net.c: make it compile without ucred
[paraslash.git] / compress.c
1 /*
2 * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
17 */
18
19 /** \file compress.c paraslash's dynamic audio range compressor */
20
21 /*
22 * Used ideas of AudioCompress, (C) 2002-2004 M. Hari Nezumi <magenta@trikuare.cx>
23 */
24
25 #include "para.h"
26 #include "compress_filter.cmdline.h"
27 #include "list.h"
28 #include "filter.h"
29 #include "string.h"
30
31 /** the size of the output data buffer */
32 #define COMPRESS_CHUNK_SIZE 40960
33
34 /** data specific to the compress filter */
35 struct private_compress_data {
36 /** the current multiplier */
37 unsigned current_gain;
38 /** points to the configuration data for this instance of the compress filter */
39 struct compress_filter_args_info *conf;
40 /** minimal admissible gain */
41 unsigned min_gain;
42 /** maximal admissible gain */
43 unsigned max_gain;
44 /** number of samples already seen */
45 unsigned num_samples;
46 /** absolute value of the maximal sample in the current block */
47 unsigned peak;
48 };
49
50 static ssize_t compress(char *inbuf, size_t inbuf_len, struct filter_node *fn)
51 {
52 size_t i, length = PARA_MIN((inbuf_len / 2) * 2,
53 (fn->bufsize - fn->loaded) / 2 * 2);
54 struct private_compress_data *pcd = fn->private_data;
55 int16_t *ip = (int16_t *)inbuf, *op = (int16_t *)(fn->buf + fn->loaded);
56 unsigned gain_shift = pcd->conf->inertia_arg + pcd->conf->damp_arg,
57 mask = (1 << pcd->conf->blocksize_arg) - 1;
58
59 if (!length)
60 return 0;
61 for (i = 0; i < length / 2; i++) {
62 /* be careful in that heat, my dear */
63 int sample = *ip++, adjusted_sample;
64
65 if (sample > 0) {
66 adjusted_sample = (sample * pcd->current_gain)
67 >> gain_shift;
68 if (unlikely(adjusted_sample > 32767)) {
69 adjusted_sample = 32767;
70 pcd->current_gain = (pcd->current_gain +
71 (1 << pcd->conf->inertia_arg)) / 2;
72 pcd->peak = 0;
73 } else
74 if (adjusted_sample > pcd->peak)
75 pcd->peak = sample;
76 } else {
77 adjusted_sample = -((-sample * pcd->current_gain)
78 >> gain_shift);
79 if (unlikely(adjusted_sample < -32768)) {
80 adjusted_sample = -32768;
81 pcd->current_gain = (pcd->current_gain +
82 (1 << pcd->conf->inertia_arg)) / 2;
83 pcd->peak = 0;
84 } else
85 if (-adjusted_sample > pcd->peak)
86 pcd->peak = -adjusted_sample;
87 }
88 *op++ = adjusted_sample;
89 if (likely(++pcd->num_samples & mask))
90 continue;
91 if (pcd->peak < pcd->conf->target_level_arg) {
92 if (pcd->current_gain < pcd->max_gain)
93 pcd->current_gain++;
94 } else {
95 if (pcd->current_gain > pcd->min_gain + 1)
96 pcd->current_gain -= 2;
97 }
98 // PARA_DEBUG_LOG("gain: %lu, peak: %d\n", pcd->current_gain,
99 // pcd->peak);
100 pcd->peak = 0;
101 // PARA_INFO_LOG("sample: %lu\n", ABS(sample));
102 }
103 fn->loaded += length;
104 return length;
105 }
106
107 static void close_compress(struct filter_node *fn)
108 {
109 free(fn->private_data);
110 free(fn->buf);
111 }
112
113 static void *compress_parse_config(int argc, char **argv)
114 {
115 struct compress_filter_args_info *ret = para_calloc(sizeof(struct compress_filter_args_info));
116 if (!compress_cmdline_parser(argc, argv, ret))
117 return ret;
118 free(ret);
119 return NULL;
120 }
121
122 static void open_compress(struct filter_node *fn)
123 {
124 struct private_compress_data *pcd = para_calloc(
125 sizeof(struct private_compress_data));
126 pcd->conf = fn->conf;
127 fn->private_data = pcd;
128 fn->bufsize = COMPRESS_CHUNK_SIZE;
129 fn->buf = para_malloc(fn->bufsize);
130 pcd->current_gain = 1 << pcd->conf->inertia_arg;
131 pcd->min_gain = 1 << (pcd->conf->inertia_arg - pcd->conf->aggressiveness_arg);
132 pcd->max_gain = 1 << (pcd->conf->inertia_arg + pcd->conf->aggressiveness_arg);
133 }
134
135 /** the init function of the compress filter */
136 void compress_init(struct filter *f)
137 {
138 f->open = open_compress;
139 f->close = close_compress;
140 f->convert = compress;
141 f->print_help = compress_cmdline_parser_print_help;
142 f->parse_config = compress_parse_config;
143 }