* modules/audio_output/oss.c: when now set the fragment size of the OSS device
   according to the size of an audio sample.
   For buggy OSS drivers, we now take into account the real size of the OSS
   internal buffer when we check how much this buffer has been filled.

modules/audio_output/oss.c

@@ -2,7 +2,7 @@
  * oss.c : OSS /dev/dsp module for vlc
  *****************************************************************************
  * Copyright (C) 2000-2002 VideoLAN
- * $Id: oss.c,v 1.31 2002/10/24 17:36:42 gbazin Exp $
+ * $Id: oss.c,v 1.32 2002/10/25 15:21:42 gbazin Exp $
  *
  * Authors: Michel Kaempf <maxx@via.ecp.fr>
  *          Samuel Hocevar <sam@zoy.org>
@@ -63,17 +63,15 @@ struct aout_sys_t
 {
     int i_fd;
     int b_workaround_buggy_driver;
+    int i_fragstotal;
+    mtime_t max_buffer_duration;
 };
 
 /* This must be a power of 2. */
 #define FRAME_SIZE 1024
-#define FRAME_COUNT 8
+#define FRAME_COUNT 4
 #define A52_FRAME_NB 1536
 
-/* estimation of the size of the internal soundcard driver
- * (used for buggy drivers) */
-#define OSS_BUFFER_SIZE 20000
-
 /*****************************************************************************
  * Local prototypes
  *****************************************************************************/
@@ -83,6 +81,8 @@ static void Close        ( vlc_object_t * );
 static void Play         ( aout_instance_t * );
 static int  OSSThread    ( aout_instance_t * );
 
+static mtime_t BufferDuration( aout_instance_t * p_aout );
+
 /*****************************************************************************
  * Module descriptor
  *****************************************************************************/
@@ -131,23 +131,15 @@ static int Open( vlc_object_t *p_this )
         return VLC_EGENERIC;
     }
 
-    p_aout->output.p_sys->b_workaround_buggy_driver =
-        config_GetInt( p_aout, "oss-buggy" );
-
-    if( p_aout->output.p_sys->b_workaround_buggy_driver )
-        p_sys->i_fd = open( psz_device, O_WRONLY|O_NONBLOCK );
-    else
-        p_sys->i_fd = open( psz_device, O_WRONLY );
-
     /* Open the sound device */
+    p_sys->i_fd = open( psz_device, O_WRONLY );
+    free( psz_device );
     if( p_sys->i_fd < 0 )
     {
         msg_Err( p_aout, "cannot open audio device (%s)", psz_device );
-        free( psz_device );
         free( p_sys );
         return VLC_EGENERIC;
     }
-    free( psz_device );
 
     p_aout->output.pf_play = Play;
 
@@ -187,6 +179,7 @@ static int Open( vlc_object_t *p_this )
         int i_frame_size, i_fragments;
         int i_rate;
         int i_nb_channels;
+        audio_buf_info audio_buf;
 
         if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
         {
@@ -224,26 +217,6 @@ static int Open( vlc_object_t *p_this )
             return VLC_EGENERIC;
         }
 
-        p_aout->output.output.i_format = AOUT_FMT_S16_NE;
-        p_aout->output.i_nb_samples = FRAME_SIZE;
-
-        aout_VolumeSoftInit( p_aout );
-
-        /* Set the fragment size
-         * i_fragment = xxxxyyyy where: xxxx        is fragtotal
-         *                              1 << yyyy   is fragsize */
-        i_fragments = 0;
-        i_frame_size = FRAME_SIZE;
-        while( i_frame_size >>= 1 )
-        {
-            ++i_fragments;
-        }
-        i_fragments |= FRAME_COUNT << 16;
-        if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFRAGMENT, &i_fragments ) < 0 )
-        {
-            msg_Warn( p_aout, "cannot set fragment size (%.8x)", i_fragments );
-        }
-
         /* These cases are desperate because of the OSS API and A/52 spec. */
         switch ( p_aout->output.output.i_channels )
         {
@@ -353,6 +326,48 @@ static int Open( vlc_object_t *p_this )
         {
             p_aout->output.output.i_rate = i_rate;
         }
+
+        /* Set the fragment size */
+        aout_FormatPrepare( &p_aout->output.output );
+
+        /* i_fragment = xxxxyyyy where: xxxx        is fragtotal
+         *                              1 << yyyy   is fragsize */
+        i_fragments = 0;
+        i_frame_size = FRAME_SIZE * p_aout->output.output.i_bytes_per_frame;
+        while( i_frame_size >>= 1 )
+        {
+            ++i_fragments;
+        }
+        i_fragments |= FRAME_COUNT << 16;
+        if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFRAGMENT, &i_fragments ) < 0 )
+        {
+            msg_Warn( p_aout, "cannot set fragment size (%.8x)", i_fragments );
+        }
+
+        if( ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf ) < 0 )
+        {
+            msg_Warn( p_aout, "cannot get fragment size" );
+            close( p_sys->i_fd );
+            free( p_sys );
+            return VLC_EGENERIC;
+        }
+	else
+        {
+            /* Number of fragments actually allocated */
+            p_aout->output.p_sys->i_fragstotal = audio_buf.fragstotal;
+
+            /* Maximum duration the soundcard's buffer can hold */
+            p_aout->output.p_sys->max_buffer_duration =
+                (mtime_t)audio_buf.fragstotal * audio_buf.fragsize * 1000000
+                / p_aout->output.output.i_bytes_per_frame
+                / p_aout->output.output.i_rate
+                * p_aout->output.output.i_frame_length;
+
+            p_aout->output.i_nb_samples = audio_buf.fragsize /
+                p_aout->output.output.i_bytes_per_frame;
+        }
+
+        aout_VolumeSoftInit( p_aout );
     }
 
     /* Create OSS thread and wait for its readiness. */
@@ -361,11 +376,13 @@ static int Open( vlc_object_t *p_this )
     {
         msg_Err( p_aout, "cannot create OSS thread (%s)", strerror(errno) );
         close( p_sys->i_fd );
-        free( psz_device );
         free( p_sys );
         return VLC_ETHREAD;
     }
 
+    p_aout->output.p_sys->b_workaround_buggy_driver =
+        config_GetInt( p_aout, "oss-buggy" );
+
     return VLC_SUCCESS;
 }
 
@@ -394,7 +411,6 @@ static void Close( vlc_object_t * p_this )
     free( p_sys );
 }
 
-
 /*****************************************************************************
  * BufferDuration: buffer status query
  *****************************************************************************
@@ -443,12 +459,16 @@ static int OSSThread( aout_instance_t * p_aout )
 
             if( p_aout->output.p_sys->b_workaround_buggy_driver )
             {
+#define i_fragstotal p_aout->output.p_sys->i_fragstotal
                 /* Wait a bit - we don't want our buffer to be full */
-                while( buffered > OSS_BUFFER_SIZE )
+                if( buffered > (p_aout->output.p_sys->max_buffer_duration
+                                / i_fragstotal * (i_fragstotal - 1)) )
                 {
-                    msleep( buffered - OSS_BUFFER_SIZE * 2 );
+                    msleep((p_aout->output.p_sys->max_buffer_duration
+                                / i_fragstotal ));
                     buffered = BufferDuration( p_aout );
                 }
+#undef i_fragstotal
             }
 
             if( !next_date )