Add generic ff_sine_window_init function and implement in codecs appropriately

Originally committed as revision 13888 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 7 insertions, 0 deletions

diff --git a/libavcodec/mdct.c b/libavcodec/mdct.c
index c51f809714..07eef2b3d4 100644
--- a/libavcodec/mdct.c
+++ b/libavcodec/mdct.c
@@ -48,6 +48,13 @@ void ff_kbd_window_init(float *window, float alpha, int n)
        window[i] = sqrt(local_window[i] / sum);
 }
 
+// Generate a sine window.
+void ff_sine_window_init(float *window, int n) {
+    int i;
+    for(i = 0; i < n; i++)
+        window[i] = sin((i + 0.5) / (2 * n) * M_PI);
+}
+
 /**
  * init MDCT or IMDCT computation.
  */