* New float32to* converter modules, courtesy of Xavier Maillard

[vlc] / modules / audio_filter / converter / float32tos16.c

diff --git a/modules/audio_filter/converter/float32tos16.c b/modules/audio_filter/converter/float32tos16.c
index 8ee754ff4a0a5c33f4c073f6cb6bf27b9a38a734..8a77a36fe9b5392ecba580c3c2de72ac6dd261b7 100644 (file)
--- a/modules/audio_filter/converter/float32tos16.c
+++ b/modules/audio_filter/converter/float32tos16.c
@@ -2,7 +2,7 @@
  * float32tos16.c : converter from float32 to signed 16 bits integer
  *****************************************************************************
  * Copyright (C) 2002 VideoLAN
- * $Id: float32tos16.c,v 1.2 2002/08/09 23:47:22 massiot Exp $
+ * $Id: float32tos16.c,v 1.6 2002/08/13 22:42:23 massiot Exp $
  *
  * Authors: Christophe Massiot <massiot@via.ecp.fr>
  *
@@ -59,7 +59,7 @@ static int Create( vlc_object_t *p_this )
     aout_filter_t * p_filter = (aout_filter_t *)p_this;
 
     if ( p_filter->input.i_format != AOUT_FMT_FLOAT32
-          && p_filter->output.i_format != AOUT_FMT_S16_NE )
+          || p_filter->output.i_format != AOUT_FMT_S16_NE )
     {
         return -1;
     }
@@ -87,11 +87,22 @@ static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
     float * p_in = (float *)p_in_buf->p_buffer;
     s16 * p_out = (s16 *)p_out_buf->p_buffer;
 
-    for ( i = 0; i < p_in_buf->i_nb_samples * p_filter->input.i_channels; i++ )
+    for ( i = p_in_buf->i_nb_samples * p_filter->input.i_channels ; i-- ; )
     {
+#if 0
+        /* Slow version */
         if ( *p_in >= 1.0 ) *p_out = 32767;
         else if ( *p_in < -1.0 ) *p_out = -32768;
         else *p_out = *p_in * 32768.0;
+#else
+        /* This is walken's trick based on IEEE float format. */
+        float f_in = *p_in + 384.0;
+        s32 i_in;
+        i_in = *(s32 *)&f_in;
+        if ( i_in > 0x43c07fff ) *p_out = 32767;
+        else if ( i_in < 0x43bf8000 ) *p_out = -32768;
+        else *p_out = i_in - 0x43c00000;
+#endif
         p_in++; p_out++;
     }