Merge branch 'maint'
[paraslash.git] / amp_filter.c
1 /*
2 * Copyright (C) 2009 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file amp_filter.c Paraslash's amplify filter. */
8
9 #include <regex.h>
10
11 #include "para.h"
12 #include "amp_filter.cmdline.h"
13 #include "list.h"
14 #include "sched.h"
15 #include "ggo.h"
16 #include "filter.h"
17 #include "string.h"
18 #include "error.h"
19
20 /** The size of the output data buffer. */
21 #define AMP_CHUNK_SIZE 40960
22
23 extern char *stat_item_values[NUM_STAT_ITEMS];
24
25 /** Data specific to the amplify filter. */
26 struct private_amp_data {
27 /** Points to the configuration data for this instance of this filter. */
28 struct amp_filter_args_info *conf;
29 /** Amplification factor. */
30 unsigned amp;
31 };
32
33 static ssize_t amp_convert(char *inbuf, size_t inbuf_len, struct filter_node *fn)
34 {
35 size_t i, length = PARA_MIN((inbuf_len / 2),
36 (fn->bufsize - fn->loaded) / 2);
37 struct private_amp_data *pad = fn->private_data;
38 int16_t *ip = (int16_t *)inbuf, *op = (int16_t *)(fn->buf + fn->loaded);
39 int factor = 64 + pad->amp;
40
41 if (!length)
42 return 0;
43
44 if (pad->amp == 0) {
45 memcpy(op, ip, length * 2);
46 goto out;
47 }
48 for (i = 0; i < length; i++) {
49 int x = (ip[i] * factor) >> 6;
50
51 op[i] = x;
52 if (op[i] != x)
53 op[i] = (x >= 32768)? 32767 : -32768;
54 }
55 out:
56 fn->loaded += length * 2;
57 return length * 2;
58 }
59
60 static void amp_close(struct filter_node *fn)
61 {
62 free(fn->private_data);
63 free(fn->buf);
64 }
65
66 static int amp_parse_config(int argc, char **argv, void **config)
67 {
68 struct amp_filter_args_info *amp_conf = para_calloc(sizeof(*amp_conf));
69 int ret = -E_AMP_SYNTAX;
70
71 if (amp_cmdline_parser(argc, argv, amp_conf))
72 goto err;
73 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
74 if (amp_conf->amp_arg < 0)
75 goto err;
76 PARA_NOTICE_LOG("amplification: %u (scaling factor: %1.2f)\n",
77 amp_conf->amp_arg, amp_conf->amp_arg / 64.0 + 1.0);
78 *config = amp_conf;
79 return 1;
80 err:
81 free(amp_conf);
82 return ret;
83 }
84
85 static void amp_open(struct filter_node *fn)
86 {
87 struct private_amp_data *pad = para_calloc(sizeof(*pad));
88
89 pad->conf = fn->conf;
90 fn->private_data = pad;
91 if (!pad->conf->amp_given && stat_item_values[SI_AMPLIFICATION])
92 sscanf(stat_item_values[SI_AMPLIFICATION], "%u", &pad->amp);
93 else
94 pad->amp = pad->conf->amp_arg;
95 fn->bufsize = AMP_CHUNK_SIZE;
96 fn->buf = para_malloc(fn->bufsize);
97 }
98
99 /**
100 * The init function of the amplify filter.
101 *
102 * \param f Pointer to the struct to initialize.
103 */
104 void amp_filter_init(struct filter *f)
105 {
106 struct amp_filter_args_info dummy;
107
108 amp_cmdline_parser_init(&dummy);
109 f->open = amp_open;
110 f->close = amp_close;
111 f->convert = amp_convert;
112 f->parse_config = amp_parse_config;
113 f->help = (struct ggo_help) {
114 .short_help = amp_filter_args_info_help,
115 .detailed_help = amp_filter_args_info_detailed_help
116 };
117 }