Add btr support to filter code.
[paraslash.git] / compress_filter.c
1 /*
2 * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file compress_filter.c Paraslash's dynamic audio range compressor. */
8
9 /*
10 * Uses ideas of AudioCompress, (C) 2002-2004 M. Hari Nezumi <magenta@trikuare.cx>
11 */
12
13 #include <regex.h>
14 #include <stdbool.h>
15
16 #include "para.h"
17 #include "compress_filter.cmdline.h"
18 #include "list.h"
19 #include "sched.h"
20 #include "ggo.h"
21 #include "buffer_tree.h"
22 #include "filter.h"
23 #include "string.h"
24 #include "error.h"
25
26 /** The size of the output data buffer. */
27 #define COMPRESS_CHUNK_SIZE 40960
28
29 /** Data specific to the compress filter. */
30 struct private_compress_data {
31 /** The current multiplier. */
32 unsigned current_gain;
33 /** Points to the configuration data for this instance of the compress filter. */
34 struct compress_filter_args_info *conf;
35 /** Maximal admissible gain. */
36 unsigned max_gain;
37 /** Number of samples already seen. */
38 unsigned num_samples;
39 /** Absolute value of the maximal sample in the current block. */
40 int peak;
41 };
42
43 static ssize_t compress(char *inbuf, size_t inbuf_len, struct filter_node *fn)
44 {
45 size_t i, length = PARA_MIN((inbuf_len / 2) * 2,
46 (fn->bufsize - fn->loaded) / 2 * 2);
47 struct private_compress_data *pcd = fn->private_data;
48 int16_t *ip = (int16_t *)inbuf, *op = (int16_t *)(fn->buf + fn->loaded);
49 unsigned gain_shift = pcd->conf->inertia_arg + pcd->conf->damp_arg,
50 mask = (1 << pcd->conf->blocksize_arg) - 1;
51
52 if (!length)
53 return 0;
54 for (i = 0; i < length / 2; i++) {
55 /* be careful in that heat, my dear */
56 int sample = *ip++, adjusted_sample = (PARA_ABS(sample) *
57 pcd->current_gain) >> gain_shift;
58 if (adjusted_sample > 32767) { /* clip */
59 PARA_NOTICE_LOG("clip: sample: %d, adjusted sample: %d\n",
60 sample, adjusted_sample);
61 adjusted_sample = 32767;
62 pcd->current_gain = (3 * pcd->current_gain +
63 (1 << pcd->conf->inertia_arg)) / 4;
64 pcd->peak = 0;
65 } else
66 pcd->peak = PARA_MAX(pcd->peak, adjusted_sample);
67 *op++ = sample >= 0? adjusted_sample : -adjusted_sample;
68 if (++pcd->num_samples & mask)
69 continue;
70 // PARA_DEBUG_LOG("gain: %u, peak: %u\n", pcd->current_gain,
71 // pcd->peak);
72 if (pcd->peak < pcd->conf->target_level_arg) {
73 if (pcd->current_gain < pcd->max_gain)
74 pcd->current_gain++;
75 } else
76 pcd->current_gain = PARA_MAX(pcd->current_gain - 2,
77 1U << pcd->conf->inertia_arg);
78 pcd->peak = 0;
79 }
80 fn->loaded += length;
81 return length;
82 }
83
84 static void close_compress(struct filter_node *fn)
85 {
86 free(fn->private_data);
87 free(fn->buf);
88 }
89
90 /** TODO: Add sanity checks */
91 static int compress_parse_config(int argc, char **argv, void **config)
92 {
93 int ret;
94 struct compress_filter_args_info *compress_conf
95 = para_calloc(sizeof(*compress_conf));
96
97 ret = -E_COMPRESS_SYNTAX;
98 if (compress_cmdline_parser(argc, argv, compress_conf))
99 goto err;
100 *config = compress_conf;
101 return 1;
102 err:
103 free(compress_conf);
104 return ret;
105 }
106
107 static void open_compress(struct filter_node *fn)
108 {
109 struct private_compress_data *pcd = para_calloc(
110 sizeof(struct private_compress_data));
111 pcd->conf = fn->conf;
112 fn->private_data = pcd;
113 fn->bufsize = COMPRESS_CHUNK_SIZE;
114 fn->buf = para_malloc(fn->bufsize);
115 pcd->current_gain = 1 << pcd->conf->inertia_arg;
116 pcd->max_gain = 1 << (pcd->conf->inertia_arg + pcd->conf->aggressiveness_arg);
117 }
118
119 /**
120 * The init function of the compress filter.
121 *
122 * \param f Pointer to the struct to initialize.
123 */
124 void compress_filter_init(struct filter *f)
125 {
126 struct compress_filter_args_info dummy;
127
128 compress_cmdline_parser_init(&dummy);
129 f->open = open_compress;
130 f->close = close_compress;
131 f->convert = compress;
132 f->parse_config = compress_parse_config;
133 f->help = (struct ggo_help) {
134 .short_help = compress_filter_args_info_help,
135 .detailed_help = compress_filter_args_info_detailed_help
136 };
137 }