compress_filter.c

   1 /*
   2  * Copyright (C) 2005-2010 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file compress_filter.c Paraslash's dynamic audio range compressor. */
   8
   9 /*
  10  * Uses ideas of AudioCompress, (C) 2002-2004  M. Hari Nezumi <magenta@trikuare.cx>
  11  */
  12
  13 #include <regex.h>
  14 #include <stdbool.h>
  15
  16 #include "para.h"
  17 #include "compress_filter.cmdline.h"
  18 #include "list.h"
  19 #include "sched.h"
  20 #include "ggo.h"
  21 #include "buffer_tree.h"
  22 #include "filter.h"
  23 #include "string.h"
  24 #include "error.h"
  25
  26 /** Data specific to the compress filter. */
  27 struct private_compress_data {
  28         /** The current multiplier. */
  29         unsigned current_gain;
  30         /** Points to the configuration data for this instance of the compress filter. */
  31         struct compress_filter_args_info *conf;
  32         /** Maximal admissible gain. */
  33         unsigned max_gain;
  34         /** Number of samples already seen. */
  35         unsigned num_samples;
  36         /** Absolute value of the maximal sample in the current block. */
  37         int peak;
  38 };
  39
  40 static void compress_close(struct filter_node *fn)
  41 {
  42         free(fn->private_data);
  43 }
  44
  45 static void compress_post_select(__a_unused struct sched *s, struct task *t)
  46 {
  47         struct filter_node *fn = container_of(t, struct filter_node, task);
  48         struct private_compress_data *pcd = fn->private_data;
  49         struct btr_node *btrn = fn->btrn;
  50         bool inplace = btr_inplace_ok(btrn);
  51         int ret;
  52         char *inbuf;
  53         size_t length, i;
  54         int16_t *ip, *op;
  55         unsigned gain_shift = pcd->conf->inertia_arg + pcd->conf->damp_arg,
  56                 mask = (1 << pcd->conf->blocksize_arg) - 1;
  57
  58         //inplace = false;
  59 next_buffer:
  60         t->error = 0;
  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;
  66         btr_merge(btrn, fn->min_iqs);
  67         length = btr_next_buffer(btrn, &inbuf) & ~(size_t)1;
  68         if (length == 0) { /* eof and 1 byte available */
  69                 ret = -E_COMPRESS_EOF;
  70                 goto err;
  71         }
  72         ip = (int16_t *)inbuf;
  73         if (inplace)
  74                 op = ip;
  75         else
  76                 op = para_malloc(length);
  77         for (i = 0; i < length / 2; i++) {
  78                 /* be careful in that heat, my dear */
  79                 int sample = *ip++, adjusted_sample = (PARA_ABS(sample) *
  80                         pcd->current_gain) >> gain_shift;
  81                 if (adjusted_sample > 32767) { /* clip */
  82                         PARA_NOTICE_LOG("clip: sample: %d, adjusted sample: %d\n",
  83                                 sample, adjusted_sample);
  84                         adjusted_sample = 32767;
  85                         pcd->current_gain = (3 * pcd->current_gain +
  86                                 (1 << pcd->conf->inertia_arg)) / 4;
  87                         pcd->peak = 0;
  88                 } else
  89                         pcd->peak = PARA_MAX(pcd->peak, adjusted_sample);
  90                 op[i] = sample >= 0? adjusted_sample : -adjusted_sample;
  91                 if (++pcd->num_samples & mask)
  92                         continue;
  93 //              PARA_DEBUG_LOG("gain: %u, peak: %u\n", pcd->current_gain,
  94 //                      pcd->peak);
  95                 if (pcd->peak < pcd->conf->target_level_arg) {
  96                         if (pcd->current_gain < pcd->max_gain)
  97                                 pcd->current_gain++;
  98                 } else
  99                         pcd->current_gain = PARA_MAX(pcd->current_gain - 2,
 100                                 1U << pcd->conf->inertia_arg);
 101                 pcd->peak = 0;
 102         }
 103         if (inplace)
 104                 btr_pushdown_one(btrn);
 105         else {
 106                 btr_consume(btrn, length);
 107                 btr_add_output((char *)op, length, btrn);
 108         }
 109         goto next_buffer;
 110 err:
 111         assert(ret < 0);
 112         t->error = ret;
 113         btr_remove_node(btrn);
 114 }
 115
 116 /** TODO: Add sanity checks */
 117 static int compress_parse_config(int argc, char **argv, void **config)
 118 {
 119         int ret;
 120         struct compress_filter_args_info *compress_conf
 121                 = para_calloc(sizeof(*compress_conf));
 122
 123         ret = -E_COMPRESS_SYNTAX;
 124         if (compress_cmdline_parser(argc, argv, compress_conf))
 125                 goto err;
 126         *config = compress_conf;
 127         return 1;
 128 err:
 129         free(compress_conf);
 130         return  ret;
 131 }
 132
 133 static void compress_open(struct filter_node *fn)
 134 {
 135         struct private_compress_data *pcd = para_calloc(
 136                 sizeof(struct private_compress_data));
 137         pcd->conf = fn->conf;
 138         fn->private_data = pcd;
 139         fn->min_iqs = 2; /* 16 bit audio */
 140         pcd->current_gain = 1 << pcd->conf->inertia_arg;
 141         pcd->max_gain = 1 << (pcd->conf->inertia_arg + pcd->conf->aggressiveness_arg);
 142 }
 143
 144 static void compress_free_config(void *conf)
 145 {
 146         compress_cmdline_parser_free(conf);
 147 }
 148
 149 /**
 150  * The init function of the compress filter.
 151  *
 152  * \param f Pointer to the struct to initialize.
 153  */
 154 void compress_filter_init(struct filter *f)
 155 {
 156         struct compress_filter_args_info dummy;
 157
 158         compress_cmdline_parser_init(&dummy);
 159         f->open = compress_open;
 160         f->close = compress_close;
 161         f->pre_select = generic_filter_pre_select;
 162         f->post_select = compress_post_select;
 163         f->parse_config = compress_parse_config;
 164         f->free_config = compress_free_config;
 165         f->help = (struct ggo_help) {
 166                 .short_help = compress_filter_args_info_help,
 167                 .detailed_help = compress_filter_args_info_detailed_help
 168         };
 169 }