2 * Copyright (C) 2009-2011 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 *amp_conf = para_calloc(sizeof(*amp_conf));
39 int ret = -E_AMP_SYNTAX;
41 if (amp_cmdline_parser(argc, argv, amp_conf))
43 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
44 if (amp_conf->amp_arg < 0)
53 static void amp_open(struct filter_node *fn)
55 struct private_amp_data *pad = para_calloc(sizeof(*pad));
58 fn->private_data = pad;
60 if (!pad->conf->amp_given && stat_item_values[SI_AMPLIFICATION])
61 sscanf(stat_item_values[SI_AMPLIFICATION], "%u", &pad->amp);
63 pad->amp = pad->conf->amp_arg;
64 PARA_NOTICE_LOG("amplification: %u (scaling factor: %1.2f)\n",
65 pad->amp, pad->amp / 64.0 + 1.0);
68 static void amp_post_select(__a_unused struct sched *s, struct task *t)
70 struct filter_node *fn = container_of(t, struct filter_node, task);
71 struct private_amp_data *pad = fn->private_data;
72 struct btr_node *btrn = fn->btrn;
73 int ret, factor = 64 + pad->amp;
74 size_t i, in_bytes, len;
76 bool inplace = btr_inplace_ok(btrn);
78 if (pad->amp == 0) { /* no amplification */
79 t->error = -E_AMP_ZERO_AMP;
80 btr_splice_out_node(btrn);
84 ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
89 btr_merge(btrn, fn->min_iqs);
90 in_bytes = btr_next_buffer(btrn, (char **)&in);
92 if (len == 0) { /* eof and in_bytes == 1 */
100 out = para_malloc(len * 2);
102 for (i = 0; i < len; i++) {
103 int x = (in[i] * factor) >> 6;
106 if (out[i] != x) /* overflow, clip */
107 out[i] = (x >= 0)? 32767 : -32768;
111 btr_pushdown_one(btrn);
113 btr_consume(btrn, len * 2);
114 btr_add_output((char *)out, len * 2, btrn);
121 btr_remove_node(btrn);
124 static void amp_free_config(void *conf)
126 amp_cmdline_parser_free(conf);
130 * The init function of the amplify filter.
132 * \param f Pointer to the struct to initialize.
134 void amp_filter_init(struct filter *f)
136 struct amp_filter_args_info dummy;
138 amp_cmdline_parser_init(&dummy);
140 f->close = amp_close;
141 f->pre_select = generic_filter_pre_select;
142 f->post_select = amp_post_select;
143 f->parse_config = amp_parse_config;
144 f->free_config = amp_free_config;
145 f->help = (struct ggo_help) {
146 .short_help = amp_filter_args_info_help,
147 .detailed_help = amp_filter_args_info_detailed_help