simple mixer: remove useless allocation and simplify

modules/audio_filter/channel_mixer/simple.c

@@ -39,24 +39,15 @@
  * Module descriptor
  *****************************************************************************/
 static int  OpenFilter( vlc_object_t * );
-static void CloseFilter( vlc_object_t * );
 
 vlc_module_begin ()
     set_description( N_("Audio filter for simple channel mixing") )
     set_category( CAT_AUDIO )
     set_subcategory( SUBCAT_AUDIO_MISC )
     set_capability( "audio converter", 10 )
-    set_callbacks( OpenFilter, CloseFilter );
+    set_callbacks( OpenFilter, NULL );
 vlc_module_end ()
 
-/*****************************************************************************
- * Local prototypes
- *****************************************************************************/
-struct filter_sys_t
-{
-    void (*pf_dowork)(filter_t *, block_t *, block_t * );
-};
-
 /*****************************************************************************
  * IsSupported: can we downmix?
  *****************************************************************************/
@@ -327,7 +318,7 @@ static void DoWork_6_1_to_5_x( filter_t * p_filter,  block_t * p_in_buf, block_t
 static int OpenFilter( vlc_object_t *p_this )
 {
     filter_t *p_filter = (filter_t *)p_this;
-    filter_sys_t *p_sys;
+    void (*do_work)(filter_t *, block_t *, block_t *) = NULL;
 
     audio_format_t fmt_in  = p_filter->fmt_in.audio;
     audio_format_t fmt_out = p_filter->fmt_out.audio;
@@ -335,12 +326,6 @@ static int OpenFilter( vlc_object_t *p_this )
     if( !IsSupported( &fmt_in, &fmt_out ) )
         return VLC_EGENERIC;
 
-    p_filter->p_sys = malloc( sizeof(*p_sys) );
-    if( unlikely(!p_filter->p_sys) )
-        return VLC_ENOMEM;
-
-    p_filter->pf_audio_filter = Filter;
-
     const unsigned i_input_physical = p_filter->fmt_in.audio.i_physical_channels;
     const bool b_input_7_0 = (i_input_physical & ~AOUT_CHAN_LFE) == AOUT_CHANS_7_0;
     const bool b_input_6_1 = !b_input_7_0 &&
@@ -356,61 +341,57 @@ static int OpenFilter( vlc_object_t *p_this )
     if( p_filter->fmt_out.audio.i_physical_channels == AOUT_CHANS_2_0 )
     {
         if( b_input_7_0 )
-            p_filter->p_sys->pf_dowork = DoWork_7_x_to_2_0;
+            do_work = DoWork_7_x_to_2_0;
         else if( b_input_6_1 )
-            p_filter->p_sys->pf_dowork = DoWork_6_1_to_2_0;
+            do_work = DoWork_6_1_to_2_0;
         else if( b_input_5_0 )
-            p_filter->p_sys->pf_dowork = DoWork_5_x_to_2_0;
+            do_work = DoWork_5_x_to_2_0;
         else if( b_input_4_center_rear )
-            p_filter->p_sys->pf_dowork = DoWork_4_0_to_2_0;
+            do_work = DoWork_4_0_to_2_0;
         else if( b_input_3_0 )
-            p_filter->p_sys->pf_dowork = DoWork_3_x_to_2_0;
+            do_work = DoWork_3_x_to_2_0;
     }
     else if( p_filter->fmt_out.audio.i_physical_channels == AOUT_CHAN_CENTER )
     {
         if( b_input_7_0 )
-            p_filter->p_sys->pf_dowork = DoWork_7_x_to_1_0;
+            do_work = DoWork_7_x_to_1_0;
         else if( b_input_5_0 )
-            p_filter->p_sys->pf_dowork = DoWork_5_x_to_1_0;
+            do_work = DoWork_5_x_to_1_0;
         else if( b_input_4_center_rear )
-            p_filter->p_sys->pf_dowork = DoWork_4_0_to_1_0;
+            do_work = DoWork_4_0_to_1_0;
         else if( b_input_3_0 )
-            p_filter->p_sys->pf_dowork = DoWork_3_x_to_1_0;
+            do_work = DoWork_3_x_to_1_0;
         else
-            p_filter->p_sys->pf_dowork = DoWork_2_x_to_1_0;
+            do_work = DoWork_2_x_to_1_0;
     }
     else if(p_filter->fmt_out.audio.i_physical_channels == AOUT_CHANS_4_0)
     {
         if( b_input_7_0 )
-            p_filter->p_sys->pf_dowork = DoWork_7_x_to_4_0;
+            do_work = DoWork_7_x_to_4_0;
         else
-            p_filter->p_sys->pf_dowork = DoWork_5_x_to_4_0;
+            do_work = DoWork_5_x_to_4_0;
     }
     else
     {
         assert( b_input_7_0 || b_input_6_1 );
         if( b_input_7_0 )
-            p_filter->p_sys->pf_dowork = DoWork_7_x_to_5_x;
+            do_work = DoWork_7_x_to_5_x;
         else
-            p_filter->p_sys->pf_dowork = DoWork_6_1_to_5_x;
+            do_work = DoWork_6_1_to_5_x;
     }
 
+    p_filter->pf_audio_filter = Filter;
+    p_filter->p_sys = (void *)do_work;
     return VLC_SUCCESS;
 }
 
-static void CloseFilter( vlc_object_t *p_this )
-{
-    filter_t *p_filter = (filter_t *) p_this;
-    filter_sys_t *p_sys = p_filter->p_sys;
-    free( p_sys );
-}
-
 /*****************************************************************************
  * Filter:
  *****************************************************************************/
 static block_t *Filter( filter_t *p_filter, block_t *p_block )
 {
-    filter_sys_t *p_sys = (filter_sys_t *)p_filter->p_sys;
+    void (*work)(filter_t *, block_t *, block_t *) = (void *)p_filter->p_sys;
+
     if( !p_block || !p_block->i_nb_samples )
     {
         if( p_block )
@@ -440,7 +421,7 @@ static block_t *Filter( filter_t *p_filter, block_t *p_block )
     p_out->i_nb_samples = p_block->i_nb_samples;
     p_out->i_buffer = p_block->i_buffer * i_output_nb / i_input_nb;
 
-    p_sys->pf_dowork( p_filter, p_block, p_out );
+    work( p_filter, p_block, p_out );
 
     block_Release( p_block );