More changes in the date handling. Should be more tolerant with

pause/play and change of audio channel.

include/aout_internal.h

@@ -2,7 +2,7 @@
  * aout_internal.h : internal defines for audio output
  *****************************************************************************
  * Copyright (C) 2002 VideoLAN
- * $Id: aout_internal.h,v 1.6 2002/08/19 21:31:11 massiot Exp $
+ * $Id: aout_internal.h,v 1.7 2002/08/19 23:12:57 massiot Exp $
  *
  * Authors: Christophe Massiot <massiot@via.ecp.fr>
  *
@@ -82,7 +82,6 @@ typedef struct aout_alloc_t
  *****************************************************************************/
 typedef struct aout_fifo_t
 {
-    vlc_mutex_t             lock;
     struct aout_buffer_t *  p_first;
     struct aout_buffer_t ** pp_last;
     mtime_t                 end_date;
@@ -91,7 +90,6 @@ typedef struct aout_fifo_t
 static inline void aout_FifoInit( struct aout_instance_t * p_aout,
                                   aout_fifo_t * p_fifo )
 {
-    vlc_mutex_init( (vlc_object_t *)p_aout, &p_fifo->lock );
     p_fifo->p_first = NULL;
     p_fifo->pp_last = &p_fifo->p_first;
     p_fifo->end_date = 0;
@@ -101,7 +99,6 @@ static inline void aout_FifoPush( struct aout_instance_t * p_aout,
                                   aout_fifo_t * p_fifo,
                                   aout_buffer_t * p_buffer )
 {
-    vlc_mutex_lock( &p_fifo->lock );
     *p_fifo->pp_last = p_buffer;
     p_fifo->pp_last = &p_buffer->p_next;
     *p_fifo->pp_last = NULL;
@@ -118,26 +115,31 @@ static inline void aout_FifoPush( struct aout_instance_t * p_aout,
     {
         p_fifo->end_date = p_buffer->end_date;
     }
-    vlc_mutex_unlock( &p_fifo->lock );
 }
 
 static inline mtime_t aout_FifoNextStart( struct aout_instance_t * p_aout,
                                           aout_fifo_t * p_fifo )
 {
-    mtime_t end_date;
-    vlc_mutex_lock( &p_fifo->lock );
-    end_date = p_fifo->end_date;
-    vlc_mutex_unlock( &p_fifo->lock );
-    return end_date;
+    return p_fifo->end_date;
 }
 
 /* Reinit the end_date (for instance after a pause). */
 static inline void aout_FifoSet( struct aout_instance_t * p_aout,
                                  aout_fifo_t * p_fifo, mtime_t date )
 {
-    vlc_mutex_lock( &p_fifo->lock );
+    aout_buffer_t * p_buffer;
     p_fifo->end_date = date;
-    vlc_mutex_unlock( &p_fifo->lock );
+
+    /* Remove all buffers. */
+    p_buffer = p_fifo->p_first;
+    while ( p_buffer != NULL )
+    {
+        aout_buffer_t * p_next = p_buffer->p_next;
+        aout_BufferFree( p_buffer );
+        p_buffer = p_next;
+    }
+    p_fifo->p_first = NULL;
+    p_fifo->pp_last = &p_fifo->p_first;
 }
 
 /* This function supposes there is at least one buffer in p_fifo. */
@@ -145,14 +147,12 @@ static inline aout_buffer_t * aout_FifoPop( struct aout_instance_t * p_aout,
                                             aout_fifo_t * p_fifo )
 {
     aout_buffer_t * p_buffer;
-    vlc_mutex_lock( &p_fifo->lock );
     p_buffer = p_fifo->p_first;
     p_fifo->p_first = p_buffer->p_next;
     if ( p_fifo->p_first == NULL )
     {
         p_fifo->pp_last = &p_fifo->p_first;
     }
-    vlc_mutex_unlock( &p_fifo->lock );
 
     return p_buffer;
 }
@@ -162,7 +162,6 @@ static inline void aout_FifoDestroy( struct aout_instance_t * p_aout,
 {
     aout_buffer_t * p_buffer;
 
-    vlc_mutex_destroy( &p_fifo->lock );
     p_buffer = p_fifo->p_first;
     while ( p_buffer != NULL )
     {
@@ -260,9 +259,7 @@ struct aout_instance_t
     int                     i_nb_inputs;
 
     /* Mixer */
-    vlc_cond_t              mixer_signal; /* the associated mutex is
-                                           * p_aout->output.fifo.lock */
-    vlc_bool_t              b_mixer_active;
+    vlc_mutex_t             mixer_lock;
     aout_mixer_t            mixer;
 
     /* Output plug-in */

modules/audio_output/file.c

@@ -2,7 +2,7 @@
  * file.c : audio output which writes the samples to a file
  *****************************************************************************
  * Copyright (C) 2002 VideoLAN
- * $Id: file.c,v 1.7 2002/08/19 23:07:30 sam Exp $
+ * $Id: file.c,v 1.8 2002/08/19 23:12:57 massiot Exp $
  *
  * Authors: Christophe Massiot <massiot@via.ecp.fr>
  *
@@ -148,7 +148,12 @@ static int SetFormat( aout_instance_t * p_aout )
  *****************************************************************************/
 static void Play( aout_instance_t * p_aout )
 {
-    aout_buffer_t * p_buffer = aout_FifoPop( p_aout, &p_aout->output.fifo );
+    aout_buffer_t * p_buffer;
+
+    /* We don't need the mixer lock, since Play is entered _with_ the
+     * mixer lock. */
+    p_buffer = aout_FifoPop( p_aout, &p_aout->output.fifo );
+
     if( fwrite( p_buffer->p_buffer, p_buffer->i_nb_bytes, 1,
                 (FILE *)p_aout->output.p_sys ) != 1 )
     {

modules/misc/dummy/aout.c

@@ -2,7 +2,7 @@
  * aout_dummy.c : dummy audio output plugin
  *****************************************************************************
  * Copyright (C) 2002 VideoLAN
- * $Id: aout.c,v 1.5 2002/08/19 21:31:11 massiot Exp $
+ * $Id: aout.c,v 1.6 2002/08/19 23:12:57 massiot Exp $
  *
  * Authors: Christophe Massiot <massiot@via.ecp.fr>
  *
@@ -77,6 +77,8 @@ static int SetFormat( aout_instance_t * p_aout )
  *****************************************************************************/
 static void Play( aout_instance_t * p_aout )
 {
+    /* We don't need the mixer lock, since Play is entered _with_ the
+     * mixer lock. */
     aout_buffer_t * p_buffer = aout_FifoPop( p_aout, &p_aout->output.fifo );
     aout_BufferFree( p_buffer );
 }

src/audio_output/audio_output.c

@@ -2,7 +2,7 @@
  * audio_output.c : audio output instance
  *****************************************************************************
  * Copyright (C) 2002 VideoLAN
- * $Id: audio_output.c,v 1.97 2002/08/19 21:31:11 massiot Exp $
+ * $Id: audio_output.c,v 1.98 2002/08/19 23:12:57 massiot Exp $
  *
  * Authors: Christophe Massiot <massiot@via.ecp.fr>
  *
@@ -57,8 +57,7 @@ aout_instance_t * __aout_NewInstance( vlc_object_t * p_parent )
     p_aout->b_change_requested = 0;
     p_aout->i_nb_inputs = 0;
 
-    vlc_cond_init( p_parent, &p_aout->mixer_signal );
-    p_aout->b_mixer_active = 0;
+    vlc_mutex_init( p_parent, &p_aout->mixer_lock );
 
     vlc_object_attach( p_aout, p_parent->p_vlc );
 
@@ -72,7 +71,7 @@ void aout_DeleteInstance( aout_instance_t * p_aout )
 {
     vlc_mutex_destroy( &p_aout->input_lock );
     vlc_cond_destroy( &p_aout->input_signal );
-    vlc_cond_destroy( &p_aout->mixer_signal );
+    vlc_mutex_destroy( &p_aout->mixer_lock );
 
     /* Free structure. */
     vlc_object_destroy( p_aout );

src/audio_output/input.c

@@ -2,7 +2,7 @@
  * input.c : internal management of input streams for the audio output
  *****************************************************************************
  * Copyright (C) 2002 VideoLAN
- * $Id: input.c,v 1.5 2002/08/19 21:31:11 massiot Exp $
+ * $Id: input.c,v 1.6 2002/08/19 23:12:57 massiot Exp $
  *
  * Authors: Christophe Massiot <massiot@via.ecp.fr>
  *
@@ -42,13 +42,7 @@ static aout_input_t * InputNew( aout_instance_t * p_aout,
 
     if ( p_input == NULL ) return NULL;
 
-    vlc_mutex_lock( &p_aout->output.fifo.lock );
-    while ( p_aout->b_mixer_active )
-    {
-        vlc_cond_wait( &p_aout->mixer_signal, &p_aout->output.fifo.lock );
-    }
-    p_aout->b_mixer_active = 1;
-    vlc_mutex_unlock( &p_aout->output.fifo.lock );
+    vlc_mutex_lock( &p_aout->mixer_lock );
 
     if ( p_aout->i_nb_inputs == 0 )
     {
@@ -110,18 +104,12 @@ static aout_input_t * InputNew( aout_instance_t * p_aout,
         {
             aout_MixerNew( p_aout );
         }
-        vlc_mutex_lock( &p_aout->output.fifo.lock );
-        p_aout->b_mixer_active = 0;
-        vlc_cond_signal( &p_aout->mixer_signal );
-        vlc_mutex_unlock( &p_aout->output.fifo.lock );
+        vlc_mutex_unlock( &p_aout->mixer_lock );
 
         return NULL;
     }
 
-    vlc_mutex_lock( &p_aout->output.fifo.lock );
-    p_aout->b_mixer_active = 0;
-    vlc_cond_signal( &p_aout->mixer_signal );
-    vlc_mutex_unlock( &p_aout->output.fifo.lock );
+    vlc_mutex_unlock( &p_aout->mixer_lock );
 
     /* Prepare hints for the buffer allocator. */
     p_input->input_alloc.i_alloc_type = AOUT_ALLOC_HEAP;
@@ -177,15 +165,7 @@ void aout_InputDelete( aout_instance_t * p_aout, aout_input_t * p_input )
 {
     int i_input;
 
-    msg_Dbg( p_aout, "input 0x%x destroyed", p_input );
-
-    vlc_mutex_lock( &p_aout->output.fifo.lock );
-    while ( p_aout->b_mixer_active )
-    {
-        vlc_cond_wait( &p_aout->mixer_signal, &p_aout->output.fifo.lock );
-    }
-    p_aout->b_mixer_active = 1;
-    vlc_mutex_unlock( &p_aout->output.fifo.lock );
+    vlc_mutex_lock( &p_aout->mixer_lock );
 
     for ( i_input = 0; i_input < p_aout->i_nb_inputs; i_input++ )
     {
@@ -206,10 +186,7 @@ void aout_InputDelete( aout_instance_t * p_aout, aout_input_t * p_input )
              (AOUT_MAX_INPUTS - i_input - 1) * sizeof(aout_input_t *) );
     p_aout->i_nb_inputs--;
 
-    vlc_mutex_lock( &p_aout->output.fifo.lock );
-    p_aout->b_mixer_active = 0;
-    vlc_cond_signal( &p_aout->mixer_signal );
-    vlc_mutex_unlock( &p_aout->output.fifo.lock );
+    vlc_mutex_unlock( &p_aout->mixer_lock );
 
     aout_FiltersDestroyPipeline( p_aout, p_input->pp_filters,
                                  p_input->i_nb_filters );
@@ -222,6 +199,8 @@ void aout_InputDelete( aout_instance_t * p_aout, aout_input_t * p_input )
         aout_OutputDelete( p_aout );
         aout_MixerDelete( p_aout );
     }
+
+    msg_Dbg( p_aout, "input 0x%x destroyed", p_input );
 }
 
 /*****************************************************************************
@@ -252,7 +231,9 @@ void aout_InputPlay( aout_instance_t * p_aout, aout_input_t * p_input,
          * happen :). */
         msg_Warn( p_aout, "Computed PTS is out of range (%lld), clearing out",
                   start_date );
+        vlc_mutex_lock( &p_aout->mixer_lock );
         aout_FifoSet( p_aout, &p_input->fifo, 0 );
+        vlc_mutex_unlock( &p_aout->mixer_lock );
         start_date = 0;
     } 
 
@@ -314,7 +295,9 @@ void aout_InputPlay( aout_instance_t * p_aout, aout_input_t * p_input,
                                          &new_output ) < 0 )
         {
             msg_Err( p_aout, "couldn't set an input pipeline for resampling" );
+            vlc_mutex_lock( &p_aout->mixer_lock );
             aout_FifoSet( p_aout, &p_input->fifo, 0 );
+            vlc_mutex_unlock( &p_aout->mixer_lock );
             aout_BufferFree( p_buffer );
 
             vlc_mutex_lock( &p_aout->input_lock );
@@ -347,7 +330,9 @@ void aout_InputPlay( aout_instance_t * p_aout, aout_input_t * p_input,
     /* Adding the start date will be managed by aout_FifoPush(). */
     p_buffer->start_date = start_date;
     p_buffer->end_date = start_date + duration;
+    vlc_mutex_lock( &p_aout->mixer_lock );
     aout_FifoPush( p_aout, &p_input->fifo, p_buffer );
+    vlc_mutex_unlock( &p_aout->mixer_lock );
 
     vlc_mutex_lock( &p_aout->input_lock );
     p_aout->i_inputs_active--;

src/audio_output/mixer.c

@@ -2,7 +2,7 @@
  * mixer.c : audio output mixing operations
  *****************************************************************************
  * Copyright (C) 2002 VideoLAN
- * $Id: mixer.c,v 1.7 2002/08/19 21:54:37 massiot Exp $
+ * $Id: mixer.c,v 1.8 2002/08/19 23:12:57 massiot Exp $
  *
  * Authors: Christophe Massiot <massiot@via.ecp.fr>
  *
@@ -59,19 +59,17 @@ void aout_MixerDelete( aout_instance_t * p_aout )
 }
 
 /*****************************************************************************
- * aout_MixerRun: entry point for the mixer & post-filters processing
+ * MixBuffer: try to prepare one output buffer
  *****************************************************************************/
-void aout_MixerRun( aout_instance_t * p_aout )
+static int MixBuffer( aout_instance_t * p_aout )
 {
     int             i;
     aout_buffer_t * p_output_buffer;
     mtime_t start_date, end_date;
 
-    /* Retrieve the date of the next buffer. We don't use aout_FifoNextStart
-     * because we need to keep the lock on the FIFO, to prevent the aout
-     * thread from triggering resampling while we are running. */
-    vlc_mutex_lock( &p_aout->output.fifo.lock );
-    start_date = p_aout->output.fifo.end_date;
+    /* Retrieve the date of the next buffer. */
+    vlc_mutex_lock( &p_aout->mixer_lock );
+    start_date = aout_FifoNextStart( p_aout, &p_aout->output.fifo );
     if ( start_date != 0 && start_date < mdate() )
     {
         /* The output is _very_ late. This can only happen if the user
@@ -81,11 +79,42 @@ void aout_MixerRun( aout_instance_t * p_aout )
                   start_date );
         start_date = p_aout->output.fifo.end_date = 0;
     } 
+
+    /* See if we have enough data to prepare a new buffer for the audio
+     * output. First : start date. */
+    if ( !start_date )
+    {
+        /* Find the latest start date available. */
+        for ( i = 0; i < p_aout->i_nb_inputs; i++ )
+        {
+            aout_input_t * p_input = p_aout->pp_inputs[i];
+            aout_fifo_t * p_fifo = &p_input->fifo;
+            aout_buffer_t * p_buffer;
+
+            p_buffer = p_fifo->p_first;
+            if ( p_buffer == NULL )
+            {
+                break;
+            }
+
+            if ( !start_date || start_date < p_buffer->start_date )
+            {
+                start_date = p_buffer->start_date;
+            }
+        }
+
+        if ( i < p_aout->i_nb_inputs )
+        {
+            /* Interrupted before the end... We can't run. */
+            vlc_mutex_unlock( &p_aout->mixer_lock );
+            return -1;
+        }
+    }
     end_date = start_date + (mtime_t)p_aout->output.i_nb_samples * 1000000
                              / p_aout->output.output.i_rate;
 
-    /* See if we have enough data to prepare a new buffer for the audio
-     * output. */
+    /* Check that start_date and end_date are available for all input
+     * streams. */
     for ( i = 0; i < p_aout->i_nb_inputs; i++ )
     {
         aout_input_t * p_input = p_aout->pp_inputs[i];
@@ -94,73 +123,60 @@ void aout_MixerRun( aout_instance_t * p_aout )
         mtime_t prev_date;
         vlc_bool_t b_drop_buffers;
 
-        vlc_mutex_lock( &p_fifo->lock );
-
         p_buffer = p_fifo->p_first;
         if ( p_buffer == NULL )
         {
-            vlc_mutex_unlock( &p_fifo->lock );
             break;
         }
 
-        if ( !start_date )
+        /* Check for the continuity of start_date */
+        while ( p_buffer != NULL && p_buffer->end_date < start_date )
         {
-            start_date = p_buffer->start_date;
-            end_date += p_buffer->start_date;
-            p_input->p_first_byte_to_mix = p_buffer->p_buffer;
+            aout_buffer_t * p_next = p_buffer->p_next;
+            msg_Err( p_aout, "the mixer got a packet in the past (%lld)",
+                     start_date - p_buffer->end_date );
+            aout_BufferFree( p_buffer );
+            p_fifo->p_first = p_buffer = p_next;
+            p_input->p_first_byte_to_mix = NULL;
         }
-        else
+        if ( p_buffer == NULL )
         {
-            /* Check for the continuity of start_date */
-            while ( p_buffer != NULL && p_buffer->end_date < start_date )
-            {
-                aout_buffer_t * p_next = p_buffer->p_next;
-                msg_Err( p_aout, "the mixer got a packet in the past (%lld)",
-                         start_date - p_buffer->end_date );
-                aout_BufferFree( p_buffer );
-                p_fifo->p_first = p_buffer = p_next;
-                p_input->p_first_byte_to_mix = NULL;
-            }
-            if ( p_buffer == NULL )
+            p_fifo->pp_last = &p_fifo->p_first;
+            break;
+        }
+
+        if ( !AOUT_FMT_NON_LINEAR( &p_aout->mixer.mixer ) )
+        {
+            /* Additionally check that p_first_byte_to_mix is well
+             * located. */
+            unsigned long i_nb_bytes = (start_date - p_buffer->start_date)
+                            * p_aout->mixer.mixer.i_bytes_per_frame
+                            * p_aout->mixer.mixer.i_rate
+                            / p_aout->mixer.mixer.i_frame_length
+                            / 1000000;
+            ptrdiff_t mixer_nb_bytes;
+
+            if ( p_input->p_first_byte_to_mix == NULL )
             {
-                p_fifo->pp_last = &p_fifo->p_first;
-                vlc_mutex_unlock( &p_fifo->lock );
-                break;
+                p_input->p_first_byte_to_mix = p_buffer->p_buffer;
             }
+            mixer_nb_bytes = p_input->p_first_byte_to_mix
+                              - p_buffer->p_buffer;
 
-            if ( !AOUT_FMT_NON_LINEAR( &p_aout->mixer.mixer ) )
+            if ( i_nb_bytes + p_aout->mixer.mixer.i_bytes_per_frame
+                  < mixer_nb_bytes ||
+                 i_nb_bytes - p_aout->mixer.mixer.i_bytes_per_frame
+                  > mixer_nb_bytes )
             {
-                /* Additionally check that p_first_byte_to_mix is well
-                 * located. */
-                unsigned long i_nb_bytes = (start_date - p_buffer->start_date)
-                                * p_aout->mixer.mixer.i_bytes_per_frame
-                                * p_aout->mixer.mixer.i_rate
-                                / p_aout->mixer.mixer.i_frame_length
-                                / 1000000;
-                ptrdiff_t mixer_nb_bytes;
-
-                if ( p_input->p_first_byte_to_mix == NULL )
-                {
-                    p_input->p_first_byte_to_mix = p_buffer->p_buffer;
-                }
-                mixer_nb_bytes = p_input->p_first_byte_to_mix
-                                  - p_buffer->p_buffer;
+                msg_Warn( p_aout,
+                          "mixer start isn't output start (%ld)",
+                          i_nb_bytes - mixer_nb_bytes );
 
-                if ( i_nb_bytes + p_aout->mixer.mixer.i_bytes_per_frame
-                      < mixer_nb_bytes ||
-                     i_nb_bytes - p_aout->mixer.mixer.i_bytes_per_frame
-                      > mixer_nb_bytes )
-                {
-                    msg_Warn( p_aout,
-                              "mixer start isn't output start (%ld)",
-                              i_nb_bytes - mixer_nb_bytes );
-
-                    /* Round to the nearest multiple */
-                    i_nb_bytes /= p_aout->mixer.mixer.i_bytes_per_frame;
-                    i_nb_bytes *= p_aout->mixer.mixer.i_bytes_per_frame;
-                    p_input->p_first_byte_to_mix = p_buffer->p_buffer
-                                                    + i_nb_bytes;
-                }
+                /* Round to the nearest multiple */
+                i_nb_bytes /= p_aout->mixer.mixer.i_bytes_per_frame;
+                i_nb_bytes *= p_aout->mixer.mixer.i_bytes_per_frame;
+                p_input->p_first_byte_to_mix = p_buffer->p_buffer
+                                                + i_nb_bytes;
             }
         }
 
@@ -180,7 +196,7 @@ void aout_MixerRun( aout_instance_t * p_aout )
                 if ( prev_date != p_buffer->start_date )
                 {
                     msg_Warn( p_aout,
-                              "buffer discontinuity, dropping packets (%lld)",
+                              "buffer hole, dropping packets (%lld)",
                               p_buffer->start_date - prev_date );
                     b_drop_buffers = 1;
                     break;
@@ -201,20 +217,16 @@ void aout_MixerRun( aout_instance_t * p_aout )
             }
             else break;
         }
-        vlc_mutex_unlock( &p_fifo->lock );
         if ( p_buffer == NULL ) break;
     }
 
     if ( i < p_aout->i_nb_inputs )
     {
         /* Interrupted before the end... We can't run. */
-        vlc_mutex_unlock( &p_aout->output.fifo.lock );
-        return;
+        vlc_mutex_unlock( &p_aout->mixer_lock );
+        return -1;
     }
 
-    p_aout->b_mixer_active = 1;
-    vlc_mutex_unlock( &p_aout->output.fifo.lock );
-
     /* Run the mixer. */
     aout_BufferAlloc( &p_aout->mixer.output_alloc,
                       ((u64)p_aout->output.i_nb_samples * 1000000)
@@ -226,22 +238,29 @@ void aout_MixerRun( aout_instance_t * p_aout )
     if ( p_output_buffer == NULL )
     {
         msg_Err( p_aout, "out of memory" );
-        return;
+        vlc_mutex_unlock( &p_aout->mixer_lock );
+        return -1;
     }
     p_output_buffer->i_nb_samples = p_aout->output.i_nb_samples;
     p_output_buffer->i_nb_bytes = p_aout->output.i_nb_samples
-                              * p_aout->output.output.i_bytes_per_frame
-                              / p_aout->output.output.i_frame_length;
+                              * p_aout->mixer.mixer.i_bytes_per_frame
+                              / p_aout->mixer.mixer.i_frame_length;
     p_output_buffer->start_date = start_date;
     p_output_buffer->end_date = end_date;
 
     p_aout->mixer.pf_do_work( p_aout, p_output_buffer );
 
+    vlc_mutex_unlock( &p_aout->mixer_lock );
+
     aout_OutputPlay( p_aout, p_output_buffer );
 
-    vlc_mutex_lock( &p_aout->output.fifo.lock );
-    p_aout->b_mixer_active = 0;
-    vlc_cond_signal( &p_aout->mixer_signal );
-    vlc_mutex_unlock( &p_aout->output.fifo.lock );
+    return 0;
 }
 
+/*****************************************************************************
+ * aout_MixerRun: entry point for the mixer & post-filters processing
+ *****************************************************************************/
+void aout_MixerRun( aout_instance_t * p_aout )
+{
+    while( MixBuffer( p_aout ) != -1 );
+}

src/audio_output/output.c

@@ -2,7 +2,7 @@
  * output.c : internal management of output streams for the audio output
  *****************************************************************************
  * Copyright (C) 2002 VideoLAN
- * $Id: output.c,v 1.7 2002/08/19 21:31:11 massiot Exp $
+ * $Id: output.c,v 1.8 2002/08/19 23:12:57 massiot Exp $
  *
  * Authors: Christophe Massiot <massiot@via.ecp.fr>
  *
@@ -43,9 +43,7 @@ int aout_OutputNew( aout_instance_t * p_aout,
     int i_channels = config_GetInt( p_aout, "aout-channels" );
 
     /* Prepare FIFO. */
-    vlc_mutex_init( p_aout, &p_aout->output.fifo.lock );
-    p_aout->output.fifo.p_first = NULL;
-    p_aout->output.fifo.pp_last = &p_aout->output.fifo.p_first;
+    aout_FifoInit( p_aout, &p_aout->output.fifo );
 
     p_aout->output.p_module = module_Need( p_aout, "audio output",
                                            psz_name );
@@ -151,6 +149,7 @@ void aout_OutputPlay( aout_instance_t * p_aout, aout_buffer_t * p_buffer )
                       p_aout->output.i_nb_filters,
                       &p_buffer );
 
+    /* Please remember that we have the mixer_lock in this function. */
     aout_FifoPush( p_aout, &p_aout->output.fifo, p_buffer );
 
     p_aout->output.pf_play( p_aout );
@@ -169,7 +168,7 @@ aout_buffer_t * aout_OutputNextBuffer( aout_instance_t * p_aout,
 {
     aout_buffer_t * p_buffer;
 
-    vlc_mutex_lock( &p_aout->output.fifo.lock );
+    vlc_mutex_lock( &p_aout->mixer_lock );
     p_buffer = p_aout->output.fifo.p_first;
 
     while ( p_buffer != NULL && p_buffer->end_date < start_date )
@@ -183,7 +182,9 @@ aout_buffer_t * aout_OutputNextBuffer( aout_instance_t * p_aout,
     if ( p_buffer == NULL )
     {
         p_aout->output.fifo.pp_last = &p_aout->output.fifo.p_first;
-        vlc_mutex_unlock( &p_aout->output.fifo.lock );
+        /* Set date to 0, to allow the mixer to send a new buffer ASAP */
+        p_aout->output.fifo.end_date = 0;
+        vlc_mutex_unlock( &p_aout->mixer_lock );
         msg_Dbg( p_aout, "audio output is starving" );
         return NULL;
     }
@@ -193,7 +194,7 @@ aout_buffer_t * aout_OutputNextBuffer( aout_instance_t * p_aout,
     if ( p_buffer->start_date > start_date
                          + (p_buffer->end_date - p_buffer->start_date) )
     {
-        vlc_mutex_unlock( &p_aout->output.fifo.lock );
+        vlc_mutex_unlock( &p_aout->mixer_lock );
         msg_Dbg( p_aout, "audio output is starving (%lld)",
                  p_buffer->start_date - start_date );
         return NULL;
@@ -222,6 +223,6 @@ aout_buffer_t * aout_OutputNextBuffer( aout_instance_t * p_aout,
         p_aout->output.fifo.pp_last = &p_aout->output.fifo.p_first;
     }
 
-    vlc_mutex_unlock( &p_aout->output.fifo.lock );
+    vlc_mutex_unlock( &p_aout->mixer_lock );
     return p_buffer;
 }