2 * Copyright (C) 2009 Andre Noll <maan@tuebingen.mpg.de>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file amp_filter.c Paraslash's amplify filter. */
12 #include "filter_cmd.lsg.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 /** Amplification factor. */
29 static void amp_close(struct filter_node *fn)
31 free(fn->private_data);
34 static void amp_open(struct filter_node *fn)
36 struct private_amp_data *pad = para_calloc(sizeof(*pad));
37 unsigned given = FILTER_CMD_OPT_GIVEN(AMP, AMP, fn->lpr);
38 uint32_t amp_arg = FILTER_CMD_OPT_UINT32_VAL(AMP, AMP, fn->lpr);
40 fn->private_data = pad;
42 if (!given && stat_item_values[SI_AMPLIFICATION])
43 sscanf(stat_item_values[SI_AMPLIFICATION], "%u", &pad->amp);
46 PARA_INFO_LOG("amplification: %u (scaling factor: %1.2f)\n",
47 pad->amp, pad->amp / 64.0 + 1.0);
50 static int amp_post_select(__a_unused struct sched *s, void *context)
52 struct filter_node *fn = context;
53 struct private_amp_data *pad = fn->private_data;
54 struct btr_node *btrn = fn->btrn;
55 int ret, factor = 64 + pad->amp;
56 size_t i, in_bytes, len;
58 bool inplace = btr_inplace_ok(btrn);
60 if (pad->amp == 0) { /* no amplification */
61 btr_splice_out_node(&fn->btrn);
62 return -E_AMP_ZERO_AMP;
65 ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
70 btr_merge(btrn, fn->min_iqs);
71 in_bytes = btr_next_buffer(btrn, (char **)&in);
73 if (len == 0) { /* eof and in_bytes == 1 */
81 out = para_malloc(len * 2);
83 for (i = 0; i < len; i++) {
84 int x = (in[i] * factor) >> 6;
87 if (out[i] != x) /* overflow, clip */
88 out[i] = (x >= 0)? 32767 : -32768;
92 btr_pushdown_one(btrn);
94 btr_consume(btrn, len * 2);
95 btr_add_output((char *)out, len * 2, btrn);
100 btr_remove_node(&fn->btrn);
104 const struct filter lsg_filter_cmd_com_amp_user_data = {
107 .pre_select = generic_filter_pre_select,
108 .post_select = amp_post_select,