[MPlayer-cvslog] r33811 - trunk/libaf/af_format.c

[iive]

Author: iive
Date: Tue Jul  5 00:24:52 2011
New Revision: 33811

Log:
Audio format conversion from float to int is not checked for overflow.
The float may be slightly off the [-1;1] range thus causing audible
crackling noise.

Add proper clipping using av_clip functions.

Fixes bug 1919.

Modified:
   trunk/libaf/af_format.c

Modified: trunk/libaf/af_format.c
==============================================================================
--- trunk/libaf/af_format.c	Mon Jul  4 21:23:03 2011	(r33810)
+++ trunk/libaf/af_format.c	Tue Jul  5 00:24:52 2011	(r33811)
@@ -32,6 +32,8 @@
 #include "mpbswap.h"
 #include "libvo/fastmemcpy.h"
 
+#include "libavutil/avutil.h"
+
 /* Functions used by play to convert the input audio to the correct
    format */
 
@@ -474,23 +476,29 @@ static void change_bps(void* in, void* o
 
 static void float2int(float* in, void* out, int len, int bps)
 {
+  float f;
   register int i;
   switch(bps){
   case(1):
     for(i=0;i<len;i++)
-      ((int8_t*)out)[i] = lrintf(127.0 * in[i]);
+      ((int8_t *)out)[i] = av_clip_int8(lrintf(128.0 * in[i]));
     break;
   case(2):
     for(i=0;i<len;i++)
-      ((int16_t*)out)[i] = lrintf(32767.0 * in[i]);
+      ((int16_t*)out)[i] = av_clip_int16(lrintf(32768.0 * in[i]));
     break;
   case(3):
-    for(i=0;i<len;i++)
-      store24bit(out, i, lrintf(2147483647.0 * in[i]));
+    for(i=0;i<len;i++){
+      f = ldexp(in[i], 23);
+      store24bit(out, i,   av_clip(lrintf(f), -1*(1<<23), (1<<23)-1) << 8);
+    }
     break;
   case(4):
-    for(i=0;i<len;i++)
-      ((int32_t*)out)[i] = lrintf(2147483647.0 * in[i]);
+    for(i=0;i<len;i++){
+      f = ldexp(in[i], 23);
+      //The mantissa is only 23 bit, that's all the precision there is.
+      ((int32_t*)out)[i] = av_clip(lrintf(f), -1*(1<<23), (1<<23)-1) << 8;
+    }
     break;
   }
 }