2 * Copyright (C) 2009-2012 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. */
12 #include "amp_filter.cmdline.h"
16 #include "buffer_tree.h"
21 extern char *stat_item_values[NUM_STAT_ITEMS];
23 /** Data specific to the amplify filter. */
24 struct private_amp_data {
25 /** Points to the configuration data for this instance of this filter. */
26 struct amp_filter_args_info *conf;
27 /** Amplification factor. */
31 static void amp_close(struct filter_node *fn)
33 free(fn->private_data);
36 static int amp_parse_config(int argc, char **argv, void **config)
38 struct amp_filter_args_info *conf = para_calloc(sizeof(*conf));
39 int ret = -E_AMP_SYNTAX;
41 amp_filter_cmdline_parser(argc, argv, conf);
42 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
43 if (conf->amp_arg < 0)
52 static void amp_open(struct filter_node *fn)
54 struct private_amp_data *pad = para_calloc(sizeof(*pad));
57 fn->private_data = pad;
59 if (!pad->conf->amp_given && stat_item_values[SI_AMPLIFICATION])
60 sscanf(stat_item_values[SI_AMPLIFICATION], "%u", &pad->amp);
62 pad->amp = pad->conf->amp_arg;
63 PARA_NOTICE_LOG("amplification: %u (scaling factor: %1.2f)\n",
64 pad->amp, pad->amp / 64.0 + 1.0);
67 static void amp_post_select(__a_unused struct sched *s, struct task *t)
69 struct filter_node *fn = container_of(t, struct filter_node, task);
70 struct private_amp_data *pad = fn->private_data;
71 struct btr_node *btrn = fn->btrn;
72 int ret, factor = 64 + pad->amp;
73 size_t i, in_bytes, len;
75 bool inplace = btr_inplace_ok(btrn);
77 if (pad->amp == 0) { /* no amplification */
78 t->error = -E_AMP_ZERO_AMP;
79 btr_splice_out_node(btrn);
83 ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
88 btr_merge(btrn, fn->min_iqs);
89 in_bytes = btr_next_buffer(btrn, (char **)&in);
91 if (len == 0) { /* eof and in_bytes == 1 */
99 out = para_malloc(len * 2);
101 for (i = 0; i < len; i++) {
102 int x = (in[i] * factor) >> 6;
105 if (out[i] != x) /* overflow, clip */
106 out[i] = (x >= 0)? 32767 : -32768;
110 btr_pushdown_one(btrn);
112 btr_consume(btrn, len * 2);
113 btr_add_output((char *)out, len * 2, btrn);
120 btr_remove_node(&fn->btrn);
123 static void amp_free_config(void *conf)
125 amp_filter_cmdline_parser_free(conf);
129 * The init function of the amplify filter.
131 * \param f Pointer to the struct to initialize.
133 void amp_filter_init(struct filter *f)
135 struct amp_filter_args_info dummy;
137 amp_filter_cmdline_parser_init(&dummy);
139 f->close = amp_close;
140 f->pre_select = generic_filter_pre_select;
141 f->post_select = amp_post_select;
142 f->parse_config = amp_parse_config;
143 f->free_config = amp_free_config;
144 f->help = (struct ggo_help) {
145 .short_help = amp_filter_args_info_help,
146 .detailed_help = amp_filter_args_info_detailed_help