git.sesse.net Git - vlc/blob - src/ac3_decoder/ac3_decoder_thread.c

   1 /*****************************************************************************
   2  * ac3_decoder_thread.c: ac3 decoder thread
   3  *****************************************************************************
   4  * Copyright (C) 1999, 2000 VideoLAN
   5  * $Id: ac3_decoder_thread.c,v 1.26 2001/02/22 05:31:55 reno Exp $
   6  *
   7  * Authors: Michel Lespinasse <walken@zoy.org>
   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  * TODO :
  26  *
  27  * - vérifier l'état de la fifo de sortie avant d'y stocker les samples
  28  *   décodés ;
  29  * - vlc_cond_signal() / vlc_cond_wait()
  30  *
  31  */
  32
  33 /*****************************************************************************
  34  * Preamble
  35  *****************************************************************************/
  36 #include "defs.h"
  37
  38 #include <unistd.h>                                              /* getpid() */
  39
  40 #include <stdio.h>                                           /* "intf_msg.h" */
  41 #include <stdlib.h>                                      /* malloc(), free() */
  42
  43 #include "config.h"
  44 #include "common.h"
  45 #include "threads.h"
  46 #include "mtime.h"
  47
  48 #include "intf_msg.h"                        /* intf_DbgMsg(), intf_ErrMsg() */
  49
  50 #include "stream_control.h"
  51 #include "input_ext-dec.h"
  52
  53 #include "audio_output.h"
  54
  55 #include "ac3_decoder.h"
  56 #include "ac3_decoder_thread.h"
  57
  58 #define AC3DEC_FRAME_SIZE (2*1536)
  59
  60 /*****************************************************************************
  61  * Local prototypes
  62  *****************************************************************************/
  63 static int      InitThread              (ac3dec_thread_t * p_adec);
  64 static void     RunThread               (ac3dec_thread_t * p_adec);
  65 static void     ErrorThread             (ac3dec_thread_t * p_adec);
  66 static void     EndThread               (ac3dec_thread_t * p_adec);
  67
  68 /*****************************************************************************
  69  * ac3dec_CreateThread: creates an ac3 decoder thread
  70  *****************************************************************************/
  71 vlc_thread_t ac3dec_CreateThread( adec_config_t * p_config )
  72 {
  73     ac3dec_thread_t *   p_ac3dec;
  74
  75     intf_DbgMsg( "ac3dec debug: creating ac3 decoder thread" );
  76
  77     /* Allocate the memory needed to store the thread's structure */
  78     if ((p_ac3dec = (ac3dec_thread_t *)malloc (sizeof(ac3dec_thread_t))) == NULL)
  79     {
  80         intf_ErrMsg ( "ac3dec error: not enough memory "
  81                       "for ac3dec_CreateThread() to create the new thread");
  82         return 0;
  83     }
  84
  85     /*
  86      * Initialize the thread properties
  87      */
  88     p_ac3dec->p_config = p_config;
  89     p_ac3dec->p_fifo = p_config->decoder_config.p_decoder_fifo;
  90
  91     /* Initialize the ac3 decoder structures */
  92     ac3_init (&p_ac3dec->ac3_decoder);
  93
  94     /*
  95      * Initialize the output properties
  96      */
  97     p_ac3dec->p_aout = p_config->p_aout;
  98     p_ac3dec->p_aout_fifo = NULL;
  99
 100     /* Spawn the ac3 decoder thread */
 101     if (vlc_thread_create(&p_ac3dec->thread_id, "ac3 decoder", (vlc_thread_func_t)RunThread, (void *)p_ac3dec))
 102     {
 103         intf_ErrMsg( "ac3dec error: can't spawn ac3 decoder thread" );
 104         free (p_ac3dec);
 105         return 0;
 106     }
 107
 108     intf_DbgMsg ("ac3dec debug: ac3 decoder thread (%p) created", p_ac3dec);
 109     return p_ac3dec->thread_id;
 110 }
 111
 112 /* Following functions are local */
 113
 114 /*****************************************************************************
 115  * InitThread : initialize an ac3 decoder thread
 116  *****************************************************************************/
 117 static int InitThread (ac3dec_thread_t * p_ac3dec)
 118 {
 119     aout_fifo_t         aout_fifo;
 120     ac3_byte_stream_t * byte_stream;
 121
 122     intf_DbgMsg ("ac3dec debug: initializing ac3 decoder thread %p", p_ac3dec);
 123
 124     /* Get the first data packet. */
 125     vlc_mutex_lock( &p_ac3dec->p_fifo->data_lock );
 126     while ( DECODER_FIFO_ISEMPTY( *p_ac3dec->p_fifo ) )
 127     {
 128         if ( p_ac3dec->p_fifo->b_die )
 129         {
 130             vlc_mutex_unlock( &p_ac3dec->p_fifo->data_lock );
 131             return -1;
 132         }
 133         vlc_cond_wait( &p_ac3dec->p_fifo->data_wait, &p_ac3dec->p_fifo->data_lock );
 134     }
 135     p_ac3dec->p_data = DECODER_FIFO_START(*p_ac3dec->p_fifo)->p_first;
 136     byte_stream = ac3_byte_stream (&p_ac3dec->ac3_decoder);
 137     byte_stream->p_byte = p_ac3dec->p_data->p_payload_start;
 138     byte_stream->p_end = p_ac3dec->p_data->p_payload_end;
 139     byte_stream->info = p_ac3dec;
 140     vlc_mutex_unlock (&p_ac3dec->p_fifo->data_lock);
 141
 142     aout_fifo.i_type = AOUT_ADEC_STEREO_FIFO;
 143     aout_fifo.i_channels = 2;
 144     aout_fifo.b_stereo = 1;
 145
 146     aout_fifo.l_frame_size = AC3DEC_FRAME_SIZE;
 147
 148     /* Creating the audio output fifo */
 149     if ((p_ac3dec->p_aout_fifo = aout_CreateFifo(p_ac3dec->p_aout, &aout_fifo)) == NULL)
 150     {
 151         return -1;
 152     }
 153
 154     intf_DbgMsg ("ac3dec debug: ac3 decoder thread %p initialized", p_ac3dec);
 155     return 0;
 156 }
 157
 158 /*****************************************************************************
 159  * RunThread : ac3 decoder thread
 160  *****************************************************************************/
 161 static void RunThread (ac3dec_thread_t * p_ac3dec)
 162 {
 163     int sync;
 164
 165     intf_DbgMsg ("ac3dec debug: running ac3 decoder thread (%p) (pid == %i)", p_ac3dec, getpid());
 166
 167     /* Initializing the ac3 decoder thread */
 168     if (InitThread (p_ac3dec)) /* XXX?? */
 169     {
 170         p_ac3dec->p_fifo->b_error = 1;
 171     }
 172
 173     sync = 0;
 174     p_ac3dec->sync_ptr = 0;
 175
 176     /* ac3 decoder thread's main loop */
 177     /* FIXME : do we have enough room to store the decoded frames ?? */
 178     while ((!p_ac3dec->p_fifo->b_die) && (!p_ac3dec->p_fifo->b_error))
 179     {
 180         s16 * buffer;
 181         ac3_sync_info_t sync_info;
 182
 183         if (!sync) { /* have to find a synchro point */
 184             int ptr;
 185             ac3_byte_stream_t * p_byte_stream;
 186
 187             intf_DbgMsg ("ac3dec: sync");
 188
 189             p_byte_stream = ac3_byte_stream (&p_ac3dec->ac3_decoder);
 190
 191             /* first read till next ac3 magic header */
 192             do
 193             {
 194                 ac3_byte_stream_next (p_byte_stream);
 195             } while ((!p_ac3dec->sync_ptr) &&
 196                     (!p_ac3dec->p_fifo->b_die) &&
 197                     (!p_ac3dec->p_fifo->b_error));
 198             /* skip the specified number of bytes */
 199
 200             if( p_ac3dec->p_fifo->b_die || p_ac3dec->p_fifo->b_error )
 201             {
 202                 goto bad_frame;
 203             }
 204
 205             ptr = p_ac3dec->sync_ptr;
 206             while (--ptr && (!p_ac3dec->p_fifo->b_die) && (!p_ac3dec->p_fifo->b_error))
 207             {
 208                 if (p_byte_stream->p_byte >= p_byte_stream->p_end)
 209                 {
 210                     ac3_byte_stream_next (p_byte_stream);
 211                 }
 212                 p_byte_stream->p_byte++;
 213             }
 214
 215             if( p_ac3dec->p_fifo->b_die || p_ac3dec->p_fifo->b_error )
 216             {
 217                 goto bad_frame;
 218             }
 219
 220             /* we are in sync now */
 221             sync = 1;
 222             p_ac3dec->sync_ptr = 0;
 223         }
 224
 225         if (DECODER_FIFO_START(*p_ac3dec->p_fifo)->i_pts)
 226         {
 227             p_ac3dec->p_aout_fifo->date[p_ac3dec->p_aout_fifo->l_end_frame] = DECODER_FIFO_START(*p_ac3dec->p_fifo)->i_pts;
 228             DECODER_FIFO_START(*p_ac3dec->p_fifo)->i_pts = 0;
 229         }
 230         else
 231         {
 232             p_ac3dec->p_aout_fifo->date[p_ac3dec->p_aout_fifo->l_end_frame] = LAST_MDATE;
 233         }
 234
 235         if (ac3_sync_frame (&p_ac3dec->ac3_decoder, &sync_info))
 236         {
 237             sync = 0;
 238             goto bad_frame;
 239         }
 240
 241         p_ac3dec->p_aout_fifo->l_rate = sync_info.sample_rate;
 242
 243         buffer = ((s16 *)p_ac3dec->p_aout_fifo->buffer) + (p_ac3dec->p_aout_fifo->l_end_frame * AC3DEC_FRAME_SIZE);
 244
 245         if (ac3_decode_frame (&p_ac3dec->ac3_decoder, buffer))
 246         {
 247             sync = 0;
 248             goto bad_frame;
 249         }
 250
 251         vlc_mutex_lock (&p_ac3dec->p_aout_fifo->data_lock);
 252         p_ac3dec->p_aout_fifo->l_end_frame = (p_ac3dec->p_aout_fifo->l_end_frame + 1) & AOUT_FIFO_SIZE;
 253         vlc_cond_signal (&p_ac3dec->p_aout_fifo->data_wait);
 254         vlc_mutex_unlock (&p_ac3dec->p_aout_fifo->data_lock);
 255
 256     bad_frame:
 257     }
 258
 259     /* If b_error is set, the ac3 decoder thread enters the error loop */
 260     if (p_ac3dec->p_fifo->b_error)
 261     {
 262         ErrorThread (p_ac3dec);
 263     }
 264
 265     /* End of the ac3 decoder thread */
 266     EndThread (p_ac3dec);
 267 }
 268
 269 /*****************************************************************************
 270  * ErrorThread : ac3 decoder's RunThread() error loop
 271  *****************************************************************************/
 272 static void ErrorThread (ac3dec_thread_t * p_ac3dec)
 273 {
 274     /* We take the lock, because we are going to read/write the start/end
 275      * indexes of the decoder fifo */
 276     vlc_mutex_lock (&p_ac3dec->p_fifo->data_lock);
 277
 278     /* Wait until a `die' order is sent */
 279     while (!p_ac3dec->p_fifo->b_die)
 280     {
 281         /* Trash all received PES packets */
 282         while (!DECODER_FIFO_ISEMPTY(*p_ac3dec->p_fifo))
 283         {
 284             p_ac3dec->p_fifo->pf_delete_pes(p_ac3dec->p_fifo->p_packets_mgt,
 285                     DECODER_FIFO_START(*p_ac3dec->p_fifo));
 286             DECODER_FIFO_INCSTART (*p_ac3dec->p_fifo);
 287         }
 288
 289         /* Waiting for the input thread to put new PES packets in the fifo */
 290         vlc_cond_wait (&p_ac3dec->p_fifo->data_wait,
 291                        &p_ac3dec->p_fifo->data_lock);
 292     }
 293
 294     /* We can release the lock before leaving */
 295     vlc_mutex_unlock (&p_ac3dec->p_fifo->data_lock);
 296 }
 297
 298 /*****************************************************************************
 299  * EndThread : ac3 decoder thread destruction
 300  *****************************************************************************/
 301 static void EndThread (ac3dec_thread_t * p_ac3dec)
 302 {
 303     intf_DbgMsg ("ac3dec debug: destroying ac3 decoder thread %p", p_ac3dec);
 304
 305     /* If the audio output fifo was created, we destroy it */
 306     if (p_ac3dec->p_aout_fifo != NULL)
 307     {
 308         aout_DestroyFifo (p_ac3dec->p_aout_fifo);
 309
 310         /* Make sure the output thread leaves the NextFrame() function */
 311         vlc_mutex_lock (&(p_ac3dec->p_aout_fifo->data_lock));
 312         vlc_cond_signal (&(p_ac3dec->p_aout_fifo->data_wait));
 313         vlc_mutex_unlock (&(p_ac3dec->p_aout_fifo->data_lock));
 314     }
 315
 316     /* Destroy descriptor */
 317     free( p_ac3dec->p_config );
 318     free( p_ac3dec );
 319
 320     intf_DbgMsg ("ac3dec debug: ac3 decoder thread %p destroyed", p_ac3dec);
 321 }
 322
 323 void ac3_byte_stream_next (ac3_byte_stream_t * p_byte_stream)
 324 {
 325     ac3dec_thread_t * p_ac3dec = p_byte_stream->info;
 326     /* We are looking for the next TS packet that contains real data,
 327      * and not just a PES header */
 328     do
 329     {
 330         /* We were reading the last TS packet of this PES packet... It's
 331          * time to jump to the next PES packet */
 332         if (p_ac3dec->p_data->p_next == NULL)
 333         {
 334             int ptr;
 335
 336             /* We are going to read/write the start and end indexes of the
 337              * decoder fifo and to use the fifo's conditional variable,
 338              * that's why we need to take the lock before */
 339             vlc_mutex_lock (&p_ac3dec->p_fifo->data_lock);
 340
 341             /* Is the input thread dying ? */
 342             if (p_ac3dec->p_fifo->b_die)
 343             {
 344                 vlc_mutex_unlock (&p_ac3dec->p_fifo->data_lock);
 345                 return;
 346             }
 347
 348             /* We should increase the start index of the decoder fifo, but
 349              * if we do this now, the input thread could overwrite the
 350              * pointer to the current PES packet, and we weren't able to
 351              * give it back to the netlist. That's why we free the PES
 352              * packet first. */
 353             p_ac3dec->p_fifo->pf_delete_pes(p_ac3dec->p_fifo->p_packets_mgt,
 354                     DECODER_FIFO_START(*p_ac3dec->p_fifo));
 355
 356             DECODER_FIFO_INCSTART (*p_ac3dec->p_fifo);
 357
 358             while (DECODER_FIFO_ISEMPTY(*p_ac3dec->p_fifo))
 359             {
 360                 vlc_cond_wait(&p_ac3dec->p_fifo->data_wait, &p_ac3dec->p_fifo->data_lock);
 361
 362                 if (p_ac3dec->p_fifo->b_die)
 363                 {
 364                     vlc_mutex_unlock (&p_ac3dec->p_fifo->data_lock);
 365                     return;
 366                 }
 367             }
 368
 369             /* The next byte could be found in the next PES packet */
 370             p_ac3dec->p_data = DECODER_FIFO_START(*p_ac3dec->p_fifo)->p_first;
 371
 372             /* parse ac3 magic header */
 373             ptr = *(p_ac3dec->p_data->p_payload_start + 1);
 374             ptr <<= 8;
 375             ptr |= *(p_ac3dec->p_data->p_payload_start + 2);
 376             p_ac3dec->sync_ptr = ptr;
 377             p_ac3dec->p_data->p_payload_start += 3;
 378
 379             /* We can release the fifo's data lock */
 380             vlc_mutex_unlock (&p_ac3dec->p_fifo->data_lock);
 381         }
 382         /* Perhaps the next TS packet of the current PES packet contains
 383          * real data (ie its payload's size is greater than 0) */
 384         else
 385         {
 386             p_ac3dec->p_data = p_ac3dec->p_data->p_next;
 387         }
 388     } while (p_ac3dec->p_data->p_payload_start == p_ac3dec->p_data->p_payload_end);
 389     p_byte_stream->p_byte = p_ac3dec->p_data->p_payload_start;
 390     p_byte_stream->p_end = p_ac3dec->p_data->p_payload_end;
 391 }