[Ffmpeg-devel] THP ADPCM overflow fix [PATCH]

[Marco Gerards]

Hi,

There are some cracks when playing some THP files (the samples on the
website work just fine).  This is because of an underflow/overflow.
Here is a patch to fix this.

--
Marco


Index: libavcodec/adpcm.c
===================================================================
--- libavcodec/adpcm.c	(revision 8698)
+++ libavcodec/adpcm.c	(working copy)
@@ -1359,8 +1359,10 @@
                     if(n&1) sampledat=  *src++    <<28;
                     else    sampledat= (*src&0xF0)<<24;
 
-                    *samples = ((prev[ch][0]*factor1
+                    sampledat = ((prev[ch][0]*factor1
                                 + prev[ch][1]*factor2) >> 11) + (sampledat>>exp);
+                    CLAMP_TO_SHORT(sampledat);
+                    *samples = sampledat;
                     prev[ch][1] = prev[ch][0];
                     prev[ch][0] = *samples++;