amp_filter.c

   1 /*
   2  * Copyright (C) 2009-2012 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 "buffer_tree.h"
  17 #include "filter.h"
  18 #include "string.h"
  19 #include "error.h"
  20
  21 extern char *stat_item_values[NUM_STAT_ITEMS];
  22
  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. */
  28         unsigned amp;
  29 };
  30
  31 static void amp_close(struct filter_node *fn)
  32 {
  33         free(fn->private_data);
  34 }
  35
  36 static int amp_parse_config(int argc, char **argv, void **config)
  37 {
  38         struct amp_filter_args_info *amp_conf = para_calloc(sizeof(*amp_conf));
  39         int ret = -E_AMP_SYNTAX;
  40
  41         if (amp_cmdline_parser(argc, argv, amp_conf))
  42                 goto err;
  43         ret = -ERRNO_TO_PARA_ERROR(EINVAL);
  44         if (amp_conf->amp_arg < 0)
  45                 goto err;
  46         *config = amp_conf;
  47         return 1;
  48 err:
  49         free(amp_conf);
  50         return ret;
  51 }
  52
  53 static void amp_open(struct filter_node *fn)
  54 {
  55         struct private_amp_data *pad = para_calloc(sizeof(*pad));
  56
  57         pad->conf = fn->conf;
  58         fn->private_data = pad;
  59         fn->min_iqs = 2;
  60         if (!pad->conf->amp_given && stat_item_values[SI_AMPLIFICATION])
  61                 sscanf(stat_item_values[SI_AMPLIFICATION], "%u", &pad->amp);
  62         else
  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);
  66 }
  67
  68 static void amp_post_select(__a_unused struct sched *s, struct task *t)
  69 {
  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;
  75         int16_t *in, *out;
  76         bool inplace = btr_inplace_ok(btrn);
  77
  78         if (pad->amp == 0) { /* no amplification */
  79                 t->error = -E_AMP_ZERO_AMP;
  80                 btr_splice_out_node(btrn);
  81                 return;
  82         }
  83 next_buffer:
  84         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
  85         if (ret < 0)
  86                 goto err;
  87         if (ret == 0)
  88                 return;
  89         btr_merge(btrn, fn->min_iqs);
  90         in_bytes = btr_next_buffer(btrn, (char **)&in);
  91         len = in_bytes / 2;
  92         if (len == 0) { /* eof and in_bytes == 1 */
  93                 ret = -E_AMP_EOF;
  94                 goto err;
  95         }
  96
  97         if (inplace)
  98                 out = in;
  99         else
 100                 out = para_malloc(len * 2);
 101
 102         for (i = 0; i < len; i++) {
 103                 int x = (in[i] * factor) >> 6;
 104
 105                 out[i] = x;
 106                 if (out[i] != x) /* overflow, clip */
 107                         out[i] = (x >= 0)? 32767 : -32768;
 108         }
 109
 110         if (inplace)
 111                 btr_pushdown_one(btrn);
 112         else {
 113                 btr_consume(btrn, len * 2);
 114                 btr_add_output((char *)out, len * 2, btrn);
 115         }
 116         t->error = 0;
 117         goto next_buffer;
 118 err:
 119         assert(ret < 0);
 120         t->error = ret;
 121         btr_remove_node(btrn);
 122 }
 123
 124 static void amp_free_config(void *conf)
 125 {
 126         amp_cmdline_parser_free(conf);
 127 }
 128
 129 /**
 130  * The init function of the amplify filter.
 131  *
 132  * \param f Pointer to the struct to initialize.
 133  */
 134 void amp_filter_init(struct filter *f)
 135 {
 136         struct amp_filter_args_info dummy;
 137
 138         amp_cmdline_parser_init(&dummy);
 139         f->open = amp_open;
 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
 148         };
 149 }