compress.c: Cosmetics.

[paraslash.git] / compress.c

diff --git a/compress.c b/compress.c
index de5448fb9eb9f5ebb33f7dffaf58ec246e270a31..1ea41107e252f80c14810c6c11720e3e2ab28b07 100644 (file)
--- a/compress.c
+++ b/compress.c
@@ -1,55 +1,45 @@
 /*
- * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
  *
- *     This program 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.
- *
- *     This program 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 this program; if not, write to the Free Software
- *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ * Licensed under the GPL v2. For licencing details see COPYING.
  */
 
-/** \file compress.c paraslash's dynamic audio range compressor */
+/** \file compress.c Paraslash's dynamic audio range compressor. */
 
 /*
- * Used ideas of AudioCompress, (C) 2002-2004  M. Hari Nezumi <magenta@trikuare.cx>
+ * Uses ideas of AudioCompress, (C) 2002-2004  M. Hari Nezumi <magenta@trikuare.cx>
  */
 
 #include "para.h"
 #include "compress_filter.cmdline.h"
 #include "list.h"
+#include "sched.h"
 #include "filter.h"
 #include "string.h"
 
-/** the size of the output data buffer */
+/** The size of the output data buffer. */
 #define COMPRESS_CHUNK_SIZE 40960
 
-/** data specific to the compress filter */
+/** Data specific to the compress filter. */
 struct private_compress_data {
-       /** the current multiplier */
+       /** The current multiplier. */
        unsigned current_gain;
-       /** points to the configuration data for this instance of the compress filter */
+       /** Points to the configuration data for this instance of the compress filter. */
        struct compress_filter_args_info *conf;
-       /** minimal admissible gain */
+       /** Minimal admissible gain. */
        unsigned min_gain;
-       /** maximal admissible gain */
+       /** Maximal admissible gain. */
        unsigned max_gain;
-       /** number of samples already seen */
+       /** Number of samples already seen. */
        unsigned num_samples;
-       /** absolute value of the maximal sample in the current block */
+       /** Absolute value of the maximal sample in the current block. */
        unsigned peak;
 };
 
 static ssize_t compress(char *inbuf, size_t inbuf_len, struct filter_node *fn)
 {
-       size_t i, length = MIN((inbuf_len / 2) * 2, (fn->bufsize - fn->loaded) / 2 * 2);
+       size_t i, length = PARA_MIN((inbuf_len / 2) * 2,
+               (fn->bufsize - fn->loaded) / 2 * 2);
        struct private_compress_data *pcd = fn->private_data;
        int16_t *ip = (int16_t *)inbuf, *op = (int16_t *)(fn->buf + fn->loaded);
        unsigned gain_shift = pcd->conf->inertia_arg + pcd->conf->damp_arg,
@@ -66,19 +56,19 @@ static ssize_t compress(char *inbuf, size_t inbuf_len, struct filter_node *fn)
                                >> gain_shift;
                        if (unlikely(adjusted_sample > 32767)) {
                                adjusted_sample = 32767;
-                               pcd->current_gain = (pcd->current_gain +
-                                       (1 << pcd->conf->inertia_arg)) / 2;
+                               pcd->current_gain = (3 * pcd->current_gain +
+                                       (1 << pcd->conf->inertia_arg)) / 4;
                                pcd->peak = 0;
                        } else
                                if (adjusted_sample > pcd->peak)
-                                       pcd->peak = sample;
+                                       pcd->peak = adjusted_sample;
                } else {
                        adjusted_sample = -((-sample * pcd->current_gain)
                                >> gain_shift);
                        if (unlikely(adjusted_sample < -32768)) {
                                adjusted_sample = -32768;
-                               pcd->current_gain = (pcd->current_gain +
-                                       (1 << pcd->conf->inertia_arg)) / 2;
+                               pcd->current_gain = (3 * pcd->current_gain +
+                                       (1 << pcd->conf->inertia_arg)) / 4;
                                pcd->peak = 0;
                        } else
                                if (-adjusted_sample > pcd->peak)
@@ -131,7 +121,11 @@ static void open_compress(struct filter_node *fn)
        pcd->max_gain = 1 << (pcd->conf->inertia_arg + pcd->conf->aggressiveness_arg);
 }
 
-/** the init function of the compress filter */
+/**
+ * The init function of the compress filter.
+ *
+ * \param f Pointer to the struct to initialize.
+ */
 void compress_init(struct filter *f)
 {
        f->open = open_compress;