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 void close_compress(struct filter_node *fn)
  44 {
  45         free(fn->private_data);
  46         free(fn->buf);
  47 }
  48
  49 static void compress_post_select(__a_unused struct sched *s, struct task *t)
  50 {
  51         struct filter_node *fn = container_of(t, struct filter_node, task);
  52         struct private_compress_data *pcd = fn->private_data;
  53         struct btr_node *btrn = fn->btrn;
  54         bool inplace = btr_inplace_ok(btrn);
  55         int ret;
  56         char *inbuf;
  57         size_t length, i;
  58         int16_t *ip, *op;
  59         unsigned gain_shift = pcd->conf->inertia_arg + pcd->conf->damp_arg,
  60                 mask = (1 << pcd->conf->blocksize_arg) - 1;
  61
  62         //inplace = false;
  63 next_buffer:
  64         t->error = 0;
  65         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
  66         if (ret < 0)
  67                 goto err;
  68         if (ret == 0)
  69                 return;
  70         btr_merge(btrn, fn->min_iqs);
  71         length = btr_next_buffer(btrn, &inbuf) & ~(size_t)1;
  72         if (length == 0) { /* eof and 1 byte available */
  73                 ret = -E_COMPRESS_EOF;
  74                 goto err;
  75         }
  76         ip = (int16_t *)inbuf;
  77         if (inplace)
  78                 op = ip;
  79         else
  80                 op = para_malloc(length);
  81         for (i = 0; i < length / 2; i++) {
  82                 /* be careful in that heat, my dear */
  83                 int sample = *ip++, adjusted_sample = (PARA_ABS(sample) *
  84                         pcd->current_gain) >> gain_shift;
  85                 if (adjusted_sample > 32767) { /* clip */
  86                         PARA_NOTICE_LOG("clip: sample: %d, adjusted sample: %d\n",
  87                                 sample, adjusted_sample);
  88                         adjusted_sample = 32767;
  89                         pcd->current_gain = (3 * pcd->current_gain +
  90                                 (1 << pcd->conf->inertia_arg)) / 4;
  91                         pcd->peak = 0;
  92                 } else
  93                         pcd->peak = PARA_MAX(pcd->peak, adjusted_sample);
  94                 op[i] = sample >= 0? adjusted_sample : -adjusted_sample;
  95                 if (++pcd->num_samples & mask)
  96                         continue;
  97 //              PARA_DEBUG_LOG("gain: %u, peak: %u\n", pcd->current_gain,
  98 //                      pcd->peak);
  99                 if (pcd->peak < pcd->conf->target_level_arg) {
 100                         if (pcd->current_gain < pcd->max_gain)
 101                                 pcd->current_gain++;
 102                 } else
 103                         pcd->current_gain = PARA_MAX(pcd->current_gain - 2,
 104                                 1U << pcd->conf->inertia_arg);
 105                 pcd->peak = 0;
 106         }
 107         if (inplace)
 108                 btr_pushdown_one(btrn);
 109         else {
 110                 btr_consume(btrn, length);
 111                 btr_add_output((char *)op, length, btrn);
 112         }
 113         goto next_buffer;
 114 err:
 115         assert(ret < 0);
 116         t->error = ret;
 117         btr_remove_node(btrn);
 118 }
 119
 120 /** TODO: Add sanity checks */
 121 static int compress_parse_config(int argc, char **argv, void **config)
 122 {
 123         int ret;
 124         struct compress_filter_args_info *compress_conf
 125                 = para_calloc(sizeof(*compress_conf));
 126
 127         ret = -E_COMPRESS_SYNTAX;
 128         if (compress_cmdline_parser(argc, argv, compress_conf))
 129                 goto err;
 130         *config = compress_conf;
 131         return 1;
 132 err:
 133         free(compress_conf);
 134         return  ret;
 135 }
 136
 137 static void open_compress(struct filter_node *fn)
 138 {
 139         struct private_compress_data *pcd = para_calloc(
 140                 sizeof(struct private_compress_data));
 141         pcd->conf = fn->conf;
 142         fn->private_data = pcd;
 143         fn->min_iqs = 2; /* 16 bit audio */
 144         fn->bufsize = COMPRESS_CHUNK_SIZE;
 145         fn->buf = para_malloc(fn->bufsize);
 146         pcd->current_gain = 1 << pcd->conf->inertia_arg;
 147         pcd->max_gain = 1 << (pcd->conf->inertia_arg + pcd->conf->aggressiveness_arg);
 148 }
 149
 150 static void compress_free_config(void *conf)
 151 {
 152         compress_cmdline_parser_free(conf);
 153 }
 154
 155 /**
 156  * The init function of the compress filter.
 157  *
 158  * \param f Pointer to the struct to initialize.
 159  */
 160 void compress_filter_init(struct filter *f)
 161 {
 162         struct compress_filter_args_info dummy;
 163
 164         compress_cmdline_parser_init(&dummy);
 165         f->open = open_compress;
 166         f->close = close_compress;
 167         f->pre_select = generic_filter_pre_select;
 168         f->post_select = compress_post_select;
 169         f->parse_config = compress_parse_config;
 170         f->free_config = compress_free_config;
 171         f->help = (struct ggo_help) {
 172                 .short_help = compress_filter_args_info_help,
 173                 .detailed_help = compress_filter_args_info_detailed_help
 174         };
 175 }