2 * Copyright (C) 2009-2010 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file amp_filter.c Paraslash's amplify filter. */
13 #include "amp_filter.cmdline.h"
17 #include "buffer_tree.h"
22 extern char *stat_item_values[NUM_STAT_ITEMS];
24 /** Data specific to the amplify filter. */
25 struct private_amp_data {
26 /** Points to the configuration data for this instance of this filter. */
27 struct amp_filter_args_info *conf;
28 /** Amplification factor. */
32 static void amp_close(struct filter_node *fn)
34 free(fn->private_data);
37 static int amp_parse_config(int argc, char **argv, void **config)
39 struct amp_filter_args_info *amp_conf = para_calloc(sizeof(*amp_conf));
40 int ret = -E_AMP_SYNTAX;
42 if (amp_cmdline_parser(argc, argv, amp_conf))
44 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
45 if (amp_conf->amp_arg < 0)
54 static void amp_open(struct filter_node *fn)
56 struct private_amp_data *pad = para_calloc(sizeof(*pad));
59 fn->private_data = pad;
61 if (!pad->conf->amp_given && stat_item_values[SI_AMPLIFICATION])
62 sscanf(stat_item_values[SI_AMPLIFICATION], "%u", &pad->amp);
64 pad->amp = pad->conf->amp_arg;
65 PARA_NOTICE_LOG("amplification: %u (scaling factor: %1.2f)\n",
66 pad->amp, pad->amp / 64.0 + 1.0);
69 static void amp_post_select(__a_unused struct sched *s, struct task *t)
71 struct filter_node *fn = container_of(t, struct filter_node, task);
72 struct private_amp_data *pad = fn->private_data;
73 struct btr_node *btrn = fn->btrn;
74 int ret, factor = 64 + pad->amp;
75 size_t i, in_bytes, len;
77 bool inplace = btr_inplace_ok(btrn);
79 if (pad->amp == 0) { /* no amplification */
80 t->error = -E_AMP_ZERO_AMP;
81 btr_splice_out_node(btrn);
85 ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
90 btr_merge(btrn, fn->min_iqs);
91 in_bytes = btr_next_buffer(btrn, (char **)&in);
93 if (len == 0) { /* eof and in_bytes == 1 */
101 out = para_malloc(len * 2);
103 for (i = 0; i < len; i++) {
104 int x = (in[i] * factor) >> 6;
107 if (out[i] != x) /* overflow, clip */
108 out[i] = (x >= 0)? 32767 : -32768;
112 btr_pushdown_one(btrn);
114 btr_consume(btrn, len * 2);
115 btr_add_output((char *)out, len * 2, btrn);
122 btr_remove_node(btrn);
125 static void amp_free_config(void *conf)
127 amp_cmdline_parser_free(conf);
131 * The init function of the amplify filter.
133 * \param f Pointer to the struct to initialize.
135 void amp_filter_init(struct filter *f)
137 struct amp_filter_args_info dummy;
139 amp_cmdline_parser_init(&dummy);
141 f->close = amp_close;
142 f->pre_select = generic_filter_pre_select;
143 f->post_select = amp_post_select;
144 f->parse_config = amp_parse_config;
145 f->free_config = amp_free_config;
146 f->help = (struct ggo_help) {
147 .short_help = amp_filter_args_info_help,
148 .detailed_help = amp_filter_args_info_detailed_help