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 ssize_t amp_convert(char *inbuf, size_t inbuf_len, struct filter_node *fn)
  36 {
  37         size_t i, length = PARA_MIN((inbuf_len / 2),
  38                 (fn->bufsize - fn->loaded) / 2);
  39         struct private_amp_data *pad = fn->private_data;
  40         int16_t *ip = (int16_t *)inbuf, *op = (int16_t *)(fn->buf + fn->loaded);
  41         int factor = 64 + pad->amp;
  42
  43         if (!length)
  44                 return 0;
  45
  46         if (pad->amp == 0) {
  47                 memcpy(op, ip, length * 2);
  48                 goto out;
  49         }
  50         for (i = 0; i < length; i++) {
  51                 int x = (ip[i] * factor) >> 6;
  52
  53                 op[i] = x;
  54                 if (op[i] != x)
  55                         op[i] = (x >= 32768)? 32767 : -32768;
  56         }
  57 out:
  58         fn->loaded += length * 2;
  59         return length * 2;
  60 }
  61
  62 static void amp_close(struct filter_node *fn)
  63 {
  64         free(fn->private_data);
  65         free(fn->buf);
  66 }
  67
  68 static int amp_parse_config(int argc, char **argv, void **config)
  69 {
  70         struct amp_filter_args_info *amp_conf = para_calloc(sizeof(*amp_conf));
  71         int ret = -E_AMP_SYNTAX;
  72
  73         if (amp_cmdline_parser(argc, argv, amp_conf))
  74                 goto err;
  75         ret = -ERRNO_TO_PARA_ERROR(EINVAL);
  76         if (amp_conf->amp_arg < 0)
  77                 goto err;
  78         *config = amp_conf;
  79         return 1;
  80 err:
  81         free(amp_conf);
  82         return ret;
  83 }
  84
  85 static void amp_open(struct filter_node *fn)
  86 {
  87         struct private_amp_data *pad = para_calloc(sizeof(*pad));
  88
  89         pad->conf = fn->conf;
  90         fn->private_data = pad;
  91         fn->min_iqs = 2;
  92         if (!pad->conf->amp_given && stat_item_values[SI_AMPLIFICATION])
  93                 sscanf(stat_item_values[SI_AMPLIFICATION], "%u", &pad->amp);
  94         else
  95                 pad->amp = pad->conf->amp_arg;
  96         fn->bufsize = AMP_CHUNK_SIZE;
  97         fn->buf = para_malloc(fn->bufsize);
  98         PARA_NOTICE_LOG("amplification: %u (scaling factor: %1.2f)\n",
  99                 pad->amp, pad->amp / 64.0 + 1.0);
 100 }
 101
 102 static void amp_post_select(__a_unused struct sched *s, struct task *t)
 103 {
 104         struct filter_node *fn = container_of(t, struct filter_node, task);
 105         struct private_amp_data *pad = fn->private_data;
 106         struct btr_node *btrn = fn->btrn;
 107         int ret, factor = 64 + pad->amp;
 108         size_t i, in_bytes, len;
 109         int16_t *in, *out;
 110         bool inplace = btr_inplace_ok(btrn);
 111
 112         if (pad->amp == 0) { /* no amplification */
 113                 t->error = -E_AMP_ZERO_AMP;
 114                 btr_splice_out_node(btrn);
 115                 return;
 116         }
 117 next_buffer:
 118         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
 119         if (ret < 0)
 120                 goto err;
 121         if (ret == 0)
 122                 return;
 123         btr_merge(btrn, fn->min_iqs);
 124         in_bytes = btr_next_buffer(btrn, (char **)&in);
 125         len = in_bytes / 2;
 126         if (len == 0) { /* eof and in_bytes == 1 */
 127                 ret = -E_AMP_EOF;
 128                 goto err;
 129         }
 130
 131         if (inplace)
 132                 out = in;
 133         else
 134                 out = para_malloc(len * 2);
 135
 136         for (i = 0; i < len; i++) {
 137                 int x = (in[i] * factor) >> 6;
 138
 139                 out[i] = x;
 140                 if (out[i] != x) /* overflow, clip */
 141                         out[i] = (x >= 0)? 32767 : -32768;
 142         }
 143
 144         if (inplace)
 145                 btr_pushdown_one(btrn);
 146         else {
 147                 btr_consume(btrn, len * 2);
 148                 btr_add_output((char *)out, len * 2, btrn);
 149         }
 150         t->error = 0;
 151         goto next_buffer;
 152 err:
 153         assert(ret < 0);
 154         t->error = ret;
 155         btr_remove_node(btrn);
 156 }
 157
 158 static void amp_free_config(void *conf)
 159 {
 160         amp_cmdline_parser_free(conf);
 161 }
 162
 163 /**
 164  * The init function of the amplify filter.
 165  *
 166  * \param f Pointer to the struct to initialize.
 167  */
 168 void amp_filter_init(struct filter *f)
 169 {
 170         struct amp_filter_args_info dummy;
 171
 172         amp_cmdline_parser_init(&dummy);
 173         f->open = amp_open;
 174         f->close = amp_close;
 175         f->convert = amp_convert;
 176         f->pre_select = generic_filter_pre_select;
 177         f->post_select = amp_post_select;
 178         f->parse_config = amp_parse_config;
 179         f->free_config = amp_free_config;
 180         f->help = (struct ggo_help) {
 181                 .short_help = amp_filter_args_info_help,
 182                 .detailed_help = amp_filter_args_info_detailed_help
 183         };
 184 }