include/vlc_codec.h

   1 /*****************************************************************************
   2  * vlc_codec.h: Definition of the decoder and encoder structures
   3  *****************************************************************************
   4  * Copyright (C) 1999-2003 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Gildas Bazin <gbazin@netcourrier.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #ifndef VLC_CODEC_H
  25 #define VLC_CODEC_H 1
  26
  27 #include <assert.h>
  28
  29 #include <vlc_block.h>
  30 #include <vlc_es.h>
  31 #include <vlc_picture.h>
  32 #include <vlc_subpicture.h>
  33
  34 /**
  35  * \defgroup decoder Decoder
  36  * \ingroup input
  37  * Audio, video and text decoders
  38  * @{
  39  *
  40  * \file
  41  * Decoder and encoder modules interface
  42  */
  43
  44 typedef struct decoder_cc_desc_t decoder_cc_desc_t;
  45
  46 struct decoder_owner_callbacks
  47 {
  48     union
  49     {
  50         struct
  51         {
  52             int         (*format_update)( decoder_t * );
  53
  54             /* cf. decoder_NewPicture */
  55             picture_t*  (*buffer_new)( decoder_t * );
  56             /* cf.decoder_QueueVideo */
  57             void        (*queue)( decoder_t *, picture_t * );
  58             /* cf.decoder_QueueCC */
  59             void        (*queue_cc)( decoder_t *, block_t *,
  60                                      const decoder_cc_desc_t * );
  61
  62             /* Display date
  63              * cf. decoder_GetDisplayDate */
  64             mtime_t     (*get_display_date)( decoder_t *, mtime_t );
  65             /* Display rate
  66              * cf. decoder_GetDisplayRate */
  67             int         (*get_display_rate)( decoder_t * );
  68         } video;
  69         struct
  70         {
  71             int     (*format_update)( decoder_t * );
  72
  73             /* cf.decoder_QueueAudio */
  74             void    (*queue)( decoder_t *, block_t * );
  75         } audio;
  76         struct
  77         {
  78             /* cf. decoder_NewSubpicture */
  79             subpicture_t*   (*buffer_new)( decoder_t *,
  80                                            const subpicture_updater_t * );
  81
  82             /* cf.decoder_QueueSub */
  83             void            (*queue)( decoder_t *, subpicture_t *);
  84         } spu;
  85     };
  86
  87     /* Input attachments
  88      * cf. decoder_GetInputAttachments */
  89     int (*get_attachments)( decoder_t *p_dec,
  90                             input_attachment_t ***ppp_attachment,
  91                             int *pi_attachment );
  92 };
  93
  94 /*
  95  * BIG FAT WARNING : the code relies in the first 4 members of filter_t
  96  * and decoder_t to be the same, so if you have anything to add, do it
  97  * at the end of the structure.
  98  */
  99 struct decoder_t
 100 {
 101     struct vlc_common_members obj;
 102
 103     /* Module properties */
 104     module_t *          p_module;
 105     void               *p_sys;
 106
 107     /* Input format ie from demuxer (XXX: a lot of field could be invalid) */
 108     es_format_t         fmt_in;
 109
 110     /* Output format of decoder/packetizer */
 111     es_format_t         fmt_out;
 112
 113     /* Tell the decoder if it is allowed to drop frames */
 114     bool                b_frame_drop_allowed;
 115
 116     /**
 117      * Number of extra (ie in addition to the DPB) picture buffers
 118      * needed for decoding.
 119      */
 120     int                 i_extra_picture_buffers;
 121
 122 #   define VLCDEC_SUCCESS   VLC_SUCCESS
 123 #   define VLCDEC_ECRITICAL VLC_EGENERIC
 124 #   define VLCDEC_RELOAD    (-100)
 125     /* This function is called to decode one packetized block.
 126      *
 127      * The module implementation will own the input block (p_block) and should
 128      * process and release it. Depending of the decoder type, the module should
 129      * send output frames/blocks via decoder_QueueVideo(), decoder_QueueAudio()
 130      * or decoder_QueueSub().
 131      *
 132      * If p_block is NULL, the decoder asks the module to drain itself. The
 133      * module should return all available output frames/block via the queue
 134      * functions.
 135      *
 136      * Return values can be:
 137      *  VLCDEC_SUCCESS: pf_decode will be called again
 138      *  VLCDEC_ECRITICAL: in case of critical error, pf_decode won't be called
 139      *  again.
 140      *  VLCDEC_RELOAD: Request that the decoder should be reloaded. The current
 141      *  module will be unloaded. Reloading a module may cause a loss of frames.
 142      *  When returning this status, the implementation shouldn't release or
 143      *  modify the p_block in argument (The same p_block will be feed to the
 144      *  next decoder module).
 145      */
 146     int                 ( * pf_decode )   ( decoder_t *, block_t *p_block );
 147
 148     /* This function is called in a loop with the same pp_block argument until
 149      * it returns NULL. This allows a module implementation to return more than
 150      * one output blocks for one input block.
 151      *
 152      * pp_block or *pp_block can be NULL.
 153      *
 154      * If pp_block and *pp_block are not NULL, the module implementation will
 155      * own the input block (*pp_block) and should process and release it. The
 156      * module can also process a part of the block. In that case, it should
 157      * modify (*pp_block)->p_buffer/i_buffer accordingly and return a valid
 158      * output block. The module can also set *pp_block to NULL when the input
 159      * block is consumed.
 160      *
 161      * If pp_block is not NULL but *pp_block is NULL, a previous call of the pf
 162      * function has set the *pp_block to NULL. Here, the module can return new
 163      * output block for the same, already processed, input block (the
 164      * pf_packetize function will be called as long as the module return an
 165      * output block).
 166      *
 167      * When the pf function returns NULL, the next call to this function will
 168      * have a new a valid pp_block (if the packetizer is not drained).
 169      *
 170      * If pp_block is NULL, the packetizer asks the module to drain itself. In
 171      * that case, the module has to return all output frames available (the
 172      * pf_packetize function will be called as long as the module return an
 173      * output block).
 174      */
 175     block_t *           ( * pf_packetize )( decoder_t *, block_t **pp_block );
 176     /* */
 177     void                ( * pf_flush ) ( decoder_t * );
 178
 179     /* Closed Caption (CEA 608/708) extraction.
 180      * If set, it *may* be called after pf_packetize returned data. It should
 181      * return CC for the pictures returned by the last pf_packetize call only,
 182      * channel bitmaps will be used to known which cc channel are present (but
 183      * globaly, not necessary for the current packet. Video decoders should use
 184      * the decoder_QueueCc() function to pass closed captions. */
 185     block_t *           ( * pf_get_cc )      ( decoder_t *, decoder_cc_desc_t * );
 186
 187     /* Meta data at codec level
 188      *  The decoder owner set it back to NULL once it has retreived what it needs.
 189      *  The decoder owner is responsible of its release except when you overwrite it.
 190      */
 191     vlc_meta_t          *p_description;
 192
 193     /* Private structure for the owner of the decoder */
 194     const struct decoder_owner_callbacks *cbs;
 195 };
 196
 197 /* struct for packetizer get_cc polling/decoder queue_cc
 198  * until we have a proper metadata way */
 199 struct decoder_cc_desc_t
 200 {
 201     uint8_t i_608_channels;  /* 608 channels bitmap */
 202     uint64_t i_708_channels; /* 708 */
 203     int i_reorder_depth;     /* reorder depth, -1 for no reorder, 0 for old P/B flag based */
 204 };
 205
 206 /**
 207  * @}
 208  */
 209
 210 /**
 211  * \defgroup encoder Encoder
 212  * \ingroup sout
 213  * Audio, video and text encoders
 214  * @{
 215  */
 216
 217 struct encoder_t
 218 {
 219     struct vlc_common_members obj;
 220
 221     /* Module properties */
 222     module_t *          p_module;
 223     void               *p_sys;
 224
 225     /* Properties of the input data fed to the encoder */
 226     es_format_t         fmt_in;
 227
 228     /* Properties of the output of the encoder */
 229     es_format_t         fmt_out;
 230
 231     block_t *           ( * pf_encode_video )( encoder_t *, picture_t * );
 232     block_t *           ( * pf_encode_audio )( encoder_t *, block_t * );
 233     block_t *           ( * pf_encode_sub )( encoder_t *, subpicture_t * );
 234
 235     /* Common encoder options */
 236     int i_threads;               /* Number of threads to use during encoding */
 237     int i_iframes;               /* One I frame per i_iframes */
 238     int i_bframes;               /* One B frame per i_bframes */
 239     int i_tolerance;             /* Bitrate tolerance */
 240
 241     /* Encoder config */
 242     config_chain_t *p_cfg;
 243 };
 244
 245 /**
 246  * @}
 247  *
 248  * \ingroup decoder
 249  * @{
 250  */
 251
 252 /**
 253  * Updates the video output format.
 254  *
 255  * This function notifies the video output pipeline of a new video output
 256  * format (fmt_out.video). If there was no video output from the decoder so far
 257  * or if the video output format has changed, a new video output will be set
 258  * up. decoder_NewPicture() can then be used to allocate picture buffers.
 259  *
 260  * If the format is unchanged, this function has no effects and returns zero.
 261  *
 262  * \note
 263  * This function is not reentrant.
 264  *
 265  * @return 0 if the video output was set up successfully, -1 otherwise.
 266  */
 267 VLC_USED
 268 static inline int decoder_UpdateVideoFormat( decoder_t *dec )
 269 {
 270     assert( dec->fmt_in.i_cat == VIDEO_ES && dec->cbs != NULL );
 271     if( dec->fmt_in.i_cat == VIDEO_ES && dec->cbs->video.format_update != NULL )
 272         return dec->cbs->video.format_update( dec );
 273     else
 274         return -1;
 275 }
 276
 277 /**
 278  * Allocates an output picture buffer.
 279  *
 280  * This function pulls an output picture buffer for the decoder from the
 281  * buffer pool of the video output. The picture must be released with
 282  * picture_Release() when it is no longer referenced by the decoder.
 283  *
 284  * \note
 285  * This function is reentrant. However, decoder_UpdateVideoFormat() cannot be
 286  * used concurrently; the caller is responsible for serialization.
 287  *
 288  * \warning
 289  * The behaviour is undefined if decoder_UpdateVideoFormat() was not called or
 290  * if the last call returned an error.
 291  *
 292  * \return a picture buffer on success, NULL on error
 293  */
 294 VLC_USED
 295 static inline picture_t *decoder_NewPicture( decoder_t *dec )
 296 {
 297     assert( dec->fmt_in.i_cat == VIDEO_ES && dec->cbs != NULL );
 298     return dec->cbs->video.buffer_new( dec );
 299 }
 300
 301 /**
 302  * Abort any calls of decoder_NewPicture
 303  *
 304  * If b_abort is true, all pending and futures calls of decoder_NewPicture
 305  * will be aborted. This function can be used by asynchronous video decoders
 306  * to unblock a thread that is waiting for a picture.
 307  */
 308 VLC_API void decoder_AbortPictures( decoder_t *dec, bool b_abort );
 309
 310 /**
 311  * This function queues a single picture to the video output.
 312  *
 313  * \note
 314  * The caller doesn't own the picture anymore after this call (even in case of
 315  * error).
 316  * FIXME: input_DecoderFrameNext won't work if a module use this function.
 317  */
 318 static inline void decoder_QueueVideo( decoder_t *dec, picture_t *p_pic )
 319 {
 320     assert( dec->fmt_in.i_cat == VIDEO_ES && dec->cbs != NULL );
 321     assert( p_pic->p_next == NULL );
 322     assert( dec->cbs->video.queue != NULL );
 323     dec->cbs->video.queue( dec, p_pic );
 324 }
 325
 326 /**
 327  * This function queues the Closed Captions
 328  *
 329  * \param dec the decoder object
 330  * \param p_cc the closed-caption to queue
 331  * \param p_desc decoder_cc_desc_t description structure
 332  */
 333 static inline void decoder_QueueCc( decoder_t *dec, block_t *p_cc,
 334                                    const decoder_cc_desc_t *p_desc )
 335 {
 336     assert( dec->fmt_in.i_cat == VIDEO_ES && dec->cbs != NULL );
 337     if( dec->cbs->video.queue_cc == NULL )
 338         block_Release( p_cc );
 339     else
 340         dec->cbs->video.queue_cc( dec, p_cc, p_desc );
 341 }
 342
 343 /**
 344  * This function queues a single audio block to the audio output.
 345  *
 346  * \note
 347  * The caller doesn't own the audio block anymore after this call (even in case
 348  * of error).
 349  */
 350 static inline void decoder_QueueAudio( decoder_t *dec, block_t *p_aout_buf )
 351 {
 352     assert( dec->fmt_in.i_cat == AUDIO_ES && dec->cbs != NULL );
 353     assert( p_aout_buf->p_next == NULL );
 354     assert( dec->cbs->audio.queue != NULL );
 355     dec->cbs->audio.queue( dec, p_aout_buf );
 356 }
 357
 358 /**
 359  * This function queues a single subtitle to the video output.
 360  *
 361  * \note
 362  * The caller doesn't own the subtitle anymore after this call (even in case of
 363  * error).
 364  */
 365 static inline void decoder_QueueSub( decoder_t *dec, subpicture_t *p_spu )
 366 {
 367     assert( dec->fmt_in.i_cat == SPU_ES && dec->cbs != NULL );
 368     assert( p_spu->p_next == NULL );
 369     assert( dec->cbs->spu.queue != NULL );
 370     dec->cbs->spu.queue( dec, p_spu );
 371 }
 372
 373 /**
 374  * This function notifies the audio output pipeline of a new audio output
 375  * format (fmt_out.audio). If there is currently no audio output or if the
 376  * audio output format has changed, a new audio output will be set up.
 377  * @return 0 if the audio output is working, -1 if not. */
 378 VLC_USED
 379 static inline int decoder_UpdateAudioFormat( decoder_t *dec )
 380 {
 381     assert( dec->fmt_in.i_cat == AUDIO_ES && dec->cbs != NULL );
 382     if( dec->fmt_in.i_cat == AUDIO_ES && dec->cbs->audio.format_update != NULL )
 383         return dec->cbs->audio.format_update( dec );
 384     else
 385         return -1;
 386 }
 387
 388 /**
 389  * This function will return a new audio buffer usable by a decoder as an
 390  * output buffer. It must be released with block_Release() or returned it to
 391  * the caller as a decoder_QueueAudio parameter.
 392  */
 393 VLC_API block_t * decoder_NewAudioBuffer( decoder_t *, int i_nb_samples ) VLC_USED;
 394
 395 /**
 396  * This function will return a new subpicture usable by a decoder as an output
 397  * buffer. You have to release it using subpicture_Delete() or by returning
 398  * it to the caller as a decoder_QueueSub parameter.
 399  */
 400 VLC_USED
 401 static inline subpicture_t *decoder_NewSubpicture( decoder_t *dec,
 402                                                    const subpicture_updater_t *p_dyn )
 403 {
 404     assert( dec->fmt_in.i_cat == SPU_ES && dec->cbs != NULL );
 405     subpicture_t *p_subpicture = dec->cbs->spu.buffer_new( dec, p_dyn );
 406     if( !p_subpicture )
 407         msg_Warn( dec, "can't get output subpicture" );
 408     return p_subpicture;
 409 }
 410
 411 /**
 412  * This function gives all input attachments at once.
 413  *
 414  * You MUST release the returned values
 415  */
 416 static inline int decoder_GetInputAttachments( decoder_t *dec,
 417                                                input_attachment_t ***ppp_attachment,
 418                                                int *pi_attachment )
 419 {
 420     assert( dec->cbs != NULL );
 421     if( !dec->cbs->get_attachments )
 422         return VLC_EGENERIC;
 423
 424     return dec->cbs->get_attachments( dec, ppp_attachment, pi_attachment );
 425 }
 426
 427 /**
 428  * This function converts a decoder timestamp into a display date comparable
 429  * to mdate().
 430  * You MUST use it *only* for gathering statistics about speed.
 431  */
 432 VLC_USED
 433 static inline mtime_t decoder_GetDisplayDate( decoder_t *dec, mtime_t i_ts )
 434 {
 435     assert( dec->fmt_in.i_cat == VIDEO_ES && dec->cbs != NULL );
 436     if( !dec->cbs->video.get_display_date )
 437         return VLC_TS_INVALID;
 438
 439     return dec->cbs->video.get_display_date( dec, i_ts );
 440 }
 441
 442 /**
 443  * This function returns the current input rate.
 444  * You MUST use it *only* for gathering statistics about speed.
 445  */
 446 VLC_USED
 447 static inline int decoder_GetDisplayRate( decoder_t *dec )
 448 {
 449     assert( dec->fmt_in.i_cat == VIDEO_ES && dec->cbs != NULL );
 450     if( !dec->cbs->video.get_display_rate )
 451         return 1000 /* XXX: INPUT_RATE_DEFAULT */;
 452
 453     return dec->cbs->video.get_display_rate( dec );
 454 }
 455
 456 /** @} */
 457 /** @} */
 458 #endif /* _VLC_CODEC_H */