src/audio_output/output.c

   1 /*****************************************************************************
   2  * output.c : internal management of output streams for the audio output
   3  *****************************************************************************
   4  * Copyright (C) 2002-2004 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Christophe Massiot <massiot@via.ecp.fr>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 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 General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <vlc_common.h>
  32 #include <vlc_aout.h>
  33 #include <vlc_cpu.h>
  34 #include <vlc_modules.h>
  35
  36 #include "aout_internal.h"
  37
  38 /*****************************************************************************
  39  * aout_OutputNew : allocate a new output and rework the filter pipeline
  40  *****************************************************************************
  41  * This function is entered with the mixer lock.
  42  *****************************************************************************/
  43 int aout_OutputNew( aout_instance_t * p_aout,
  44                     audio_sample_format_t * p_format )
  45 {
  46     /* Retrieve user defaults. */
  47     int i_rate = var_InheritInteger( p_aout, "aout-rate" );
  48     vlc_value_t val, text;
  49     /* kludge to avoid a fpu error when rate is 0... */
  50     if( i_rate == 0 ) i_rate = -1;
  51
  52     memcpy( &p_aout->output.output, p_format, sizeof(audio_sample_format_t) );
  53     if ( i_rate != -1 )
  54         p_aout->output.output.i_rate = i_rate;
  55     aout_FormatPrepare( &p_aout->output.output );
  56
  57     /* Find the best output plug-in. */
  58     p_aout->output.p_module = module_need( p_aout, "audio output", "$aout", false );
  59     if ( p_aout->output.p_module == NULL )
  60     {
  61         msg_Err( p_aout, "no suitable audio output module" );
  62         return -1;
  63     }
  64
  65     if ( var_Type( p_aout, "audio-channels" ) ==
  66              (VLC_VAR_INTEGER | VLC_VAR_HASCHOICE) )
  67     {
  68         /* The user may have selected a different channels configuration. */
  69         var_Get( p_aout, "audio-channels", &val );
  70
  71         if ( val.i_int == AOUT_VAR_CHAN_RSTEREO )
  72         {
  73             p_aout->output.output.i_original_channels |=
  74                                         AOUT_CHAN_REVERSESTEREO;
  75         }
  76         else if ( val.i_int == AOUT_VAR_CHAN_STEREO )
  77         {
  78             p_aout->output.output.i_original_channels =
  79                 AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
  80         }
  81         else if ( val.i_int == AOUT_VAR_CHAN_LEFT )
  82         {
  83             p_aout->output.output.i_original_channels = AOUT_CHAN_LEFT;
  84         }
  85         else if ( val.i_int == AOUT_VAR_CHAN_RIGHT )
  86         {
  87             p_aout->output.output.i_original_channels = AOUT_CHAN_RIGHT;
  88         }
  89         else if ( val.i_int == AOUT_VAR_CHAN_DOLBYS )
  90         {
  91             p_aout->output.output.i_original_channels
  92                 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_DOLBYSTEREO;
  93         }
  94     }
  95     else if ( p_aout->output.output.i_physical_channels == AOUT_CHAN_CENTER
  96               && (p_aout->output.output.i_original_channels
  97                    & AOUT_CHAN_PHYSMASK) == (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT) )
  98     {
  99         /* Mono - create the audio-channels variable. */
 100         var_Create( p_aout, "audio-channels",
 101                     VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
 102         text.psz_string = _("Audio Channels");
 103         var_Change( p_aout, "audio-channels", VLC_VAR_SETTEXT, &text, NULL );
 104
 105         val.i_int = AOUT_VAR_CHAN_STEREO; text.psz_string = _("Stereo");
 106         var_Change( p_aout, "audio-channels", VLC_VAR_ADDCHOICE, &val, &text );
 107         val.i_int = AOUT_VAR_CHAN_LEFT; text.psz_string = _("Left");
 108         var_Change( p_aout, "audio-channels", VLC_VAR_ADDCHOICE, &val, &text );
 109         val.i_int = AOUT_VAR_CHAN_RIGHT; text.psz_string = _("Right");
 110         var_Change( p_aout, "audio-channels", VLC_VAR_ADDCHOICE, &val, &text );
 111         if ( p_aout->output.output.i_original_channels & AOUT_CHAN_DUALMONO )
 112         {
 113             /* Go directly to the left channel. */
 114             p_aout->output.output.i_original_channels = AOUT_CHAN_LEFT;
 115             val.i_int = AOUT_VAR_CHAN_LEFT;
 116             var_Set( p_aout, "audio-channels", val );
 117         }
 118         var_AddCallback( p_aout, "audio-channels", aout_ChannelsRestart,
 119                          NULL );
 120     }
 121     else if ( p_aout->output.output.i_physical_channels ==
 122                (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)
 123                 && (p_aout->output.output.i_original_channels &
 124                      (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)) )
 125     {
 126         /* Stereo - create the audio-channels variable. */
 127         var_Create( p_aout, "audio-channels",
 128                     VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
 129         text.psz_string = _("Audio Channels");
 130         var_Change( p_aout, "audio-channels", VLC_VAR_SETTEXT, &text, NULL );
 131
 132         if ( p_aout->output.output.i_original_channels & AOUT_CHAN_DOLBYSTEREO )
 133         {
 134             val.i_int = AOUT_VAR_CHAN_DOLBYS;
 135             text.psz_string = _("Dolby Surround");
 136         }
 137         else
 138         {
 139             val.i_int = AOUT_VAR_CHAN_STEREO;
 140             text.psz_string = _("Stereo");
 141         }
 142         var_Change( p_aout, "audio-channels", VLC_VAR_ADDCHOICE, &val, &text );
 143         val.i_int = AOUT_VAR_CHAN_LEFT; text.psz_string = _("Left");
 144         var_Change( p_aout, "audio-channels", VLC_VAR_ADDCHOICE, &val, &text );
 145         val.i_int = AOUT_VAR_CHAN_RIGHT; text.psz_string = _("Right");
 146         var_Change( p_aout, "audio-channels", VLC_VAR_ADDCHOICE, &val, &text );
 147         val.i_int = AOUT_VAR_CHAN_RSTEREO; text.psz_string=_("Reverse stereo");
 148         var_Change( p_aout, "audio-channels", VLC_VAR_ADDCHOICE, &val, &text );
 149         if ( p_aout->output.output.i_original_channels & AOUT_CHAN_DUALMONO )
 150         {
 151             /* Go directly to the left channel. */
 152             p_aout->output.output.i_original_channels = AOUT_CHAN_LEFT;
 153             val.i_int = AOUT_VAR_CHAN_LEFT;
 154             var_Set( p_aout, "audio-channels", val );
 155         }
 156         var_AddCallback( p_aout, "audio-channels", aout_ChannelsRestart,
 157                          NULL );
 158     }
 159     val.b_bool = true;
 160     var_Set( p_aout, "intf-change", val );
 161
 162     aout_FormatPrepare( &p_aout->output.output );
 163
 164     aout_lock_output_fifo( p_aout );
 165
 166     /* Prepare FIFO. */
 167     aout_FifoInit( p_aout, &p_aout->output.fifo,
 168                    p_aout->output.output.i_rate );
 169
 170     aout_unlock_output_fifo( p_aout );
 171
 172     aout_FormatPrint( p_aout, "output", &p_aout->output.output );
 173
 174     /* Calculate the resulting mixer output format. */
 175     p_aout->mixer_format = p_aout->output.output;
 176     if ( !AOUT_FMT_NON_LINEAR(&p_aout->output.output) )
 177     {
 178         /* Non-S/PDIF mixer only deals with float32 or fixed32. */
 179         p_aout->mixer_format.i_format
 180                      = HAVE_FPU ? VLC_CODEC_FL32 : VLC_CODEC_FI32;
 181         aout_FormatPrepare( &p_aout->mixer_format );
 182     }
 183     else
 184     {
 185         p_aout->mixer_format.i_format = p_format->i_format;
 186     }
 187
 188     aout_FormatPrint( p_aout, "mixer", &p_aout->mixer_format );
 189
 190     /* Create filters. */
 191     p_aout->output.i_nb_filters = 0;
 192     if ( aout_FiltersCreatePipeline( p_aout, p_aout->output.pp_filters,
 193                                      &p_aout->output.i_nb_filters,
 194                                      &p_aout->mixer_format,
 195                                      &p_aout->output.output ) < 0 )
 196     {
 197         msg_Err( p_aout, "couldn't create audio output pipeline" );
 198         module_unneed( p_aout, p_aout->output.p_module );
 199         return -1;
 200     }
 201
 202     /* Prepare hints for the buffer allocator. */
 203     p_aout->mixer_allocation.b_alloc = true;
 204     p_aout->mixer_allocation.i_bytes_per_sec
 205                         = p_aout->mixer_format.i_bytes_per_frame
 206                            * p_aout->mixer_format.i_rate
 207                            / p_aout->mixer_format.i_frame_length;
 208
 209     aout_FiltersHintBuffers( p_aout, p_aout->output.pp_filters,
 210                              p_aout->output.i_nb_filters,
 211                              &p_aout->mixer_allocation );
 212
 213     p_aout->output.b_error = 0;
 214     return 0;
 215 }
 216
 217 /*****************************************************************************
 218  * aout_OutputDelete : delete the output
 219  *****************************************************************************
 220  * This function is entered with the mixer lock.
 221  *****************************************************************************/
 222 void aout_OutputDelete( aout_instance_t * p_aout )
 223 {
 224     if ( p_aout->output.b_error )
 225     {
 226         return;
 227     }
 228
 229     module_unneed( p_aout, p_aout->output.p_module );
 230
 231     aout_FiltersDestroyPipeline( p_aout, p_aout->output.pp_filters,
 232                                  p_aout->output.i_nb_filters );
 233
 234     aout_lock_output_fifo( p_aout );
 235     aout_FifoDestroy( p_aout, &p_aout->output.fifo );
 236     aout_unlock_output_fifo( p_aout );
 237
 238     p_aout->output.b_error = true;
 239 }
 240
 241 /*****************************************************************************
 242  * aout_OutputPlay : play a buffer
 243  *****************************************************************************
 244  * This function is entered with the mixer lock.
 245  *****************************************************************************/
 246 void aout_OutputPlay( aout_instance_t * p_aout, aout_buffer_t * p_buffer )
 247 {
 248     aout_FiltersPlay( p_aout->output.pp_filters, p_aout->output.i_nb_filters,
 249                       &p_buffer );
 250
 251     if( !p_buffer )
 252         return;
 253     if( p_buffer->i_buffer == 0 )
 254     {
 255         block_Release( p_buffer );
 256         return;
 257     }
 258
 259     aout_lock_output_fifo( p_aout );
 260     aout_FifoPush( p_aout, &p_aout->output.fifo, p_buffer );
 261     p_aout->output.pf_play( p_aout );
 262     aout_unlock_output_fifo( p_aout );
 263 }
 264
 265 /*****************************************************************************
 266  * aout_OutputNextBuffer : give the audio output plug-in the right buffer
 267  *****************************************************************************
 268  * If b_can_sleek is 1, the aout core functions won't try to resample
 269  * new buffers to catch up - that is we suppose that the output plug-in can
 270  * compensate it by itself. S/PDIF outputs should always set b_can_sleek = 1.
 271  * This function is entered with no lock at all :-).
 272  *****************************************************************************/
 273 aout_buffer_t * aout_OutputNextBuffer( aout_instance_t * p_aout,
 274                                        mtime_t start_date,
 275                                        bool b_can_sleek )
 276 {
 277     aout_buffer_t * p_buffer;
 278
 279     aout_lock_output_fifo( p_aout );
 280
 281     p_buffer = p_aout->output.fifo.p_first;
 282
 283     /* Drop the audio sample if the audio output is really late.
 284      * In the case of b_can_sleek, we don't use a resampler so we need to be
 285      * a lot more severe. */
 286     while ( p_buffer && p_buffer->i_pts <
 287             (b_can_sleek ? start_date : mdate()) - AOUT_PTS_TOLERANCE )
 288     {
 289         msg_Dbg( p_aout, "audio output is too slow (%"PRId64"), "
 290                  "trashing %"PRId64"us", mdate() - p_buffer->i_pts,
 291                  p_buffer->i_length );
 292         p_buffer = p_buffer->p_next;
 293         aout_BufferFree( p_aout->output.fifo.p_first );
 294         p_aout->output.fifo.p_first = p_buffer;
 295     }
 296
 297     if ( p_buffer == NULL )
 298     {
 299         p_aout->output.fifo.pp_last = &p_aout->output.fifo.p_first;
 300
 301 #if 0 /* This is bad because the audio output might just be trying to fill
 302        * in its internal buffers. And anyway, it's up to the audio output
 303        * to deal with this kind of starvation. */
 304
 305         /* Set date to 0, to allow the mixer to send a new buffer ASAP */
 306         aout_FifoSet( p_aout, &p_aout->output.fifo, 0 );
 307         if ( !p_aout->output.b_starving )
 308             msg_Dbg( p_aout,
 309                  "audio output is starving (no input), playing silence" );
 310         p_aout->output.b_starving = 1;
 311 #endif
 312
 313         aout_unlock_output_fifo( p_aout );
 314         return NULL;
 315     }
 316
 317     /* Here we suppose that all buffers have the same duration - this is
 318      * generally true, and anyway if it's wrong it won't be a disaster.
 319      */
 320     if ( p_buffer->i_pts > start_date + p_buffer->i_length )
 321     /*
 322      *                   + AOUT_PTS_TOLERANCE )
 323      * There is no reason to want that, it just worsen the scheduling of
 324      * an audio sample after an output starvation (ie. on start or on resume)
 325      * --Gibalou
 326      */
 327     {
 328         const mtime_t i_delta = p_buffer->i_pts - start_date;
 329         aout_unlock_output_fifo( p_aout );
 330
 331         if ( !p_aout->output.b_starving )
 332             msg_Dbg( p_aout, "audio output is starving (%"PRId64"), "
 333                      "playing silence", i_delta );
 334         p_aout->output.b_starving = 1;
 335         return NULL;
 336     }
 337
 338     p_aout->output.b_starving = 0;
 339
 340     p_aout->output.fifo.p_first = p_buffer->p_next;
 341     if ( p_buffer->p_next == NULL )
 342     {
 343         p_aout->output.fifo.pp_last = &p_aout->output.fifo.p_first;
 344     }
 345
 346     if ( !b_can_sleek &&
 347           ( (p_buffer->i_pts - start_date > AOUT_PTS_TOLERANCE)
 348              || (start_date - p_buffer->i_pts > AOUT_PTS_TOLERANCE) ) )
 349     {
 350         /* Try to compensate the drift by doing some resampling. */
 351         int i;
 352         mtime_t difference = start_date - p_buffer->i_pts;
 353         msg_Warn( p_aout, "output date isn't PTS date, requesting "
 354                   "resampling (%"PRId64")", difference );
 355
 356         aout_FifoMoveDates( p_aout, &p_aout->output.fifo, difference );
 357         aout_unlock_output_fifo( p_aout );
 358
 359         aout_lock_input_fifos( p_aout );
 360         for ( i = 0; i < p_aout->i_nb_inputs; i++ )
 361         {
 362             aout_fifo_t * p_fifo = &p_aout->pp_inputs[i]->mixer.fifo;
 363
 364             aout_FifoMoveDates( p_aout, p_fifo, difference );
 365         }
 366         aout_unlock_input_fifos( p_aout );
 367     }
 368     else
 369         aout_unlock_output_fifo( p_aout );
 370
 371     return p_buffer;
 372 }