git.sesse.net Git - vlc/blob - src/ac3_decoder/ac3_decoder.c

   1 /*****************************************************************************
   2  * ac3_decoder.c: ac3 decoder thread
   3  * (c)1999 VideoLAN
   4  *****************************************************************************/
   5
   6 /*
   7  * TODO :
   8  *
   9  * - vérifier l'état de la fifo de sortie avant d'y stocker les samples
  10  *   décodés ;
  11  * - vlc_cond_signal() / vlc_cond_wait()
  12  *
  13  */
  14
  15 /*****************************************************************************
  16  * Preamble
  17  *****************************************************************************/
  18 #include <sys/types.h>
  19 #include <sys/stat.h>
  20 #include <fcntl.h>
  21
  22 #include <unistd.h>                                              /* getpid() */
  23
  24 #include <stdio.h>                                           /* "intf_msg.h" */
  25 #include <stdlib.h>                                      /* malloc(), free() */
  26 #include <sys/soundcard.h>                               /* "audio_output.h" */
  27 #include <sys/uio.h>                                            /* "input.h" */
  28
  29 #include "common.h"
  30 #include "config.h"
  31 #include "mtime.h"
  32 #include "vlc_thread.h"
  33 #include "debug.h"                                      /* "input_netlist.h" */
  34
  35 #include "intf_msg.h"                        /* intf_DbgMsg(), intf_ErrMsg() */
  36
  37 #include "input.h"                                           /* pes_packet_t */
  38 #include "input_netlist.h"                         /* input_NetlistFreePES() */
  39 #include "decoder_fifo.h"         /* DECODER_FIFO_(ISEMPTY|START|INCSTART)() */
  40
  41 #include "audio_output.h"
  42
  43 #include "ac3_decoder.h"
  44 #include "ac3_parse.h"
  45 #include "ac3_exponent.h"
  46 #include "ac3_bit_allocate.h"
  47 #include "ac3_mantissa.h"
  48 #include "ac3_rematrix.h"
  49 #include "ac3_imdct.h"
  50 #include "ac3_downmix.h"
  51
  52 /*****************************************************************************
  53  * Local prototypes
  54  *****************************************************************************/
  55 static int      InitThread              ( ac3dec_thread_t * p_adec );
  56 static void     RunThread               ( ac3dec_thread_t * p_adec );
  57 static void     ErrorThread             ( ac3dec_thread_t * p_adec );
  58 static void     EndThread               ( ac3dec_thread_t * p_adec );
  59
  60 /*****************************************************************************
  61  * ac3dec_CreateThread: creates an ac3 decoder thread
  62  *****************************************************************************/
  63 ac3dec_thread_t * ac3dec_CreateThread( input_thread_t * p_input )
  64 {
  65     ac3dec_thread_t *   p_ac3dec;
  66
  67     intf_DbgMsg("ac3dec debug: creating ac3 decoder thread\n");
  68
  69     /* Allocate the memory needed to store the thread's structure */
  70     if ( (p_ac3dec = (ac3dec_thread_t *)malloc( sizeof(ac3dec_thread_t) )) == NULL )
  71     {
  72         intf_ErrMsg("ac3dec error: not enough memory for ac3dec_CreateThread() to create the new thread\n");
  73         return( NULL );
  74     }
  75
  76     /*
  77      * Initialize the thread properties
  78      */
  79     p_ac3dec->b_die = 0;
  80     p_ac3dec->b_error = 0;
  81
  82     /*
  83      * Initialize the input properties
  84      */
  85     /* Initialize the decoder fifo's data lock and conditional variable and set
  86      * its buffer as empty */
  87     vlc_mutex_init( &p_ac3dec->fifo.data_lock );
  88     vlc_cond_init( &p_ac3dec->fifo.data_wait );
  89     p_ac3dec->fifo.i_start = 0;
  90     p_ac3dec->fifo.i_end = 0;
  91     /* Initialize the bit stream structure */
  92     p_ac3dec->bit_stream.p_input = p_input;
  93     p_ac3dec->bit_stream.p_decoder_fifo = &p_ac3dec->fifo;
  94     p_ac3dec->bit_stream.fifo.buffer = 0;
  95     p_ac3dec->bit_stream.fifo.i_available = 0;
  96
  97     /*
  98      * Initialize the output properties
  99      */
 100     p_ac3dec->p_aout = p_input->p_aout;
 101     p_ac3dec->p_aout_fifo = NULL;
 102
 103     imdct_init();
 104
 105     /* Spawn the ac3 decoder thread */
 106     if ( vlc_thread_create(&p_ac3dec->thread_id, "ac3 decoder", (vlc_thread_func_t)RunThread, (void *)p_ac3dec) )
 107     {
 108         intf_ErrMsg( "ac3dec error: can't spawn ac3 decoder thread\n" );
 109         free( p_ac3dec );
 110         return( NULL );
 111     }
 112
 113     intf_DbgMsg( "ac3dec debug: ac3 decoder thread (%p) created\n", p_ac3dec );
 114     return( p_ac3dec );
 115 }
 116
 117 /*****************************************************************************
 118  * ac3dec_DestroyThread: destroys an ac3 decoder thread
 119  *****************************************************************************/
 120 void ac3dec_DestroyThread( ac3dec_thread_t * p_ac3dec )
 121 {
 122     intf_DbgMsg( "ac3dec debug: requesting termination of ac3 decoder thread %p\n", p_ac3dec );
 123
 124     /* Ask thread to kill itself */
 125     p_ac3dec->b_die = 1;
 126
 127     /* Make sure the decoder thread leaves the GetByte() function */
 128     vlc_mutex_lock( &(p_ac3dec->fifo.data_lock) );
 129     vlc_cond_signal( &(p_ac3dec->fifo.data_wait) );
 130     vlc_mutex_unlock( &(p_ac3dec->fifo.data_lock) );
 131
 132     /* Waiting for the decoder thread to exit */
 133     /* Remove this as soon as the "status" flag is implemented */
 134     vlc_thread_join( p_ac3dec->thread_id );
 135 }
 136
 137 /* Following functions are local */
 138
 139 /*****************************************************************************
 140  * decode_find_sync()
 141  *****************************************************************************/
 142 static __inline__ int decode_find_sync( ac3dec_thread_t * p_ac3dec )
 143 {
 144     while ( (!p_ac3dec->b_die) && (!p_ac3dec->b_error) )
 145     {
 146         NeedBits( &(p_ac3dec->bit_stream), 16 );
 147         if ( (p_ac3dec->bit_stream.fifo.buffer >> (32 - 16)) == 0x0b77 )
 148         {
 149             DumpBits( &(p_ac3dec->bit_stream), 16 );
 150             p_ac3dec->total_bits_read = 16;
 151             return( 0 );
 152         }
 153         DumpBits( &(p_ac3dec->bit_stream), 1 ); /* XXX */
 154     }
 155     return( -1 );
 156 }
 157
 158 /*****************************************************************************
 159  * InitThread : initialize an ac3 decoder thread
 160  *****************************************************************************/
 161 static int InitThread( ac3dec_thread_t * p_ac3dec )
 162 {
 163     aout_fifo_t         aout_fifo;
 164
 165     intf_DbgMsg( "ac3dec debug: initializing ac3 decoder thread %p\n", p_ac3dec );
 166
 167     /* Our first job is to initialize the bit stream structure with the
 168      * beginning of the input stream */
 169     vlc_mutex_lock( &p_ac3dec->fifo.data_lock );
 170     while ( DECODER_FIFO_ISEMPTY(p_ac3dec->fifo) )
 171     {
 172         if ( p_ac3dec->b_die )
 173         {
 174             vlc_mutex_unlock( &p_ac3dec->fifo.data_lock );
 175             return( -1 );
 176         }
 177         vlc_cond_wait( &p_ac3dec->fifo.data_wait, &p_ac3dec->fifo.data_lock );
 178     }
 179     p_ac3dec->bit_stream.p_ts = DECODER_FIFO_START( p_ac3dec->fifo )->p_first_ts;
 180     p_ac3dec->bit_stream.i_byte = p_ac3dec->bit_stream.p_ts->i_payload_start;
 181     vlc_mutex_unlock( &p_ac3dec->fifo.data_lock );
 182
 183     aout_fifo.i_type = AOUT_ADEC_STEREO_FIFO;
 184     aout_fifo.i_channels = 2;
 185     aout_fifo.b_stereo = 1;
 186
 187     aout_fifo.l_frame_size = AC3DEC_FRAME_SIZE;
 188
 189     /* Creating the audio output fifo */
 190     if ( (p_ac3dec->p_aout_fifo = aout_CreateFifo(p_ac3dec->p_aout, &aout_fifo)) == NULL )
 191     {
 192         return( -1 );
 193     }
 194
 195     intf_DbgMsg( "ac3dec debug: ac3 decoder thread %p initialized\n", p_ac3dec );
 196     return( 0 );
 197 }
 198
 199 /*****************************************************************************
 200  * RunThread : ac3 decoder thread
 201  *****************************************************************************/
 202 static void RunThread( ac3dec_thread_t * p_ac3dec )
 203 {
 204     intf_DbgMsg( "ac3dec debug: running ac3 decoder thread (%p) (pid == %i)\n", p_ac3dec, getpid() );
 205
 206     msleep( INPUT_PTS_DELAY );
 207
 208     /* Initializing the ac3 decoder thread */
 209     if ( InitThread(p_ac3dec) ) /* XXX */
 210     {
 211         p_ac3dec->b_error = 1;
 212     }
 213
 214     /* ac3 decoder thread's main loop */
 215     /* FIXME : do we have enough room to store the decoded frames ? */
 216     while ( (!p_ac3dec->b_die) && (!p_ac3dec->b_error) )
 217     {
 218         p_ac3dec->b_invalid = 0;
 219
 220         decode_find_sync( p_ac3dec );
 221
 222         if ( DECODER_FIFO_START(p_ac3dec->fifo)->b_has_pts )
 223         {
 224                 p_ac3dec->p_aout_fifo->date[p_ac3dec->p_aout_fifo->l_end_frame] = DECODER_FIFO_START(p_ac3dec->fifo)->i_pts;
 225                 DECODER_FIFO_START(p_ac3dec->fifo)->b_has_pts = 0;
 226         }
 227         else
 228         {
 229                 p_ac3dec->p_aout_fifo->date[p_ac3dec->p_aout_fifo->l_end_frame] = LAST_MDATE;
 230         }
 231
 232         parse_syncinfo( p_ac3dec );
 233         switch ( p_ac3dec->syncinfo.fscod )
 234         {
 235                 case 0:
 236                         p_ac3dec->p_aout_fifo->l_rate = 48000;
 237                         break;
 238
 239                 case 1:
 240                         p_ac3dec->p_aout_fifo->l_rate = 44100;
 241                         break;
 242
 243                 case 2:
 244                         p_ac3dec->p_aout_fifo->l_rate = 32000;
 245                         break;
 246
 247                 default: /* XXX */
 248                         fprintf( stderr, "ac3dec debug: invalid fscod\n" );
 249                         p_ac3dec->b_invalid = 1;
 250                         break;
 251         }
 252         if ( p_ac3dec->b_invalid ) /* XXX */
 253         {
 254                 continue;
 255         }
 256
 257         parse_bsi( p_ac3dec );
 258
 259         /* frame 1 */
 260         parse_audblk( p_ac3dec );
 261         exponent_unpack( p_ac3dec );
 262         if ( p_ac3dec->b_invalid )
 263         {
 264                 continue;
 265         }
 266         bit_allocate( p_ac3dec );
 267         mantissa_unpack( p_ac3dec );
 268         if ( p_ac3dec->b_invalid )
 269         {
 270                 continue;
 271         }
 272         if ( p_ac3dec->bsi.acmod == 0x2 )
 273         {
 274                 rematrix( p_ac3dec );
 275         }
 276         imdct( p_ac3dec );
 277         downmix( p_ac3dec, ((ac3dec_frame_t *)p_ac3dec->p_aout_fifo->buffer)[ p_ac3dec->p_aout_fifo->l_end_frame ] );
 278         vlc_mutex_lock( &p_ac3dec->p_aout_fifo->data_lock );
 279         p_ac3dec->p_aout_fifo->l_end_frame = (p_ac3dec->p_aout_fifo->l_end_frame + 1) & AOUT_FIFO_SIZE;
 280         vlc_cond_signal( &p_ac3dec->p_aout_fifo->data_wait );
 281         vlc_mutex_unlock( &p_ac3dec->p_aout_fifo->data_lock );
 282
 283         /* frame 2 */
 284         parse_audblk( p_ac3dec );
 285         exponent_unpack( p_ac3dec );
 286         if ( p_ac3dec->b_invalid )
 287         {
 288                 continue;
 289         }
 290         bit_allocate( p_ac3dec );
 291         mantissa_unpack( p_ac3dec );
 292         if ( p_ac3dec->b_invalid )
 293         {
 294                 continue;
 295         }
 296         if ( p_ac3dec->bsi.acmod == 0x2 )
 297         {
 298                 rematrix( p_ac3dec );
 299         }
 300         imdct( p_ac3dec );
 301         downmix( p_ac3dec, ((ac3dec_frame_t *)p_ac3dec->p_aout_fifo->buffer)[ p_ac3dec->p_aout_fifo->l_end_frame ] );
 302         p_ac3dec->p_aout_fifo->date[p_ac3dec->p_aout_fifo->l_end_frame] = LAST_MDATE;
 303         vlc_mutex_lock( &p_ac3dec->p_aout_fifo->data_lock );
 304         p_ac3dec->p_aout_fifo->l_end_frame = (p_ac3dec->p_aout_fifo->l_end_frame + 1) & AOUT_FIFO_SIZE;
 305         vlc_cond_signal( &p_ac3dec->p_aout_fifo->data_wait );
 306         vlc_mutex_unlock( &p_ac3dec->p_aout_fifo->data_lock );
 307
 308         /* frame 3 */
 309         parse_audblk( p_ac3dec );
 310         exponent_unpack( p_ac3dec );
 311         if ( p_ac3dec->b_invalid )
 312         {
 313                 continue;
 314         }
 315         bit_allocate( p_ac3dec );
 316         mantissa_unpack( p_ac3dec );
 317         if ( p_ac3dec->b_invalid )
 318         {
 319                 continue;
 320         }
 321         if ( p_ac3dec->bsi.acmod == 0x2 )
 322         {
 323                 rematrix( p_ac3dec );
 324         }
 325         imdct( p_ac3dec );
 326         downmix( p_ac3dec, ((ac3dec_frame_t *)p_ac3dec->p_aout_fifo->buffer)[ p_ac3dec->p_aout_fifo->l_end_frame ] );
 327         p_ac3dec->p_aout_fifo->date[p_ac3dec->p_aout_fifo->l_end_frame] = LAST_MDATE;
 328         vlc_mutex_lock( &p_ac3dec->p_aout_fifo->data_lock );
 329         p_ac3dec->p_aout_fifo->l_end_frame = (p_ac3dec->p_aout_fifo->l_end_frame + 1) & AOUT_FIFO_SIZE;
 330         vlc_cond_signal( &p_ac3dec->p_aout_fifo->data_wait );
 331         vlc_mutex_unlock( &p_ac3dec->p_aout_fifo->data_lock );
 332
 333         /* frame 4 */
 334         parse_audblk( p_ac3dec );
 335         exponent_unpack( p_ac3dec );
 336         if ( p_ac3dec->b_invalid )
 337         {
 338                 continue;
 339         }
 340         bit_allocate( p_ac3dec );
 341         mantissa_unpack( p_ac3dec );
 342         if ( p_ac3dec->b_invalid )
 343         {
 344                 continue;
 345         }
 346         if ( p_ac3dec->bsi.acmod == 0x2 )
 347         {
 348                 rematrix( p_ac3dec );
 349         }
 350         imdct( p_ac3dec );
 351         downmix( p_ac3dec, ((ac3dec_frame_t *)p_ac3dec->p_aout_fifo->buffer)[ p_ac3dec->p_aout_fifo->l_end_frame ] );
 352         p_ac3dec->p_aout_fifo->date[p_ac3dec->p_aout_fifo->l_end_frame] = LAST_MDATE;
 353         vlc_mutex_lock( &p_ac3dec->p_aout_fifo->data_lock );
 354         p_ac3dec->p_aout_fifo->l_end_frame = (p_ac3dec->p_aout_fifo->l_end_frame + 1) & AOUT_FIFO_SIZE;
 355         vlc_cond_signal( &p_ac3dec->p_aout_fifo->data_wait );
 356         vlc_mutex_unlock( &p_ac3dec->p_aout_fifo->data_lock );
 357
 358         /* frame 5 */
 359         parse_audblk( p_ac3dec );
 360         exponent_unpack( p_ac3dec );
 361         if ( p_ac3dec->b_invalid )
 362         {
 363                 continue;
 364         }
 365         bit_allocate( p_ac3dec );
 366         mantissa_unpack( p_ac3dec );
 367         if ( p_ac3dec->b_invalid )
 368         {
 369                 continue;
 370         }
 371         if ( p_ac3dec->bsi.acmod == 0x2 )
 372         {
 373                 rematrix( p_ac3dec );
 374         }
 375         imdct( p_ac3dec );
 376         downmix( p_ac3dec, ((ac3dec_frame_t *)p_ac3dec->p_aout_fifo->buffer)[ p_ac3dec->p_aout_fifo->l_end_frame ] );
 377         p_ac3dec->p_aout_fifo->date[p_ac3dec->p_aout_fifo->l_end_frame] = LAST_MDATE;
 378         vlc_mutex_lock( &p_ac3dec->p_aout_fifo->data_lock );
 379         p_ac3dec->p_aout_fifo->l_end_frame = (p_ac3dec->p_aout_fifo->l_end_frame + 1) & AOUT_FIFO_SIZE;
 380         vlc_cond_signal( &p_ac3dec->p_aout_fifo->data_wait );
 381         vlc_mutex_unlock( &p_ac3dec->p_aout_fifo->data_lock );
 382
 383         /* frame 6 */
 384         parse_audblk( p_ac3dec );
 385         exponent_unpack( p_ac3dec );
 386         if ( p_ac3dec->b_invalid )
 387         {
 388                 continue;
 389         }
 390         bit_allocate( p_ac3dec );
 391         mantissa_unpack( p_ac3dec );
 392         if ( p_ac3dec->b_invalid )
 393         {
 394                 continue;
 395         }
 396         if ( p_ac3dec->bsi.acmod == 0x2 )
 397         {
 398                 rematrix( p_ac3dec );
 399         }
 400         imdct( p_ac3dec );
 401         downmix( p_ac3dec, ((ac3dec_frame_t *)p_ac3dec->p_aout_fifo->buffer)[ p_ac3dec->p_aout_fifo->l_end_frame ] );
 402         p_ac3dec->p_aout_fifo->date[p_ac3dec->p_aout_fifo->l_end_frame] = LAST_MDATE;
 403         vlc_mutex_lock( &p_ac3dec->p_aout_fifo->data_lock );
 404         p_ac3dec->p_aout_fifo->l_end_frame = (p_ac3dec->p_aout_fifo->l_end_frame + 1) & AOUT_FIFO_SIZE;
 405         vlc_cond_signal( &p_ac3dec->p_aout_fifo->data_wait );
 406         vlc_mutex_unlock( &p_ac3dec->p_aout_fifo->data_lock );
 407
 408         parse_auxdata( p_ac3dec );
 409     }
 410
 411     /* If b_error is set, the ac3 decoder thread enters the error loop */
 412     if ( p_ac3dec->b_error )
 413     {
 414         ErrorThread( p_ac3dec );
 415     }
 416
 417     /* End of the ac3 decoder thread */
 418     EndThread( p_ac3dec );
 419 }
 420
 421 /*****************************************************************************
 422  * ErrorThread : ac3 decoder's RunThread() error loop
 423  *****************************************************************************/
 424 static void ErrorThread( ac3dec_thread_t * p_ac3dec )
 425 {
 426     /* We take the lock, because we are going to read/write the start/end
 427      * indexes of the decoder fifo */
 428     vlc_mutex_lock( &p_ac3dec->fifo.data_lock );
 429
 430     /* Wait until a `die' order is sent */
 431     while( !p_ac3dec->b_die )
 432     {
 433         /* Trash all received PES packets */
 434         while( !DECODER_FIFO_ISEMPTY(p_ac3dec->fifo) )
 435         {
 436             input_NetlistFreePES( p_ac3dec->bit_stream.p_input, DECODER_FIFO_START(p_ac3dec->fifo) );
 437             DECODER_FIFO_INCSTART( p_ac3dec->fifo );
 438         }
 439
 440         /* Waiting for the input thread to put new PES packets in the fifo */
 441         vlc_cond_wait( &p_ac3dec->fifo.data_wait, &p_ac3dec->fifo.data_lock );
 442     }
 443
 444     /* We can release the lock before leaving */
 445     vlc_mutex_unlock( &p_ac3dec->fifo.data_lock );
 446 }
 447
 448 /*****************************************************************************
 449  * EndThread : ac3 decoder thread destruction
 450  *****************************************************************************/
 451 static void EndThread( ac3dec_thread_t * p_ac3dec )
 452 {
 453     intf_DbgMsg( "ac3dec debug: destroying ac3 decoder thread %p\n", p_ac3dec );
 454
 455     /* If the audio output fifo was created, we destroy it */
 456     if ( p_ac3dec->p_aout_fifo != NULL )
 457     {
 458         aout_DestroyFifo( p_ac3dec->p_aout_fifo );
 459
 460         /* Make sure the output thread leaves the NextFrame() function */
 461         vlc_mutex_lock( &(p_ac3dec->p_aout_fifo->data_lock) );
 462         vlc_cond_signal( &(p_ac3dec->p_aout_fifo->data_wait) );
 463         vlc_mutex_unlock( &(p_ac3dec->p_aout_fifo->data_lock) );
 464     }
 465
 466     /* Destroy descriptor */
 467     free( p_ac3dec );
 468
 469     intf_DbgMsg( "ac3dec debug: ac3 decoder thread %p destroyed\n", p_ac3dec );
 470 }