compress_filter.c

   1 /*
   2  * Copyright (C) 2005-2009 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 /** The size of the output data buffer. */
  27 #define COMPRESS_CHUNK_SIZE 40960
  28
  29 /** Data specific to the compress filter. */
  30 struct private_compress_data {
  31         /** The current multiplier. */
  32         unsigned current_gain;
  33         /** Points to the configuration data for this instance of the compress filter. */
  34         struct compress_filter_args_info *conf;
  35         /** Maximal admissible gain. */
  36         unsigned max_gain;
  37         /** Number of samples already seen. */
  38         unsigned num_samples;
  39         /** Absolute value of the maximal sample in the current block. */
  40         int peak;
  41 };
  42
  43 static ssize_t compress(char *inbuf, size_t inbuf_len, struct filter_node *fn)
  44 {
  45         size_t i, length = PARA_MIN((inbuf_len / 2) * 2,
  46                 (fn->bufsize - fn->loaded) / 2 * 2);
  47         struct private_compress_data *pcd = fn->private_data;
  48         int16_t *ip = (int16_t *)inbuf, *op = (int16_t *)(fn->buf + fn->loaded);
  49         unsigned gain_shift = pcd->conf->inertia_arg + pcd->conf->damp_arg,
  50                 mask = (1 << pcd->conf->blocksize_arg) - 1;
  51
  52         if (!length)
  53                 return 0;
  54         for (i = 0; i < length / 2; i++) {
  55                 /* be careful in that heat, my dear */
  56                 int sample = *ip++, adjusted_sample = (PARA_ABS(sample) *
  57                         pcd->current_gain) >> gain_shift;
  58                 if (adjusted_sample > 32767) { /* clip */
  59                         PARA_NOTICE_LOG("clip: sample: %d, adjusted sample: %d\n",
  60                                 sample, adjusted_sample);
  61                         adjusted_sample = 32767;
  62                         pcd->current_gain = (3 * pcd->current_gain +
  63                                 (1 << pcd->conf->inertia_arg)) / 4;
  64                         pcd->peak = 0;
  65                 } else
  66                         pcd->peak = PARA_MAX(pcd->peak, adjusted_sample);
  67                 *op++ = sample >= 0? adjusted_sample : -adjusted_sample;
  68                 if (++pcd->num_samples & mask)
  69                         continue;
  70 //              PARA_DEBUG_LOG("gain: %u, peak: %u\n", pcd->current_gain,
  71 //                      pcd->peak);
  72                 if (pcd->peak < pcd->conf->target_level_arg) {
  73                         if (pcd->current_gain < pcd->max_gain)
  74                                 pcd->current_gain++;
  75                 } else
  76                         pcd->current_gain = PARA_MAX(pcd->current_gain - 2,
  77                                 1U << pcd->conf->inertia_arg);
  78                 pcd->peak = 0;
  79         }
  80         fn->loaded += length;
  81         return length;
  82 }
  83
  84 static void close_compress(struct filter_node *fn)
  85 {
  86         free(fn->private_data);
  87         free(fn->buf);
  88 }
  89
  90 static void compress_post_select(__a_unused struct sched *s, struct task *t)
  91 {
  92         struct filter_node *fn = container_of(t, struct filter_node, task);
  93         struct private_compress_data *pcd = fn->private_data;
  94         struct btr_node *btrn = fn->btrn;
  95         bool inplace = btr_inplace_ok(btrn);
  96         int ret;
  97         char *inbuf;
  98         size_t length, i;
  99         int16_t *ip, *op;
 100         unsigned gain_shift = pcd->conf->inertia_arg + pcd->conf->damp_arg,
 101                 mask = (1 << pcd->conf->blocksize_arg) - 1;
 102
 103         //inplace = false;
 104 next_buffer:
 105         t->error = 0;
 106         ret = prepare_filter_node(fn);
 107         if (ret < 0)
 108                 goto err;
 109         if (ret == 0)
 110                 return;
 111         length = btr_next_buffer(btrn, &inbuf) & ~(size_t)1;
 112         ip = (int16_t *)inbuf;
 113         if (inplace)
 114                 op = ip;
 115         else
 116                 op = para_malloc(length);
 117         for (i = 0; i < length / 2; i++) {
 118                 /* be careful in that heat, my dear */
 119                 int sample = *ip++, adjusted_sample = (PARA_ABS(sample) *
 120                         pcd->current_gain) >> gain_shift;
 121                 if (adjusted_sample > 32767) { /* clip */
 122                         PARA_NOTICE_LOG("clip: sample: %d, adjusted sample: %d\n",
 123                                 sample, adjusted_sample);
 124                         adjusted_sample = 32767;
 125                         pcd->current_gain = (3 * pcd->current_gain +
 126                                 (1 << pcd->conf->inertia_arg)) / 4;
 127                         pcd->peak = 0;
 128                 } else
 129                         pcd->peak = PARA_MAX(pcd->peak, adjusted_sample);
 130                 op[i] = sample >= 0? adjusted_sample : -adjusted_sample;
 131                 if (++pcd->num_samples & mask)
 132                         continue;
 133 //              PARA_DEBUG_LOG("gain: %u, peak: %u\n", pcd->current_gain,
 134 //                      pcd->peak);
 135                 if (pcd->peak < pcd->conf->target_level_arg) {
 136                         if (pcd->current_gain < pcd->max_gain)
 137                                 pcd->current_gain++;
 138                 } else
 139                         pcd->current_gain = PARA_MAX(pcd->current_gain - 2,
 140                                 1U << pcd->conf->inertia_arg);
 141                 pcd->peak = 0;
 142         }
 143         if (inplace)
 144                 btr_pushdown_one(btrn);
 145         else {
 146                 btr_consume(btrn, length);
 147                 btr_add_output((char *)op, length, btrn);
 148         }
 149         goto next_buffer;
 150 err:
 151         assert(ret < 0);
 152         close_compress(fn);
 153         t->error = ret;
 154         btr_del_node(btrn);
 155 }
 156
 157 /** TODO: Add sanity checks */
 158 static int compress_parse_config(int argc, char **argv, void **config)
 159 {
 160         int ret;
 161         struct compress_filter_args_info *compress_conf
 162                 = para_calloc(sizeof(*compress_conf));
 163
 164         ret = -E_COMPRESS_SYNTAX;
 165         if (compress_cmdline_parser(argc, argv, compress_conf))
 166                 goto err;
 167         *config = compress_conf;
 168         return 1;
 169 err:
 170         free(compress_conf);
 171         return  ret;
 172 }
 173
 174 static void open_compress(struct filter_node *fn)
 175 {
 176         struct private_compress_data *pcd = para_calloc(
 177                 sizeof(struct private_compress_data));
 178         pcd->conf = fn->conf;
 179         fn->private_data = pcd;
 180         fn->min_iqs = 2; /* 16 bit audio */
 181         fn->bufsize = COMPRESS_CHUNK_SIZE;
 182         fn->buf = para_malloc(fn->bufsize);
 183         pcd->current_gain = 1 << pcd->conf->inertia_arg;
 184         pcd->max_gain = 1 << (pcd->conf->inertia_arg + pcd->conf->aggressiveness_arg);
 185 }
 186
 187 /**
 188  * The init function of the compress filter.
 189  *
 190  * \param f Pointer to the struct to initialize.
 191  */
 192 void compress_filter_init(struct filter *f)
 193 {
 194         struct compress_filter_args_info dummy;
 195
 196         compress_cmdline_parser_init(&dummy);
 197         f->open = open_compress;
 198         f->close = close_compress;
 199         f->convert = compress;
 200         f->pre_select = generic_filter_pre_select;
 201         f->post_select = compress_post_select;
 202         f->parse_config = compress_parse_config;
 203         f->help = (struct ggo_help) {
 204                 .short_help = compress_filter_args_info_help,
 205                 .detailed_help = compress_filter_args_info_detailed_help
 206         };
 207 }