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         /** Amplification factor. */
  27         unsigned amp;
  28 };
  29
  30 static void amp_close(struct filter_node *fn)
  31 {
  32         free(fn->private_data);
  33 }
  34
  35 static int amp_parse_config(int argc, char **argv, void **config)
  36 {
  37         struct amp_filter_args_info *conf = para_calloc(sizeof(*conf));
  38         int ret = -E_AMP_SYNTAX;
  39
  40         amp_filter_cmdline_parser(argc, argv, conf);
  41         ret = -ERRNO_TO_PARA_ERROR(EINVAL);
  42         if (conf->amp_arg < 0)
  43                 goto err;
  44         *config = conf;
  45         return 1;
  46 err:
  47         free(conf);
  48         return ret;
  49 }
  50
  51 static void amp_open(struct filter_node *fn)
  52 {
  53         struct private_amp_data *pad = para_calloc(sizeof(*pad));
  54         struct amp_filter_args_info *conf = fn->conf;
  55
  56         fn->private_data = pad;
  57         fn->min_iqs = 2;
  58         if (!conf->amp_given && stat_item_values[SI_AMPLIFICATION])
  59                 sscanf(stat_item_values[SI_AMPLIFICATION], "%u", &pad->amp);
  60         else
  61                 pad->amp = conf->amp_arg;
  62         PARA_NOTICE_LOG("amplification: %u (scaling factor: %1.2f)\n",
  63                 pad->amp, pad->amp / 64.0 + 1.0);
  64 }
  65
  66 static void amp_post_select(__a_unused struct sched *s, struct task *t)
  67 {
  68         struct filter_node *fn = container_of(t, struct filter_node, task);
  69         struct private_amp_data *pad = fn->private_data;
  70         struct btr_node *btrn = fn->btrn;
  71         int ret, factor = 64 + pad->amp;
  72         size_t i, in_bytes, len;
  73         int16_t *in, *out;
  74         bool inplace = btr_inplace_ok(btrn);
  75
  76         if (pad->amp == 0) { /* no amplification */
  77                 t->error = -E_AMP_ZERO_AMP;
  78                 btr_splice_out_node(btrn);
  79                 return;
  80         }
  81 next_buffer:
  82         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
  83         if (ret < 0)
  84                 goto err;
  85         if (ret == 0)
  86                 return;
  87         btr_merge(btrn, fn->min_iqs);
  88         in_bytes = btr_next_buffer(btrn, (char **)&in);
  89         len = in_bytes / 2;
  90         if (len == 0) { /* eof and in_bytes == 1 */
  91                 ret = -E_AMP_EOF;
  92                 goto err;
  93         }
  94
  95         if (inplace)
  96                 out = in;
  97         else
  98                 out = para_malloc(len * 2);
  99
 100         for (i = 0; i < len; i++) {
 101                 int x = (in[i] * factor) >> 6;
 102
 103                 out[i] = x;
 104                 if (out[i] != x) /* overflow, clip */
 105                         out[i] = (x >= 0)? 32767 : -32768;
 106         }
 107
 108         if (inplace)
 109                 btr_pushdown_one(btrn);
 110         else {
 111                 btr_consume(btrn, len * 2);
 112                 btr_add_output((char *)out, len * 2, btrn);
 113         }
 114         t->error = 0;
 115         goto next_buffer;
 116 err:
 117         assert(ret < 0);
 118         t->error = ret;
 119         btr_remove_node(&fn->btrn);
 120 }
 121
 122 static void amp_free_config(void *conf)
 123 {
 124         amp_filter_cmdline_parser_free(conf);
 125 }
 126
 127 /**
 128  * The init function of the amplify filter.
 129  *
 130  * \param f Pointer to the struct to initialize.
 131  */
 132 void amp_filter_init(struct filter *f)
 133 {
 134         struct amp_filter_args_info dummy;
 135
 136         amp_filter_cmdline_parser_init(&dummy);
 137         f->open = amp_open;
 138         f->close = amp_close;
 139         f->pre_select = generic_filter_pre_select;
 140         f->post_select = amp_post_select;
 141         f->parse_config = amp_parse_config;
 142         f->free_config = amp_free_config;
 143         f->help = (struct ggo_help) {
 144                 .short_help = amp_filter_args_info_help,
 145                 .detailed_help = amp_filter_args_info_detailed_help
 146         };
 147 }