Merge branch 't/image-0.5'
[paraslash.git] / compress_filter.c
1 /*
2 * Copyright (C) 2005-2013 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
15 #include "para.h"
16 #include "compress_filter.cmdline.h"
17 #include "list.h"
18 #include "sched.h"
19 #include "ggo.h"
20 #include "buffer_tree.h"
21 #include "filter.h"
22 #include "string.h"
23 #include "error.h"
24
25 /** Data specific to the compress filter. */
26 struct private_compress_data {
27 /** The current multiplier. */
28 unsigned current_gain;
29 /** Points to the configuration data for this instance of the compress filter. */
30 struct compress_filter_args_info *conf;
31 /** Maximal admissible gain. */
32 unsigned max_gain;
33 /** Number of samples already seen. */
34 unsigned num_samples;
35 /** Absolute value of the maximal sample in the current block. */
36 int peak;
37 };
38
39 static void compress_close(struct filter_node *fn)
40 {
41 free(fn->private_data);
42 }
43
44 static int compress_post_select(__a_unused struct sched *s, struct task *t)
45 {
46 struct filter_node *fn = container_of(t, struct filter_node, task);
47 struct private_compress_data *pcd = fn->private_data;
48 struct btr_node *btrn = fn->btrn;
49 bool inplace = btr_inplace_ok(btrn);
50 int ret;
51 char *inbuf;
52 size_t length, i;
53 int16_t *ip, *op;
54 unsigned gain_shift = pcd->conf->inertia_arg + pcd->conf->damp_arg,
55 mask = (1 << pcd->conf->blocksize_arg) - 1;
56
57 //inplace = false;
58 next_buffer:
59 ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
60 if (ret < 0)
61 goto err;
62 if (ret == 0)
63 return 0;
64 btr_merge(btrn, fn->min_iqs);
65 length = btr_next_buffer(btrn, &inbuf) & ~(size_t)1;
66 if (length == 0) { /* eof and 1 byte available */
67 ret = -E_COMPRESS_EOF;
68 goto err;
69 }
70 ip = (int16_t *)inbuf;
71 if (inplace)
72 op = ip;
73 else
74 op = para_malloc(length);
75 for (i = 0; i < length / 2; i++) {
76 /* be careful in that heat, my dear */
77 int sample = *ip++;
78 bool neg = false;
79
80 if (sample < 0) {
81 sample = -sample;
82 neg = true;
83 }
84 sample *= pcd->current_gain;
85 sample >>= gain_shift;
86 if (sample > 32767) { /* clip */
87 sample = 32767;
88 pcd->current_gain = (3 * pcd->current_gain +
89 (1 << pcd->conf->inertia_arg)) / 4;
90 pcd->peak = 0;
91 } else if (sample > pcd->peak)
92 pcd->peak = sample;
93 op[i] = neg? -sample : sample;
94 if (++pcd->num_samples & mask)
95 continue;
96 // PARA_DEBUG_LOG("gain: %u, peak: %u\n", pcd->current_gain,
97 // pcd->peak);
98 if (pcd->peak < pcd->conf->target_level_arg) {
99 if (pcd->current_gain < pcd->max_gain)
100 pcd->current_gain++;
101 } else
102 pcd->current_gain = PARA_MAX(pcd->current_gain - 2,
103 1U << pcd->conf->inertia_arg);
104 pcd->peak = 0;
105 }
106 if (inplace)
107 btr_pushdown_one(btrn);
108 else {
109 btr_consume(btrn, length);
110 btr_add_output((char *)op, length, btrn);
111 }
112 goto next_buffer;
113 err:
114 assert(ret < 0);
115 btr_remove_node(&fn->btrn);
116 return ret;
117 }
118
119 /** TODO: Add sanity checks */
120 static int compress_parse_config(int argc, char **argv, void **config)
121 {
122 struct compress_filter_args_info *conf = para_calloc(sizeof(*conf));
123
124 compress_filter_cmdline_parser(argc, argv, conf);
125 *config = conf;
126 return 1;
127 }
128
129 static void compress_open(struct filter_node *fn)
130 {
131 struct private_compress_data *pcd = para_calloc(
132 sizeof(struct private_compress_data));
133 pcd->conf = fn->conf;
134 fn->private_data = pcd;
135 fn->min_iqs = 2; /* 16 bit audio */
136 pcd->current_gain = 1 << pcd->conf->inertia_arg;
137 pcd->max_gain = 1 << (pcd->conf->inertia_arg + pcd->conf->aggressiveness_arg);
138 }
139
140 static void compress_free_config(void *conf)
141 {
142 compress_filter_cmdline_parser_free(conf);
143 }
144
145 /**
146 * The init function of the compress filter.
147 *
148 * \param f Pointer to the struct to initialize.
149 */
150 void compress_filter_init(struct filter *f)
151 {
152 struct compress_filter_args_info dummy;
153
154 compress_filter_cmdline_parser_init(&dummy);
155 f->open = compress_open;
156 f->close = compress_close;
157 f->pre_select = generic_filter_pre_select;
158 f->post_select = compress_post_select;
159 f->parse_config = compress_parse_config;
160 f->free_config = compress_free_config;
161 f->help = (struct ggo_help)DEFINE_GGO_HELP(compress_filter);
162 }