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 *amp_conf = para_calloc(sizeof(*amp_conf));
  38         int ret = -E_AMP_SYNTAX;
  39
  40         if (amp_filter_cmdline_parser(argc, argv, amp_conf))
  41                 goto err;
  42         ret = -ERRNO_TO_PARA_ERROR(EINVAL);
  43         if (amp_conf->amp_arg < 0)
  44                 goto err;
  45         *config = amp_conf;
  46         return 1;
  47 err:
  48         free(amp_conf);
  49         return ret;
  50 }
  51
  52 static void amp_open(struct filter_node *fn)
  53 {
  54         struct private_amp_data *pad = para_calloc(sizeof(*pad));
  55         struct amp_filter_args_info *conf = fn->conf;
  56
  57         fn->private_data = pad;
  58         fn->min_iqs = 2;
  59         if (!conf->amp_given && stat_item_values[SI_AMPLIFICATION])
  60                 sscanf(stat_item_values[SI_AMPLIFICATION], "%u", &pad->amp);
  61         else
  62                 pad->amp = conf->amp_arg;
  63         PARA_NOTICE_LOG("amplification: %u (scaling factor: %1.2f)\n",
  64                 pad->amp, pad->amp / 64.0 + 1.0);
  65 }
  66
  67 static void amp_post_select(__a_unused struct sched *s, struct task *t)
  68 {
  69         struct filter_node *fn = container_of(t, struct filter_node, task);
  70         struct private_amp_data *pad = fn->private_data;
  71         struct btr_node *btrn = fn->btrn;
  72         int ret, factor = 64 + pad->amp;
  73         size_t i, in_bytes, len;
  74         int16_t *in, *out;
  75         bool inplace = btr_inplace_ok(btrn);
  76
  77         if (pad->amp == 0) { /* no amplification */
  78                 t->error = -E_AMP_ZERO_AMP;
  79                 btr_splice_out_node(btrn);
  80                 return;
  81         }
  82 next_buffer:
  83         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
  84         if (ret < 0)
  85                 goto err;
  86         if (ret == 0)
  87                 return;
  88         btr_merge(btrn, fn->min_iqs);
  89         in_bytes = btr_next_buffer(btrn, (char **)&in);
  90         len = in_bytes / 2;
  91         if (len == 0) { /* eof and in_bytes == 1 */
  92                 ret = -E_AMP_EOF;
  93                 goto err;
  94         }
  95
  96         if (inplace)
  97                 out = in;
  98         else
  99                 out = para_malloc(len * 2);
 100
 101         for (i = 0; i < len; i++) {
 102                 int x = (in[i] * factor) >> 6;
 103
 104                 out[i] = x;
 105                 if (out[i] != x) /* overflow, clip */
 106                         out[i] = (x >= 0)? 32767 : -32768;
 107         }
 108
 109         if (inplace)
 110                 btr_pushdown_one(btrn);
 111         else {
 112                 btr_consume(btrn, len * 2);
 113                 btr_add_output((char *)out, len * 2, btrn);
 114         }
 115         t->error = 0;
 116         goto next_buffer;
 117 err:
 118         assert(ret < 0);
 119         t->error = ret;
 120         btr_remove_node(&fn->btrn);
 121 }
 122
 123 static void amp_free_config(void *conf)
 124 {
 125         amp_filter_cmdline_parser_free(conf);
 126 }
 127
 128 /**
 129  * The init function of the amplify filter.
 130  *
 131  * \param f Pointer to the struct to initialize.
 132  */
 133 void amp_filter_init(struct filter *f)
 134 {
 135         struct amp_filter_args_info dummy;
 136
 137         amp_filter_cmdline_parser_init(&dummy);
 138         f->open = amp_open;
 139         f->close = amp_close;
 140         f->pre_select = generic_filter_pre_select;
 141         f->post_select = amp_post_select;
 142         f->parse_config = amp_parse_config;
 143         f->free_config = amp_free_config;
 144         f->help = (struct ggo_help) {
 145                 .short_help = amp_filter_args_info_help,
 146                 .detailed_help = amp_filter_args_info_detailed_help
 147         };
 148 }