/* * 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 { … }; enum AVActiveFormatDescription { … }; /** * 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. */ AVFrameSideData; enum AVSideDataProps { … }; /** * 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(). */ 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. */ 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. */ 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 { … }; /** * 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); /** * Remove existing entries before adding new ones. */ #define AV_FRAME_SIDE_DATA_FLAG_UNIQUE … /** * Don't add a new entry if another of the same type exists. * Applies only for side data types without the AV_SIDE_DATA_PROP_MULTI prop. */ #define AV_FRAME_SIDE_DATA_FLAG_REPLACE … /** * 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. * @note In case of AV_FRAME_SIDE_DATA_FLAG_UNIQUE being set, entries of * matching AVFrameSideDataType will be removed before the addition * is attempted. * @note In case of AV_FRAME_SIDE_DATA_FLAG_REPLACE being set, if an * entry of the same type already exists, it will be replaced instead. */ 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 from an existing 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 type type of the added side data * @param buf Pointer to AVBufferRef to add to the array. On success, * the function takes ownership of the AVBufferRef and *buf is * set to NULL, unless AV_FRAME_SIDE_DATA_FLAG_NEW_REF is set * in which case the ownership will remain with the caller. * @param flags Some combination of AV_FRAME_SIDE_DATA_FLAG_* flags, or 0. * * @return newly added side data on success, NULL on error. * @note In case of AV_FRAME_SIDE_DATA_FLAG_UNIQUE being set, entries of * matching AVFrameSideDataType will be removed before the addition * is attempted. * @note In case of AV_FRAME_SIDE_DATA_FLAG_REPLACE being set, if an * entry of the same type already exists, it will be replaced instead. * */ AVFrameSideData *av_frame_side_data_add(AVFrameSideData ***sd, int *nb_sd, enum AVFrameSideDataType type, AVBufferRef **buf, 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. * @note In case of AV_FRAME_SIDE_DATA_FLAG_UNIQUE being set, entries of * matching AVFrameSideDataType will be removed before the addition * is attempted. * @note In case of AV_FRAME_SIDE_DATA_FLAG_REPLACE being set, if an * entry of the same type already exists, it will be replaced instead. */ 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) { … } /** * Remove and free all side data instances of the given type from an array. */ void av_frame_side_data_remove(AVFrameSideData ***sd, int *nb_sd, enum AVFrameSideDataType type); /** * @} */ #endif /* AVUTIL_FRAME_H */
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