include/vlc_filter.h

   1 /*****************************************************************************
   2  * vlc_filter.h: filter related structures and functions
   3  *****************************************************************************
   4  * Copyright (C) 1999-2014 VLC authors and VideoLAN
   5  *
   6  * Authors: Gildas Bazin <gbazin@videolan.org>
   7  *          Antoine Cellerier <dionoea at videolan dot org>
   8  *          Rémi Denis-Courmont
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 #ifndef VLC_FILTER_H
  26 #define VLC_FILTER_H 1
  27
  28 #include <vlc_es.h>
  29
  30 /**
  31  * \defgroup filter Filters
  32  * \ingroup output
  33  * Audio, video, text filters
  34  * @{
  35  * \file
  36  * Filter modules interface
  37  */
  38
  39 typedef struct filter_owner_sys_t filter_owner_sys_t;
  40
  41 typedef struct filter_owner_t
  42 {
  43     void *sys;
  44
  45     union
  46     {
  47         struct
  48         {
  49             picture_t * (*buffer_new)( filter_t * );
  50         } video;
  51         struct
  52         {
  53             subpicture_t * (*buffer_new)( filter_t * );
  54         } sub;
  55     };
  56 } filter_owner_t;
  57
  58 struct vlc_mouse_t;
  59
  60 /** Structure describing a filter
  61  * @warning BIG FAT WARNING : the code relies on the first 4 members of
  62  * filter_t and decoder_t to be the same, so if you have anything to add,
  63  * do it at the end of the structure.
  64  */
  65 struct filter_t
  66 {
  67     VLC_COMMON_MEMBERS
  68
  69     /* Module properties */
  70     module_t *          p_module;
  71     filter_sys_t *      p_sys;
  72
  73     /* Input format */
  74     es_format_t         fmt_in;
  75
  76     /* Output format of filter */
  77     es_format_t         fmt_out;
  78     bool                b_allow_fmt_out_change;
  79
  80     /* Name of the "video filter" shortcut that is requested, can be NULL */
  81     const char *        psz_name;
  82     /* Filter configuration */
  83     config_chain_t *    p_cfg;
  84
  85     union
  86     {
  87         /** Filter a picture (video filter) */
  88         picture_t * (*pf_video_filter)( filter_t *, picture_t * );
  89
  90         /** Filter an audio block (audio filter) */
  91         block_t * (*pf_audio_filter)( filter_t *, block_t * );
  92
  93         /** Blend a subpicture onto a picture (blend) */
  94         void (*pf_video_blend)( filter_t *,  picture_t *, const picture_t *,
  95                                  int, int, int );
  96
  97         /** Generate a subpicture (sub source) */
  98         subpicture_t *(*pf_sub_source)( filter_t *, mtime_t );
  99
 100         /** Filter a subpicture (sub filter) */
 101         subpicture_t *(*pf_sub_filter)( filter_t *, subpicture_t * );
 102
 103         /** Render text (text render) */
 104         int (*pf_render)( filter_t *, subpicture_region_t *,
 105                           subpicture_region_t *, const vlc_fourcc_t * );
 106     };
 107
 108     union
 109     {
 110         /* TODO: video filter drain */
 111         /** Drain (audio filter) */
 112         block_t *(*pf_audio_drain) ( filter_t * );
 113     };
 114
 115     /** Flush
 116      *
 117      * Flush (i.e. discard) any internal buffer in a video or audio filter.
 118      */
 119     void (*pf_flush)( filter_t * );
 120
 121     /** Change viewpoint
 122      *
 123      * Pass a new viewpoint to audio filters. Filters like the spatialaudio one
 124      * used for Ambisonics rendering will change its output according to this
 125      * viewpoint.
 126      */
 127     void (*pf_change_viewpoint)( filter_t *, const vlc_viewpoint_t * );
 128
 129     union
 130     {
 131         /** Filter mouse state (video filter).
 132          *
 133          * If non-NULL, you must convert from output to input formats:
 134          * - If VLC_SUCCESS is returned, the mouse state is propagated.
 135          * - Otherwise, the mouse change is not propagated.
 136          * If NULL, the mouse state is considered unchanged and will be
 137          * propagated. */
 138         int (*pf_video_mouse)( filter_t *, struct vlc_mouse_t *,
 139                                const struct vlc_mouse_t *p_old,
 140                                const struct vlc_mouse_t *p_new );
 141         int (*pf_sub_mouse)( filter_t *, const struct vlc_mouse_t *p_old,
 142                              const struct vlc_mouse_t *p_new,
 143                              const video_format_t * );
 144     };
 145
 146     /* Input attachments
 147      * XXX use filter_GetInputAttachments */
 148     int (*pf_get_attachments)( filter_t *, input_attachment_t ***, int * );
 149
 150     /* Private structure for the owner of the decoder */
 151     filter_owner_t      owner;
 152 };
 153
 154 /**
 155  * This function will return a new picture usable by p_filter as an output
 156  * buffer. You have to release it using picture_Release or by returning
 157  * it to the caller as a pf_video_filter return value.
 158  * Provided for convenience.
 159  *
 160  * \param p_filter filter_t object
 161  * \return new picture on success or NULL on failure
 162  */
 163 static inline picture_t *filter_NewPicture( filter_t *p_filter )
 164 {
 165     picture_t *pic = p_filter->owner.video.buffer_new( p_filter );
 166     if( pic == NULL )
 167         msg_Warn( p_filter, "can't get output picture" );
 168     return pic;
 169 }
 170
 171 /**
 172  * Flush a filter
 173  *
 174  * This function will flush the state of a filter (audio or video).
 175  */
 176 static inline void filter_Flush( filter_t *p_filter )
 177 {
 178     if( p_filter->pf_flush != NULL )
 179         p_filter->pf_flush( p_filter );
 180 }
 181
 182 static inline void filter_ChangeViewpoint( filter_t *p_filter,
 183                                            const vlc_viewpoint_t *vp)
 184 {
 185     if( p_filter->pf_change_viewpoint != NULL )
 186         p_filter->pf_change_viewpoint( p_filter, vp );
 187 }
 188
 189 /**
 190  * This function will drain, then flush an audio filter.
 191  */
 192 static inline block_t *filter_DrainAudio( filter_t *p_filter )
 193 {
 194     if( p_filter->pf_audio_drain )
 195         return p_filter->pf_audio_drain( p_filter );
 196     else
 197         return NULL;
 198 }
 199
 200 /**
 201  * This function will return a new subpicture usable by p_filter as an output
 202  * buffer. You have to release it using subpicture_Delete or by returning it to
 203  * the caller as a pf_sub_source return value.
 204  * Provided for convenience.
 205  *
 206  * \param p_filter filter_t object
 207  * \return new subpicture
 208  */
 209 static inline subpicture_t *filter_NewSubpicture( filter_t *p_filter )
 210 {
 211     subpicture_t *subpic = p_filter->owner.sub.buffer_new( p_filter );
 212     if( subpic == NULL )
 213         msg_Warn( p_filter, "can't get output subpicture" );
 214     return subpic;
 215 }
 216
 217 /**
 218  * This function gives all input attachments at once.
 219  *
 220  * You MUST release the returned values
 221  */
 222 static inline int filter_GetInputAttachments( filter_t *p_filter,
 223                                               input_attachment_t ***ppp_attachment,
 224                                               int *pi_attachment )
 225 {
 226     if( !p_filter->pf_get_attachments )
 227         return VLC_EGENERIC;
 228     return p_filter->pf_get_attachments( p_filter,
 229                                          ppp_attachment, pi_attachment );
 230 }
 231
 232 /**
 233  * This function duplicates every variables from the filter, and adds a proxy
 234  * callback to trigger filter events from obj.
 235  *
 236  * \param restart_cb a vlc_callback_t to call if the event means restarting the
 237  * filter (i.e. an event on a non-command variable)
 238  */
 239 VLC_API void filter_AddProxyCallbacks( vlc_object_t *obj, filter_t *filter,
 240                                        vlc_callback_t restart_cb );
 241 # define filter_AddProxyCallbacks(a, b, c) \
 242     filter_AddProxyCallbacks(VLC_OBJECT(a), b, c)
 243
 244 /**
 245  * This function removes the callbacks previously added to every duplicated
 246  * variables, and removes them afterward.
 247  *
 248  * \param restart_cb the same vlc_callback_t passed to filter_AddProxyCallbacks
 249  */
 250 VLC_API void filter_DelProxyCallbacks( vlc_object_t *obj, filter_t *filter,
 251                                        vlc_callback_t restart_cb);
 252 # define filter_DelProxyCallbacks(a, b, c) \
 253     filter_DelProxyCallbacks(VLC_OBJECT(a), b, c)
 254
 255 /**
 256  * It creates a blend filter.
 257  *
 258  * Only the chroma properties of the dest format is used (chroma
 259  * type, rgb masks and shifts)
 260  */
 261 VLC_API filter_t * filter_NewBlend( vlc_object_t *, const video_format_t *p_dst_chroma ) VLC_USED;
 262
 263 /**
 264  * It configures blend filter parameters that are allowed to changed
 265  * after the creation.
 266  */
 267 VLC_API int filter_ConfigureBlend( filter_t *, int i_dst_width, int i_dst_height, const video_format_t *p_src );
 268
 269 /**
 270  * It blends a picture into another one.
 271  *
 272  * The input picture is not modified and not released.
 273  */
 274 VLC_API int filter_Blend( filter_t *, picture_t *p_dst, int i_dst_x, int i_dst_y, const picture_t *p_src, int i_alpha );
 275
 276 /**
 277  * It destroys a blend filter created by filter_NewBlend.
 278  */
 279 VLC_API void filter_DeleteBlend( filter_t * );
 280
 281 /**
 282  * Create a picture_t *(*)( filter_t *, picture_t * ) compatible wrapper
 283  * using a void (*)( filter_t *, picture_t *, picture_t * ) function
 284  *
 285  * Currently used by the chroma video filters
 286  */
 287 #define VIDEO_FILTER_WRAPPER( name )                                    \
 288     static picture_t *name ## _Filter ( filter_t *p_filter,             \
 289                                         picture_t *p_pic )              \
 290     {                                                                   \
 291         picture_t *p_outpic = filter_NewPicture( p_filter );            \
 292         if( p_outpic )                                                  \
 293         {                                                               \
 294             name( p_filter, p_pic, p_outpic );                          \
 295             picture_CopyProperties( p_outpic, p_pic );                  \
 296         }                                                               \
 297         picture_Release( p_pic );                                       \
 298         return p_outpic;                                                \
 299     }
 300
 301 /**
 302  * Filter chain management API
 303  * The filter chain management API is used to dynamically construct filters
 304  * and add them in a chain.
 305  */
 306
 307 typedef struct filter_chain_t filter_chain_t;
 308
 309 /**
 310  * Create new filter chain
 311  *
 312  * \param p_object pointer to a vlc object
 313  * \param psz_capability vlc capability of filters in filter chain
 314  * \return pointer to a filter chain
 315  */
 316 filter_chain_t * filter_chain_New( vlc_object_t *, const char *, enum es_format_category_e )
 317 VLC_USED;
 318 #define filter_chain_New( a, b, c ) filter_chain_New( VLC_OBJECT( a ), b, c )
 319
 320 /**
 321  * Creates a new video filter chain.
 322  *
 323  * \param obj pointer to parent VLC object
 324  * \param change whether to allow changing the output format
 325  * \param owner owner video buffer callbacks
 326  * \return new filter chain, or NULL on error
 327  */
 328 VLC_API filter_chain_t * filter_chain_NewVideo( vlc_object_t *obj, bool change,
 329                                                 const filter_owner_t *owner )
 330 VLC_USED;
 331 #define filter_chain_NewVideo( a, b, c ) \
 332         filter_chain_NewVideo( VLC_OBJECT( a ), b, c )
 333
 334 /**
 335  * Delete filter chain will delete all filters in the chain and free all
 336  * allocated data. The pointer to the filter chain is then no longer valid.
 337  *
 338  * \param p_chain pointer to filter chain
 339  */
 340 VLC_API void filter_chain_Delete( filter_chain_t * );
 341
 342 /**
 343  * Reset filter chain will delete all filters in the chain and
 344  * reset p_fmt_in and p_fmt_out to the new values.
 345  *
 346  * \param p_chain pointer to filter chain
 347  * \param p_fmt_in new fmt_in params, may be NULL to leave input fmt unchanged
 348  * \param p_fmt_out new fmt_out params, may be NULL to leave output fmt unchanged
 349  */
 350 VLC_API void filter_chain_Reset( filter_chain_t *, const es_format_t *, const es_format_t * );
 351
 352 /**
 353  * Append a filter to the chain.
 354  *
 355  * \param chain filter chain to append a filter to
 356  * \param name filter name
 357  * \param fmt_in filter input format
 358  * \param fmt_out filter output format
 359  * \return a pointer to the filter or NULL on error
 360  */
 361 VLC_API filter_t *filter_chain_AppendFilter(filter_chain_t *chain,
 362     const char *name, config_chain_t *cfg, const es_format_t *fmt_in,
 363     const es_format_t *fmt_out);
 364
 365 /**
 366  * Append a conversion to the chain.
 367  *
 368  * \param chain filter chain to append a filter to
 369  * \param fmt_in filter input format
 370  * \param fmt_out filter output format
 371  * \retval 0 on success
 372  * \retval -1 on failure
 373  */
 374 VLC_API int filter_chain_AppendConverter(filter_chain_t *chain,
 375     const es_format_t *fmt_in, const es_format_t *fmt_out);
 376
 377 /**
 378  * Append new filter to filter chain from string.
 379  *
 380  * \param chain filter chain to append a filter to
 381  * \param str filters chain nul-terminated string
 382  */
 383 VLC_API int filter_chain_AppendFromString(filter_chain_t *chain,
 384                                           const char *str);
 385
 386 /**
 387  * Delete filter from filter chain. This function also releases the filter
 388  * object and unloads the filter modules. The pointer to p_filter is no
 389  * longer valid after this function successfully returns.
 390  *
 391  * \param chain filter chain to remove the filter from
 392  * \param filter filter to remove from the chain and delete
 393  */
 394 VLC_API void filter_chain_DeleteFilter(filter_chain_t *chain,
 395                                        filter_t *filter);
 396
 397 /**
 398  * Checks if the filter chain is empty.
 399  *
 400  * \param chain pointer to filter chain
 401  * \return true if and only if there are no filters in this filter chain
 402  */
 403 VLC_API bool filter_chain_IsEmpty(const filter_chain_t *chain);
 404
 405 /**
 406  * Get last output format of the last element in the filter chain.
 407  *
 408  * \param chain filter chain
 409  */
 410 VLC_API const es_format_t *filter_chain_GetFmtOut(filter_chain_t *chain);
 411
 412 /**
 413  * Apply the filter chain to a video picture.
 414  *
 415  * \param chain pointer to filter chain
 416  * \param pic picture to apply filters to
 417  * \return modified picture after applying all video filters
 418  */
 419 VLC_API picture_t *filter_chain_VideoFilter(filter_chain_t *chain,
 420                                             picture_t *pic);
 421
 422 /**
 423  * Flush a video filter chain.
 424  */
 425 VLC_API void filter_chain_VideoFlush( filter_chain_t * );
 426
 427 /**
 428  * Generate subpictures from a chain of subpicture source "filters".
 429  *
 430  * \param chain filter chain
 431  * \param display_date of subpictures
 432  */
 433 void filter_chain_SubSource(filter_chain_t *chain, spu_t *,
 434                             mtime_t display_date);
 435
 436 /**
 437  * Apply filter chain to subpictures.
 438  *
 439  * \param chain filter chain
 440  * \param subpic subpicture to apply filters on
 441  * \return modified subpicture after applying all subpicture filters
 442  */
 443 VLC_API subpicture_t *filter_chain_SubFilter(filter_chain_t *chain,
 444                                              subpicture_t *subpic);
 445
 446 /**
 447  * Apply the filter chain to a mouse state.
 448  *
 449  * It will be applied from the output to the input. It makes sense only
 450  * for a video filter chain.
 451  *
 452  * The vlc_mouse_t* pointers may be the same.
 453  */
 454 VLC_API int filter_chain_MouseFilter( filter_chain_t *, struct vlc_mouse_t *,
 455                                       const struct vlc_mouse_t * );
 456
 457 /**
 458  * Inform the filter chain of mouse state.
 459  *
 460  * It makes sense only for a sub source chain.
 461  */
 462 VLC_API int filter_chain_MouseEvent( filter_chain_t *,
 463                                      const struct vlc_mouse_t *,
 464                                      const video_format_t * );
 465
 466 int filter_chain_ForEach( filter_chain_t *chain,
 467                           int (*cb)( filter_t *, void * ), void *opaque );
 468
 469 /** @} */
 470 #endif /* _VLC_FILTER_H */