include/vlc_aout.h

   1 /*****************************************************************************
   2  * vlc_aout.h : audio output interface
   3  *****************************************************************************
   4  * Copyright (C) 2002-2011 VLC authors and VideoLAN
   5  *
   6  * Authors: Christophe Massiot <massiot@via.ecp.fr>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License as published by
  10  * the Free Software Foundation; either version 2.1 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program; if not, write to the Free Software Foundation,
  20  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22
  23 #ifndef VLC_AOUT_H
  24 #define VLC_AOUT_H 1
  25
  26 #include <assert.h>
  27
  28 /**
  29  * \defgroup audio_output Audio output
  30  * \ingroup output
  31  * @{
  32  * \file
  33  * Audio output modules interface
  34  */
  35
  36 /* Buffers which arrive in advance of more than AOUT_MAX_ADVANCE_TIME
  37  * will be considered as bogus and be trashed */
  38 #define AOUT_MAX_ADVANCE_TIME           (AOUT_MAX_PREPARE_TIME + VLC_TICK_FROM_SEC(1))
  39
  40 /* Buffers which arrive in advance of more than AOUT_MAX_PREPARE_TIME
  41  * will cause the calling thread to sleep */
  42 #define AOUT_MAX_PREPARE_TIME           VLC_TICK_FROM_SEC(2)
  43
  44 /* Buffers which arrive after pts - AOUT_MIN_PREPARE_TIME will be trashed
  45  * to avoid too heavy resampling */
  46 #define AOUT_MIN_PREPARE_TIME           AOUT_MAX_PTS_ADVANCE
  47
  48 /* Tolerance values from EBU Recommendation 37 */
  49 /** Maximum advance of actual audio playback time to coded PTS,
  50  * above which downsampling will be performed */
  51 #define AOUT_MAX_PTS_ADVANCE            VLC_TICK_FROM_MS(40)
  52
  53 /** Maximum delay of actual audio playback time from coded PTS,
  54  * above which upsampling will be performed */
  55 #define AOUT_MAX_PTS_DELAY              VLC_TICK_FROM_MS(60)
  56
  57 /* Max acceptable resampling (in %) */
  58 #define AOUT_MAX_RESAMPLING             10
  59
  60 #include "vlc_es.h"
  61
  62 #define AOUT_FMTS_IDENTICAL( p_first, p_second ) (                          \
  63     ((p_first)->i_format == (p_second)->i_format)                           \
  64       && AOUT_FMTS_SIMILAR(p_first, p_second) )
  65
  66 /* Check if i_rate == i_rate and i_channels == i_channels */
  67 #define AOUT_FMTS_SIMILAR( p_first, p_second ) (                            \
  68     ((p_first)->i_rate == (p_second)->i_rate)                               \
  69       && ((p_first)->channel_type == (p_second)->channel_type)            \
  70       && ((p_first)->i_physical_channels == (p_second)->i_physical_channels)\
  71       && ((p_first)->i_chan_mode == (p_second)->i_chan_mode) )
  72
  73 #define AOUT_FMT_LINEAR( p_format ) \
  74     (aout_BitsPerSample((p_format)->i_format) != 0)
  75
  76 #define VLC_CODEC_SPDIFL VLC_FOURCC('s','p','d','i')
  77 #define VLC_CODEC_SPDIFB VLC_FOURCC('s','p','d','b')
  78
  79 #define AOUT_FMT_SPDIF( p_format ) \
  80     ( ((p_format)->i_format == VLC_CODEC_SPDIFL)       \
  81        || ((p_format)->i_format == VLC_CODEC_SPDIFB)   \
  82        || ((p_format)->i_format == VLC_CODEC_A52)      \
  83        || ((p_format)->i_format == VLC_CODEC_DTS) )
  84
  85 #define AOUT_FMT_HDMI( p_format )                   \
  86     ( (p_format)->i_format == VLC_CODEC_EAC3        \
  87     ||(p_format)->i_format == VLC_CODEC_TRUEHD      \
  88     ||(p_format)->i_format == VLC_CODEC_MLP         \
  89     )
  90
  91 /* Values used for the audio-channels object variable */
  92 #define AOUT_VAR_CHAN_UNSET         0 /* must be zero */
  93 #define AOUT_VAR_CHAN_STEREO        1
  94 #define AOUT_VAR_CHAN_RSTEREO       2
  95 #define AOUT_VAR_CHAN_LEFT          3
  96 #define AOUT_VAR_CHAN_RIGHT         4
  97 #define AOUT_VAR_CHAN_DOLBYS        5
  98 #define AOUT_VAR_CHAN_HEADPHONES    6
  99 #define AOUT_VAR_CHAN_MONO          7
 100
 101 /*****************************************************************************
 102  * Main audio output structures
 103  *****************************************************************************/
 104
 105 /* Size of a frame for S/PDIF output. */
 106 #define AOUT_SPDIF_SIZE 6144
 107
 108 /* Number of samples in an A/52 frame. */
 109 #define A52_FRAME_NB 1536
 110
 111 /* FIXME to remove once aout.h is cleaned a bit more */
 112 #include <vlc_block.h>
 113
 114 struct vlc_audio_output_events {
 115     void (*volume_report)(audio_output_t *, float);
 116     void (*mute_report)(audio_output_t *, bool);
 117     void (*policy_report)(audio_output_t *, bool);
 118     void (*device_report)(audio_output_t *, const char *);
 119     void (*hotplug_report)(audio_output_t *, const char *, const char *);
 120     void (*restart_request)(audio_output_t *, unsigned);
 121     int (*gain_request)(audio_output_t *, float);
 122 };
 123
 124 /** Audio output object
 125  *
 126  * The audio output object is the abstraction for rendering decoded
 127  * (or pass-through) audio samples. In addition to playing samples,
 128  * the abstraction exposes controls for pause/resume, flush/drain,
 129  * changing the volume or mut flag, and listing and changing output device.
 130  *
 131  * An audio output can be in one of three different states:
 132  * stopped, playing or paused.
 133  * The audio output is always created in stopped state and is always destroyed
 134  * in that state also. It is moved from stopped to playing state by start(),
 135  * and from playing or paused states back to stopped state by stop().
 136  **/
 137 struct audio_output
 138 {
 139     struct vlc_common_members obj;
 140
 141     void *sys; /**< Private data for callbacks */
 142
 143     int (*start)(audio_output_t *, audio_sample_format_t *fmt);
 144     /**< Starts a new stream (mandatory, cannot be NULL).
 145       *
 146       * This callback changes the audio output from stopped to playing state
 147       * (if succesful). After the callback returns, time_get(), play(),
 148       * pause(), flush() and eventually stop() callbacks may be called.
 149       *
 150       * \param fmt input stream sample format upon entry,
 151       *            output stream sample format upon return [IN/OUT]
 152       * \return VLC_SUCCESS on success, non-zero on failure
 153       *
 154       * \note This callback can only be called while the audio output is in
 155       * stopped state. There can be only one stream per audio output at a time.
 156       *
 157       * \note This callbacks needs not be reentrant.
 158       */
 159
 160     void (*stop)(audio_output_t *);
 161     /**< Stops the existing stream (optional, may be NULL).
 162       *
 163       * This callback terminates the current audio stream,
 164       * and returns the audio output to stopped state.
 165       *
 166       * \note This callback needs not be reentrant.
 167       */
 168
 169     int (*time_get)(audio_output_t *, vlc_tick_t *delay);
 170     /**< Estimates playback buffer latency (mandatory, cannot be NULL).
 171       *
 172       * This callback computes an estimation of the delay until the current
 173       * tail of the audio output buffer would be rendered. This is essential
 174       * for (lip) synchronization and long term drift between the audio output
 175       * clock and the media upstream clock (if any).
 176       *
 177       * If the audio output clock is exactly synchronized with the system
 178       * monotonic clock (i.e. vlc_tick_now()), then aout_TimeGetDefault() can
 179       * implement this callback.
 180       *
 181       * \param delay pointer to the delay until the next sample to be written
 182       *              to the playback buffer is rendered [OUT]
 183       * \return 0 on success, non-zero on failure or lack of data
 184       *
 185       * \note This callback cannot be called in stopped state.
 186       */
 187
 188     void (*play)(audio_output_t *, block_t *block, vlc_tick_t date);
 189     /**< Queues a block of samples for playback (mandatory, cannot be NULL).
 190       *
 191       * \param block block of audio samples
 192       * \param date intended system time to render the first sample
 193       *
 194       * \note This callback cannot be called in stopped state.
 195       */
 196
 197     void (*pause)( audio_output_t *, bool pause, vlc_tick_t date);
 198     /**< Pauses or resumes playback (mandatory, cannot be NULL).
 199       *
 200       * This callback pauses or resumes audio playback as quickly as possible.
 201       * When pausing, it is desirable to stop producing sound immediately, but
 202       * retain already queued audio samples in the buffer to play when later
 203       * when resuming.
 204       *
 205       * If pausing is impossible, then aout_PauseDefault() can provide a
 206       * fallback implementation of this callback.
 207       *
 208       * \param pause pause if true, resume from pause if false
 209       * \param date timestamp when the pause or resume was requested
 210       *
 211       * \note This callback cannot be called in stopped state.
 212       */
 213
 214     void (*flush)( audio_output_t *, bool wait);
 215     /**< Flushes or drains the playback buffers (mandatory, cannot be NULL).
 216       *
 217       * \param wait true to wait for playback of pending buffers (drain),
 218       *             false to discard pending buffers (flush)
 219       *
 220       * \note This callback cannot be called in stopped state.
 221       */
 222
 223     int (*volume_set)(audio_output_t *, float volume);
 224     /**< Changes playback volume (optional, may be NULL).
 225       *
 226       * \param volume requested volume (0. = mute, 1. = nominal)
 227       *
 228       * \note The volume is always a positive number.
 229       *
 230       * \warning A stream may or may not have been started when called.
 231       * \warning This callback may be called concurrently with
 232       * time_get(), play(), pause() or flush().
 233       * It will however be protected against concurrent calls to
 234       * start(), stop(), volume_set(), mute_set() or device_select().
 235       */
 236
 237     int (*mute_set)(audio_output_t *, bool mute);
 238     /**< Changes muting (optinal, may be NULL).
 239       *
 240       * \param mute true to mute, false to unmute
 241       * \warning The same constraints apply as with volume_set().
 242       */
 243
 244     int (*device_select)(audio_output_t *, const char *id);
 245     /**< Selects an audio output device (optional, may be NULL).
 246       *
 247       * \param id nul-terminated device unique identifier.
 248       * \return 0 on success, non-zero on failure.
 249       *
 250       * \warning The same constraints apply as with volume_set().
 251       */
 252
 253     struct {
 254         bool headphones; /**< Default to false, set it to true if the current
 255                               sink is using headphones */
 256     } current_sink_info;
 257     /**< Current sink informations set by the module from the start() function */
 258
 259     const struct vlc_audio_output_events *events;
 260 };
 261
 262 typedef enum
 263 {
 264     AOUT_CHANIDX_DISABLE = -1,
 265     AOUT_CHANIDX_LEFT,
 266     AOUT_CHANIDX_RIGHT,
 267     AOUT_CHANIDX_MIDDLELEFT,
 268     AOUT_CHANIDX_MIDDLERIGHT,
 269     AOUT_CHANIDX_REARLEFT,
 270     AOUT_CHANIDX_REARRIGHT,
 271     AOUT_CHANIDX_REARCENTER,
 272     AOUT_CHANIDX_CENTER,
 273     AOUT_CHANIDX_LFE,
 274     AOUT_CHANIDX_MAX
 275 } vlc_chan_order_idx_t;
 276
 277 static_assert(AOUT_CHANIDX_MAX == AOUT_CHAN_MAX, "channel count mismatch");
 278
 279 #define AOUT_CHAN_REMAP_INIT { \
 280     AOUT_CHANIDX_LEFT,  \
 281     AOUT_CHANIDX_RIGHT, \
 282     AOUT_CHANIDX_MIDDLELEFT, \
 283     AOUT_CHANIDX_MIDDLERIGHT, \
 284     AOUT_CHANIDX_REARLEFT, \
 285     AOUT_CHANIDX_REARRIGHT, \
 286     AOUT_CHANIDX_REARCENTER, \
 287     AOUT_CHANIDX_CENTER, \
 288     AOUT_CHANIDX_LFE, \
 289 }
 290
 291 /**
 292  * It describes the audio channel order VLC expect.
 293  */
 294 static const uint32_t pi_vlc_chan_order_wg4[] =
 295 {
 296     AOUT_CHAN_LEFT, AOUT_CHAN_RIGHT,
 297     AOUT_CHAN_MIDDLELEFT, AOUT_CHAN_MIDDLERIGHT,
 298     AOUT_CHAN_REARLEFT, AOUT_CHAN_REARRIGHT, AOUT_CHAN_REARCENTER,
 299     AOUT_CHAN_CENTER, AOUT_CHAN_LFE, 0
 300 };
 301
 302 #define AOUT_RESTART_FILTERS        0x1
 303 #define AOUT_RESTART_OUTPUT         (AOUT_RESTART_FILTERS|0x2)
 304 #define AOUT_RESTART_STEREOMODE     (AOUT_RESTART_OUTPUT|0x4)
 305
 306 /*****************************************************************************
 307  * Prototypes
 308  *****************************************************************************/
 309
 310 /**
 311  * This function computes the reordering needed to go from pi_chan_order_in to
 312  * pi_chan_order_out.
 313  * If pi_chan_order_in or pi_chan_order_out is NULL, it will assume that vlc
 314  * internal (WG4) order is requested.
 315  */
 316 VLC_API unsigned aout_CheckChannelReorder( const uint32_t *, const uint32_t *,
 317                                            uint32_t mask, uint8_t *table );
 318 VLC_API void aout_ChannelReorder(void *, size_t, uint8_t, const uint8_t *, vlc_fourcc_t);
 319
 320 VLC_API void aout_Interleave(void *dst, const void *const *planes,
 321                              unsigned samples, unsigned channels,
 322                              vlc_fourcc_t fourcc);
 323 VLC_API void aout_Deinterleave(void *dst, const void *src, unsigned samples,
 324                              unsigned channels, vlc_fourcc_t fourcc);
 325
 326 /**
 327  * This function will compute the extraction parameter into pi_selection to go
 328  * from i_channels with their type given by pi_order_src[] into the order
 329  * describe by pi_order_dst.
 330  * It will also set :
 331  * - *pi_channels as the number of channels that will be extracted which is
 332  * lower (in case of non understood channels type) or equal to i_channels.
 333  * - the layout of the channels (*pi_layout).
 334  *
 335  * It will return true if channel extraction is really needed, in which case
 336  * aout_ChannelExtract must be used
 337  *
 338  * XXX It must be used when the source may have channel type not understood
 339  * by VLC. In this case the channel type pi_order_src[] must be set to 0.
 340  * XXX It must also be used if multiple channels have the same type.
 341  */
 342 VLC_API bool aout_CheckChannelExtraction( int *pi_selection, uint32_t *pi_layout, int *pi_channels, const uint32_t pi_order_dst[AOUT_CHAN_MAX], const uint32_t *pi_order_src, int i_channels );
 343
 344 /**
 345  * Do the actual channels extraction using the parameters created by
 346  * aout_CheckChannelExtraction.
 347  *
 348  * XXX this function does not work in place (p_dst and p_src must not overlap).
 349  * XXX Only 8, 16, 32, 64 bits per sample are supported.
 350  */
 351 VLC_API void aout_ChannelExtract( void *p_dst, int i_dst_channels, const void *p_src, int i_src_channels, int i_sample_count, const int *pi_selection, int i_bits_per_sample );
 352
 353 /* */
 354 static inline unsigned aout_FormatNbChannels(const audio_sample_format_t *fmt)
 355 {
 356     return vlc_popcount(fmt->i_physical_channels);
 357 }
 358
 359 VLC_API unsigned int aout_BitsPerSample( vlc_fourcc_t i_format ) VLC_USED;
 360 VLC_API void aout_FormatPrepare( audio_sample_format_t * p_format );
 361 VLC_API void aout_FormatPrint(vlc_object_t *, const char *,
 362                               const audio_sample_format_t *);
 363 #define aout_FormatPrint(o, t, f) aout_FormatPrint(VLC_OBJECT(o), t, f)
 364 VLC_API const char * aout_FormatPrintChannels( const audio_sample_format_t * ) VLC_USED;
 365
 366 #define AOUT_VOLUME_DEFAULT             256
 367 #define AOUT_VOLUME_MAX                 512
 368
 369 VLC_API float aout_VolumeGet (audio_output_t *);
 370 VLC_API int aout_VolumeSet (audio_output_t *, float);
 371 VLC_API int aout_VolumeUpdate (audio_output_t *, int, float *);
 372 VLC_API int aout_MuteGet (audio_output_t *);
 373 VLC_API int aout_MuteSet (audio_output_t *, bool);
 374 VLC_API char *aout_DeviceGet (audio_output_t *);
 375 VLC_API int aout_DeviceSet (audio_output_t *, const char *);
 376 VLC_API int aout_DevicesList (audio_output_t *, char ***, char ***);
 377
 378 /**
 379  * Report change of configured audio volume to the core and UI.
 380  */
 381 static inline void aout_VolumeReport(audio_output_t *aout, float volume)
 382 {
 383     aout->events->volume_report(aout, volume);
 384 }
 385
 386 /**
 387  * Report change of muted flag to the core and UI.
 388  */
 389 static inline void aout_MuteReport(audio_output_t *aout, bool mute)
 390 {
 391     aout->events->mute_report(aout, mute);
 392 }
 393
 394 /**
 395  * Report audio policy status.
 396  * \param cork true to request a cork, false to undo any pending cork.
 397  */
 398 static inline void aout_PolicyReport(audio_output_t *aout, bool cork)
 399 {
 400     aout->events->policy_report(aout, cork);
 401 }
 402
 403 /**
 404  * Report change of output device.
 405  */
 406 static inline void aout_DeviceReport(audio_output_t *aout, const char *id)
 407 {
 408     aout->events->device_report(aout, id);
 409 }
 410
 411 /**
 412  * Report a device hot-plug event.
 413  * @param id device ID
 414  * @param name human-readable device name (NULL for hot unplug)
 415  */
 416 static inline void aout_HotplugReport(audio_output_t *aout,
 417                                       const char *id, const char *name)
 418 {
 419     aout->events->hotplug_report(aout, id, name);
 420 }
 421
 422 /**
 423  * Request a change of software audio amplification.
 424  * \param gain linear amplitude gain (must be positive)
 425  * \warning Values in excess 1.0 may cause overflow and distorsion.
 426  */
 427 static inline int aout_GainRequest(audio_output_t *aout, float gain)
 428 {
 429     return aout->events->gain_request(aout, gain);
 430 }
 431
 432 static inline void aout_RestartRequest(audio_output_t *aout, unsigned mode)
 433 {
 434     aout->events->restart_request(aout, mode);
 435 }
 436
 437 /**
 438  * Default implementation for audio_output_t.time_get
 439  */
 440 static inline int aout_TimeGetDefault(audio_output_t *aout,
 441                                       vlc_tick_t *restrict delay)
 442 {
 443     (void) aout; (void) delay;
 444     return -1;
 445 }
 446
 447 /**
 448  * Default implementation for audio_output_t.pause
 449  *
 450  * \warning This default callback implementation is suboptimal as it will
 451  * discard some audio samples.
 452  * Do not use this unless there are really no possible better alternatives.
 453  */
 454 static inline void aout_PauseDefault(audio_output_t *aout, bool paused,
 455                                      vlc_tick_t date)
 456 {
 457     if (paused && aout->flush != NULL)
 458         aout->flush(aout, false);
 459     (void) date;
 460 }
 461
 462 /* Audio output filters */
 463
 464 typedef struct
 465 {
 466     /**
 467      * If the remap order differs from the WG4 order, a remap audio filter will
 468      * be inserted to remap channels according to this array.
 469      */
 470     int remap[AOUT_CHANIDX_MAX];
 471     /**
 472      * If true, a filter will be inserted to add a headphones effect (like a
 473      * binauralizer audio filter).
 474      */
 475     bool headphones;
 476 } aout_filters_cfg_t;
 477
 478 #define AOUT_FILTERS_CFG_INIT (aout_filters_cfg_t) \
 479     { .remap = AOUT_CHAN_REMAP_INIT, \
 480       .headphones = false, \
 481     };
 482
 483 typedef struct aout_filters aout_filters_t;
 484 typedef struct aout_request_vout aout_request_vout_t;
 485
 486 VLC_API aout_filters_t *aout_FiltersNew(vlc_object_t *,
 487                                         const audio_sample_format_t *,
 488                                         const audio_sample_format_t *,
 489                                         const aout_request_vout_t *,
 490                                         const aout_filters_cfg_t *cfg) VLC_USED;
 491 #define aout_FiltersNew(o,inf,outf,rv,remap) \
 492         aout_FiltersNew(VLC_OBJECT(o),inf,outf,rv,remap)
 493 VLC_API void aout_FiltersDelete(vlc_object_t *, aout_filters_t *);
 494 #define aout_FiltersDelete(o,f) \
 495         aout_FiltersDelete(VLC_OBJECT(o),f)
 496 VLC_API bool aout_FiltersAdjustResampling(aout_filters_t *, int);
 497 VLC_API block_t *aout_FiltersPlay(aout_filters_t *, block_t *, float rate);
 498 VLC_API block_t *aout_FiltersDrain(aout_filters_t *);
 499 VLC_API void     aout_FiltersFlush(aout_filters_t *);
 500 VLC_API void     aout_FiltersChangeViewpoint(aout_filters_t *, const vlc_viewpoint_t *vp);
 501
 502 VLC_API vout_thread_t * aout_filter_RequestVout( filter_t *, vout_thread_t *p_vout, const video_format_t *p_fmt );
 503
 504 /** @} */
 505
 506 #endif /* VLC_AOUT_H */