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 1.33 2001/05/15 16:19:42 sam 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 <stdlib.h>                                      /* malloc(), free() */
  41 #include <string.h>                                              /* memset() */
  42
  43 #include "config.h"
  44 #include "common.h"
  45 #include "threads.h"
  46 #include "mtime.h"
  47 #include "modules.h"
  48
  49 #include "intf_msg.h"                        /* intf_DbgMsg(), intf_ErrMsg() */
  50
  51 #include "stream_control.h"
  52 #include "input_ext-dec.h"
  53
  54 #include "audio_output.h"
  55
  56 #include "ac3_imdct.h"
  57 #include "ac3_downmix.h"
  58 #include "ac3_decoder.h"
  59 #include "ac3_decoder_thread.h"
  60
  61 #define AC3DEC_FRAME_SIZE (2*1536)
  62
  63 /*****************************************************************************
  64  * Local prototypes
  65  *****************************************************************************/
  66 static int      InitThread              (ac3dec_thread_t * p_adec);
  67 static void     RunThread               (ac3dec_thread_t * p_adec);
  68 static void     ErrorThread             (ac3dec_thread_t * p_adec);
  69 static void     EndThread               (ac3dec_thread_t * p_adec);
  70 static void     BitstreamCallback       ( bit_stream_t *p_bit_stream,
  71                                               boolean_t b_new_pes );
  72
  73 /*****************************************************************************
  74  * ac3dec_CreateThread: creates an ac3 decoder thread
  75  *****************************************************************************/
  76 vlc_thread_t ac3dec_CreateThread( adec_config_t * p_config )
  77 {
  78     ac3dec_thread_t *   p_ac3thread;
  79
  80     intf_DbgMsg( "ac3dec debug: creating ac3 decoder thread" );
  81
  82     /* Allocate the memory needed to store the thread's structure */
  83     if((p_ac3thread = (ac3dec_thread_t *)malloc(sizeof(ac3dec_thread_t)))==NULL)
  84     {
  85         intf_ErrMsg ( "ac3dec error: not enough memory "
  86                       "for ac3dec_CreateThread() to create the new thread");
  87         return 0;
  88     }
  89
  90     /*
  91      * Initialize the thread properties
  92      */
  93     p_ac3thread->p_config = p_config;
  94     p_ac3thread->p_fifo = p_config->decoder_config.p_decoder_fifo;
  95
  96     /*
  97      * Choose the best downmix module
  98      */
  99 #define DOWNMIX p_ac3thread->ac3_decoder.downmix
 100     DOWNMIX.p_module = module_Need( MODULE_CAPABILITY_DOWNMIX, NULL );
 101
 102     if( DOWNMIX.p_module == NULL )
 103     {
 104         intf_ErrMsg( "ac3dec error: no suitable downmix module" );
 105         free( p_ac3thread );
 106         return( 0 );
 107     }
 108
 109 #define F DOWNMIX.p_module->p_functions->downmix.functions.downmix
 110     DOWNMIX.pf_downmix_3f_2r_to_2ch     = F.pf_downmix_3f_2r_to_2ch;
 111     DOWNMIX.pf_downmix_2f_2r_to_2ch     = F.pf_downmix_2f_2r_to_2ch;
 112     DOWNMIX.pf_downmix_3f_1r_to_2ch     = F.pf_downmix_3f_1r_to_2ch;
 113     DOWNMIX.pf_downmix_2f_1r_to_2ch     = F.pf_downmix_2f_1r_to_2ch;
 114     DOWNMIX.pf_downmix_3f_0r_to_2ch     = F.pf_downmix_3f_0r_to_2ch;
 115     DOWNMIX.pf_stream_sample_2ch_to_s16 = F.pf_stream_sample_2ch_to_s16;
 116     DOWNMIX.pf_stream_sample_1ch_to_s16 = F.pf_stream_sample_1ch_to_s16;
 117 #undef F
 118 #undef DOWNMIX
 119
 120     /*
 121      * Choose the best IMDCT module
 122      */
 123 #define IMDCT p_ac3thread->ac3_decoder.imdct
 124     IMDCT.p_module = module_Need( MODULE_CAPABILITY_IMDCT, NULL );
 125
 126     if( IMDCT.p_module == NULL )
 127     {
 128         intf_ErrMsg( "ac3dec error: no suitable IMDCT module" );
 129         module_Unneed( p_ac3thread->ac3_decoder.downmix.p_module );
 130         free( p_ac3thread );
 131         return( 0 );
 132     }
 133
 134 #define F IMDCT.p_module->p_functions->imdct.functions.imdct
 135     IMDCT.pf_imdct_init    = F.pf_imdct_init;
 136     IMDCT.pf_imdct_256     = F.pf_imdct_256;
 137     IMDCT.pf_imdct_256_nol = F.pf_imdct_256_nol;
 138     IMDCT.pf_imdct_512     = F.pf_imdct_512;
 139     IMDCT.pf_imdct_512_nol = F.pf_imdct_512_nol;
 140 #undef F
 141 #undef IMDCT
 142
 143     /* Initialize the ac3 decoder structures */
 144     ac3_init (&p_ac3thread->ac3_decoder);
 145
 146     /*
 147      * Initialize the output properties
 148      */
 149     p_ac3thread->p_aout_fifo = NULL;
 150
 151     /* Spawn the ac3 decoder thread */
 152     if (vlc_thread_create(&p_ac3thread->thread_id, "ac3 decoder",
 153                 (vlc_thread_func_t)RunThread, (void *)p_ac3thread))
 154     {
 155         intf_ErrMsg( "ac3dec error: can't spawn ac3 decoder thread" );
 156         module_Unneed( p_ac3thread->ac3_decoder.downmix.p_module );
 157         module_Unneed( p_ac3thread->ac3_decoder.imdct.p_module );
 158         free (p_ac3thread);
 159         return 0;
 160     }
 161
 162     intf_DbgMsg ("ac3dec debug: ac3 decoder thread (%p) created", p_ac3thread);
 163     return p_ac3thread->thread_id;
 164 }
 165
 166 /* Following functions are local */
 167
 168 /*****************************************************************************
 169  * InitThread : initialize an ac3 decoder thread
 170  *****************************************************************************/
 171 static int InitThread (ac3dec_thread_t * p_ac3thread)
 172 {
 173     intf_DbgMsg("ac3dec debug: initializing ac3 decoder thread %p",p_ac3thread);
 174
 175     p_ac3thread->p_config->decoder_config.pf_init_bit_stream(
 176             &p_ac3thread->ac3_decoder.bit_stream,
 177             p_ac3thread->p_config->decoder_config.p_decoder_fifo,
 178             BitstreamCallback, (void *) p_ac3thread );
 179
 180     /* Creating the audio output fifo */
 181     p_ac3thread->p_aout_fifo = aout_CreateFifo( AOUT_ADEC_STEREO_FIFO, 2, 0, 0,
 182                                                AC3DEC_FRAME_SIZE, NULL  );
 183     if ( p_ac3thread->p_aout_fifo == NULL )
 184     {
 185         return -1;
 186     }
 187
 188     intf_DbgMsg("ac3dec debug: ac3 decoder thread %p initialized", p_ac3thread);
 189     return 0;
 190 }
 191
 192 /*****************************************************************************
 193  * RunThread : ac3 decoder thread
 194  *****************************************************************************/
 195 static void RunThread (ac3dec_thread_t * p_ac3thread)
 196 {
 197     int sync;
 198
 199     intf_DbgMsg ("ac3dec debug: running ac3 decoder thread (%p) (pid == %i)", p_ac3thread, getpid());
 200
 201     /* Initializing the ac3 decoder thread */
 202     if (InitThread (p_ac3thread)) /* XXX?? */
 203     {
 204         p_ac3thread->p_fifo->b_error = 1;
 205     }
 206
 207     sync = 0;
 208     p_ac3thread->sync_ptr = 0;
 209
 210     /* ac3 decoder thread's main loop */
 211     /* FIXME : do we have enough room to store the decoded frames ?? */
 212     while ((!p_ac3thread->p_fifo->b_die) && (!p_ac3thread->p_fifo->b_error))
 213     {
 214         s16 * buffer;
 215         ac3_sync_info_t sync_info;
 216         int ptr;
 217
 218         if (!sync) {
 219             do {
 220                 GetBits(&p_ac3thread->ac3_decoder.bit_stream,8);
 221             } while ((!p_ac3thread->sync_ptr) && (!p_ac3thread->p_fifo->b_die)
 222                     && (!p_ac3thread->p_fifo->b_error));
 223
 224             ptr = p_ac3thread->sync_ptr;
 225
 226             while(ptr-- && (!p_ac3thread->p_fifo->b_die)
 227                 && (!p_ac3thread->p_fifo->b_error))
 228             {
 229                 p_ac3thread->ac3_decoder.bit_stream.p_byte++;
 230             }
 231
 232             /* we are in sync now */
 233             sync = 1;
 234         }
 235
 236         if (DECODER_FIFO_START(*p_ac3thread->p_fifo)->i_pts)
 237         {
 238             p_ac3thread->p_aout_fifo->date[p_ac3thread->p_aout_fifo->l_end_frame] =
 239                 DECODER_FIFO_START(*p_ac3thread->p_fifo)->i_pts;
 240             DECODER_FIFO_START(*p_ac3thread->p_fifo)->i_pts = 0;
 241         } else {
 242             p_ac3thread->p_aout_fifo->date[p_ac3thread->p_aout_fifo->l_end_frame] =
 243                 LAST_MDATE;
 244         }
 245
 246         if (ac3_sync_frame (&p_ac3thread->ac3_decoder, &sync_info))
 247         {
 248             sync = 0;
 249             goto bad_frame;
 250         }
 251
 252         p_ac3thread->p_aout_fifo->l_rate = sync_info.sample_rate;
 253
 254         buffer = ((s16 *)p_ac3thread->p_aout_fifo->buffer) +
 255             (p_ac3thread->p_aout_fifo->l_end_frame * AC3DEC_FRAME_SIZE);
 256
 257         if (ac3_decode_frame (&p_ac3thread->ac3_decoder, buffer))
 258         {
 259             sync = 0;
 260             goto bad_frame;
 261         }
 262
 263         vlc_mutex_lock (&p_ac3thread->p_aout_fifo->data_lock);
 264         p_ac3thread->p_aout_fifo->l_end_frame =
 265             (p_ac3thread->p_aout_fifo->l_end_frame + 1) & AOUT_FIFO_SIZE;
 266         vlc_cond_signal (&p_ac3thread->p_aout_fifo->data_wait);
 267         vlc_mutex_unlock (&p_ac3thread->p_aout_fifo->data_lock);
 268
 269         bad_frame:
 270             RealignBits(&p_ac3thread->ac3_decoder.bit_stream);
 271     }
 272
 273     /* If b_error is set, the ac3 decoder thread enters the error loop */
 274     if (p_ac3thread->p_fifo->b_error)
 275     {
 276         ErrorThread (p_ac3thread);
 277     }
 278
 279     /* End of the ac3 decoder thread */
 280     EndThread (p_ac3thread);
 281 }
 282
 283 /*****************************************************************************
 284  * ErrorThread : ac3 decoder's RunThread() error loop
 285  *****************************************************************************/
 286 static void ErrorThread (ac3dec_thread_t * p_ac3thread)
 287 {
 288     /* We take the lock, because we are going to read/write the start/end
 289      * indexes of the decoder fifo */
 290     vlc_mutex_lock (&p_ac3thread->p_fifo->data_lock);
 291
 292     /* Wait until a `die' order is sent */
 293     while (!p_ac3thread->p_fifo->b_die)
 294     {
 295         /* Trash all received PES packets */
 296         while (!DECODER_FIFO_ISEMPTY(*p_ac3thread->p_fifo))
 297         {
 298             p_ac3thread->p_fifo->pf_delete_pes(p_ac3thread->p_fifo->p_packets_mgt,
 299                     DECODER_FIFO_START(*p_ac3thread->p_fifo));
 300             DECODER_FIFO_INCSTART (*p_ac3thread->p_fifo);
 301         }
 302
 303         /* Waiting for the input thread to put new PES packets in the fifo */
 304         vlc_cond_wait (&p_ac3thread->p_fifo->data_wait,
 305                        &p_ac3thread->p_fifo->data_lock);
 306     }
 307
 308     /* We can release the lock before leaving */
 309     vlc_mutex_unlock (&p_ac3thread->p_fifo->data_lock);
 310 }
 311
 312 /*****************************************************************************
 313  * EndThread : ac3 decoder thread destruction
 314  *****************************************************************************/
 315 static void EndThread (ac3dec_thread_t * p_ac3thread)
 316 {
 317     intf_DbgMsg ("ac3dec debug: destroying ac3 decoder thread %p", p_ac3thread);
 318
 319     /* If the audio output fifo was created, we destroy it */
 320     if (p_ac3thread->p_aout_fifo != NULL)
 321     {
 322         aout_DestroyFifo (p_ac3thread->p_aout_fifo);
 323
 324         /* Make sure the output thread leaves the NextFrame() function */
 325         vlc_mutex_lock (&(p_ac3thread->p_aout_fifo->data_lock));
 326         vlc_cond_signal (&(p_ac3thread->p_aout_fifo->data_wait));
 327         vlc_mutex_unlock (&(p_ac3thread->p_aout_fifo->data_lock));
 328     }
 329
 330     /* Unlock the modules */
 331     module_Unneed( p_ac3thread->ac3_decoder.downmix.p_module );
 332     module_Unneed( p_ac3thread->ac3_decoder.imdct.p_module );
 333
 334     /* Destroy descriptor */
 335     free( p_ac3thread->p_config );
 336     free( p_ac3thread );
 337
 338     intf_DbgMsg ("ac3dec debug: ac3 decoder thread %p destroyed", p_ac3thread);
 339 }
 340
 341 /*****************************************************************************
 342 * BitstreamCallback: Import parameters from the new data/PES packet
 343 *****************************************************************************
 344 * This function is called by input's NextDataPacket.
 345 *****************************************************************************/
 346 static void BitstreamCallback ( bit_stream_t * p_bit_stream,
 347                                         boolean_t b_new_pes)
 348 {
 349
 350     ac3dec_thread_t *p_ac3thread=(ac3dec_thread_t *)p_bit_stream->p_callback_arg;
 351
 352     if( b_new_pes )
 353     {
 354         int ptr;
 355
 356         ptr = *(p_bit_stream->p_byte + 1);
 357         ptr <<= 8;
 358         ptr |= *(p_bit_stream->p_byte + 2);
 359         p_ac3thread->sync_ptr = ptr;
 360         p_bit_stream->p_byte += 3;
 361     }
 362 }
 363