src/audio_output/mixer.c

   1 /*****************************************************************************
   2  * mixer.c : audio output mixing operations
   3  *****************************************************************************
   4  * Copyright (C) 2002-2004 VideoLAN
   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., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #include <stdlib.h>                            /* calloc(), malloc(), free() */
  28 #include <string.h>
  29
  30 #include <vlc/vlc.h>
  31
  32 #ifdef HAVE_ALLOCA_H
  33 #   include <alloca.h>
  34 #endif
  35
  36 #include "audio_output.h"
  37 #include "aout_internal.h"
  38
  39 /*****************************************************************************
  40  * aout_MixerNew: prepare a mixer plug-in
  41  *****************************************************************************
  42  * Please note that you must hold the mixer lock.
  43  *****************************************************************************/
  44 int aout_MixerNew( aout_instance_t * p_aout )
  45 {
  46     p_aout->mixer.p_module = module_Need( p_aout, "audio mixer", NULL, 0 );
  47     if ( p_aout->mixer.p_module == NULL )
  48     {
  49         msg_Err( p_aout, "no suitable aout mixer" );
  50         return -1;
  51     }
  52     p_aout->mixer.b_error = 0;
  53     return 0;
  54 }
  55
  56 /*****************************************************************************
  57  * aout_MixerDelete: delete the mixer
  58  *****************************************************************************
  59  * Please note that you must hold the mixer lock.
  60  *****************************************************************************/
  61 void aout_MixerDelete( aout_instance_t * p_aout )
  62 {
  63     if ( p_aout->mixer.b_error ) return;
  64     module_Unneed( p_aout, p_aout->mixer.p_module );
  65     p_aout->mixer.b_error = 1;
  66 }
  67
  68 /*****************************************************************************
  69  * MixBuffer: try to prepare one output buffer
  70  *****************************************************************************
  71  * Please note that you must hold the mixer lock.
  72  *****************************************************************************/
  73 static int MixBuffer( aout_instance_t * p_aout )
  74 {
  75     int             i, i_first_input = 0;
  76     aout_buffer_t * p_output_buffer;
  77     mtime_t start_date, end_date;
  78     audio_date_t exact_start_date;
  79
  80     if ( p_aout->mixer.b_error )
  81     {
  82         /* Free all incoming buffers. */
  83         vlc_mutex_lock( &p_aout->input_fifos_lock );
  84         for ( i = 0; i < p_aout->i_nb_inputs; i++ )
  85         {
  86             aout_input_t * p_input = p_aout->pp_inputs[i];
  87             aout_buffer_t * p_buffer = p_input->fifo.p_first;
  88             if ( p_input->b_error ) continue;
  89             while ( p_buffer != NULL )
  90             {
  91                 aout_buffer_t * p_next = p_buffer->p_next;
  92                 aout_BufferFree( p_buffer );
  93                 p_buffer = p_next;
  94             }
  95         }
  96         vlc_mutex_unlock( &p_aout->input_fifos_lock );
  97         return -1;
  98     }
  99
 100
 101     vlc_mutex_lock( &p_aout->output_fifo_lock );
 102     vlc_mutex_lock( &p_aout->input_fifos_lock );
 103
 104     /* Retrieve the date of the next buffer. */
 105     memcpy( &exact_start_date, &p_aout->output.fifo.end_date,
 106             sizeof(audio_date_t) );
 107     start_date = aout_DateGet( &exact_start_date );
 108
 109     if ( start_date != 0 && start_date < mdate() )
 110     {
 111         /* The output is _very_ late. This can only happen if the user
 112          * pauses the stream (or if the decoder is buggy, which cannot
 113          * happen :). */
 114         msg_Warn( p_aout, "output PTS is out of range ("I64Fd"), clearing out",
 115                   mdate() - start_date );
 116         aout_FifoSet( p_aout, &p_aout->output.fifo, 0 );
 117         aout_DateSet( &exact_start_date, 0 );
 118         start_date = 0;
 119     }
 120
 121     vlc_mutex_unlock( &p_aout->output_fifo_lock );
 122
 123     /* See if we have enough data to prepare a new buffer for the audio
 124      * output. First : start date. */
 125     if ( !start_date )
 126     {
 127         /* Find the latest start date available. */
 128         for ( i = 0; i < p_aout->i_nb_inputs; i++ )
 129         {
 130             aout_input_t * p_input = p_aout->pp_inputs[i];
 131             aout_fifo_t * p_fifo = &p_input->fifo;
 132             aout_buffer_t * p_buffer;
 133
 134             if ( p_input->b_error ) continue;
 135
 136             p_buffer = p_fifo->p_first;
 137             while ( p_buffer != NULL && p_buffer->start_date < mdate() )
 138             {
 139                 msg_Warn( p_aout, "input PTS is out of range ("I64Fd"), "
 140                           "trashing", mdate() - p_buffer->start_date );
 141                 p_buffer = aout_FifoPop( p_aout, p_fifo );
 142                 aout_BufferFree( p_buffer );
 143                 p_buffer = p_fifo->p_first;
 144                 p_input->p_first_byte_to_mix = NULL;
 145             }
 146
 147             if ( p_buffer == NULL )
 148             {
 149                 break;
 150             }
 151
 152             if ( !start_date || start_date < p_buffer->start_date )
 153             {
 154                 aout_DateSet( &exact_start_date, p_buffer->start_date );
 155                 start_date = p_buffer->start_date;
 156             }
 157         }
 158
 159         if ( i < p_aout->i_nb_inputs )
 160         {
 161             /* Interrupted before the end... We can't run. */
 162             vlc_mutex_unlock( &p_aout->input_fifos_lock );
 163             return -1;
 164         }
 165     }
 166     aout_DateIncrement( &exact_start_date, p_aout->output.i_nb_samples );
 167     end_date = aout_DateGet( &exact_start_date );
 168
 169     /* Check that start_date and end_date are available for all input
 170      * streams. */
 171     for ( i = 0; i < p_aout->i_nb_inputs; i++ )
 172     {
 173         aout_input_t * p_input = p_aout->pp_inputs[i];
 174         aout_fifo_t * p_fifo = &p_input->fifo;
 175         aout_buffer_t * p_buffer;
 176         mtime_t prev_date;
 177         vlc_bool_t b_drop_buffers;
 178
 179         if ( p_input->b_error )
 180         {
 181             if ( i_first_input == i ) i_first_input++;
 182             continue;
 183         }
 184
 185         p_buffer = p_fifo->p_first;
 186         if ( p_buffer == NULL )
 187         {
 188             break;
 189         }
 190
 191         /* Check for the continuity of start_date */
 192         while ( p_buffer != NULL && p_buffer->end_date < start_date - 1 )
 193         {
 194             /* We authorize a +-1 because rounding errors get compensated
 195              * regularly. */
 196             aout_buffer_t * p_next = p_buffer->p_next;
 197             msg_Warn( p_aout, "the mixer got a packet in the past ("I64Fd")",
 198                       start_date - p_buffer->end_date );
 199             aout_BufferFree( p_buffer );
 200             p_fifo->p_first = p_buffer = p_next;
 201             p_input->p_first_byte_to_mix = NULL;
 202         }
 203         if ( p_buffer == NULL )
 204         {
 205             p_fifo->pp_last = &p_fifo->p_first;
 206             break;
 207         }
 208
 209         /* Check that we have enough samples. */
 210         for ( ; ; )
 211         {
 212             p_buffer = p_fifo->p_first;
 213             if ( p_buffer == NULL ) break;
 214             if ( p_buffer->end_date >= end_date ) break;
 215
 216             /* Check that all buffers are contiguous. */
 217             prev_date = p_fifo->p_first->end_date;
 218             p_buffer = p_buffer->p_next;
 219             b_drop_buffers = 0;
 220             for ( ; p_buffer != NULL; p_buffer = p_buffer->p_next )
 221             {
 222                 if ( prev_date != p_buffer->start_date )
 223                 {
 224                     msg_Warn( p_aout,
 225                               "buffer hole, dropping packets ("I64Fd")",
 226                               p_buffer->start_date - prev_date );
 227                     b_drop_buffers = 1;
 228                     break;
 229                 }
 230                 if ( p_buffer->end_date >= end_date ) break;
 231                 prev_date = p_buffer->end_date;
 232             }
 233             if ( b_drop_buffers )
 234             {
 235                 aout_buffer_t * p_deleted = p_fifo->p_first;
 236                 while ( p_deleted != NULL && p_deleted != p_buffer )
 237                 {
 238                     aout_buffer_t * p_next = p_deleted->p_next;
 239                     aout_BufferFree( p_deleted );
 240                     p_deleted = p_next;
 241                 }
 242                 p_fifo->p_first = p_deleted; /* == p_buffer */
 243             }
 244             else break;
 245         }
 246         if ( p_buffer == NULL ) break;
 247
 248         p_buffer = p_fifo->p_first;
 249         if ( !AOUT_FMT_NON_LINEAR( &p_aout->mixer.mixer ) )
 250         {
 251             /* Additionally check that p_first_byte_to_mix is well
 252              * located. */
 253             mtime_t i_nb_bytes = (start_date - p_buffer->start_date)
 254                             * p_aout->mixer.mixer.i_bytes_per_frame
 255                             * p_aout->mixer.mixer.i_rate
 256                             / p_aout->mixer.mixer.i_frame_length
 257                             / 1000000;
 258             ptrdiff_t mixer_nb_bytes;
 259
 260             if ( p_input->p_first_byte_to_mix == NULL )
 261             {
 262                 p_input->p_first_byte_to_mix = p_buffer->p_buffer;
 263             }
 264             mixer_nb_bytes = p_input->p_first_byte_to_mix - p_buffer->p_buffer;
 265
 266             if ( !((i_nb_bytes + p_aout->mixer.mixer.i_bytes_per_frame
 267                      > mixer_nb_bytes) &&
 268                    (i_nb_bytes < p_aout->mixer.mixer.i_bytes_per_frame
 269                      + mixer_nb_bytes)) )
 270             {
 271                 msg_Warn( p_aout, "mixer start isn't output start ("I64Fd")",
 272                           i_nb_bytes - mixer_nb_bytes );
 273
 274                 /* Round to the nearest multiple */
 275                 i_nb_bytes /= p_aout->mixer.mixer.i_bytes_per_frame;
 276                 i_nb_bytes *= p_aout->mixer.mixer.i_bytes_per_frame;
 277                 if( i_nb_bytes < 0 )
 278                 {
 279                     /* Is it really the best way to do it ? */
 280                     aout_FifoSet( p_aout, &p_aout->output.fifo, 0 );
 281                     aout_DateSet( &exact_start_date, 0 );
 282                     break;
 283                 }
 284
 285                 p_input->p_first_byte_to_mix = p_buffer->p_buffer + i_nb_bytes;
 286             }
 287         }
 288     }
 289
 290     if ( i < p_aout->i_nb_inputs || i_first_input == p_aout->i_nb_inputs )
 291     {
 292         /* Interrupted before the end... We can't run. */
 293         vlc_mutex_unlock( &p_aout->input_fifos_lock );
 294         return -1;
 295     }
 296
 297     /* Run the mixer. */
 298     aout_BufferAlloc( &p_aout->mixer.output_alloc,
 299                       ((uint64_t)p_aout->output.i_nb_samples * 1000000)
 300                         / p_aout->output.output.i_rate,
 301                       /* This is a bit kludgy, but is actually only used
 302                        * for the S/PDIF dummy mixer : */
 303                       p_aout->pp_inputs[i_first_input]->fifo.p_first,
 304                       p_output_buffer );
 305     if ( p_output_buffer == NULL )
 306     {
 307         msg_Err( p_aout, "out of memory" );
 308         vlc_mutex_unlock( &p_aout->input_fifos_lock );
 309         return -1;
 310     }
 311     /* This is again a bit kludgy - for the S/PDIF mixer. */
 312     if ( p_aout->mixer.output_alloc.i_alloc_type != AOUT_ALLOC_NONE )
 313     {
 314         p_output_buffer->i_nb_samples = p_aout->output.i_nb_samples;
 315         p_output_buffer->i_nb_bytes = p_aout->output.i_nb_samples
 316                               * p_aout->mixer.mixer.i_bytes_per_frame
 317                               / p_aout->mixer.mixer.i_frame_length;
 318     }
 319     p_output_buffer->start_date = start_date;
 320     p_output_buffer->end_date = end_date;
 321
 322     p_aout->mixer.pf_do_work( p_aout, p_output_buffer );
 323
 324     vlc_mutex_unlock( &p_aout->input_fifos_lock );
 325
 326     aout_OutputPlay( p_aout, p_output_buffer );
 327
 328     return 0;
 329 }
 330
 331 /*****************************************************************************
 332  * aout_MixerRun: entry point for the mixer & post-filters processing
 333  *****************************************************************************
 334  * Please note that you must hold the mixer lock.
 335  *****************************************************************************/
 336 void aout_MixerRun( aout_instance_t * p_aout )
 337 {
 338     while( MixBuffer( p_aout ) != -1 );
 339 }
 340
 341 /*****************************************************************************
 342  * aout_MixerMultiplierSet: set p_aout->mixer.f_multiplier
 343  *****************************************************************************
 344  * Please note that we assume that you own the mixer lock when entering this
 345  * function. This function returns -1 on error.
 346  *****************************************************************************/
 347 int aout_MixerMultiplierSet( aout_instance_t * p_aout, float f_multiplier )
 348 {
 349     float f_old = p_aout->mixer.f_multiplier;
 350     vlc_bool_t b_new_mixer = 0;
 351
 352     if ( !p_aout->mixer.b_error )
 353     {
 354         aout_MixerDelete( p_aout );
 355         b_new_mixer = 1;
 356     }
 357
 358     p_aout->mixer.f_multiplier = f_multiplier;
 359
 360     if ( b_new_mixer && aout_MixerNew( p_aout ) )
 361     {
 362         p_aout->mixer.f_multiplier = f_old;
 363         aout_MixerNew( p_aout );
 364         return -1;
 365     }
 366
 367     return 0;
 368 }
 369
 370 /*****************************************************************************
 371  * aout_MixerMultiplierGet: get p_aout->mixer.f_multiplier
 372  *****************************************************************************
 373  * Please note that we assume that you own the mixer lock when entering this
 374  * function. This function returns -1 on error.
 375  *****************************************************************************/
 376 int aout_MixerMultiplierGet( aout_instance_t * p_aout, float * pf_multiplier )
 377 {
 378     *pf_multiplier = p_aout->mixer.f_multiplier;
 379     return 0;
 380 }
 381