amp_filter.c

   1 /*
   2  * Copyright (C) 2009-2010 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 #include <stdbool.h>
  11
  12 #include "para.h"
  13 #include "amp_filter.cmdline.h"
  14 #include "list.h"
  15 #include "sched.h"
  16 #include "ggo.h"
  17 #include "buffer_tree.h"
  18 #include "filter.h"
  19 #include "string.h"
  20 #include "error.h"
  21
  22 extern char *stat_item_values[NUM_STAT_ITEMS];
  23
  24 /** Data specific to the amplify filter. */
  25 struct private_amp_data {
  26         /** Points to the configuration data for this instance of this filter. */
  27         struct amp_filter_args_info *conf;
  28         /** Amplification factor. */
  29         unsigned amp;
  30 };
  31
  32 static void amp_close(struct filter_node *fn)
  33 {
  34         free(fn->private_data);
  35 }
  36
  37 static int amp_parse_config(int argc, char **argv, void **config)
  38 {
  39         struct amp_filter_args_info *amp_conf = para_calloc(sizeof(*amp_conf));
  40         int ret = -E_AMP_SYNTAX;
  41
  42         if (amp_cmdline_parser(argc, argv, amp_conf))
  43                 goto err;
  44         ret = -ERRNO_TO_PARA_ERROR(EINVAL);
  45         if (amp_conf->amp_arg < 0)
  46                 goto err;
  47         *config = amp_conf;
  48         return 1;
  49 err:
  50         free(amp_conf);
  51         return ret;
  52 }
  53
  54 static void amp_open(struct filter_node *fn)
  55 {
  56         struct private_amp_data *pad = para_calloc(sizeof(*pad));
  57
  58         pad->conf = fn->conf;
  59         fn->private_data = pad;
  60         fn->min_iqs = 2;
  61         if (!pad->conf->amp_given && stat_item_values[SI_AMPLIFICATION])
  62                 sscanf(stat_item_values[SI_AMPLIFICATION], "%u", &pad->amp);
  63         else
  64                 pad->amp = pad->conf->amp_arg;
  65         PARA_NOTICE_LOG("amplification: %u (scaling factor: %1.2f)\n",
  66                 pad->amp, pad->amp / 64.0 + 1.0);
  67 }
  68
  69 static void amp_post_select(__a_unused struct sched *s, struct task *t)
  70 {
  71         struct filter_node *fn = container_of(t, struct filter_node, task);
  72         struct private_amp_data *pad = fn->private_data;
  73         struct btr_node *btrn = fn->btrn;
  74         int ret, factor = 64 + pad->amp;
  75         size_t i, in_bytes, len;
  76         int16_t *in, *out;
  77         bool inplace = btr_inplace_ok(btrn);
  78
  79         if (pad->amp == 0) { /* no amplification */
  80                 t->error = -E_AMP_ZERO_AMP;
  81                 btr_splice_out_node(btrn);
  82                 return;
  83         }
  84 next_buffer:
  85         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
  86         if (ret < 0)
  87                 goto err;
  88         if (ret == 0)
  89                 return;
  90         btr_merge(btrn, fn->min_iqs);
  91         in_bytes = btr_next_buffer(btrn, (char **)&in);
  92         len = in_bytes / 2;
  93         if (len == 0) { /* eof and in_bytes == 1 */
  94                 ret = -E_AMP_EOF;
  95                 goto err;
  96         }
  97
  98         if (inplace)
  99                 out = in;
 100         else
 101                 out = para_malloc(len * 2);
 102
 103         for (i = 0; i < len; i++) {
 104                 int x = (in[i] * factor) >> 6;
 105
 106                 out[i] = x;
 107                 if (out[i] != x) /* overflow, clip */
 108                         out[i] = (x >= 0)? 32767 : -32768;
 109         }
 110
 111         if (inplace)
 112                 btr_pushdown_one(btrn);
 113         else {
 114                 btr_consume(btrn, len * 2);
 115                 btr_add_output((char *)out, len * 2, btrn);
 116         }
 117         t->error = 0;
 118         goto next_buffer;
 119 err:
 120         assert(ret < 0);
 121         t->error = ret;
 122         btr_remove_node(btrn);
 123 }
 124
 125 static void amp_free_config(void *conf)
 126 {
 127         amp_cmdline_parser_free(conf);
 128 }
 129
 130 /**
 131  * The init function of the amplify filter.
 132  *
 133  * \param f Pointer to the struct to initialize.
 134  */
 135 void amp_filter_init(struct filter *f)
 136 {
 137         struct amp_filter_args_info dummy;
 138
 139         amp_cmdline_parser_init(&dummy);
 140         f->open = amp_open;
 141         f->close = amp_close;
 142         f->pre_select = generic_filter_pre_select;
 143         f->post_select = amp_post_select;
 144         f->parse_config = amp_parse_config;
 145         f->free_config = amp_free_config;
 146         f->help = (struct ggo_help) {
 147                 .short_help = amp_filter_args_info_help,
 148                 .detailed_help = amp_filter_args_info_detailed_help
 149         };
 150 }