amp_filter.c

   1 /* Copyright (C) 2009 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
   2
   3 /** \file amp_filter.c Paraslash's amplify filter. */
   4
   5 #include <regex.h>
   6 #include <lopsub.h>
   7
   8 #include "filter_cmd.lsg.h"
   9 #include "para.h"
  10 #include "list.h"
  11 #include "sched.h"
  12 #include "buffer_tree.h"
  13 #include "filter.h"
  14 #include "string.h"
  15 #include "error.h"
  16
  17 extern char *stat_item_values[NUM_STAT_ITEMS];
  18
  19 /** Data specific to the amplify filter. */
  20 struct private_amp_data {
  21         /** Amplification factor. */
  22         unsigned amp;
  23 };
  24
  25 static void amp_close(struct filter_node *fn)
  26 {
  27         free(fn->private_data);
  28 }
  29
  30 static void amp_open(struct filter_node *fn)
  31 {
  32         struct private_amp_data *pad = para_calloc(sizeof(*pad));
  33         unsigned given = FILTER_CMD_OPT_GIVEN(AMP, AMP, fn->lpr);
  34         uint32_t amp_arg = FILTER_CMD_OPT_UINT32_VAL(AMP, AMP, fn->lpr);
  35
  36         fn->private_data = pad;
  37         fn->min_iqs = 2;
  38         if (!given && stat_item_values[SI_amplification])
  39                 sscanf(stat_item_values[SI_amplification], "%u", &pad->amp);
  40         else
  41                 pad->amp = amp_arg;
  42         PARA_INFO_LOG("amplification: %u (scaling factor: %1.2f)\n",
  43                 pad->amp, pad->amp / 64.0 + 1.0);
  44 }
  45
  46 static int amp_post_select(__a_unused struct sched *s, void *context)
  47 {
  48         struct filter_node *fn = context;
  49         struct private_amp_data *pad = fn->private_data;
  50         struct btr_node *btrn = fn->btrn;
  51         int ret, factor = 64 + pad->amp;
  52         size_t i, in_bytes, len;
  53         int16_t *in, *out;
  54         bool inplace = btr_inplace_ok(btrn);
  55
  56         if (pad->amp == 0) { /* no amplification */
  57                 btr_splice_out_node(&fn->btrn);
  58                 return -E_AMP_ZERO_AMP;
  59         }
  60 next_buffer:
  61         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
  62         if (ret < 0)
  63                 goto err;
  64         if (ret == 0)
  65                 return 0;
  66         btr_merge(btrn, fn->min_iqs);
  67         in_bytes = btr_next_buffer(btrn, (char **)&in);
  68         len = in_bytes / 2;
  69         if (len == 0) { /* eof and in_bytes == 1 */
  70                 ret = -E_AMP_EOF;
  71                 goto err;
  72         }
  73
  74         if (inplace)
  75                 out = in;
  76         else
  77                 out = para_malloc(len * 2);
  78
  79         for (i = 0; i < len; i++) {
  80                 int x = (in[i] * factor) >> 6;
  81
  82                 out[i] = x;
  83                 if (out[i] != x) /* overflow, clip */
  84                         out[i] = (x >= 0)? 32767 : -32768;
  85         }
  86
  87         if (inplace)
  88                 btr_pushdown_one(btrn);
  89         else {
  90                 btr_consume(btrn, len * 2);
  91                 btr_add_output((char *)out, len * 2, btrn);
  92         }
  93         goto next_buffer;
  94 err:
  95         assert(ret < 0);
  96         btr_remove_node(&fn->btrn);
  97         return ret;
  98 }
  99
 100 const struct filter lsg_filter_cmd_com_amp_user_data = {
 101         .open = amp_open,
 102         .close = amp_close,
 103         .pre_select = generic_filter_pre_select,
 104         .post_select = amp_post_select,
 105 };