amp_filter.c

   1 /*
   2  * Copyright (C) 2009 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 /** The size of the output data buffer. */
  23 #define AMP_CHUNK_SIZE 40960
  24
  25 extern char *stat_item_values[NUM_STAT_ITEMS];
  26
  27 /** Data specific to the amplify filter. */
  28 struct private_amp_data {
  29         /** Points to the configuration data for this instance of this filter. */
  30         struct amp_filter_args_info *conf;
  31         /** Amplification factor. */
  32         unsigned amp;
  33 };
  34
  35 static void amp_close(struct filter_node *fn)
  36 {
  37         free(fn->private_data);
  38         free(fn->buf);
  39 }
  40
  41 static int amp_parse_config(int argc, char **argv, void **config)
  42 {
  43         struct amp_filter_args_info *amp_conf = para_calloc(sizeof(*amp_conf));
  44         int ret = -E_AMP_SYNTAX;
  45
  46         if (amp_cmdline_parser(argc, argv, amp_conf))
  47                 goto err;
  48         ret = -ERRNO_TO_PARA_ERROR(EINVAL);
  49         if (amp_conf->amp_arg < 0)
  50                 goto err;
  51         *config = amp_conf;
  52         return 1;
  53 err:
  54         free(amp_conf);
  55         return ret;
  56 }
  57
  58 static void amp_open(struct filter_node *fn)
  59 {
  60         struct private_amp_data *pad = para_calloc(sizeof(*pad));
  61
  62         pad->conf = fn->conf;
  63         fn->private_data = pad;
  64         fn->min_iqs = 2;
  65         if (!pad->conf->amp_given && stat_item_values[SI_AMPLIFICATION])
  66                 sscanf(stat_item_values[SI_AMPLIFICATION], "%u", &pad->amp);
  67         else
  68                 pad->amp = pad->conf->amp_arg;
  69         fn->bufsize = AMP_CHUNK_SIZE;
  70         fn->buf = para_malloc(fn->bufsize);
  71         PARA_NOTICE_LOG("amplification: %u (scaling factor: %1.2f)\n",
  72                 pad->amp, pad->amp / 64.0 + 1.0);
  73 }
  74
  75 static void amp_post_select(__a_unused struct sched *s, struct task *t)
  76 {
  77         struct filter_node *fn = container_of(t, struct filter_node, task);
  78         struct private_amp_data *pad = fn->private_data;
  79         struct btr_node *btrn = fn->btrn;
  80         int ret, factor = 64 + pad->amp;
  81         size_t i, in_bytes, len;
  82         int16_t *in, *out;
  83         bool inplace = btr_inplace_ok(btrn);
  84
  85         if (pad->amp == 0) { /* no amplification */
  86                 t->error = -E_AMP_ZERO_AMP;
  87                 btr_splice_out_node(btrn);
  88                 return;
  89         }
  90 next_buffer:
  91         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
  92         if (ret < 0)
  93                 goto err;
  94         if (ret == 0)
  95                 return;
  96         btr_merge(btrn, fn->min_iqs);
  97         in_bytes = btr_next_buffer(btrn, (char **)&in);
  98         len = in_bytes / 2;
  99         if (len == 0) { /* eof and in_bytes == 1 */
 100                 ret = -E_AMP_EOF;
 101                 goto err;
 102         }
 103
 104         if (inplace)
 105                 out = in;
 106         else
 107                 out = para_malloc(len * 2);
 108
 109         for (i = 0; i < len; i++) {
 110                 int x = (in[i] * factor) >> 6;
 111
 112                 out[i] = x;
 113                 if (out[i] != x) /* overflow, clip */
 114                         out[i] = (x >= 0)? 32767 : -32768;
 115         }
 116
 117         if (inplace)
 118                 btr_pushdown_one(btrn);
 119         else {
 120                 btr_consume(btrn, len * 2);
 121                 btr_add_output((char *)out, len * 2, btrn);
 122         }
 123         t->error = 0;
 124         goto next_buffer;
 125 err:
 126         assert(ret < 0);
 127         t->error = ret;
 128         btr_remove_node(btrn);
 129 }
 130
 131 static void amp_free_config(void *conf)
 132 {
 133         amp_cmdline_parser_free(conf);
 134 }
 135
 136 /**
 137  * The init function of the amplify filter.
 138  *
 139  * \param f Pointer to the struct to initialize.
 140  */
 141 void amp_filter_init(struct filter *f)
 142 {
 143         struct amp_filter_args_info dummy;
 144
 145         amp_cmdline_parser_init(&dummy);
 146         f->open = amp_open;
 147         f->close = amp_close;
 148         f->pre_select = generic_filter_pre_select;
 149         f->post_select = amp_post_select;
 150         f->parse_config = amp_parse_config;
 151         f->free_config = amp_free_config;
 152         f->help = (struct ggo_help) {
 153                 .short_help = amp_filter_args_info_help,
 154                 .detailed_help = amp_filter_args_info_detailed_help
 155         };
 156 }