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