From d4bdd0473d6f43132257c9fb3848d829755167a3 Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Mon, 5 Nov 2012 17:02:04 +0100
Subject: Rename directories, move files (step 1 of 2) (does not compile)

Tis drops the silly lib prefixes, and attempts to organize the tree in
a more logical way. Make the top-level directory less cluttered as
well.

Renames the following directories:
    libaf -> audio/filter
    libao2 -> audio/out
    libvo -> video/out
    libmpdemux -> demux

Split libmpcodecs:
    vf* -> video/filter
    vd*, dec_video.* -> video/decode
    mp_image*, img_format*, ... -> video/
    ad*, dec_audio.* -> audio/decode

libaf/format.* is moved to audio/ - this is similar to how mp_image.*
is located in video/.

Move most top-level .c/.h files to core. (talloc.c/.h is left on top-
level, because it's external.) Park some of the more annoying files
in compat/. Some of these are relicts from the time mplayer used
ffmpeg internals.

sub/ is not split, because it's too much of a mess (subtitle code is
mixed with OSD display and rendering).

Maybe the organization of core is not ideal: it mixes playback core
(like mplayer.c) and utility helpers (like bstr.c/h). Should the need
arise, the playback core will be moved somewhere else, while core
contains all helper and common code.
---
 audio/filter/window.c | 213 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 213 insertions(+)
 create mode 100644 audio/filter/window.c

(limited to 'audio/filter/window.c')

diff --git a/audio/filter/window.c b/audio/filter/window.c
new file mode 100644
index 0000000000..a970bdcbea
--- /dev/null
+++ b/audio/filter/window.c
@@ -0,0 +1,213 @@
+/*
+ * Copyright (C) 2001 Anders Johansson ajh@atri.curtin.edu.au
+ *
+ * This file is part of MPlayer.
+ *
+ * MPlayer is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * MPlayer is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with MPlayer; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/* Calculates a number of window functions. The following window
+   functions are currently implemented: Boxcar, Triang, Hanning,
+   Hamming, Blackman, Flattop and Kaiser. In the function call n is
+   the number of filter taps and w the buffer in which the filter
+   coefficients will be stored.
+*/
+
+#include <math.h>
+#include "dsp.h"
+
+/*
+// Boxcar
+//
+// n window length
+// w buffer for the window parameters
+*/
+void af_window_boxcar(int n, FLOAT_TYPE* w)
+{
+  int i;
+  // Calculate window coefficients
+  for (i=0 ; i<n ; i++)
+    w[i] = 1.0;
+}
+
+
+/*
+// Triang a.k.a Bartlett
+//
+//               |    (N-1)|
+//           2 * |k - -----|
+//               |      2  |
+// w = 1.0 - ---------------
+//                    N+1
+// n window length
+// w buffer for the window parameters
+*/
+void af_window_triang(int n, FLOAT_TYPE* w)
+{
+  FLOAT_TYPE k1  = (FLOAT_TYPE)(n & 1);
+  FLOAT_TYPE k2  = 1/((FLOAT_TYPE)n + k1);
+  int      end = (n + 1) >> 1;
+  int	   i;
+
+  // Calculate window coefficients
+  for (i=0 ; i<end ; i++)
+    w[i] = w[n-i-1] = (2.0*((FLOAT_TYPE)(i+1))-(1.0-k1))*k2;
+}
+
+
+/*
+// Hanning
+//                   2*pi*k
+// w = 0.5 - 0.5*cos(------), where 0 < k <= N
+//                    N+1
+// n window length
+// w buffer for the window parameters
+*/
+void af_window_hanning(int n, FLOAT_TYPE* w)
+{
+  int	   i;
+  FLOAT_TYPE k = 2*M_PI/((FLOAT_TYPE)(n+1)); // 2*pi/(N+1)
+
+  // Calculate window coefficients
+  for (i=0; i<n; i++)
+    *w++ = 0.5*(1.0 - cos(k*(FLOAT_TYPE)(i+1)));
+}
+
+/*
+// Hamming
+//                        2*pi*k
+// w(k) = 0.54 - 0.46*cos(------), where 0 <= k < N
+//                         N-1
+//
+// n window length
+// w buffer for the window parameters
+*/
+void af_window_hamming(int n,FLOAT_TYPE* w)
+{
+  int      i;
+  FLOAT_TYPE k = 2*M_PI/((FLOAT_TYPE)(n-1)); // 2*pi/(N-1)
+
+  // Calculate window coefficients
+  for (i=0; i<n; i++)
+    *w++ = 0.54 - 0.46*cos(k*(FLOAT_TYPE)i);
+}
+
+/*
+// Blackman
+//                       2*pi*k             4*pi*k
+// w(k) = 0.42 - 0.5*cos(------) + 0.08*cos(------), where 0 <= k < N
+//                        N-1                 N-1
+//
+// n window length
+// w buffer for the window parameters
+*/
+void af_window_blackman(int n,FLOAT_TYPE* w)
+{
+  int      i;
+  FLOAT_TYPE k1 = 2*M_PI/((FLOAT_TYPE)(n-1)); // 2*pi/(N-1)
+  FLOAT_TYPE k2 = 2*k1; // 4*pi/(N-1)
+
+  // Calculate window coefficients
+  for (i=0; i<n; i++)
+    *w++ = 0.42 - 0.50*cos(k1*(FLOAT_TYPE)i) + 0.08*cos(k2*(FLOAT_TYPE)i);
+}
+
+/*
+// Flattop
+//                                        2*pi*k                     4*pi*k
+// w(k) = 0.2810638602 - 0.5208971735*cos(------) + 0.1980389663*cos(------), where 0 <= k < N
+//                                          N-1                        N-1
+//
+// n window length
+// w buffer for the window parameters
+*/
+void af_window_flattop(int n,FLOAT_TYPE* w)
+{
+  int      i;
+  FLOAT_TYPE k1 = 2*M_PI/((FLOAT_TYPE)(n-1)); // 2*pi/(N-1)
+  FLOAT_TYPE k2 = 2*k1;                   // 4*pi/(N-1)
+
+  // Calculate window coefficients
+  for (i=0; i<n; i++)
+    *w++ = 0.2810638602 - 0.5208971735*cos(k1*(FLOAT_TYPE)i)
+                        + 0.1980389663*cos(k2*(FLOAT_TYPE)i);
+}
+
+/* Computes the 0th order modified Bessel function of the first kind.
+// (Needed to compute Kaiser window)
+//
+// y = sum( (x/(2*n))^2 )
+//      n
+*/
+#define BIZ_EPSILON 1E-21 // Max error acceptable
+
+static FLOAT_TYPE besselizero(FLOAT_TYPE x)
+{
+  FLOAT_TYPE temp;
+  FLOAT_TYPE sum   = 1.0;
+  FLOAT_TYPE u     = 1.0;
+  FLOAT_TYPE halfx = x/2.0;
+  int      n     = 1;
+
+  do {
+    temp = halfx/(FLOAT_TYPE)n;
+    u *=temp * temp;
+    sum += u;
+    n++;
+  } while (u >= BIZ_EPSILON * sum);
+  return sum;
+}
+
+/*
+// Kaiser
+//
+// n window length
+// w buffer for the window parameters
+// b beta parameter of Kaiser window, Beta >= 1
+//
+// Beta trades the rejection of the low pass filter against the
+// transition width from passband to stop band.  Larger Beta means a
+// slower transition and greater stop band rejection.  See Rabiner and
+// Gold (Theory and Application of DSP) under Kaiser windows for more
+// about Beta.  The following table from Rabiner and Gold gives some
+// feel for the effect of Beta:
+//
+// All ripples in dB, width of transition band = D*N where N = window
+// length
+//
+// BETA    D       PB RIP   SB RIP
+// 2.120   1.50  +-0.27      -30
+// 3.384   2.23    0.0864    -40
+// 4.538   2.93    0.0274    -50
+// 5.658   3.62    0.00868   -60
+// 6.764   4.32    0.00275   -70
+// 7.865   5.0     0.000868  -80
+// 8.960   5.7     0.000275  -90
+// 10.056  6.4     0.000087  -100
+*/
+void af_window_kaiser(int n, FLOAT_TYPE* w, FLOAT_TYPE b)
+{
+  FLOAT_TYPE tmp;
+  FLOAT_TYPE k1  = 1.0/besselizero(b);
+  int	   k2  = 1 - (n & 1);
+  int      end = (n + 1) >> 1;
+  int      i;
+
+  // Calculate window coefficients
+  for (i=0 ; i<end ; i++){
+    tmp = (FLOAT_TYPE)(2*i + k2) / ((FLOAT_TYPE)n - 1.0);
+    w[end-(1&(!k2))+i] = w[end-1-i] = k1 * besselizero(b*sqrt(1.0 - tmp*tmp));
+  }
+}
-- 
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