]> git.sesse.net Git - vlc/blobdiff - src/ac3_decoder/ac3_decoder_thread.c
* Mandatory step for video output IV and the audio output quality
[vlc] / src / ac3_decoder / ac3_decoder_thread.c
index 76b1def656f696f8f6fd87d4f887fc1fd5adce20..278942cb0a422930e32a272c9763d653b877ca5d 100644 (file)
@@ -2,23 +2,23 @@
  * ac3_decoder_thread.c: ac3 decoder thread
  *****************************************************************************
  * Copyright (C) 1999, 2000 VideoLAN
+ * $Id: ac3_decoder_thread.c,v 1.31 2001/05/01 04:18:18 sam Exp $
  *
- * Authors:
+ * Authors: Michel Lespinasse <walken@zoy.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
- *
+ * 
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
  *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  *****************************************************************************/
 
 /*
 /*****************************************************************************
  * Preamble
  *****************************************************************************/
+#include "defs.h"
+
 #include <unistd.h>                                              /* getpid() */
 
 #include <stdio.h>                                           /* "intf_msg.h" */
 #include <stdlib.h>                                      /* malloc(), free() */
-#include <sys/types.h>                        /* on BSD, uio.h needs types.h */
-#include <sys/uio.h>                                            /* "input.h" */
 
-#include "threads.h"
-#include "common.h"
 #include "config.h"
+#include "common.h"
+#include "threads.h"
 #include "mtime.h"
-#include "plugins.h"
-#include "debug.h"                                      /* "input_netlist.h" */
 
 #include "intf_msg.h"                        /* intf_DbgMsg(), intf_ErrMsg() */
 
-#include "input.h"                                           /* pes_packet_t */
-#include "input_netlist.h"                         /* input_NetlistFreePES() */
-#include "decoder_fifo.h"         /* DECODER_FIFO_(ISEMPTY|START|INCSTART)() */
+#include "stream_control.h"
+#include "input_ext-dec.h"
 
 #include "audio_output.h"
 
 #include "ac3_decoder_thread.h"
 
 #define AC3DEC_FRAME_SIZE (2*1536) 
-typedef s16 ac3dec_frame_t[ AC3DEC_FRAME_SIZE ];
 
 /*****************************************************************************
  * Local prototypes
  *****************************************************************************/
-static int      InitThread              ( ac3dec_thread_t * p_adec );
-static void     RunThread               ( ac3dec_thread_t * p_adec );
-static void     ErrorThread             ( ac3dec_thread_t * p_adec );
-static void     EndThread               ( ac3dec_thread_t * p_adec );
+static int      InitThread              (ac3dec_thread_t * p_adec);
+static void     RunThread               (ac3dec_thread_t * p_adec);
+static void     ErrorThread             (ac3dec_thread_t * p_adec);
+static void     EndThread               (ac3dec_thread_t * p_adec);
+static void     BitstreamCallback       ( bit_stream_t *p_bit_stream,
+                                              boolean_t b_new_pes );
+
 
 /*****************************************************************************
  * ac3dec_CreateThread: creates an ac3 decoder thread
  *****************************************************************************/
-ac3dec_thread_t * ac3dec_CreateThread( input_thread_t * p_input )
+vlc_thread_t ac3dec_CreateThread( adec_config_t * p_config )
 {
-    ac3dec_thread_t *   p_ac3dec;
+    ac3dec_thread_t *   p_ac3dec_t;
 
-    intf_DbgMsg("ac3dec debug: creating ac3 decoder thread\n");
+    intf_DbgMsg( "ac3dec debug: creating ac3 decoder thread" );
 
     /* Allocate the memory needed to store the thread's structure */
-    if ( (p_ac3dec = (ac3dec_thread_t *)malloc( sizeof(ac3dec_thread_t) )) == NULL )
+    if((p_ac3dec_t = (ac3dec_thread_t *)malloc(sizeof(ac3dec_thread_t)))==NULL)
     {
-        intf_ErrMsg("ac3dec error: not enough memory for ac3dec_CreateThread() to create the new thread\n");
-        return( NULL );
+        intf_ErrMsg ( "ac3dec error: not enough memory "
+                      "for ac3dec_CreateThread() to create the new thread");
+        return 0;
     }
-
+    
     /*
      * Initialize the thread properties
      */
-    p_ac3dec->b_die = 0;
-    p_ac3dec->b_error = 0;
-
-    /*
-     * Initialize the input properties
-     */
-    /* Initialize the decoder fifo's data lock and conditional variable and set
-     * its buffer as empty */
-    vlc_mutex_init( &p_ac3dec->fifo.data_lock );
-    vlc_cond_init( &p_ac3dec->fifo.data_wait );
-    p_ac3dec->fifo.i_start = 0;
-    p_ac3dec->fifo.i_end = 0;
+    p_ac3dec_t->p_config = p_config;
+    p_ac3dec_t->p_fifo = p_config->decoder_config.p_decoder_fifo;
 
     /* Initialize the ac3 decoder structures */
-    ac3_init (&p_ac3dec->ac3_decoder);
-
-    /* Initialize the bit stream structure */
-    p_ac3dec->p_input = p_input;
+    ac3_init (&p_ac3dec_t->ac3_decoder);
 
     /*
      * Initialize the output properties
      */
-    p_ac3dec->p_aout = p_input->p_aout;
-    p_ac3dec->p_aout_fifo = NULL;
+    p_ac3dec_t->p_aout_fifo = NULL;
 
     /* Spawn the ac3 decoder thread */
-    if ( vlc_thread_create(&p_ac3dec->thread_id, "ac3 decoder", (vlc_thread_func_t)RunThread, (void *)p_ac3dec) )
+    if (vlc_thread_create(&p_ac3dec_t->thread_id, "ac3 decoder", 
+                (vlc_thread_func_t)RunThread, (void *)p_ac3dec_t))
     {
-        intf_ErrMsg( "ac3dec error: can't spawn ac3 decoder thread\n" );
-        free( p_ac3dec );
-        return( NULL );
+        intf_ErrMsg( "ac3dec error: can't spawn ac3 decoder thread" );
+        free (p_ac3dec_t);
+        return 0;
     }
 
-    intf_DbgMsg( "ac3dec debug: ac3 decoder thread (%p) created\n", p_ac3dec );
-    return( p_ac3dec );
-}
-
-/*****************************************************************************
- * ac3dec_DestroyThread: destroys an ac3 decoder thread
- *****************************************************************************/
-void ac3dec_DestroyThread( ac3dec_thread_t * p_ac3dec )
-{
-    intf_DbgMsg( "ac3dec debug: requesting termination of ac3 decoder thread %p\n", p_ac3dec );
-
-    /* Ask thread to kill itself */
-    p_ac3dec->b_die = 1;
-
-    /* Make sure the decoder thread leaves the GetByte() function */
-    vlc_mutex_lock( &(p_ac3dec->fifo.data_lock) );
-    vlc_cond_signal( &(p_ac3dec->fifo.data_wait) );
-    vlc_mutex_unlock( &(p_ac3dec->fifo.data_lock) );
-
-    /* Waiting for the decoder thread to exit */
-    /* Remove this as soon as the "status" flag is implemented */
-    vlc_thread_join( p_ac3dec->thread_id );
+    intf_DbgMsg ("ac3dec debug: ac3 decoder thread (%p) created", p_ac3dec_t);
+    return p_ac3dec_t->thread_id;
 }
 
 /* Following functions are local */
@@ -150,263 +117,192 @@ void ac3dec_DestroyThread( ac3dec_thread_t * p_ac3dec )
 /*****************************************************************************
  * InitThread : initialize an ac3 decoder thread
  *****************************************************************************/
-static int InitThread( ac3dec_thread_t * p_ac3dec )
+static int InitThread (ac3dec_thread_t * p_ac3dec_t)
 {
-    aout_fifo_t         aout_fifo;
-    ac3_byte_stream_t * byte_stream;
-
-    intf_DbgMsg( "ac3dec debug: initializing ac3 decoder thread %p\n", p_ac3dec );
-
-    /* Our first job is to initialize the bit stream structure with the
-     * beginning of the input stream */
-    vlc_mutex_lock( &p_ac3dec->fifo.data_lock );
-    while ( DECODER_FIFO_ISEMPTY(p_ac3dec->fifo) )
-    {
-        if ( p_ac3dec->b_die )
-        {
-            vlc_mutex_unlock( &p_ac3dec->fifo.data_lock );
-            return( -1 );
-        }
-        vlc_cond_wait( &p_ac3dec->fifo.data_wait, &p_ac3dec->fifo.data_lock );
-    }
-    p_ac3dec->p_ts = DECODER_FIFO_START( p_ac3dec->fifo )->p_first_ts;
-    byte_stream = ac3_byte_stream (&p_ac3dec->ac3_decoder);
-    byte_stream->p_byte =
-       p_ac3dec->p_ts->buffer + p_ac3dec->p_ts->i_payload_start;
-    byte_stream->p_end =
-       p_ac3dec->p_ts->buffer + p_ac3dec->p_ts->i_payload_end;
-    byte_stream->info = p_ac3dec;
-    vlc_mutex_unlock( &p_ac3dec->fifo.data_lock );
+    intf_DbgMsg("ac3dec debug: initializing ac3 decoder thread %p",p_ac3dec_t);
 
-    aout_fifo.i_type = AOUT_ADEC_STEREO_FIFO;
-    aout_fifo.i_channels = 2;
-    aout_fifo.b_stereo = 1;
-
-    aout_fifo.l_frame_size = AC3DEC_FRAME_SIZE;
+    p_ac3dec_t->p_config->decoder_config.pf_init_bit_stream(
+            &p_ac3dec_t->ac3_decoder.bit_stream,
+            p_ac3dec_t->p_config->decoder_config.p_decoder_fifo,
+            BitstreamCallback, (void *) p_ac3dec_t );
 
     /* Creating the audio output fifo */
-    if ( (p_ac3dec->p_aout_fifo = aout_CreateFifo(p_ac3dec->p_aout, &aout_fifo)) == NULL )
+    p_ac3dec_t->p_aout_fifo = aout_CreateFifo( AOUT_ADEC_STEREO_FIFO, 2, 0, 0,
+                                               AC3DEC_FRAME_SIZE, NULL  );
+    if ( p_ac3dec_t->p_aout_fifo == NULL )
     {
-        return( -1 );
+        return -1;
     }
 
-    intf_DbgMsg( "ac3dec debug: ac3 decoder thread %p initialized\n", p_ac3dec );
-    return( 0 );
+    intf_DbgMsg("ac3dec debug: ac3 decoder thread %p initialized", p_ac3dec_t);
+    return 0;
 }
 
 /*****************************************************************************
  * RunThread : ac3 decoder thread
  *****************************************************************************/
-static void RunThread( ac3dec_thread_t * p_ac3dec )
+static void RunThread (ac3dec_thread_t * p_ac3dec_t)
 {
     int sync;
 
-    intf_DbgMsg( "ac3dec debug: running ac3 decoder thread (%p) (pid == %i)\n", p_ac3dec, getpid() );
-
-    msleep( INPUT_PTS_DELAY );
+    intf_DbgMsg ("ac3dec debug: running ac3 decoder thread (%p) (pid == %i)", p_ac3dec_t, getpid());
 
     /* Initializing the ac3 decoder thread */
-    if ( InitThread(p_ac3dec) ) /* XXX?? */
+    if (InitThread (p_ac3dec_t)) /* XXX?? */
     {
-        p_ac3dec->b_error = 1;
+        p_ac3dec_t->p_fifo->b_error = 1;
     }
 
     sync = 0;
-    p_ac3dec->sync_ptr = 0;
+    p_ac3dec_t->sync_ptr = 0;
 
     /* ac3 decoder thread's main loop */
     /* FIXME : do we have enough room to store the decoded frames ?? */
-    while ( (!p_ac3dec->b_die) && (!p_ac3dec->b_error) )
+    while ((!p_ac3dec_t->p_fifo->b_die) && (!p_ac3dec_t->p_fifo->b_error))
     {
-       s16 * buffer;
-       ac3_sync_info_t sync_info;
-
-       if (!sync) { /* have to find a synchro point */
-           int ptr;
-           ac3_byte_stream_t * p_byte_stream;
-
-           printf ("sync\n");
-
-           p_byte_stream = ac3_byte_stream (&p_ac3dec->ac3_decoder);
-
-           /* first read till next ac3 magic header */
-           do {
-               ac3_byte_stream_next (p_byte_stream);
-           } while ((!p_ac3dec->sync_ptr) &&
-                    (!p_ac3dec->b_die) &&
-                    (!p_ac3dec->b_error));
-           /* skip the specified number of bytes */
-
-           ptr = p_ac3dec->sync_ptr;
-           while (--ptr && (!p_ac3dec->b_die) && (!p_ac3dec->b_error)) {
-               if (p_byte_stream->p_byte >= p_byte_stream->p_end) {
-                   ac3_byte_stream_next (p_byte_stream);                   
-               }
-               p_byte_stream->p_byte++;
-           }
-
-           /* we are in sync now */
-
-           sync = 1;
-           p_ac3dec->sync_ptr = 0;
-       }
+        s16 * buffer;
+        ac3_sync_info_t sync_info;
+        int ptr;
+
+        if (!sync) {
+            do {
+                GetBits(&p_ac3dec_t->ac3_decoder.bit_stream,8);
+            } while ((!p_ac3dec_t->sync_ptr) && (!p_ac3dec_t->p_fifo->b_die)
+                    && (!p_ac3dec_t->p_fifo->b_error));
+            
+            ptr = p_ac3dec_t->sync_ptr;
+
+            while(ptr-- && (!p_ac3dec_t->p_fifo->b_die)
+                && (!p_ac3dec_t->p_fifo->b_error))
+            {
+                p_ac3dec_t->ac3_decoder.bit_stream.p_byte++;
+            }
+                        
+            /* we are in sync now */
+            sync = 1;
+        }
 
-        if ( DECODER_FIFO_START(p_ac3dec->fifo)->b_has_pts )
+        if (DECODER_FIFO_START(*p_ac3dec_t->p_fifo)->i_pts)
         {
-                p_ac3dec->p_aout_fifo->date[p_ac3dec->p_aout_fifo->l_end_frame] = DECODER_FIFO_START(p_ac3dec->fifo)->i_pts;
-                DECODER_FIFO_START(p_ac3dec->fifo)->b_has_pts = 0;
+            p_ac3dec_t->p_aout_fifo->date[p_ac3dec_t->p_aout_fifo->l_end_frame] =
+                DECODER_FIFO_START(*p_ac3dec_t->p_fifo)->i_pts;
+            DECODER_FIFO_START(*p_ac3dec_t->p_fifo)->i_pts = 0;
+        } else {
+            p_ac3dec_t->p_aout_fifo->date[p_ac3dec_t->p_aout_fifo->l_end_frame] =
+                LAST_MDATE;
         }
-        else
+    
+        if (ac3_sync_frame (&p_ac3dec_t->ac3_decoder, &sync_info))
         {
-                p_ac3dec->p_aout_fifo->date[p_ac3dec->p_aout_fifo->l_end_frame] = LAST_MDATE;
+            sync = 0;
+            goto bad_frame;
         }
 
-        if (ac3_sync_frame (&p_ac3dec->ac3_decoder, &sync_info)) {
-           sync = 0;
-           goto bad_frame;
-       }
-
-       p_ac3dec->p_aout_fifo->l_rate = sync_info.sample_rate;
-
-       buffer = ((ac3dec_frame_t *)p_ac3dec->p_aout_fifo->buffer)[ p_ac3dec->p_aout_fifo->l_end_frame ];
+        p_ac3dec_t->p_aout_fifo->l_rate = sync_info.sample_rate;
 
-       if (ac3_decode_frame (&p_ac3dec->ac3_decoder, buffer)) {
-           sync = 0;
-           goto bad_frame;
-       }
+        buffer = ((s16 *)p_ac3dec_t->p_aout_fifo->buffer) + 
+            (p_ac3dec_t->p_aout_fifo->l_end_frame * AC3DEC_FRAME_SIZE);
 
-       vlc_mutex_lock( &p_ac3dec->p_aout_fifo->data_lock );
-       p_ac3dec->p_aout_fifo->l_end_frame = (p_ac3dec->p_aout_fifo->l_end_frame + 1) & AOUT_FIFO_SIZE;
-       vlc_cond_signal( &p_ac3dec->p_aout_fifo->data_wait );
-       vlc_mutex_unlock( &p_ac3dec->p_aout_fifo->data_lock );
-
-bad_frame:
+        if (ac3_decode_frame (&p_ac3dec_t->ac3_decoder, buffer))
+        {
+            sync = 0;
+            goto bad_frame;
+        }
+        
+        vlc_mutex_lock (&p_ac3dec_t->p_aout_fifo->data_lock);
+        p_ac3dec_t->p_aout_fifo->l_end_frame = 
+            (p_ac3dec_t->p_aout_fifo->l_end_frame + 1) & AOUT_FIFO_SIZE;
+        vlc_cond_signal (&p_ac3dec_t->p_aout_fifo->data_wait);
+        vlc_mutex_unlock (&p_ac3dec_t->p_aout_fifo->data_lock);
+
+        bad_frame:
+            RealignBits(&p_ac3dec_t->ac3_decoder.bit_stream);
     }
 
     /* If b_error is set, the ac3 decoder thread enters the error loop */
-    if ( p_ac3dec->b_error )
+    if (p_ac3dec_t->p_fifo->b_error)
     {
-        ErrorThread( p_ac3dec );
+        ErrorThread (p_ac3dec_t);
     }
 
     /* End of the ac3 decoder thread */
-    EndThread( p_ac3dec );
+    EndThread (p_ac3dec_t);
 }
 
 /*****************************************************************************
  * ErrorThread : ac3 decoder's RunThread() error loop
  *****************************************************************************/
-static void ErrorThread( ac3dec_thread_t * p_ac3dec )
+static void ErrorThread (ac3dec_thread_t * p_ac3dec_t)
 {
     /* We take the lock, because we are going to read/write the start/end
      * indexes of the decoder fifo */
-    vlc_mutex_lock( &p_ac3dec->fifo.data_lock );
+    vlc_mutex_lock (&p_ac3dec_t->p_fifo->data_lock);
 
     /* Wait until a `die' order is sent */
-    while( !p_ac3dec->b_die )
+    while (!p_ac3dec_t->p_fifo->b_die)
     {
         /* Trash all received PES packets */
-        while( !DECODER_FIFO_ISEMPTY(p_ac3dec->fifo) )
+        while (!DECODER_FIFO_ISEMPTY(*p_ac3dec_t->p_fifo))
         {
-            input_NetlistFreePES( p_ac3dec->p_input, DECODER_FIFO_START(p_ac3dec->fifo) );
-            DECODER_FIFO_INCSTART( p_ac3dec->fifo );
+            p_ac3dec_t->p_fifo->pf_delete_pes(p_ac3dec_t->p_fifo->p_packets_mgt,
+                    DECODER_FIFO_START(*p_ac3dec_t->p_fifo));
+            DECODER_FIFO_INCSTART (*p_ac3dec_t->p_fifo);
         }
 
         /* Waiting for the input thread to put new PES packets in the fifo */
-        vlc_cond_wait( &p_ac3dec->fifo.data_wait, &p_ac3dec->fifo.data_lock );
+        vlc_cond_wait (&p_ac3dec_t->p_fifo->data_wait,
+                       &p_ac3dec_t->p_fifo->data_lock);
     }
 
     /* We can release the lock before leaving */
-    vlc_mutex_unlock( &p_ac3dec->fifo.data_lock );
+    vlc_mutex_unlock (&p_ac3dec_t->p_fifo->data_lock);
 }
 
 /*****************************************************************************
  * EndThread : ac3 decoder thread destruction
  *****************************************************************************/
-static void EndThread( ac3dec_thread_t * p_ac3dec )
+static void EndThread (ac3dec_thread_t * p_ac3dec_t)
 {
-    intf_DbgMsg( "ac3dec debug: destroying ac3 decoder thread %p\n", p_ac3dec );
+    intf_DbgMsg ("ac3dec debug: destroying ac3 decoder thread %p", p_ac3dec_t);
 
     /* If the audio output fifo was created, we destroy it */
-    if ( p_ac3dec->p_aout_fifo != NULL )
+    if (p_ac3dec_t->p_aout_fifo != NULL)
     {
-        aout_DestroyFifo( p_ac3dec->p_aout_fifo );
+        aout_DestroyFifo (p_ac3dec_t->p_aout_fifo);
 
         /* Make sure the output thread leaves the NextFrame() function */
-        vlc_mutex_lock( &(p_ac3dec->p_aout_fifo->data_lock) );
-        vlc_cond_signal( &(p_ac3dec->p_aout_fifo->data_wait) );
-        vlc_mutex_unlock( &(p_ac3dec->p_aout_fifo->data_lock) );
+        vlc_mutex_lock (&(p_ac3dec_t->p_aout_fifo->data_lock));
+        vlc_cond_signal (&(p_ac3dec_t->p_aout_fifo->data_wait));
+        vlc_mutex_unlock (&(p_ac3dec_t->p_aout_fifo->data_lock));
+        
     }
 
     /* Destroy descriptor */
-    free( p_ac3dec );
+    free( p_ac3dec_t->p_config );
+    free( p_ac3dec_t );
 
-    intf_DbgMsg( "ac3dec debug: ac3 decoder thread %p destroyed\n", p_ac3dec );
+    intf_DbgMsg ("ac3dec debug: ac3 decoder thread %p destroyed", p_ac3dec_t);
 }
 
-void ac3_byte_stream_next (ac3_byte_stream_t * p_byte_stream)
+/*****************************************************************************
+* BitstreamCallback: Import parameters from the new data/PES packet
+*****************************************************************************
+* This function is called by input's NextDataPacket.
+*****************************************************************************/
+static void BitstreamCallback ( bit_stream_t * p_bit_stream,
+                                        boolean_t b_new_pes)
 {
-    ac3dec_thread_t * p_ac3dec = p_byte_stream->info;
-
-    /* We are looking for the next TS packet that contains real data,
-     * and not just a PES header */
-    do {
-       /* We were reading the last TS packet of this PES packet... It's
-        * time to jump to the next PES packet */
-       if (p_ac3dec->p_ts->p_next_ts == NULL) {
-           int ptr;
-
-           /* We are going to read/write the start and end indexes of the 
-            * decoder fifo and to use the fifo's conditional variable, 
-            * that's why we need to take the lock before */ 
-           vlc_mutex_lock (&p_ac3dec->fifo.data_lock);
-           
-           /* Is the input thread dying ? */
-           if (p_ac3dec->p_input->b_die) {
-               vlc_mutex_unlock (&(p_ac3dec->fifo.data_lock));
-               return;
-           }
-
-           /* We should increase the start index of the decoder fifo, but
-             * if we do this now, the input thread could overwrite the
-             * pointer to the current PES packet, and we weren't able to
-             * give it back to the netlist. That's why we free the PES
-             * packet first. */
-           input_NetlistFreePES (p_ac3dec->p_input, DECODER_FIFO_START(p_ac3dec->fifo) );
-
-           DECODER_FIFO_INCSTART (p_ac3dec->fifo);
-
-           while (DECODER_FIFO_ISEMPTY(p_ac3dec->fifo)) {
-               vlc_cond_wait (&p_ac3dec->fifo.data_wait, &p_ac3dec->fifo.data_lock );
-
-               if (p_ac3dec->p_input->b_die) {
-                   vlc_mutex_unlock (&(p_ac3dec->fifo.data_lock));
-                   return;
-               }
-           }
-
-           /* The next byte could be found in the next PES packet */
-           p_ac3dec->p_ts = DECODER_FIFO_START (p_ac3dec->fifo)->p_first_ts;
-
-           /* parse ac3 magic header */
-           ptr = p_ac3dec->p_ts->buffer [p_ac3dec->p_ts->i_payload_start+2];
-           ptr <<= 8;
-           ptr |= p_ac3dec->p_ts->buffer [p_ac3dec->p_ts->i_payload_start+3];
-           p_ac3dec->sync_ptr = ptr;
-           p_ac3dec->p_ts->i_payload_start += 4;
-
-           /* We can release the fifo's data lock */
-           vlc_mutex_unlock (&p_ac3dec->fifo.data_lock);
-       }
-
-       /* Perhaps the next TS packet of the current PES packet contains 
-        * real data (ie its payload's size is greater than 0) */
-       else {
-           p_ac3dec->p_ts = p_ac3dec->p_ts->p_next_ts;
-       }
-    } while (p_ac3dec->p_ts->i_payload_start == p_ac3dec->p_ts->i_payload_end);
-    p_byte_stream->p_byte =
-       p_ac3dec->p_ts->buffer + p_ac3dec->p_ts->i_payload_start; 
-    p_byte_stream->p_end =
-       p_ac3dec->p_ts->buffer + p_ac3dec->p_ts->i_payload_end; 
+
+    ac3dec_thread_t *p_ac3dec_t=(ac3dec_thread_t *)p_bit_stream->p_callback_arg;
+
+    if( b_new_pes )
+    {
+        int ptr;
+        
+        ptr = *(p_bit_stream->p_byte + 1);
+        ptr <<= 8;
+        ptr |= *(p_bit_stream->p_byte + 2);
+        p_ac3dec_t->sync_ptr = ptr;
+        p_bit_stream->p_byte += 3;                                                            
+    }
 }