include/vlc_picture.h

   1 /*****************************************************************************
   2  * vlc_picture.h: picture definitions
   3  *****************************************************************************
   4  * Copyright (C) 1999 - 2009 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Vincent Seguin <seguin@via.ecp.fr>
   8  *          Samuel Hocevar <sam@via.ecp.fr>
   9  *          Olivier Aubert <oaubert 47 videolan d07 org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU Lesser General Public License as published by
  13  * the Free Software Foundation; either version 2.1 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19  * GNU Lesser General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public License
  22  * along with this program; if not, write to the Free Software Foundation,
  23  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  24  *****************************************************************************/
  25
  26 #ifndef VLC_PICTURE_H
  27 #define VLC_PICTURE_H 1
  28
  29 #include <assert.h>
  30 #ifndef __cplusplus
  31 #include <stdatomic.h>
  32 #else
  33 #include <atomic>
  34 using std::atomic_uintptr_t;
  35 using std::memory_order_relaxed;
  36 using std::memory_order_release;
  37 #endif
  38
  39 /**
  40  * \file
  41  * This file defines picture structures and functions in vlc
  42  */
  43
  44 #include <vlc_es.h>
  45
  46 /** Description of a planar graphic field */
  47 typedef struct plane_t
  48 {
  49     uint8_t *p_pixels;                        /**< Start of the plane's data */
  50
  51     /* Variables used for fast memcpy operations */
  52     int i_lines;           /**< Number of lines, including margins */
  53     int i_pitch;           /**< Number of bytes in a line, including margins */
  54
  55     /** Size of a macropixel, defaults to 1 */
  56     int i_pixel_pitch;
  57
  58     /* Variables used for pictures with margins */
  59     int i_visible_lines;            /**< How many visible lines are there? */
  60     int i_visible_pitch;            /**< How many visible pixels are there? */
  61
  62 } plane_t;
  63
  64 /**
  65  * Maximum number of plane for a picture
  66  */
  67 #define PICTURE_PLANE_MAX (VOUT_MAX_PLANES)
  68
  69 typedef struct picture_context_t
  70 {
  71     void (*destroy)(struct picture_context_t *);
  72     struct picture_context_t *(*copy)(struct picture_context_t *);
  73 } picture_context_t;
  74
  75 typedef struct picture_buffer_t
  76 {
  77     int fd;
  78     void *base;
  79     size_t size;
  80     off_t offset;
  81 } picture_buffer_t;
  82
  83 typedef struct vlc_video_context vlc_video_context;
  84
  85 /**
  86  * Video picture
  87  */
  88 struct picture_t
  89 {
  90     /**
  91      * The properties of the picture
  92      */
  93     video_frame_format_t format;
  94
  95     plane_t         p[PICTURE_PLANE_MAX];     /**< description of the planes */
  96     int             i_planes;                /**< number of allocated planes */
  97
  98     /** \name Picture management properties
  99      * These properties can be modified using the video output thread API,
 100      * but should never be written directly */
 101     /**@{*/
 102     vlc_tick_t      date;                                  /**< display date */
 103     bool            b_force;
 104     bool            b_still;
 105     /**@}*/
 106
 107     /** \name Picture dynamic properties
 108      * Those properties can be changed by the decoder
 109      * @{
 110      */
 111     bool            b_progressive;          /**< is it a progressive frame? */
 112     bool            b_top_field_first;             /**< which field is first */
 113     unsigned int    i_nb_fields;                  /**< number of displayed fields */
 114     picture_context_t *context;      /**< video format-specific data pointer */
 115     /**@}*/
 116
 117     /** Private data - the video output plugin might want to put stuff here to
 118      * keep track of the picture */
 119     void           *p_sys;
 120
 121     /** Next picture in a FIFO a pictures */
 122     struct picture_t *p_next;
 123
 124     atomic_uintptr_t refs;
 125 };
 126
 127 /**
 128  * This function will create a new picture.
 129  * The picture created will implement a default release management compatible
 130  * with picture_Hold and picture_Release. This default management will release
 131  * p_sys, gc.p_sys fields if non NULL.
 132  */
 133 VLC_API picture_t * picture_New( vlc_fourcc_t i_chroma, int i_width, int i_height, int i_sar_num, int i_sar_den ) VLC_USED;
 134
 135 /**
 136  * This function will create a new picture using the given format.
 137  *
 138  * When possible, it is preferred to use this function over picture_New
 139  * as more information about the format is kept.
 140  */
 141 VLC_API picture_t * picture_NewFromFormat( const video_format_t *p_fmt ) VLC_USED;
 142
 143 /**
 144  * Resource for a picture.
 145  */
 146 typedef struct
 147 {
 148     void *p_sys;
 149     void (*pf_destroy)(picture_t *);
 150
 151     /* Plane resources
 152      * XXX all fields MUST be set to the right value.
 153      */
 154     struct
 155     {
 156         uint8_t *p_pixels;  /**< Start of the plane's data */
 157         int i_lines;        /**< Number of lines, including margins */
 158         int i_pitch;        /**< Number of bytes in a line, including margins */
 159     } p[PICTURE_PLANE_MAX];
 160
 161 } picture_resource_t;
 162
 163 /**
 164  * This function will create a new picture using the provided resource.
 165  *
 166  * If the resource is NULL then a plain picture_NewFromFormat is returned.
 167  */
 168 VLC_API picture_t * picture_NewFromResource( const video_format_t *, const picture_resource_t * ) VLC_USED;
 169
 170 /**
 171  * Destroys a picture without references.
 172  *
 173  * This function destroys a picture with zero references left.
 174  * Never call this function directly. Use picture_Release() instead.
 175  */
 176 VLC_API void picture_Destroy(picture_t *picture);
 177
 178 /**
 179  * Increments the picture reference count.
 180  *
 181  * \return picture
 182  */
 183 static inline picture_t *picture_Hold(picture_t *picture)
 184 {
 185     atomic_fetch_add_explicit(&picture->refs, (uintptr_t)1,
 186                               memory_order_relaxed);
 187     return picture;
 188 }
 189
 190 /**
 191  * Decrements the picture reference count.
 192  *
 193  * If the reference count reaches zero, the picture is destroyed. If it was
 194  * allocated from a pool, the underlying picture buffer will be returned to the
 195  * pool. Otherwise, the picture buffer will be freed.
 196  */
 197 static inline void picture_Release(picture_t *picture)
 198 {
 199     uintptr_t refs = atomic_fetch_sub_explicit(&picture->refs, (uintptr_t)1,
 200                                                memory_order_release);
 201     vlc_assert(refs > 0);
 202     if (refs == 1)
 203         picture_Destroy(picture);
 204 }
 205
 206 /**
 207  * This function will copy all picture dynamic properties.
 208  */
 209 VLC_API void picture_CopyProperties( picture_t *p_dst, const picture_t *p_src );
 210
 211 /**
 212  * This function will reset a picture information (properties and quantizers).
 213  * It is sometimes useful for reusing pictures (like from a pool).
 214  */
 215 VLC_API void picture_Reset( picture_t * );
 216
 217 /**
 218  * This function will copy the picture pixels.
 219  * You can safely copy between pictures that do not have the same size,
 220  * only the compatible(smaller) part will be copied.
 221  */
 222 VLC_API void picture_CopyPixels( picture_t *p_dst, const picture_t *p_src );
 223 VLC_API void plane_CopyPixels( plane_t *p_dst, const plane_t *p_src );
 224
 225 /**
 226  * This function will copy both picture dynamic properties and pixels.
 227  * You have to notice that sometime a simple picture_Hold may do what
 228  * you want without the copy overhead.
 229  * Provided for convenience.
 230  *
 231  * \param p_dst pointer to the destination picture.
 232  * \param p_src pointer to the source picture.
 233  */
 234 VLC_API void picture_Copy( picture_t *p_dst, const picture_t *p_src );
 235
 236 /**
 237  * Perform a shallow picture copy
 238  *
 239  * This function makes a shallow copy of an existing picture. The same planes
 240  * and resources will be used, and the cloned picture reference count will be
 241  * incremented.
 242  *
 243  * \return A clone picture on success, NULL on error.
 244  */
 245 VLC_API picture_t *picture_Clone(picture_t *pic);
 246
 247 /**
 248  * This function will export a picture to an encoded bitstream.
 249  *
 250  * pp_image will contain the encoded bitstream in psz_format format.
 251  *
 252  * p_fmt can be NULL otherwise it will be set with the format used for the
 253  * picture before encoding.
 254  *
 255  * i_override_width/height allow to override the width and/or the height of the
 256  * picture to be encoded:
 257  *  - if strictly lower than 0, the original dimension will be used.
 258  *  - if equal to 0, it will be deduced from the other dimension which must be
 259  *  different to 0.
 260  *  - if strictly higher than 0, it will override the dimension.
 261  * If at most one of them is > 0 then the picture aspect ratio will be kept.
 262  */
 263 VLC_API int picture_Export( vlc_object_t *p_obj, block_t **pp_image, video_format_t *p_fmt, picture_t *p_picture, vlc_fourcc_t i_format, int i_override_width, int i_override_height );
 264
 265 /**
 266  * This function will setup all fields of a picture_t without allocating any
 267  * memory.
 268  * XXX The memory must already be initialized.
 269  * It does not need to be released.
 270  *
 271  * It will return VLC_EGENERIC if the core does not understand the requested
 272  * format.
 273  *
 274  * It can be useful to get the properties of planes.
 275  */
 276 VLC_API int picture_Setup( picture_t *, const video_format_t * );
 277
 278
 279 /*****************************************************************************
 280  * Shortcuts to access image components
 281  *****************************************************************************/
 282
 283 /* Plane indices */
 284 enum
 285 {
 286     Y_PLANE = 0,
 287     U_PLANE = 1,
 288     V_PLANE = 2,
 289     A_PLANE = 3,
 290 };
 291
 292 /* Shortcuts */
 293 #define Y_PIXELS     p[Y_PLANE].p_pixels
 294 #define Y_PITCH      p[Y_PLANE].i_pitch
 295 #define U_PIXELS     p[U_PLANE].p_pixels
 296 #define U_PITCH      p[U_PLANE].i_pitch
 297 #define V_PIXELS     p[V_PLANE].p_pixels
 298 #define V_PITCH      p[V_PLANE].i_pitch
 299 #define A_PIXELS     p[A_PLANE].p_pixels
 300 #define A_PITCH      p[A_PLANE].i_pitch
 301
 302 /**
 303  * Swap UV planes of a Tri Planars picture.
 304  *
 305  * It just swap the planes information without doing any copy.
 306  */
 307 static inline void picture_SwapUV(picture_t *picture)
 308 {
 309     vlc_assert(picture->i_planes == 3);
 310
 311     plane_t tmp_plane   = picture->p[U_PLANE];
 312     picture->p[U_PLANE] = picture->p[V_PLANE];
 313     picture->p[V_PLANE] = tmp_plane;
 314 }
 315
 316 /**@}*/
 317
 318 #endif /* VLC_PICTURE_H */