configure: Document --enable-libfontconfig

[ffmpeg] / libavcodec / apedec.c

diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c
index d33139be7dae0f2b9dfec5c460ed104693331d12..2f6448867a1aaf2cf721fe560d5fcd0b7ceec358 100644 (file)
--- a/libavcodec/apedec.c
+++ b/libavcodec/apedec.c
@@ -359,10 +359,10 @@ static inline void range_dec_normalize(APEContext *ctx)
 }
 
 /**
- * Calculate culmulative frequency for next symbol. Does NO update!
+ * Calculate cumulative frequency for next symbol. Does NO update!
  * @param ctx decoder context
  * @param tot_f is the total frequency or (code_value)1<<shift
- * @return the culmulative frequency
+ * @return the cumulative frequency
  */
 static inline int range_decode_culfreq(APEContext *ctx, int tot_f)
 {
@@ -1305,8 +1305,16 @@ static void do_apply_filter(APEContext *ctx, int version, APEFilter *f,
             /* Update the adaption coefficients */
             absres = FFABS(res);
             if (absres)
-                *f->adaptcoeffs = ((res & (-1<<31)) ^ (-1<<30)) >>
-                                  (25 + (absres <= f->avg*3) + (absres <= f->avg*4/3));
+                *f->adaptcoeffs = APESIGN(res) *
+                                  (8 << ((absres > f->avg * 3) + (absres > f->avg * 4 / 3)));
+                /* equivalent to the following code
+                    if (absres <= f->avg * 4 / 3)
+                        *f->adaptcoeffs = APESIGN(res) * 8;
+                    else if (absres <= f->avg * 3)
+                        *f->adaptcoeffs = APESIGN(res) * 16;
+                    else
+                        *f->adaptcoeffs = APESIGN(res) * 32;
+                */
             else
                 *f->adaptcoeffs = 0;