src/audio_decoder/audio_decoder.c

   1 /*****************************************************************************
   2  * audio_decoder.c: MPEG audio decoder thread
   3  *****************************************************************************
   4  * Copyright (C) 1999, 2000 VideoLAN
   5  * $Id: audio_decoder.c,v 1.50 2001/05/01 04:18:18 sam Exp $
   6  *
   7  * Authors: Michel Kaempf <maxx@via.ecp.fr>
   8  *          Michel Lespinasse <walken@via.ecp.fr>
   9  *          Samuel Hocevar <sam@via.ecp.fr>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  24  *****************************************************************************/
  25
  26 /*
  27  * TODO :
  28  *
  29  * - optimiser les NeedBits() et les GetBits() du code là où c'est possible ;
  30  * - vlc_cond_signal() / vlc_cond_wait() ;
  31  *
  32  */
  33
  34 /*****************************************************************************
  35  * Preamble
  36  *****************************************************************************/
  37 #include "defs.h"
  38
  39 #include <unistd.h>                                              /* getpid() */
  40
  41 #include <stdio.h>                                           /* "intf_msg.h" */
  42 #include <string.h>                                    /* memcpy(), memset() */
  43 #include <stdlib.h>                                      /* malloc(), free() */
  44
  45 #include "config.h"
  46 #include "common.h"
  47 #include "threads.h"
  48 #include "mtime.h"
  49
  50 #include "intf_msg.h"                        /* intf_DbgMsg(), intf_ErrMsg() */
  51
  52 #include "stream_control.h"
  53 #include "input_ext-dec.h"
  54
  55 #include "audio_output.h"               /* aout_fifo_t (for audio_decoder.h) */
  56
  57 #include "adec_generic.h"
  58 #include "audio_decoder.h"
  59 #include "adec_math.h"                                     /* DCT32(), PCM() */
  60
  61 #define ADEC_FRAME_SIZE (2*1152)
  62
  63 /*****************************************************************************
  64  * Local prototypes
  65  *****************************************************************************/
  66 static int      InitThread             (adec_thread_t * p_adec);
  67 static void     RunThread              (adec_thread_t * p_adec);
  68 static void     ErrorThread            (adec_thread_t * p_adec);
  69 static void     EndThread              (adec_thread_t * p_adec);
  70
  71 /*****************************************************************************
  72  * adec_CreateThread: creates an audio decoder thread
  73  *****************************************************************************
  74  * This function creates a new audio decoder thread, and returns a pointer to
  75  * its description. On error, it returns NULL.
  76  *****************************************************************************/
  77 vlc_thread_t adec_CreateThread ( adec_config_t * p_config )
  78 {
  79     adec_thread_t *     p_adec;
  80
  81     intf_DbgMsg ( "adec debug: creating audio decoder thread" );
  82
  83     /* Allocate the memory needed to store the thread's structure */
  84     if ( (p_adec = (adec_thread_t *)malloc (sizeof(adec_thread_t))) == NULL )
  85     {
  86         intf_ErrMsg ( "adec error: not enough memory for"
  87                       " adec_CreateThread() to create the new thread" );
  88         return 0;
  89     }
  90
  91     /*
  92      * Initialize the thread properties
  93      */
  94     p_adec->p_config = p_config;
  95     p_adec->p_fifo = p_config->decoder_config.p_decoder_fifo;
  96
  97     /*
  98      * Initialize the decoder properties
  99      */
 100     adec_Init ( p_adec );
 101
 102     /*
 103      * Initialize the output properties
 104      */
 105     p_adec->p_aout_fifo = NULL;
 106
 107     /* Spawn the audio decoder thread */
 108     if ( vlc_thread_create(&p_adec->thread_id, "audio decoder",
 109          (vlc_thread_func_t)RunThread, (void *)p_adec) )
 110     {
 111         intf_ErrMsg ("adec error: can't spawn audio decoder thread");
 112         free (p_adec);
 113         return 0;
 114     }
 115
 116     intf_DbgMsg ("adec debug: audio decoder thread (%p) created", p_adec);
 117     return p_adec->thread_id;
 118 }
 119
 120 /* following functions are local */
 121
 122 /*****************************************************************************
 123  * InitThread : initialize an audio decoder thread
 124  *****************************************************************************
 125  * This function is called from RunThread and performs the second step of the
 126  * initialization. It returns 0 on success.
 127  *****************************************************************************/
 128 static int InitThread (adec_thread_t * p_adec)
 129 {
 130     intf_DbgMsg ("adec debug: initializing audio decoder thread %p", p_adec);
 131
 132     p_adec->p_config->decoder_config.pf_init_bit_stream( &p_adec->bit_stream,
 133         p_adec->p_config->decoder_config.p_decoder_fifo, NULL, NULL );
 134
 135     /* Creating the audio output fifo */
 136     p_adec->p_aout_fifo = aout_CreateFifo( AOUT_ADEC_STEREO_FIFO, 2, 0, 0,
 137                                            ADEC_FRAME_SIZE, NULL );
 138     if ( p_adec->p_aout_fifo == NULL )
 139     {
 140         return -1;
 141     }
 142
 143     intf_DbgMsg ( "adec debug: audio decoder thread %p initialized", p_adec );
 144     return 0;
 145 }
 146
 147 /*****************************************************************************
 148  * RunThread : audio decoder thread
 149  *****************************************************************************
 150  * Audio decoder thread. This function does only returns when the thread is
 151  * terminated.
 152  *****************************************************************************/
 153 static void RunThread (adec_thread_t * p_adec)
 154 {
 155     int sync;
 156
 157     intf_DbgMsg ( "adec debug: running audio decoder thread (%p) (pid == %i)",
 158                   p_adec, getpid() );
 159
 160     /* Initializing the audio decoder thread */
 161     p_adec->p_fifo->b_error = InitThread (p_adec);
 162
 163     sync = 0;
 164
 165     /* Audio decoder thread's main loop */
 166     while( (!p_adec->p_fifo->b_die) && (!p_adec->p_fifo->b_error) )
 167     {
 168         s16 * buffer;
 169         adec_sync_info_t sync_info;
 170
 171         if( DECODER_FIFO_START( *p_adec->p_fifo)->i_pts )
 172         {
 173             p_adec->p_aout_fifo->date[p_adec->p_aout_fifo->l_end_frame] =
 174                 DECODER_FIFO_START( *p_adec->p_fifo )->i_pts;
 175             DECODER_FIFO_START(*p_adec->p_fifo)->i_pts = 0;
 176         }
 177         else
 178         {
 179             p_adec->p_aout_fifo->date[p_adec->p_aout_fifo->l_end_frame] =
 180                 LAST_MDATE;
 181         }
 182
 183         if( ! adec_SyncFrame (p_adec, &sync_info) )
 184         {
 185             sync = 1;
 186
 187             p_adec->p_aout_fifo->l_rate = sync_info.sample_rate;
 188
 189             buffer = ((s16 *)p_adec->p_aout_fifo->buffer)
 190                         + (p_adec->p_aout_fifo->l_end_frame * ADEC_FRAME_SIZE);
 191
 192             if( adec_DecodeFrame (p_adec, buffer) )
 193             {
 194                 /* Ouch, failed decoding... We'll have to resync */
 195                 sync = 0;
 196             }
 197             else
 198             {
 199                 vlc_mutex_lock (&p_adec->p_aout_fifo->data_lock);
 200
 201                 p_adec->p_aout_fifo->l_end_frame =
 202                     (p_adec->p_aout_fifo->l_end_frame + 1) & AOUT_FIFO_SIZE;
 203                 vlc_cond_signal (&p_adec->p_aout_fifo->data_wait);
 204                 vlc_mutex_unlock (&p_adec->p_aout_fifo->data_lock);
 205             }
 206         }
 207     }
 208
 209     /* If b_error is set, the audio decoder thread enters the error loop */
 210     if( p_adec->p_fifo->b_error )
 211     {
 212         ErrorThread( p_adec );
 213     }
 214
 215     /* End of the audio decoder thread */
 216     EndThread( p_adec );
 217 }
 218
 219 /*****************************************************************************
 220  * ErrorThread : audio decoder's RunThread() error loop
 221  *****************************************************************************
 222  * This function is called when an error occured during thread main's loop. The
 223  * thread can still receive feed, but must be ready to terminate as soon as
 224  * possible.
 225  *****************************************************************************/
 226 static void ErrorThread ( adec_thread_t *p_adec )
 227 {
 228     /* We take the lock, because we are going to read/write the start/end
 229      * indexes of the decoder fifo */
 230     vlc_mutex_lock ( &p_adec->p_fifo->data_lock );
 231
 232     /* Wait until a `die' order is sent */
 233     while ( !p_adec->p_fifo->b_die )
 234     {
 235         /* Trash all received PES packets */
 236         while ( !DECODER_FIFO_ISEMPTY(*p_adec->p_fifo) )
 237         {
 238             p_adec->p_fifo->pf_delete_pes ( p_adec->p_fifo->p_packets_mgt,
 239                                    DECODER_FIFO_START(*p_adec->p_fifo) );
 240             DECODER_FIFO_INCSTART ( *p_adec->p_fifo );
 241         }
 242
 243         /* Waiting for the input thread to put new PES packets in the fifo */
 244         vlc_cond_wait ( &p_adec->p_fifo->data_wait, &p_adec->p_fifo->data_lock );
 245     }
 246
 247     /* We can release the lock before leaving */
 248     vlc_mutex_unlock ( &p_adec->p_fifo->data_lock );
 249 }
 250
 251 /*****************************************************************************
 252  * EndThread : audio decoder thread destruction
 253  *****************************************************************************
 254  * This function is called when the thread ends after a sucessful
 255  * initialization.
 256  *****************************************************************************/
 257 static void EndThread ( adec_thread_t *p_adec )
 258 {
 259     intf_DbgMsg ( "adec debug: destroying audio decoder thread %p", p_adec );
 260
 261     /* If the audio output fifo was created, we destroy it */
 262     if ( p_adec->p_aout_fifo != NULL )
 263     {
 264         aout_DestroyFifo ( p_adec->p_aout_fifo );
 265
 266         /* Make sure the output thread leaves the NextFrame() function */
 267         vlc_mutex_lock (&(p_adec->p_aout_fifo->data_lock));
 268         vlc_cond_signal (&(p_adec->p_aout_fifo->data_wait));
 269         vlc_mutex_unlock (&(p_adec->p_aout_fifo->data_lock));
 270     }
 271     /* Destroy descriptor */
 272     free( p_adec->p_config );
 273     free( p_adec );
 274
 275     intf_DbgMsg ("adec debug: audio decoder thread %p destroyed", p_adec);
 276 }
 277