size;
568 
569  /**
570  * Not to be accessed directly from outside libavutil
571  */
573 } AVFrame;
574 
575 /**
576  * Accessors for some AVFrame fields.
577  * The position of these field in the structure is not part of the ABI,
578  * they should not be accessed directly outside libavcodec.
579  */
582 int64_t av_frame_get_pkt_duration (const AVFrame *frame);
583 void av_frame_set_pkt_duration (AVFrame *frame, int64_t val);
584 int64_t av_frame_get_pkt_pos (const AVFrame *frame);
585 void av_frame_set_pkt_pos (AVFrame *frame, int64_t val);
586 int64_t av_frame_get_channel_layout (const AVFrame *frame);
588 int av_frame_get_channels (const AVFrame *frame);
599 int8_t *av_frame_get_qp_table(AVFrame *f, int *stride, int *type);
605 
606 /**
607  * Get the name of a colorspace.
608  * @return a static string identifying the colorspace; can be NULL.
609  */
610 const char *av_get_colorspace_name(enum AVColorSpace val);
611 
612 /**
613  * Allocate an AVFrame and set its fields to default values. The resulting
614  * struct must be freed using av_frame_free().
615  *
616  * @return An AVFrame filled with default values or NULL on failure.
617  *
618  * @note this only allocates the AVFrame itself, not the data buffers. Those
619  * must be allocated through other means, e.g. with av_frame_get_buffer() or
620  * manually.
621  */
622 AVFrame *av_frame_alloc(void);
623 
624 /**
625  * Free the frame and any dynamically allocated objects in it,
626  * e.g. extended_data. If the frame is reference counted, it will be
627  * unreferenced first.
628  *
629  * @param frame frame to be freed. The pointer will be set to NULL.
630  */
631 void av_frame_free(AVFrame **frame);
632 
633 /**
634  * Set up a new reference to the data described by the source frame.
635  *
636  * Copy frame properties from src to dst and create a new reference for each
637  * AVBufferRef from src.
638  *
639  * If src is not reference counted, new buffers are allocated and the data is
640  * copied.
641  *
642  * @return 0 on success, a negative AVERROR on error
643  */
644 int av_frame_ref(AVFrame *dst, const AVFrame *src);
645 
646 /**
647  * Create a new frame that references the same data as src.
648  *
649  * This is a shortcut for av_frame_alloc()+av_frame_ref().
650  *
651  * @return newly created AVFrame on success, NULL on error.
652  */
654 
655 /**
656  * Unreference all the buffers referenced by frame and reset the frame fields.
657  */
659 
660 /**
661  * Move everythnig contained in src to dst and reset src.
662  */
663 void av_frame_move_ref(AVFrame *dst, AVFrame *src);
664 
665 /**
666  * Allocate new buffer(s) for audio or video data.
667  *
668  * The following fields must be set on frame before calling this function:
669  * - format (pixel format for video, sample format for audio)
670  * - width and height for video
671  * - nb_samples and channel_layout for audio
672  *
673  * This function will fill AVFrame.data and AVFrame.buf arrays and, if
674  * necessary, allocate and fill AVFrame.extended_data and AVFrame.extended_buf.
675  * For planar formats, one buffer will be allocated for each plane.
676  *
677  * @param frame frame in which to store the new buffers.
678  * @param align required buffer size alignment
679  *
680  * @return 0 on success, a negative AVERROR on error.
681  */
683 
684 /**
685  * Check if the frame data is writable.
686  *
687  * @return A positive value if the frame data is writable (which is true if and
688  * only if each of the underlying buffers has only one reference, namely the one
689  * stored in this frame). Return 0 otherwise.
690  *
691  * If 1 is returned the answer is valid until av_buffer_ref() is called on any
692  * of the underlying AVBufferRefs (e.g. through av_frame_ref() or directly).
693  *
694  * @see av_frame_make_writable(), av_buffer_is_writable()
695  */
697 
698 /**
699  * Ensure that the frame data is writable, avoiding data copy if possible.
700  *
701  * Do nothing if the frame is writable, allocate new buffers and copy the data
702  * if it is not.
703  *
704  * @return 0 on success, a negative AVERROR on error.
705  *
706  * @see av_frame_is_writable(), av_buffer_is_writable(),
707  * av_buffer_make_writable()
708  */
710 
711 /**
712  * Copy the frame data from src to dst.
713  *
714  * This function does not allocate anything, dst must be already initialized and
715  * allocated with the same parameters as src.
716  *
717  * This function only copies the frame data (i.e. the contents of the data /
718  * extended data arrays), not any other properties.
719  *
720  * @return >= 0 on success, a negative AVERROR on error.
721  */
722 int av_frame_copy(AVFrame *dst, const AVFrame *src);
723 
724 /**
725  * Copy only "metadata" fields from src to dst.
726  *
727  * Metadata for the purpose of this function are those fields that do not affect
728  * the data layout in the buffers. E.g. pts, sample rate (for audio) or sample
729  * aspect ratio (for video), but not width/height or channel layout.
730  * Side data is also copied.
731  */
732 int av_frame_copy_props(AVFrame *dst, const AVFrame *src);
733 
734 /**
735  * Get the buffer reference a given data plane is stored in.
736  *
737  * @param plane index of the data plane of interest in frame->extended_data.
738  *
739  * @return the buffer reference that contains the plane or NULL if the input
740  * frame is not valid.
741  */
743 
744 /**
745  * Add a new side data to a frame.
746  *
747  * @param frame a frame to which the side data should be added
748  * @param type type of the added side data
749  * @param size size of the side data
750  *
751  * @return newly added side data on success, NULL on error
752  */
755  int size);
756 
757 /**
758  * @return a pointer to the side data of a given type on success, NULL if there
759  * is no side data with such type in this frame.
760  */
763 
764 /**
765  * If side data of the supplied type exists in the frame, free it and remove it
766  * from the frame.
767  */
769 
770 /**
771  * @return a string identifying the side data type
772  */
774 
775 /**
776  * @}
777  */
778 
779 #endif /* AVUTIL_FRAME_H */