mpv/video/mp_image.h

/*
 * This file is part of mpv.
 *
 * mpv 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.
 *
 * mpv 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 mpv.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef MPLAYER_MP_IMAGE_H
#define MPLAYER_MP_IMAGE_H

#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
#include "common/common.h"
#include "common/msg.h"
#include "csputils.h"
#include "video/img_format.h"

// Assumed minimum align needed for image allocation. It's notable that FFmpeg's
// libraries except libavcodec don't really know what alignment they want.
// Things will randomly crash or get slower if the alignment is not satisfied.
// Whatever. This value should be pretty safe with current CPU architectures.
#define MP_IMAGE_BYTE_ALIGN 64

#define MP_IMGFIELD_TOP_FIRST 0x02
#define MP_IMGFIELD_REPEAT_FIRST 0x04
#define MP_IMGFIELD_INTERLACED 0x20

// Describes image parameters that usually stay constant.
// New fields can be added in the future. Code changing the parameters should
// usually copy the whole struct, so that fields added later will be preserved.
struct mp_image_params {
    enum mp_imgfmt imgfmt;      // pixel format
    enum mp_imgfmt hw_subfmt;   // underlying format for some hwaccel pixfmts
    int w, h;                   // image dimensions
    int p_w, p_h;               // define pixel aspect ratio (undefined: 0/0)
    struct mp_colorspace color;
    enum mp_chroma_location chroma_location;
    // The image should be rotated clockwise (0-359 degrees).
    int rotate;
    enum mp_stereo3d_mode stereo3d; // image is encoded with this mode
    enum mp_alpha_type alpha;   // usually auto; only set if explicitly known
};

/* Memory management:
 * - mp_image is a light-weight reference to the actual image data (pixels).
 *   The actual image data is reference counted and can outlive mp_image
 *   allocations. mp_image references can be created with mp_image_new_ref()
 *   and free'd with talloc_free() (the helpers mp_image_setrefp() and
 *   mp_image_unrefp() can also be used). The actual image data is free'd when
 *   the last mp_image reference to it is free'd.
 * - Each mp_image has a clear owner. The owner can do anything with it, such
 *   as changing mp_image fields. Instead of making ownership ambiguous by
 *   sharing a mp_image reference, new references should be created.
 * - Write access to the actual image data is allowed only after calling
 *   mp_image_make_writeable(), or if mp_image_is_writeable() returns true.
 *   Conceptually, images can be changed by their owner only, and copy-on-write
 *   is used to ensure that other references do not see any changes to the
 *   image data. mp_image_make_writeable() will do that copy if required.
 */
typedef struct mp_image {
    int w, h;  // visible dimensions (redundant with params.w/h)

    struct mp_image_params params;

    // fields redundant to params.imgfmt, for convenience or compatibility
    struct mp_imgfmt_desc fmt;
    enum mp_imgfmt imgfmt;
    int num_planes;

    uint8_t *planes[MP_MAX_PLANES];
    int stride[MP_MAX_PLANES];

    int pict_type; // 0->unknown, 1->I, 2->P, 3->B
    int fields;

    /* only inside filter chain */
    double pts;
    /* only after decoder */
    double dts, pkt_duration;
    /* container reported FPS; can be incorrect, or 0 if unknown */
    double nominal_fps;
    /* for private use */
    void* priv;

    // Reference-counted data references.
    // These do not necessarily map directly to planes[]. They can have
    // different order or count. There shouldn't be more buffers than planes.
    // If bufs[n] is NULL, bufs[n+1] must also be NULL.
    // All mp_* functions manage this automatically; do not mess with it.
    // (See also AVFrame.buf.)
    struct AVBufferRef *bufs[MP_MAX_PLANES];
    // Points to AVHWFramesContext* (same as AVFrame.hw_frames_ctx)
    struct AVBufferRef *hwctx;
    // Embedded ICC profile, if any
    struct AVBufferRef *icc_profile;
    // Closed captions packet, if any (only after decoder)
    struct AVBufferRef *a53_cc;
    // Other side data we don't care about.
    struct mp_ff_side_data *ff_side_data;
    int num_ff_side_data;
} mp_image_t;

struct mp_ff_side_data {
    int type;
    struct AVBufferRef *buf;
};

int mp_chroma_div_up(int size, int shift);

int mp_image_get_alloc_size(int imgfmt, int w, int h, int stride_align);
struct mp_image *mp_image_from_buffer(int imgfmt, int w, int h, int stride_align,
                                      uint8_t *buffer, int buffer_size,
                                      void *free_opaque,
                                      void (*free)(void *opaque, uint8_t *data));

struct mp_image *mp_image_alloc(int fmt, int w, int h);
void mp_image_copy(struct mp_image *dmpi, struct mp_image *mpi);
void mp_image_copy_attributes(struct mp_image *dmpi, struct mp_image *mpi);
struct mp_image *mp_image_new_copy(struct mp_image *img);
struct mp_image *mp_image_new_ref(struct mp_image *img);
bool mp_image_is_writeable(struct mp_image *img);
bool mp_image_make_writeable(struct mp_image *img);
void mp_image_setrefp(struct mp_image **p_img, struct mp_image *new_value);
void mp_image_unrefp(struct mp_image **p_img);

void mp_image_clear(struct mp_image *mpi, int x0, int y0, int x1, int y1);
void mp_image_crop(struct mp_image *img, int x0, int y0, int x1, int y1);
void mp_image_crop_rc(struct mp_image *img, struct mp_rect rc);
void mp_image_vflip(struct mp_image *img);

void mp_image_set_size(struct mp_image *mpi, int w, int h);
int mp_image_plane_w(struct mp_image *mpi, int plane);
int mp_image_plane_h(struct mp_image *mpi, int plane);

void mp_image_setfmt(mp_image_t* mpi, int out_fmt);
void mp_image_steal_data(struct mp_image *dst, struct mp_image *src);
void mp_image_unref_data(struct mp_image *img);

int mp_image_approx_byte_size(struct mp_image *img);

struct mp_image *mp_image_new_dummy_ref(struct mp_image *img);
struct mp_image *mp_image_new_custom_ref(struct mp_image *img, void *arg,
                                         void (*free)(void *arg));

void mp_image_params_guess_csp(struct mp_image_params *params);

char *mp_image_params_to_str_buf(char *b, size_t bs,
                                 const struct mp_image_params *p);
#define mp_image_params_to_str(p) mp_image_params_to_str_buf((char[256]){0}, 256, p)

bool mp_image_params_valid(const struct mp_image_params *p);
bool mp_image_params_equal(const struct mp_image_params *p1,
                           const struct mp_image_params *p2);

void mp_image_params_get_dsize(const struct mp_image_params *p,
                               int *d_w, int *d_h);
void mp_image_params_set_dsize(struct mp_image_params *p, int d_w, int d_h);

void mp_image_set_params(struct mp_image *image,
                         const struct mp_image_params *params);

void mp_image_set_attributes(struct mp_image *image,
                             const struct mp_image_params *params);

struct AVFrame;
struct mp_image *mp_image_from_av_frame(struct AVFrame *av_frame);
struct AVFrame *mp_image_to_av_frame(struct mp_image *img);
struct AVFrame *mp_image_to_av_frame_and_unref(struct mp_image *img);

void memcpy_pic(void *dst, const void *src, int bytesPerLine, int height,
                int dstStride, int srcStride);
void memset_pic(void *dst, int fill, int bytesPerLine, int height, int stride);
void memset16_pic(void *dst, int fill, int unitsPerLine, int height, int stride);

#endif /* MPLAYER_MP_IMAGE_H */