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 /**
  27  * \defgroup audio_output Audio output
  28  * \ingroup output
  29  * @{
  30  * \file
  31  * Audio output modules interface
  32  */
  33
  34 /* Buffers which arrive in advance of more than AOUT_MAX_ADVANCE_TIME
  35  * will be considered as bogus and be trashed */
  36 #define AOUT_MAX_ADVANCE_TIME           (AOUT_MAX_PREPARE_TIME + CLOCK_FREQ)
  37
  38 /* Buffers which arrive in advance of more than AOUT_MAX_PREPARE_TIME
  39  * will cause the calling thread to sleep */
  40 #define AOUT_MAX_PREPARE_TIME           (2 * CLOCK_FREQ)
  41
  42 /* Buffers which arrive after pts - AOUT_MIN_PREPARE_TIME will be trashed
  43  * to avoid too heavy resampling */
  44 #define AOUT_MIN_PREPARE_TIME           AOUT_MAX_PTS_ADVANCE
  45
  46 /* Tolerance values from EBU Recommendation 37 */
  47 /** Maximum advance of actual audio playback time to coded PTS,
  48  * above which downsampling will be performed */
  49 #define AOUT_MAX_PTS_ADVANCE            (CLOCK_FREQ / 25)
  50
  51 /** Maximum delay of actual audio playback time from coded PTS,
  52  * above which upsampling will be performed */
  53 #define AOUT_MAX_PTS_DELAY              (3 * CLOCK_FREQ / 50)
  54
  55 /* Max acceptable resampling (in %) */
  56 #define AOUT_MAX_RESAMPLING             10
  57
  58 #include "vlc_es.h"
  59
  60 #define AOUT_FMTS_IDENTICAL( p_first, p_second ) (                          \
  61     ((p_first)->i_format == (p_second)->i_format)                           \
  62       && AOUT_FMTS_SIMILAR(p_first, p_second) )
  63
  64 /* Check if i_rate == i_rate and i_channels == i_channels */
  65 #define AOUT_FMTS_SIMILAR( p_first, p_second ) (                            \
  66     ((p_first)->i_rate == (p_second)->i_rate)                               \
  67       && ((p_first)->i_physical_channels == (p_second)->i_physical_channels)\
  68       && ((p_first)->i_original_channels == (p_second)->i_original_channels) )
  69
  70 #define AOUT_FMT_LINEAR( p_format ) \
  71     (aout_BitsPerSample((p_format)->i_format) != 0)
  72
  73 #define VLC_CODEC_SPDIFL VLC_FOURCC('s','p','d','i')
  74 #define VLC_CODEC_SPDIFB VLC_FOURCC('s','p','d','b')
  75
  76 #define AOUT_FMT_SPDIF( p_format ) \
  77     ( ((p_format)->i_format == VLC_CODEC_SPDIFL)       \
  78        || ((p_format)->i_format == VLC_CODEC_SPDIFB)   \
  79        || ((p_format)->i_format == VLC_CODEC_A52)       \
  80        || ((p_format)->i_format == VLC_CODEC_DTS) )
  81
  82 /* Values used for the audio-channels object variable */
  83 #define AOUT_VAR_CHAN_UNSET         0 /* must be zero */
  84 #define AOUT_VAR_CHAN_STEREO        1
  85 #define AOUT_VAR_CHAN_RSTEREO       2
  86 #define AOUT_VAR_CHAN_LEFT          3
  87 #define AOUT_VAR_CHAN_RIGHT         4
  88 #define AOUT_VAR_CHAN_DOLBYS        5
  89
  90 /*****************************************************************************
  91  * Main audio output structures
  92  *****************************************************************************/
  93
  94 /* Size of a frame for S/PDIF output. */
  95 #define AOUT_SPDIF_SIZE 6144
  96
  97 /* Number of samples in an A/52 frame. */
  98 #define A52_FRAME_NB 1536
  99
 100 /* FIXME to remove once aout.h is cleaned a bit more */
 101 #include <vlc_block.h>
 102
 103 /** Audio output object */
 104 struct audio_output
 105 {
 106     VLC_COMMON_MEMBERS
 107
 108     struct aout_sys_t *sys; /**< Private data for callbacks */
 109
 110     int (*start)(audio_output_t *, audio_sample_format_t *fmt);
 111     /**< Starts a new stream (mandatory, cannot be NULL).
 112       * \param fmt input stream sample format upon entry,
 113       *            output stream sample format upon return [IN/OUT]
 114       * \return VLC_SUCCESS on success, non-zero on failure
 115       * \note No other stream may be already started when called.
 116       */
 117     void (*stop)(audio_output_t *);
 118     /**< Stops the existing stream (optional, may be NULL).
 119       * \note A stream must have been started when called.
 120       */
 121     int (*time_get)(audio_output_t *, mtime_t *delay);
 122     /**< Estimates playback buffer latency (optional, may be NULL).
 123       * \param delay pointer to the delay until the next sample to be written
 124       *              to the playback buffer is rendered [OUT]
 125       * \return 0 on success, non-zero on failure or lack of data
 126       * \note A stream must have been started when called.
 127       */
 128     void (*play)(audio_output_t *, block_t *);
 129     /**< Queues a block of samples for playback (mandatory, cannot be NULL).
 130       * \note A stream must have been started when called.
 131       */
 132     void (*pause)( audio_output_t *, bool pause, mtime_t date);
 133     /**< Pauses or resumes playback (optional, may be NULL).
 134       * \param pause pause if true, resume from pause if false
 135       * \param date timestamp when the pause or resume was requested
 136       * \note A stream must have been started when called.
 137       */
 138     void (*flush)( audio_output_t *, bool wait);
 139     /**< Flushes or drains the playback buffers (mandatory, cannot be NULL).
 140       * \param wait true to wait for playback of pending buffers (drain),
 141       *             false to discard pending buffers (flush)
 142       * \note A stream must have been started when called.
 143       */
 144     int (*volume_set)(audio_output_t *, float volume);
 145     /**< Changes playback volume (optional, may be NULL).
 146       * \param volume requested volume (0. = mute, 1. = nominal)
 147       * \note The volume is always a positive number.
 148       * \warning A stream may or may not have been started when called.
 149       */
 150     int (*mute_set)(audio_output_t *, bool mute);
 151     /**< Changes muting (optinal, may be NULL).
 152       * \param mute true to mute, false to unmute
 153       * \warning A stream may or may not have been started when called.
 154       */
 155     int (*device_select)(audio_output_t *, const char *id);
 156     /**< Selects an audio output device (optional, may be NULL).
 157       * \param id nul-terminated device unique identifier.
 158       * \return 0 on success, non-zero on failure.
 159       * \warning A stream may or may not have been started when called.
 160       */
 161     struct {
 162         void (*volume_report)(audio_output_t *, float);
 163         void (*mute_report)(audio_output_t *, bool);
 164         void (*policy_report)(audio_output_t *, bool);
 165         void (*device_report)(audio_output_t *, const char *);
 166         void (*hotplug_report)(audio_output_t *, const char *, const char *);
 167         int (*gain_request)(audio_output_t *, float);
 168         void (*restart_request)(audio_output_t *, unsigned);
 169     } event;
 170 };
 171
 172 /**
 173  * It describes the audio channel order VLC expect.
 174  */
 175 static const uint32_t pi_vlc_chan_order_wg4[] =
 176 {
 177     AOUT_CHAN_LEFT, AOUT_CHAN_RIGHT,
 178     AOUT_CHAN_MIDDLELEFT, AOUT_CHAN_MIDDLERIGHT,
 179     AOUT_CHAN_REARLEFT, AOUT_CHAN_REARRIGHT, AOUT_CHAN_REARCENTER,
 180     AOUT_CHAN_CENTER, AOUT_CHAN_LFE, 0
 181 };
 182
 183 #define AOUT_RESTART_FILTERS 1
 184 #define AOUT_RESTART_OUTPUT  2
 185 #define AOUT_RESTART_DECODER 4
 186
 187 /*****************************************************************************
 188  * Prototypes
 189  *****************************************************************************/
 190
 191 /**
 192  * This function computes the reordering needed to go from pi_chan_order_in to
 193  * pi_chan_order_out.
 194  * If pi_chan_order_in or pi_chan_order_out is NULL, it will assume that vlc
 195  * internal (WG4) order is requested.
 196  */
 197 VLC_API unsigned aout_CheckChannelReorder( const uint32_t *, const uint32_t *,
 198                                            uint32_t mask, uint8_t *table );
 199 VLC_API void aout_ChannelReorder(void *, size_t, uint8_t, const uint8_t *, vlc_fourcc_t);
 200
 201 VLC_API void aout_Interleave(void *dst, const void *const *planes,
 202                              unsigned samples, unsigned channels,
 203                              vlc_fourcc_t fourcc);
 204 VLC_API void aout_Deinterleave(void *dst, const void *src, unsigned samples,
 205                              unsigned channels, vlc_fourcc_t fourcc);
 206
 207 /**
 208  * This function will compute the extraction parameter into pi_selection to go
 209  * from i_channels with their type given by pi_order_src[] into the order
 210  * describe by pi_order_dst.
 211  * It will also set :
 212  * - *pi_channels as the number of channels that will be extracted which is
 213  * lower (in case of non understood channels type) or equal to i_channels.
 214  * - the layout of the channels (*pi_layout).
 215  *
 216  * It will return true if channel extraction is really needed, in which case
 217  * aout_ChannelExtract must be used
 218  *
 219  * XXX It must be used when the source may have channel type not understood
 220  * by VLC. In this case the channel type pi_order_src[] must be set to 0.
 221  * XXX It must also be used if multiple channels have the same type.
 222  */
 223 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 );
 224
 225 /**
 226  * Do the actual channels extraction using the parameters created by
 227  * aout_CheckChannelExtraction.
 228  *
 229  * XXX this function does not work in place (p_dst and p_src must not overlap).
 230  * XXX Only 8, 16, 24, 32, 64 bits per sample are supported.
 231  */
 232 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 );
 233
 234 /* */
 235 static inline unsigned aout_FormatNbChannels(const audio_sample_format_t *fmt)
 236 {
 237     return popcount(fmt->i_physical_channels);
 238 }
 239
 240 VLC_API unsigned int aout_BitsPerSample( vlc_fourcc_t i_format ) VLC_USED;
 241 VLC_API void aout_FormatPrepare( audio_sample_format_t * p_format );
 242 VLC_API void aout_FormatPrint(vlc_object_t *, const char *,
 243                               const audio_sample_format_t *);
 244 #define aout_FormatPrint(o, t, f) aout_FormatPrint(VLC_OBJECT(o), t, f)
 245 VLC_API const char * aout_FormatPrintChannels( const audio_sample_format_t * ) VLC_USED;
 246
 247 VLC_API float aout_VolumeGet (audio_output_t *);
 248 VLC_API int aout_VolumeSet (audio_output_t *, float);
 249 VLC_API int aout_MuteGet (audio_output_t *);
 250 VLC_API int aout_MuteSet (audio_output_t *, bool);
 251 VLC_API char *aout_DeviceGet (audio_output_t *);
 252 VLC_API int aout_DeviceSet (audio_output_t *, const char *);
 253 VLC_API int aout_DevicesList (audio_output_t *, char ***, char ***);
 254
 255 /**
 256  * Report change of configured audio volume to the core and UI.
 257  */
 258 static inline void aout_VolumeReport(audio_output_t *aout, float volume)
 259 {
 260     aout->event.volume_report(aout, volume);
 261 }
 262
 263 /**
 264  * Report change of muted flag to the core and UI.
 265  */
 266 static inline void aout_MuteReport(audio_output_t *aout, bool mute)
 267 {
 268     aout->event.mute_report(aout, mute);
 269 }
 270
 271 /**
 272  * Report audio policy status.
 273  * \param cork true to request a cork, false to undo any pending cork.
 274  */
 275 static inline void aout_PolicyReport(audio_output_t *aout, bool cork)
 276 {
 277     aout->event.policy_report(aout, cork);
 278 }
 279
 280 /**
 281  * Report change of output device.
 282  */
 283 static inline void aout_DeviceReport(audio_output_t *aout, const char *id)
 284 {
 285     aout->event.device_report(aout, id);
 286 }
 287
 288 /**
 289  * Report a device hot-plug event.
 290  * @param id device ID
 291  * @param name human-readable device name (NULL for hot unplug)
 292  */
 293 static inline void aout_HotplugReport(audio_output_t *aout,
 294                                       const char *id, const char *name)
 295 {
 296     aout->event.hotplug_report(aout, id, name);
 297 }
 298
 299 /**
 300  * Request a change of software audio amplification.
 301  * \param gain linear amplitude gain (must be positive)
 302  * \warning Values in excess 1.0 may cause overflow and distorsion.
 303  */
 304 static inline int aout_GainRequest(audio_output_t *aout, float gain)
 305 {
 306     return aout->event.gain_request(aout, gain);
 307 }
 308
 309 static inline void aout_RestartRequest(audio_output_t *aout, unsigned mode)
 310 {
 311     aout->event.restart_request(aout, mode);
 312 }
 313
 314 static inline int aout_ChannelsRestart (vlc_object_t *obj, const char *varname,
 315                             vlc_value_t oldval, vlc_value_t newval, void *data)
 316 {
 317     audio_output_t *aout = (audio_output_t *)obj;
 318     (void)varname; (void)oldval; (void)newval; (void)data;
 319
 320     aout_RestartRequest (aout, AOUT_RESTART_OUTPUT);
 321     return 0;
 322 }
 323
 324 /* Audio output filters */
 325 typedef struct aout_filters aout_filters_t;
 326 typedef struct aout_request_vout aout_request_vout_t;
 327
 328 VLC_API aout_filters_t *aout_FiltersNew(vlc_object_t *,
 329                                         const audio_sample_format_t *,
 330                                         const audio_sample_format_t *,
 331                                         const aout_request_vout_t *) VLC_USED;
 332 #define aout_FiltersNew(o,inf,outf,rv) \
 333         aout_FiltersNew(VLC_OBJECT(o),inf,outf,rv)
 334 VLC_API void aout_FiltersDelete(vlc_object_t *, aout_filters_t *);
 335 #define aout_FiltersDelete(o,f) \
 336         aout_FiltersDelete(VLC_OBJECT(o),f)
 337 VLC_API bool aout_FiltersAdjustResampling(aout_filters_t *, int);
 338 VLC_API block_t *aout_FiltersPlay(aout_filters_t *, block_t *, int rate);
 339
 340 VLC_API vout_thread_t * aout_filter_RequestVout( filter_t *, vout_thread_t *p_vout, video_format_t *p_fmt );
 341
 342 /** @} */
 343
 344 #endif /* VLC_AOUT_H */