/*
 * 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
 */

/**
 * @file
 * @ingroup lavu_frame
 * reference-counted frame API
 */

#ifndef AVUTIL_FRAME_H
#define AVUTIL_FRAME_H

#include <stddef.h>
#include <stdint.h>

#include "avutil.h"
#include "buffer.h"
#include "channel_layout.h"
#include "dict.h"
#include "rational.h"
#include "samplefmt.h"
#include "pixfmt.h"
#include "version.h"

/**
 * @defgroup lavu_frame AVFrame
 * @ingroup lavu_data
 *
 * @{
 * AVFrame is an abstraction for reference-counted raw multimedia data.
 */

enum AVFrameSideDataType {
  /**
   * The data is the AVPanScan struct defined in libavcodec.
   */
  AV_FRAME_DATA_PANSCAN,
  /**
   * ATSC A53 Part 4 Closed Captions.
   * A53 CC bitstream is stored as uint8_t in AVFrameSideData.data.
   * The number of bytes of CC data is AVFrameSideData.size.
   */
  AV_FRAME_DATA_A53_CC,
  /**
   * Stereoscopic 3d metadata.
   * The data is the AVStereo3D struct defined in libavutil/stereo3d.h.
   */
  AV_FRAME_DATA_STEREO3D,
  /**
   * The data is the AVMatrixEncoding enum defined in
   * libavutil/channel_layout.h.
   */
  AV_FRAME_DATA_MATRIXENCODING,
  /**
   * Metadata relevant to a downmix procedure.
   * The data is the AVDownmixInfo struct defined in libavutil/downmix_info.h.
   */
  AV_FRAME_DATA_DOWNMIX_INFO,
  /**
   * ReplayGain information in the form of the AVReplayGain struct.
   */
  AV_FRAME_DATA_REPLAYGAIN,
  /**
   * This side data contains a 3x3 transformation matrix describing an affine
   * transformation that needs to be applied to the frame for correct
   * presentation.
   *
   * See libavutil/display.h for a detailed description of the data.
   */
  AV_FRAME_DATA_DISPLAYMATRIX,
  /**
   * Active Format Description data consisting of a single byte as specified
   * in ETSI TS 101 154 using AVActiveFormatDescription enum.
   */
  AV_FRAME_DATA_AFD,
  /**
   * Motion vectors exported by some codecs (on demand through the export_mvs
   * flag set in the libavcodec AVCodecContext flags2 option).
   * The data is the AVMotionVector struct defined in
   * libavutil/motion_vector.h.
   */
  AV_FRAME_DATA_MOTION_VECTORS,
  /**
   * Recommmends skipping the specified number of samples. This is exported
   * only if the "skip_manual" AVOption is set in libavcodec.
   * This has the same format as AV_PKT_DATA_SKIP_SAMPLES.
   * @code
   * u32le number of samples to skip from start of this packet
   * u32le number of samples to skip from end of this packet
   * u8    reason for start skip
   * u8    reason for end   skip (0=padding silence, 1=convergence)
   * @endcode
   */
  AV_FRAME_DATA_SKIP_SAMPLES,
  /**
   * This side data must be associated with an audio frame and corresponds to
   * enum AVAudioServiceType defined in avcodec.h.
   */
  AV_FRAME_DATA_AUDIO_SERVICE_TYPE,
  /**
   * Mastering display metadata associated with a video frame. The payload is
   * an AVMasteringDisplayMetadata type and contains information about the
   * mastering display color volume.
   */
  AV_FRAME_DATA_MASTERING_DISPLAY_METADATA,
  /**
   * The GOP timecode in 25 bit timecode format. Data format is 64-bit integer.
   * This is set on the first frame of a GOP that has a temporal reference of 0.
   */
  AV_FRAME_DATA_GOP_TIMECODE,

  /**
   * The data represents the AVSphericalMapping structure defined in
   * libavutil/spherical.h.
   */
  AV_FRAME_DATA_SPHERICAL,

  /**
   * Content light level (based on CTA-861.3). This payload contains data in
   * the form of the AVContentLightMetadata struct.
   */
  AV_FRAME_DATA_CONTENT_LIGHT_LEVEL,

  /**
   * The data contains an ICC profile as an opaque octet buffer following the
   * format described by ISO 15076-1 with an optional name defined in the
   * metadata key entry "name".
   */
  AV_FRAME_DATA_ICC_PROFILE,

  /**
   * Timecode which conforms to SMPTE ST 12-1. The data is an array of 4
   * uint32_t where the first uint32_t describes how many (1-3) of the other
   * timecodes are used. The timecode format is described in the documentation
   * of av_timecode_get_smpte_from_framenum() function in libavutil/timecode.h.
   */
  AV_FRAME_DATA_S12M_TIMECODE,

  /**
   * HDR dynamic metadata associated with a video frame. The payload is
   * an AVDynamicHDRPlus type and contains information for color
   * volume transform - application 4 of SMPTE 2094-40:2016 standard.
   */
  AV_FRAME_DATA_DYNAMIC_HDR_PLUS,

  /**
   * Regions Of Interest, the data is an array of AVRegionOfInterest type, the
   * number of array element is implied by AVFrameSideData.size /
   * AVRegionOfInterest.self_size.
   */
  AV_FRAME_DATA_REGIONS_OF_INTEREST,

  /**
   * Encoding parameters for a video frame, as described by AVVideoEncParams.
   */
  AV_FRAME_DATA_VIDEO_ENC_PARAMS,

  /**
   * User data unregistered metadata associated with a video frame.
   * This is the H.26[45] UDU SEI message, and shouldn't be used for any other
   * purpose The data is stored as uint8_t in AVFrameSideData.data which is 16
   * bytes of uuid_iso_iec_11578 followed by AVFrameSideData.size - 16 bytes of
   * user_data_payload_byte.
   */
  AV_FRAME_DATA_SEI_UNREGISTERED,

  /**
   * Film grain parameters for a frame, described by AVFilmGrainParams.
   * Must be present for every frame which should have film grain applied.
   *
   * May be present multiple times, for example when there are multiple
   * alternative parameter sets for different video signal characteristics.
   * The user should select the most appropriate set for the application.
   */
  AV_FRAME_DATA_FILM_GRAIN_PARAMS,

  /**
   * Bounding boxes for object detection and classification,
   * as described by AVDetectionBBoxHeader.
   */
  AV_FRAME_DATA_DETECTION_BBOXES,

  /**
   * Dolby Vision RPU raw data, suitable for passing to x265
   * or other libraries. Array of uint8_t, with NAL emulation
   * bytes intact.
   */
  AV_FRAME_DATA_DOVI_RPU_BUFFER,

  /**
   * Parsed Dolby Vision metadata, suitable for passing to a software
   * implementation. The payload is the AVDOVIMetadata struct defined in
   * libavutil/dovi_meta.h.
   */
  AV_FRAME_DATA_DOVI_METADATA,

  /**
   * HDR Vivid dynamic metadata associated with a video frame. The payload is
   * an AVDynamicHDRVivid type and contains information for color
   * volume transform - CUVA 005.1-2021.
   */
  AV_FRAME_DATA_DYNAMIC_HDR_VIVID,

  /**
   * Ambient viewing environment metadata, as defined by H.274.
   */
  AV_FRAME_DATA_AMBIENT_VIEWING_ENVIRONMENT,

  /**
   * Provide encoder-specific hinting information about changed/unchanged
   * portions of a frame.  It can be used to pass information about which
   * macroblocks can be skipped because they didn't change from the
   * corresponding ones in the previous frame. This could be useful for
   * applications which know this information in advance to speed up
   * encoding.
   */
  AV_FRAME_DATA_VIDEO_HINT,
};

enum AVActiveFormatDescription {
  AV_AFD_SAME = 8,
  AV_AFD_4_3 = 9,
  AV_AFD_16_9 = 10,
  AV_AFD_14_9 = 11,
  AV_AFD_4_3_SP_14_9 = 13,
  AV_AFD_16_9_SP_14_9 = 14,
  AV_AFD_SP_4_3 = 15,
};

/**
 * Structure to hold side data for an AVFrame.
 *
 * sizeof(AVFrameSideData) is not a part of the public ABI, so new fields may be
 * added to the end with a minor bump.
 */
typedef struct AVFrameSideData {
  enum AVFrameSideDataType type;
  uint8_t* data;
  size_t size;
  AVDictionary* metadata;
  AVBufferRef* buf;
} AVFrameSideData;

enum AVSideDataProps {
  /**
   * The side data type can be used in stream-global structures.
   * Side data types without this property are only meaningful on per-frame
   * basis.
   */
  AV_SIDE_DATA_PROP_GLOBAL = (1 << 0),

  /**
   * Multiple instances of this side data type can be meaningfully present in
   * a single side data array.
   */
  AV_SIDE_DATA_PROP_MULTI = (1 << 1),
};

/**
 * This struct describes the properties of a side data type. Its instance
 * corresponding to a given type can be obtained from av_frame_side_data_desc().
 */
typedef struct AVSideDataDescriptor {
  /**
   * Human-readable side data description.
   */
  const char* name;

  /**
   * Side data property flags, a combination of AVSideDataProps values.
   */
  unsigned props;
} AVSideDataDescriptor;

/**
 * Structure describing a single Region Of Interest.
 *
 * When multiple regions are defined in a single side-data block, they
 * should be ordered from most to least important - some encoders are only
 * capable of supporting a limited number of distinct regions, so will have
 * to truncate the list.
 *
 * When overlapping regions are defined, the first region containing a given
 * area of the frame applies.
 */
typedef struct AVRegionOfInterest {
  /**
   * Must be set to the size of this data structure (that is,
   * sizeof(AVRegionOfInterest)).
   */
  uint32_t self_size;
  /**
   * Distance in pixels from the top edge of the frame to the top and
   * bottom edges and from the left edge of the frame to the left and
   * right edges of the rectangle defining this region of interest.
   *
   * The constraints on a region are encoder dependent, so the region
   * actually affected may be slightly larger for alignment or other
   * reasons.
   */
  int top;
  int bottom;
  int left;
  int right;
  /**
   * Quantisation offset.
   *
   * Must be in the range -1 to +1.  A value of zero indicates no quality
   * change.  A negative value asks for better quality (less quantisation),
   * while a positive value asks for worse quality (greater quantisation).
   *
   * The range is calibrated so that the extreme values indicate the
   * largest possible offset - if the rest of the frame is encoded with the
   * worst possible quality, an offset of -1 indicates that this region
   * should be encoded with the best possible quality anyway.  Intermediate
   * values are then interpolated in some codec-dependent way.
   *
   * For example, in 10-bit H.264 the quantisation parameter varies between
   * -12 and 51.  A typical qoffset value of -1/10 therefore indicates that
   * this region should be encoded with a QP around one-tenth of the full
   * range better than the rest of the frame.  So, if most of the frame
   * were to be encoded with a QP of around 30, this region would get a QP
   * of around 24 (an offset of approximately -1/10 * (51 - -12) = -6.3).
   * An extreme value of -1 would indicate that this region should be
   * encoded with the best possible quality regardless of the treatment of
   * the rest of the frame - that is, should be encoded at a QP of -12.
   */
  AVRational qoffset;
} AVRegionOfInterest;

/**
 * This structure describes decoded (raw) audio or video data.
 *
 * AVFrame must be allocated using av_frame_alloc(). Note that this only
 * allocates the AVFrame itself, the buffers for the data must be managed
 * through other means (see below).
 * AVFrame must be freed with av_frame_free().
 *
 * AVFrame is typically allocated once and then reused multiple times to hold
 * different data (e.g. a single AVFrame to hold frames received from a
 * decoder). In such a case, av_frame_unref() will free any references held by
 * the frame and reset it to its original clean state before it
 * is reused again.
 *
 * The data described by an AVFrame is usually reference counted through the
 * AVBuffer API. The underlying buffer references are stored in AVFrame.buf /
 * AVFrame.extended_buf. An AVFrame is considered to be reference counted if at
 * least one reference is set, i.e. if AVFrame.buf[0] != NULL. In such a case,
 * every single data plane must be contained in one of the buffers in
 * AVFrame.buf or AVFrame.extended_buf.
 * There may be a single buffer for all the data, or one separate buffer for
 * each plane, or anything in between.
 *
 * sizeof(AVFrame) is not a part of the public ABI, so new fields may be added
 * to the end with a minor bump.
 *
 * Fields can be accessed through AVOptions, the name string used, matches the
 * C structure field name for fields accessible through AVOptions. The AVClass
 * for AVFrame can be obtained from avcodec_get_frame_class()
 */
typedef struct AVFrame {
#define AV_NUM_DATA_POINTERS 8
  /**
   * pointer to the picture/channel planes.
   * This might be different from the first allocated byte. For video,
   * it could even point to the end of the image data.
   *
   * All pointers in data and extended_data must point into one of the
   * AVBufferRef in buf or extended_buf.
   *
   * Some decoders access areas outside 0,0 - width,height, please
   * see avcodec_align_dimensions2(). Some filters and swscale can read
   * up to 16 bytes beyond the planes, if these filters are to be used,
   * then 16 extra bytes must be allocated.
   *
   * NOTE: Pointers not needed by the format MUST be set to NULL.
   *
   * @attention In case of video, the data[] pointers can point to the
   * end of image data in order to reverse line order, when used in
   * combination with negative values in the linesize[] array.
   */
  uint8_t* data[AV_NUM_DATA_POINTERS];

  /**
   * For video, a positive or negative value, which is typically indicating
   * the size in bytes of each picture line, but it can also be:
   * - the negative byte size of lines for vertical flipping
   *   (with data[n] pointing to the end of the data
   * - a positive or negative multiple of the byte size as for accessing
   *   even and odd fields of a frame (possibly flipped)
   *
   * For audio, only linesize[0] may be set. For planar audio, each channel
   * plane must be the same size.
   *
   * For video the linesizes should be multiples of the CPUs alignment
   * preference, this is 16 or 32 for modern desktop CPUs.
   * Some code requires such alignment other code can be slower without
   * correct alignment, for yet other it makes no difference.
   *
   * @note The linesize may be larger than the size of usable data -- there
   * may be extra padding present for performance reasons.
   *
   * @attention In case of video, line size values can be negative to achieve
   * a vertically inverted iteration over image lines.
   */
  int linesize[AV_NUM_DATA_POINTERS];

  /**
   * pointers to the data planes/channels.
   *
   * For video, this should simply point to data[].
   *
   * For planar audio, each channel has a separate data pointer, and
   * linesize[0] contains the size of each channel buffer.
   * For packed audio, there is just one data pointer, and linesize[0]
   * contains the total size of the buffer for all channels.
   *
   * Note: Both data and extended_data should always be set in a valid frame,
   * but for planar audio with more channels that can fit in data,
   * extended_data must be used in order to access all channels.
   */
  uint8_t** extended_data;

  /**
   * @name Video dimensions
   * Video frames only. The coded dimensions (in pixels) of the video frame,
   * i.e. the size of the rectangle that contains some well-defined values.
   *
   * @note The part of the frame intended for display/presentation is further
   * restricted by the @ref cropping "Cropping rectangle".
   * @{
   */
  int width, height;
  /**
   * @}
   */

  /**
   * number of audio samples (per channel) described by this frame
   */
  int nb_samples;

  /**
   * format of the frame, -1 if unknown or unset
   * Values correspond to enum AVPixelFormat for video frames,
   * enum AVSampleFormat for audio)
   */
  int format;

#if FF_API_FRAME_KEY
  /**
   * 1 -> keyframe, 0-> not
   *
   * @deprecated Use AV_FRAME_FLAG_KEY instead
   */
  attribute_deprecated int key_frame;
#endif

  /**
   * Picture type of the frame.
   */
  enum AVPictureType pict_type;

  /**
   * Sample aspect ratio for the video frame, 0/1 if unknown/unspecified.
   */
  AVRational sample_aspect_ratio;

  /**
   * Presentation timestamp in time_base units (time when frame should be shown
   * to user).
   */
  int64_t pts;

  /**
   * DTS copied from the AVPacket that triggered returning this frame. (if frame
   * threading isn't used) This is also the Presentation time of this AVFrame
   * calculated from only AVPacket.dts values without pts values.
   */
  int64_t pkt_dts;

  /**
   * Time base for the timestamps in this frame.
   * In the future, this field may be set on frames output by decoders or
   * filters, but its value will be by default ignored on input to encoders
   * or filters.
   */
  AVRational time_base;

  /**
   * quality (between 1 (good) and FF_LAMBDA_MAX (bad))
   */
  int quality;

  /**
   * Frame owner's private data.
   *
   * This field may be set by the code that allocates/owns the frame data.
   * It is then not touched by any library functions, except:
   * - it is copied to other references by av_frame_copy_props() (and hence by
   *   av_frame_ref());
   * - it is set to NULL when the frame is cleared by av_frame_unref()
   * - on the caller's explicit request. E.g. libavcodec encoders/decoders
   *   will copy this field to/from @ref AVPacket "AVPackets" if the caller sets
   *   @ref AV_CODEC_FLAG_COPY_OPAQUE.
   *
   * @see opaque_ref the reference-counted analogue
   */
  void* opaque;

  /**
   * Number of fields in this frame which should be repeated, i.e. the total
   * duration of this frame should be repeat_pict + 2 normal field durations.
   *
   * For interlaced frames this field may be set to 1, which signals that this
   * frame should be presented as 3 fields: beginning with the first field (as
   * determined by AV_FRAME_FLAG_TOP_FIELD_FIRST being set or not), followed
   * by the second field, and then the first field again.
   *
   * For progressive frames this field may be set to a multiple of 2, which
   * signals that this frame's duration should be (repeat_pict + 2) / 2
   * normal frame durations.
   *
   * @note This field is computed from MPEG2 repeat_first_field flag and its
   * associated flags, H.264 pic_struct from picture timing SEI, and
   * their analogues in other codecs. Typically it should only be used when
   * higher-layer timing information is not available.
   */
  int repeat_pict;

#if FF_API_INTERLACED_FRAME
  /**
   * The content of the picture is interlaced.
   *
   * @deprecated Use AV_FRAME_FLAG_INTERLACED instead
   */
  attribute_deprecated int interlaced_frame;

  /**
   * If the content is interlaced, is top field displayed first.
   *
   * @deprecated Use AV_FRAME_FLAG_TOP_FIELD_FIRST instead
   */
  attribute_deprecated int top_field_first;
#endif

#if FF_API_PALETTE_HAS_CHANGED
  /**
   * Tell user application that palette has changed from previous frame.
   */
  attribute_deprecated int palette_has_changed;
#endif

  /**
   * Sample rate of the audio data.
   */
  int sample_rate;

  /**
   * AVBuffer references backing the data for this frame. All the pointers in
   * data and extended_data must point inside one of the buffers in buf or
   * extended_buf. This array must be filled contiguously -- if buf[i] is
   * non-NULL then buf[j] must also be non-NULL for all j < i.
   *
   * There may be at most one AVBuffer per data plane, so for video this array
   * always contains all the references. For planar audio with more than
   * AV_NUM_DATA_POINTERS channels, there may be more buffers than can fit in
   * this array. Then the extra AVBufferRef pointers are stored in the
   * extended_buf array.
   */
  AVBufferRef* buf[AV_NUM_DATA_POINTERS];

  /**
   * For planar audio which requires more than AV_NUM_DATA_POINTERS
   * AVBufferRef pointers, this array will hold all the references which
   * cannot fit into AVFrame.buf.
   *
   * Note that this is different from AVFrame.extended_data, which always
   * contains all the pointers. This array only contains the extra pointers,
   * which cannot fit into AVFrame.buf.
   *
   * This array is always allocated using av_malloc() by whoever constructs
   * the frame. It is freed in av_frame_unref().
   */
  AVBufferRef** extended_buf;
  /**
   * Number of elements in extended_buf.
   */
  int nb_extended_buf;

  AVFrameSideData** side_data;
  int nb_side_data;

/**
 * @defgroup lavu_frame_flags AV_FRAME_FLAGS
 * @ingroup lavu_frame
 * Flags describing additional frame properties.
 *
 * @{
 */

/**
 * The frame data may be corrupted, e.g. due to decoding errors.
 */
#define AV_FRAME_FLAG_CORRUPT (1 << 0)
/**
 * A flag to mark frames that are keyframes.
 */
#define AV_FRAME_FLAG_KEY (1 << 1)
/**
 * A flag to mark the frames which need to be decoded, but shouldn't be output.
 */
#define AV_FRAME_FLAG_DISCARD (1 << 2)
/**
 * A flag to mark frames whose content is interlaced.
 */
#define AV_FRAME_FLAG_INTERLACED (1 << 3)
/**
 * A flag to mark frames where the top field is displayed first if the content
 * is interlaced.
 */
#define AV_FRAME_FLAG_TOP_FIELD_FIRST (1 << 4)
  /**
   * @}
   */

  /**
   * Frame flags, a combination of @ref lavu_frame_flags
   */
  int flags;

  /**
   * MPEG vs JPEG YUV range.
   * - encoding: Set by user
   * - decoding: Set by libavcodec
   */
  enum AVColorRange color_range;

  enum AVColorPrimaries color_primaries;

  enum AVColorTransferCharacteristic color_trc;

  /**
   * YUV colorspace type.
   * - encoding: Set by user
   * - decoding: Set by libavcodec
   */
  enum AVColorSpace colorspace;

  enum AVChromaLocation chroma_location;

  /**
   * frame timestamp estimated using various heuristics, in stream time base
   * - encoding: unused
   * - decoding: set by libavcodec, read by user.
   */
  int64_t best_effort_timestamp;

#if FF_API_FRAME_PKT
  /**
   * reordered pos from the last AVPacket that has been input into the decoder
   * - encoding: unused
   * - decoding: Read by user.
   * @deprecated use AV_CODEC_FLAG_COPY_OPAQUE to pass through arbitrary user
   *             data from packets to frames
   */
  attribute_deprecated int64_t pkt_pos;
#endif

  /**
   * metadata.
   * - encoding: Set by user.
   * - decoding: Set by libavcodec.
   */
  AVDictionary* metadata;

  /**
   * decode error flags of the frame, set to a combination of
   * FF_DECODE_ERROR_xxx flags if the decoder produced a frame, but there
   * were errors during the decoding.
   * - encoding: unused
   * - decoding: set by libavcodec, read by user.
   */
  int decode_error_flags;
#define FF_DECODE_ERROR_INVALID_BITSTREAM 1
#define FF_DECODE_ERROR_MISSING_REFERENCE 2
#define FF_DECODE_ERROR_CONCEALMENT_ACTIVE 4
#define FF_DECODE_ERROR_DECODE_SLICES 8

#if FF_API_FRAME_PKT
  /**
   * size of the corresponding packet containing the compressed
   * frame.
   * It is set to a negative value if unknown.
   * - encoding: unused
   * - decoding: set by libavcodec, read by user.
   * @deprecated use AV_CODEC_FLAG_COPY_OPAQUE to pass through arbitrary user
   *             data from packets to frames
   */
  attribute_deprecated int pkt_size;
#endif

  /**
   * For hwaccel-format frames, this should be a reference to the
   * AVHWFramesContext describing the frame.
   */
  AVBufferRef* hw_frames_ctx;

  /**
   * Frame owner's private data.
   *
   * This field may be set by the code that allocates/owns the frame data.
   * It is then not touched by any library functions, except:
   * - a new reference to the underlying buffer is propagated by
   *   av_frame_copy_props() (and hence by av_frame_ref());
   * - it is unreferenced in av_frame_unref();
   * - on the caller's explicit request. E.g. libavcodec encoders/decoders
   *   will propagate a new reference to/from @ref AVPacket "AVPackets" if the
   *   caller sets @ref AV_CODEC_FLAG_COPY_OPAQUE.
   *
   * @see opaque the plain pointer analogue
   */
  AVBufferRef* opaque_ref;

  /**
   * @anchor cropping
   * @name Cropping
   * Video frames only. The number of pixels to discard from the the
   * top/bottom/left/right border of the frame to obtain the sub-rectangle of
   * the frame intended for presentation.
   * @{
   */
  size_t crop_top;
  size_t crop_bottom;
  size_t crop_left;
  size_t crop_right;
  /**
   * @}
   */

  /**
   * AVBufferRef for internal use by a single libav* library.
   * Must not be used to transfer data between libraries.
   * Has to be NULL when ownership of the frame leaves the respective library.
   *
   * Code outside the FFmpeg libs should never check or change the contents of
   * the buffer ref.
   *
   * FFmpeg calls av_buffer_unref() on it when the frame is unreferenced.
   * av_frame_copy_props() calls create a new reference with av_buffer_ref()
   * for the target frame's private_ref field.
   */
  AVBufferRef* private_ref;

  /**
   * Channel layout of the audio data.
   */
  AVChannelLayout ch_layout;

  /**
   * Duration of the frame, in the same units as pts. 0 if unknown.
   */
  int64_t duration;
} AVFrame;

/**
 * Allocate an AVFrame and set its fields to default values.  The resulting
 * struct must be freed using av_frame_free().
 *
 * @return An AVFrame filled with default values or NULL on failure.
 *
 * @note this only allocates the AVFrame itself, not the data buffers. Those
 * must be allocated through other means, e.g. with av_frame_get_buffer() or
 * manually.
 */
AVFrame* av_frame_alloc(void);

/**
 * Free the frame and any dynamically allocated objects in it,
 * e.g. extended_data. If the frame is reference counted, it will be
 * unreferenced first.
 *
 * @param frame frame to be freed. The pointer will be set to NULL.
 */
void av_frame_free(AVFrame** frame);

/**
 * Set up a new reference to the data described by the source frame.
 *
 * Copy frame properties from src to dst and create a new reference for each
 * AVBufferRef from src.
 *
 * If src is not reference counted, new buffers are allocated and the data is
 * copied.
 *
 * @warning: dst MUST have been either unreferenced with av_frame_unref(dst),
 *           or newly allocated with av_frame_alloc() before calling this
 *           function, or undefined behavior will occur.
 *
 * @return 0 on success, a negative AVERROR on error
 */
int av_frame_ref(AVFrame* dst, const AVFrame* src);

/**
 * Ensure the destination frame refers to the same data described by the source
 * frame, either by creating a new reference for each AVBufferRef from src if
 * they differ from those in dst, by allocating new buffers and copying data if
 * src is not reference counted, or by unrefencing it if src is empty.
 *
 * Frame properties on dst will be replaced by those from src.
 *
 * @return 0 on success, a negative AVERROR on error. On error, dst is
 *         unreferenced.
 */
int av_frame_replace(AVFrame* dst, const AVFrame* src);

/**
 * Create a new frame that references the same data as src.
 *
 * This is a shortcut for av_frame_alloc()+av_frame_ref().
 *
 * @return newly created AVFrame on success, NULL on error.
 */
AVFrame* av_frame_clone(const AVFrame* src);

/**
 * Unreference all the buffers referenced by frame and reset the frame fields.
 */
void av_frame_unref(AVFrame* frame);

/**
 * Move everything contained in src to dst and reset src.
 *
 * @warning: dst is not unreferenced, but directly overwritten without reading
 *           or deallocating its contents. Call av_frame_unref(dst) manually
 *           before calling this function to ensure that no memory is leaked.
 */
void av_frame_move_ref(AVFrame* dst, AVFrame* src);

/**
 * Allocate new buffer(s) for audio or video data.
 *
 * The following fields must be set on frame before calling this function:
 * - format (pixel format for video, sample format for audio)
 * - width and height for video
 * - nb_samples and ch_layout for audio
 *
 * This function will fill AVFrame.data and AVFrame.buf arrays and, if
 * necessary, allocate and fill AVFrame.extended_data and AVFrame.extended_buf.
 * For planar formats, one buffer will be allocated for each plane.
 *
 * @warning: if frame already has been allocated, calling this function will
 *           leak memory. In addition, undefined behavior can occur in certain
 *           cases.
 *
 * @param frame frame in which to store the new buffers.
 * @param align Required buffer size alignment. If equal to 0, alignment will be
 *              chosen automatically for the current CPU. It is highly
 *              recommended to pass 0 here unless you know what you are doing.
 *
 * @return 0 on success, a negative AVERROR on error.
 */
int av_frame_get_buffer(AVFrame* frame, int align);

/**
 * Check if the frame data is writable.
 *
 * @return A positive value if the frame data is writable (which is true if and
 * only if each of the underlying buffers has only one reference, namely the one
 * stored in this frame). Return 0 otherwise.
 *
 * If 1 is returned the answer is valid until av_buffer_ref() is called on any
 * of the underlying AVBufferRefs (e.g. through av_frame_ref() or directly).
 *
 * @see av_frame_make_writable(), av_buffer_is_writable()
 */
int av_frame_is_writable(AVFrame* frame);

/**
 * Ensure that the frame data is writable, avoiding data copy if possible.
 *
 * Do nothing if the frame is writable, allocate new buffers and copy the data
 * if it is not. Non-refcounted frames behave as non-writable, i.e. a copy
 * is always made.
 *
 * @return 0 on success, a negative AVERROR on error.
 *
 * @see av_frame_is_writable(), av_buffer_is_writable(),
 * av_buffer_make_writable()
 */
int av_frame_make_writable(AVFrame* frame);

/**
 * Copy the frame data from src to dst.
 *
 * This function does not allocate anything, dst must be already initialized and
 * allocated with the same parameters as src.
 *
 * This function only copies the frame data (i.e. the contents of the data /
 * extended data arrays), not any other properties.
 *
 * @return >= 0 on success, a negative AVERROR on error.
 */
int av_frame_copy(AVFrame* dst, const AVFrame* src);

/**
 * Copy only "metadata" fields from src to dst.
 *
 * Metadata for the purpose of this function are those fields that do not affect
 * the data layout in the buffers.  E.g. pts, sample rate (for audio) or sample
 * aspect ratio (for video), but not width/height or channel layout.
 * Side data is also copied.
 */
int av_frame_copy_props(AVFrame* dst, const AVFrame* src);

/**
 * Get the buffer reference a given data plane is stored in.
 *
 * @param frame the frame to get the plane's buffer from
 * @param plane index of the data plane of interest in frame->extended_data.
 *
 * @return the buffer reference that contains the plane or NULL if the input
 * frame is not valid.
 */
AVBufferRef* av_frame_get_plane_buffer(const AVFrame* frame, int plane);

/**
 * Add a new side data to a frame.
 *
 * @param frame a frame to which the side data should be added
 * @param type type of the added side data
 * @param size size of the side data
 *
 * @return newly added side data on success, NULL on error
 */
AVFrameSideData* av_frame_new_side_data(AVFrame* frame,
                                        enum AVFrameSideDataType type,
                                        size_t size);

/**
 * Add a new side data to a frame from an existing AVBufferRef
 *
 * @param frame a frame to which the side data should be added
 * @param type  the type of the added side data
 * @param buf   an AVBufferRef to add as side data. The ownership of
 *              the reference is transferred to the frame.
 *
 * @return newly added side data on success, NULL on error. On failure
 *         the frame is unchanged and the AVBufferRef remains owned by
 *         the caller.
 */
AVFrameSideData* av_frame_new_side_data_from_buf(AVFrame* frame,
                                                 enum AVFrameSideDataType type,
                                                 AVBufferRef* buf);

/**
 * @return a pointer to the side data of a given type on success, NULL if there
 * is no side data with such type in this frame.
 */
AVFrameSideData* av_frame_get_side_data(const AVFrame* frame,
                                        enum AVFrameSideDataType type);

/**
 * Remove and free all side data instances of the given type.
 */
void av_frame_remove_side_data(AVFrame* frame, enum AVFrameSideDataType type);

/**
 * Flags for frame cropping.
 */
enum {
  /**
   * Apply the maximum possible cropping, even if it requires setting the
   * AVFrame.data[] entries to unaligned pointers. Passing unaligned data
   * to FFmpeg API is generally not allowed, and causes undefined behavior
   * (such as crashes). You can pass unaligned data only to FFmpeg APIs that
   * are explicitly documented to accept it. Use this flag only if you
   * absolutely know what you are doing.
   */
  AV_FRAME_CROP_UNALIGNED = 1 << 0,
};

/**
 * Crop the given video AVFrame according to its crop_left/crop_top/crop_right/
 * crop_bottom fields. If cropping is successful, the function will adjust the
 * data pointers and the width/height fields, and set the crop fields to 0.
 *
 * In all cases, the cropping boundaries will be rounded to the inherent
 * alignment of the pixel format. In some cases, such as for opaque hwaccel
 * formats, the left/top cropping is ignored. The crop fields are set to 0 even
 * if the cropping was rounded or ignored.
 *
 * @param frame the frame which should be cropped
 * @param flags Some combination of AV_FRAME_CROP_* flags, or 0.
 *
 * @return >= 0 on success, a negative AVERROR on error. If the cropping fields
 * were invalid, AVERROR(ERANGE) is returned, and nothing is changed.
 */
int av_frame_apply_cropping(AVFrame* frame, int flags);

/**
 * @return a string identifying the side data type
 */
const char* av_frame_side_data_name(enum AVFrameSideDataType type);

/**
 * @return side data descriptor corresponding to a given side data type, NULL
 *         when not available.
 */
const AVSideDataDescriptor* av_frame_side_data_desc(
    enum AVFrameSideDataType type);

/**
 * Free all side data entries and their contents, then zeroes out the
 * values which the pointers are pointing to.
 *
 * @param sd    pointer to array of side data to free. Will be set to NULL
 *              upon return.
 * @param nb_sd pointer to an integer containing the number of entries in
 *              the array. Will be set to 0 upon return.
 */
void av_frame_side_data_free(AVFrameSideData*** sd, int* nb_sd);

#define AV_FRAME_SIDE_DATA_FLAG_UNIQUE (1 << 0)

/**
 * Add new side data entry to an array.
 *
 * @param sd    pointer to array of side data to which to add another entry,
 *              or to NULL in order to start a new array.
 * @param nb_sd pointer to an integer containing the number of entries in
 *              the array.
 * @param type  type of the added side data
 * @param size  size of the side data
 * @param flags Some combination of AV_FRAME_SIDE_DATA_FLAG_* flags, or 0.
 *
 * @return newly added side data on success, NULL on error. In case of
 *         AV_FRAME_SIDE_DATA_FLAG_UNIQUE being set, entries of matching
 *         AVFrameSideDataType will be removed before the addition is
 *         attempted.
 */
AVFrameSideData* av_frame_side_data_new(AVFrameSideData*** sd, int* nb_sd,
                                        enum AVFrameSideDataType type,
                                        size_t size, unsigned int flags);

/**
 * Add a new side data entry to an array based on existing side data, taking
 * a reference towards the contained AVBufferRef.
 *
 * @param sd    pointer to array of side data to which to add another entry,
 *              or to NULL in order to start a new array.
 * @param nb_sd pointer to an integer containing the number of entries in
 *              the array.
 * @param src   side data to be cloned, with a new reference utilized
 *              for the buffer.
 * @param flags Some combination of AV_FRAME_SIDE_DATA_FLAG_* flags, or 0.
 *
 * @return negative error code on failure, >=0 on success. In case of
 *         AV_FRAME_SIDE_DATA_FLAG_UNIQUE being set, entries of matching
 *         AVFrameSideDataType will be removed before the addition is
 *         attempted.
 */
int av_frame_side_data_clone(AVFrameSideData*** sd, int* nb_sd,
                             const AVFrameSideData* src, unsigned int flags);

/**
 * Get a side data entry of a specific type from an array.
 *
 * @param sd    array of side data.
 * @param nb_sd integer containing the number of entries in the array.
 * @param type  type of side data to be queried
 *
 * @return a pointer to the side data of a given type on success, NULL if there
 *         is no side data with such type in this set.
 */
const AVFrameSideData* av_frame_side_data_get_c(
    const AVFrameSideData* const* sd, const int nb_sd,
    enum AVFrameSideDataType type);

/**
 * Wrapper around av_frame_side_data_get_c() to workaround the limitation
 * that for any type T the conversion from T * const * to const T * const *
 * is not performed automatically in C.
 * @see av_frame_side_data_get_c()
 */
static inline const AVFrameSideData* av_frame_side_data_get(
    AVFrameSideData* const* sd, const int nb_sd,
    enum AVFrameSideDataType type) {
  return av_frame_side_data_get_c((const AVFrameSideData* const*)sd, nb_sd,
                                  type);
}

/**
 * @}
 */

#endif /* AVUTIL_FRAME_H */