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 #include <vlc_picture.h>
  30 #include <vlc_codec.h>
  31
  32 typedef struct vlc_video_context  vlc_video_context;
  33
  34 /**
  35  * \defgroup filter Filters
  36  * \ingroup output
  37  * Audio, video, text filters
  38  * @{
  39  * \file
  40  * Filter modules interface
  41  */
  42
  43 struct filter_video_callbacks
  44 {
  45     picture_t *(*buffer_new)(filter_t *);
  46     vlc_decoder_device * (*hold_device)(vlc_object_t *, void *sys);
  47 };
  48
  49 struct filter_subpicture_callbacks
  50 {
  51     subpicture_t *(*buffer_new)(filter_t *);
  52 };
  53
  54 typedef struct filter_owner_t
  55 {
  56     union
  57     {
  58         const struct filter_video_callbacks *video;
  59         const struct filter_subpicture_callbacks *sub;
  60     };
  61     void *sys;
  62 } filter_owner_t;
  63
  64 struct vlc_mouse_t;
  65
  66 /** Structure describing a filter
  67  * @warning BIG FAT WARNING : the code relies on the first 4 members of
  68  * filter_t and decoder_t to be the same, so if you have anything to add,
  69  * do it at the end of the structure.
  70  */
  71 struct filter_t
  72 {
  73     struct vlc_object_t obj;
  74
  75     /* Module properties */
  76     module_t *          p_module;
  77     void               *p_sys;
  78
  79     /* Input format */
  80     es_format_t         fmt_in;
  81     vlc_video_context   *vctx_in;  // video filter, set by owner
  82
  83     /* Output format of filter */
  84     es_format_t         fmt_out;
  85     vlc_video_context   *vctx_out; // video filter, handled by the filter
  86     bool                b_allow_fmt_out_change;
  87
  88     /* Name of the "video filter" shortcut that is requested, can be NULL */
  89     const char *        psz_name;
  90     /* Filter configuration */
  91     config_chain_t *    p_cfg;
  92
  93     union
  94     {
  95         /** Filter a picture (video filter) */
  96         picture_t * (*pf_video_filter)( filter_t *, picture_t * );
  97
  98         /** Filter an audio block (audio filter) */
  99         block_t * (*pf_audio_filter)( filter_t *, block_t * );
 100
 101         /** Blend a subpicture onto a picture (blend) */
 102         void (*pf_video_blend)( filter_t *,  picture_t *, const picture_t *,
 103                                  int, int, int );
 104
 105         /** Generate a subpicture (sub source) */
 106         subpicture_t *(*pf_sub_source)( filter_t *, vlc_tick_t );
 107
 108         /** Filter a subpicture (sub filter) */
 109         subpicture_t *(*pf_sub_filter)( filter_t *, subpicture_t * );
 110
 111         /** Render text (text render) */
 112         int (*pf_render)( filter_t *, subpicture_region_t *,
 113                           subpicture_region_t *, const vlc_fourcc_t * );
 114     };
 115
 116     union
 117     {
 118         /* TODO: video filter drain */
 119         /** Drain (audio filter) */
 120         block_t *(*pf_audio_drain) ( filter_t * );
 121     };
 122
 123     /** Flush
 124      *
 125      * Flush (i.e. discard) any internal buffer in a video or audio filter.
 126      */
 127     void (*pf_flush)( filter_t * );
 128
 129     /** Change viewpoint
 130      *
 131      * Pass a new viewpoint to audio filters. Filters like the spatialaudio one
 132      * used for Ambisonics rendering will change its output according to this
 133      * viewpoint.
 134      */
 135     void (*pf_change_viewpoint)( filter_t *, const vlc_viewpoint_t * );
 136
 137     union
 138     {
 139         /** Filter mouse state (video filter).
 140          *
 141          * If non-NULL, you must convert from output to input formats:
 142          * - If VLC_SUCCESS is returned, the mouse state is propagated.
 143          * - Otherwise, the mouse change is not propagated.
 144          * If NULL, the mouse state is considered unchanged and will be
 145          * propagated. */
 146         int (*pf_video_mouse)( filter_t *, struct vlc_mouse_t *,
 147                                const struct vlc_mouse_t *p_old,
 148                                const struct vlc_mouse_t *p_new );
 149     };
 150
 151     /* Input attachments
 152      * XXX use filter_GetInputAttachments */
 153     int (*pf_get_attachments)( filter_t *, input_attachment_t ***, int * );
 154
 155     /** Private structure for the owner of the filter */
 156     filter_owner_t      owner;
 157 };
 158
 159 /**
 160  * This function will return a new picture usable by p_filter as an output
 161  * buffer. You have to release it using picture_Release or by returning
 162  * it to the caller as a pf_video_filter return value.
 163  * Provided for convenience.
 164  *
 165  * \param p_filter filter_t object
 166  * \return new picture on success or NULL on failure
 167  */
 168 static inline picture_t *filter_NewPicture( filter_t *p_filter )
 169 {
 170     picture_t *pic = NULL;
 171     if ( p_filter->owner.video != NULL && p_filter->owner.video->buffer_new != NULL)
 172         pic = p_filter->owner.video->buffer_new( p_filter );
 173     if ( pic == NULL )
 174     {
 175         // legacy filter owners not setting a default filter_allocator
 176         pic = picture_NewFromFormat( &p_filter->fmt_out.video );
 177     }
 178     if( pic == NULL )
 179         msg_Warn( p_filter, "can't get output picture" );
 180     return pic;
 181 }
 182
 183 /**
 184  * Flush a filter
 185  *
 186  * This function will flush the state of a filter (audio or video).
 187  */
 188 static inline void filter_Flush( filter_t *p_filter )
 189 {
 190     if( p_filter->pf_flush != NULL )
 191         p_filter->pf_flush( p_filter );
 192 }
 193
 194 static inline void filter_ChangeViewpoint( filter_t *p_filter,
 195                                            const vlc_viewpoint_t *vp)
 196 {
 197     if( p_filter->pf_change_viewpoint != NULL )
 198         p_filter->pf_change_viewpoint( p_filter, vp );
 199 }
 200
 201 static inline vlc_decoder_device * filter_HoldDecoderDevice( filter_t *p_filter )
 202 {
 203     if ( !p_filter->owner.video || !p_filter->owner.video->hold_device )
 204         return NULL;
 205
 206     return p_filter->owner.video->hold_device( VLC_OBJECT(p_filter), p_filter->owner.sys );
 207 }
 208
 209 static inline vlc_decoder_device * filter_HoldDecoderDeviceType( filter_t *p_filter,
 210                                                                  enum vlc_decoder_device_type type )
 211 {
 212     if ( !p_filter->owner.video || !p_filter->owner.video->hold_device )
 213         return NULL;
 214
 215     vlc_decoder_device *dec_dev = p_filter->owner.video->hold_device( VLC_OBJECT(p_filter),
 216                                                                       p_filter->owner.sys );
 217     if ( dec_dev != NULL )
 218     {
 219         if ( dec_dev->type == type )
 220             return dec_dev;
 221         vlc_decoder_device_Release(dec_dev);
 222     }
 223     return NULL;
 224 }
 225
 226 /**
 227  * This function will drain, then flush an audio filter.
 228  */
 229 static inline block_t *filter_DrainAudio( filter_t *p_filter )
 230 {
 231     if( p_filter->pf_audio_drain )
 232         return p_filter->pf_audio_drain( p_filter );
 233     else
 234         return NULL;
 235 }
 236
 237 /**
 238  * This function will return a new subpicture usable by p_filter as an output
 239  * buffer. You have to release it using subpicture_Delete or by returning it to
 240  * the caller as a pf_sub_source return value.
 241  * Provided for convenience.
 242  *
 243  * \param p_filter filter_t object
 244  * \return new subpicture
 245  */
 246 static inline subpicture_t *filter_NewSubpicture( filter_t *p_filter )
 247 {
 248     subpicture_t *subpic = p_filter->owner.sub->buffer_new( p_filter );
 249     if( subpic == NULL )
 250         msg_Warn( p_filter, "can't get output subpicture" );
 251     return subpic;
 252 }
 253
 254 /**
 255  * This function gives all input attachments at once.
 256  *
 257  * You MUST release the returned values
 258  */
 259 static inline int filter_GetInputAttachments( filter_t *p_filter,
 260                                               input_attachment_t ***ppp_attachment,
 261                                               int *pi_attachment )
 262 {
 263     if( !p_filter->pf_get_attachments )
 264         return VLC_EGENERIC;
 265     return p_filter->pf_get_attachments( p_filter,
 266                                          ppp_attachment, pi_attachment );
 267 }
 268
 269 /**
 270  * This function duplicates every variables from the filter, and adds a proxy
 271  * callback to trigger filter events from obj.
 272  *
 273  * \param restart_cb a vlc_callback_t to call if the event means restarting the
 274  * filter (i.e. an event on a non-command variable)
 275  */
 276 VLC_API void filter_AddProxyCallbacks( vlc_object_t *obj, filter_t *filter,
 277                                        vlc_callback_t restart_cb );
 278 # define filter_AddProxyCallbacks(a, b, c) \
 279     filter_AddProxyCallbacks(VLC_OBJECT(a), b, c)
 280
 281 /**
 282  * This function removes the callbacks previously added to every duplicated
 283  * variables, and removes them afterward.
 284  *
 285  * \param restart_cb the same vlc_callback_t passed to filter_AddProxyCallbacks
 286  */
 287 VLC_API void filter_DelProxyCallbacks( vlc_object_t *obj, filter_t *filter,
 288                                        vlc_callback_t restart_cb);
 289 # define filter_DelProxyCallbacks(a, b, c) \
 290     filter_DelProxyCallbacks(VLC_OBJECT(a), b, c)
 291
 292 typedef filter_t vlc_blender_t;
 293
 294 /**
 295  * It creates a blend filter.
 296  *
 297  * Only the chroma properties of the dest format is used (chroma
 298  * type, rgb masks and shifts)
 299  */
 300 VLC_API vlc_blender_t * filter_NewBlend( vlc_object_t *, const video_format_t *p_dst_chroma ) VLC_USED;
 301
 302 /**
 303  * It configures blend filter parameters that are allowed to changed
 304  * after the creation.
 305  */
 306 VLC_API int filter_ConfigureBlend( vlc_blender_t *, int i_dst_width, int i_dst_height, const video_format_t *p_src );
 307
 308 /**
 309  * It blends a picture into another one.
 310  *
 311  * The input picture is not modified and not released.
 312  */
 313 VLC_API int filter_Blend( vlc_blender_t *, picture_t *p_dst, int i_dst_x, int i_dst_y, const picture_t *p_src, int i_alpha );
 314
 315 /**
 316  * It destroys a blend filter created by filter_NewBlend.
 317  */
 318 VLC_API void filter_DeleteBlend( vlc_blender_t * );
 319
 320 /**
 321  * Create a picture_t *(*)( filter_t *, picture_t * ) compatible wrapper
 322  * using a void (*)( filter_t *, picture_t *, picture_t * ) function
 323  *
 324  * Currently used by the chroma video filters
 325  */
 326 #define VIDEO_FILTER_WRAPPER( name )                                    \
 327     static picture_t *name ## _Filter ( filter_t *p_filter,             \
 328                                         picture_t *p_pic )              \
 329     {                                                                   \
 330         picture_t *p_outpic = filter_NewPicture( p_filter );            \
 331         if( p_outpic )                                                  \
 332         {                                                               \
 333             name( p_filter, p_pic, p_outpic );                          \
 334             picture_CopyProperties( p_outpic, p_pic );                  \
 335         }                                                               \
 336         picture_Release( p_pic );                                       \
 337         return p_outpic;                                                \
 338     }
 339
 340 /**
 341  * Filter chain management API
 342  * The filter chain management API is used to dynamically construct filters
 343  * and add them in a chain.
 344  */
 345
 346 typedef struct filter_chain_t filter_chain_t;
 347
 348 /**
 349  * Create new filter chain
 350  *
 351  * \param obj pointer to a vlc object
 352  * \param psz_capability vlc capability of filters in filter chain
 353  * \return pointer to a filter chain
 354  */
 355 filter_chain_t * filter_chain_NewSPU( vlc_object_t *obj, const char *psz_capability )
 356 VLC_USED;
 357 #define filter_chain_NewSPU( a, b ) filter_chain_NewSPU( VLC_OBJECT( a ), b )
 358
 359 /**
 360  * Creates a new video filter chain.
 361  *
 362  * \param obj pointer to parent VLC object
 363  * \param change whether to allow changing the output format
 364  * \param owner owner video buffer callbacks
 365  * \return new filter chain, or NULL on error
 366  */
 367 VLC_API filter_chain_t * filter_chain_NewVideo( vlc_object_t *obj, bool change,
 368                                                 const filter_owner_t *owner )
 369 VLC_USED;
 370 #define filter_chain_NewVideo( a, b, c ) \
 371         filter_chain_NewVideo( VLC_OBJECT( a ), b, c )
 372
 373 /**
 374  * Delete filter chain will delete all filters in the chain and free all
 375  * allocated data. The pointer to the filter chain is then no longer valid.
 376  *
 377  * \param p_chain pointer to filter chain
 378  */
 379 VLC_API void filter_chain_Delete( filter_chain_t * );
 380
 381 /**
 382  * Reset filter chain will delete all filters in the chain and
 383  * reset p_fmt_in and p_fmt_out to the new values.
 384  *
 385  * \param p_chain pointer to filter chain
 386  * \param p_fmt_in new fmt_in params
 387  * \paramt vctx_in new input video context
 388  * \param p_fmt_out new fmt_out params
 389  */
 390 VLC_API void filter_chain_Reset( filter_chain_t *p_chain,
 391                                  const es_format_t *p_fmt_in,
 392                                  vlc_video_context *vctx_in,
 393                                  const es_format_t *p_fmt_out );
 394
 395 /**
 396  * Remove all existing filters
 397  *
 398  * \param p_chain pointer to filter chain
 399  */
 400 VLC_API void filter_chain_Clear(filter_chain_t *);
 401
 402 /**
 403  * Append a filter to the chain.
 404  *
 405  * \param chain filter chain to append a filter to
 406  * \param name filter name
 407  * \param fmt_out filter output format
 408  * \return a pointer to the filter or NULL on error
 409  */
 410 VLC_API filter_t *filter_chain_AppendFilter(filter_chain_t *chain,
 411     const char *name, config_chain_t *cfg,
 412     const es_format_t *fmt_out);
 413
 414 /**
 415  * Append a conversion to the chain.
 416  *
 417  * \param chain filter chain to append a filter to
 418  * \param fmt_out filter output format
 419  * \retval 0 on success
 420  * \retval -1 on failure
 421  */
 422 VLC_API int filter_chain_AppendConverter(filter_chain_t *chain,
 423     const es_format_t *fmt_out);
 424
 425 /**
 426  * Append new filter to filter chain from string.
 427  *
 428  * \param chain filter chain to append a filter to
 429  * \param str filters chain nul-terminated string
 430  */
 431 VLC_API int filter_chain_AppendFromString(filter_chain_t *chain,
 432                                           const char *str);
 433
 434 /**
 435  * Delete filter from filter chain. This function also releases the filter
 436  * object and unloads the filter modules. The pointer to p_filter is no
 437  * longer valid after this function successfully returns.
 438  *
 439  * \param chain filter chain to remove the filter from
 440  * \param filter filter to remove from the chain and delete
 441  */
 442 VLC_API void filter_chain_DeleteFilter(filter_chain_t *chain,
 443                                        filter_t *filter);
 444
 445 /**
 446  * Checks if the filter chain is empty.
 447  *
 448  * \param chain pointer to filter chain
 449  * \return true if and only if there are no filters in this filter chain
 450  */
 451 VLC_API bool filter_chain_IsEmpty(const filter_chain_t *chain);
 452
 453 /**
 454  * Get last output format of the last element in the filter chain.
 455  *
 456  * \param chain filter chain
 457  */
 458 VLC_API const es_format_t *filter_chain_GetFmtOut(const filter_chain_t *chain);
 459
 460 /**
 461  * Get last output video context of the last element in the filter chain.
 462  * \note doesn't create change the reference count
 463  *
 464  * \param chain filter chain
 465  */
 466 VLC_API vlc_video_context *filter_chain_GetVideoCtxOut(const filter_chain_t *chain);
 467
 468 /**
 469  * Apply the filter chain to a video picture.
 470  *
 471  * \param chain pointer to filter chain
 472  * \param pic picture to apply filters to
 473  * \return modified picture after applying all video filters
 474  */
 475 VLC_API picture_t *filter_chain_VideoFilter(filter_chain_t *chain,
 476                                             picture_t *pic);
 477
 478 /**
 479  * Flush a video filter chain.
 480  */
 481 VLC_API void filter_chain_VideoFlush( filter_chain_t * );
 482
 483 /**
 484  * Generate subpictures from a chain of subpicture source "filters".
 485  *
 486  * \param chain filter chain
 487  * \param display_date of subpictures
 488  */
 489 void filter_chain_SubSource(filter_chain_t *chain, spu_t *,
 490                             vlc_tick_t display_date);
 491
 492 /**
 493  * Apply filter chain to subpictures.
 494  *
 495  * \param chain filter chain
 496  * \param subpic subpicture to apply filters on
 497  * \return modified subpicture after applying all subpicture filters
 498  */
 499 VLC_API subpicture_t *filter_chain_SubFilter(filter_chain_t *chain,
 500                                              subpicture_t *subpic);
 501
 502 /**
 503  * Apply the filter chain to a mouse state.
 504  *
 505  * It will be applied from the output to the input. It makes sense only
 506  * for a video filter chain.
 507  *
 508  * The vlc_mouse_t* pointers may be the same.
 509  */
 510 VLC_API int filter_chain_MouseFilter( filter_chain_t *, struct vlc_mouse_t *,
 511                                       const struct vlc_mouse_t * );
 512
 513 VLC_API int filter_chain_ForEach( filter_chain_t *chain,
 514                           int (*cb)( filter_t *, void * ), void *opaque );
 515
 516 /** @} */
 517 #endif /* _VLC_FILTER_H */