amp_filter.c

   1 /*
   2  * Copyright (C) 2009 Andre Noll <maan@tuebingen.mpg.de>
   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         /** Amplification factor. */
  26         unsigned amp;
  27 };
  28
  29 static void amp_close(struct filter_node *fn)
  30 {
  31         free(fn->private_data);
  32 }
  33
  34 static int amp_parse_config(int argc, char **argv, void **config)
  35 {
  36         struct amp_filter_args_info *conf = para_calloc(sizeof(*conf));
  37         int ret;
  38
  39         amp_filter_cmdline_parser(argc, argv, conf);
  40         ret = -ERRNO_TO_PARA_ERROR(EINVAL);
  41         if (conf->amp_arg < 0)
  42                 goto err;
  43         *config = conf;
  44         return 1;
  45 err:
  46         free(conf);
  47         return ret;
  48 }
  49
  50 static void amp_open(struct filter_node *fn)
  51 {
  52         struct private_amp_data *pad = para_calloc(sizeof(*pad));
  53         struct amp_filter_args_info *conf = fn->conf;
  54
  55         fn->private_data = pad;
  56         fn->min_iqs = 2;
  57         if (!conf->amp_given && stat_item_values[SI_AMPLIFICATION])
  58                 sscanf(stat_item_values[SI_AMPLIFICATION], "%u", &pad->amp);
  59         else
  60                 pad->amp = conf->amp_arg;
  61         PARA_INFO_LOG("amplification: %u (scaling factor: %1.2f)\n",
  62                 pad->amp, pad->amp / 64.0 + 1.0);
  63 }
  64
  65 static int amp_post_select(__a_unused struct sched *s, void *context)
  66 {
  67         struct filter_node *fn = context;
  68         struct private_amp_data *pad = fn->private_data;
  69         struct btr_node *btrn = fn->btrn;
  70         int ret, factor = 64 + pad->amp;
  71         size_t i, in_bytes, len;
  72         int16_t *in, *out;
  73         bool inplace = btr_inplace_ok(btrn);
  74
  75         if (pad->amp == 0) { /* no amplification */
  76                 btr_splice_out_node(&fn->btrn);
  77                 return -E_AMP_ZERO_AMP;
  78         }
  79 next_buffer:
  80         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
  81         if (ret < 0)
  82                 goto err;
  83         if (ret == 0)
  84                 return 0;
  85         btr_merge(btrn, fn->min_iqs);
  86         in_bytes = btr_next_buffer(btrn, (char **)&in);
  87         len = in_bytes / 2;
  88         if (len == 0) { /* eof and in_bytes == 1 */
  89                 ret = -E_AMP_EOF;
  90                 goto err;
  91         }
  92
  93         if (inplace)
  94                 out = in;
  95         else
  96                 out = para_malloc(len * 2);
  97
  98         for (i = 0; i < len; i++) {
  99                 int x = (in[i] * factor) >> 6;
 100
 101                 out[i] = x;
 102                 if (out[i] != x) /* overflow, clip */
 103                         out[i] = (x >= 0)? 32767 : -32768;
 104         }
 105
 106         if (inplace)
 107                 btr_pushdown_one(btrn);
 108         else {
 109                 btr_consume(btrn, len * 2);
 110                 btr_add_output((char *)out, len * 2, btrn);
 111         }
 112         goto next_buffer;
 113 err:
 114         assert(ret < 0);
 115         btr_remove_node(&fn->btrn);
 116         return ret;
 117 }
 118
 119 static void amp_free_config(void *conf)
 120 {
 121         amp_filter_cmdline_parser_free(conf);
 122 }
 123
 124 /**
 125  * The init function of the amplify filter.
 126  *
 127  * \param f Pointer to the struct to initialize.
 128  */
 129 void amp_filter_init(struct filter *f)
 130 {
 131         struct amp_filter_args_info dummy;
 132
 133         amp_filter_cmdline_parser_init(&dummy);
 134         f->open = amp_open;
 135         f->close = amp_close;
 136         f->pre_select = generic_filter_pre_select;
 137         f->post_select = amp_post_select;
 138         f->parse_config = amp_parse_config;
 139         f->free_config = amp_free_config;
 140         f->help = (struct ggo_help)DEFINE_GGO_HELP(amp_filter);
 141 }