deps/flac-1.3.2/src/share/grabbag/seektable.c

   1 /* grabbag - Convenience lib for various routines common to several tools
   2  * Copyright (C) 2002-2009  Josh Coalson
   3  * Copyright (C) 2011-2016  Xiph.Org Foundation
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19
  20 #ifdef HAVE_CONFIG_H
  21 #  include <config.h>
  22 #endif
  23
  24 #include "share/grabbag.h"
  25 #include "share/compat.h"
  26 #include "FLAC/assert.h"
  27 #include <stdlib.h> /* for atoi() */
  28 #include <string.h>
  29
  30 FLAC__bool grabbag__seektable_convert_specification_to_template(const char *spec, FLAC__bool only_explicit_placeholders, FLAC__uint64 total_samples_to_encode, unsigned sample_rate, FLAC__StreamMetadata *seektable_template, FLAC__bool *spec_has_real_points)
  31 {
  32         unsigned i;
  33         const char *pt;
  34
  35         FLAC__ASSERT(0 != spec);
  36         FLAC__ASSERT(0 != seektable_template);
  37         FLAC__ASSERT(seektable_template->type == FLAC__METADATA_TYPE_SEEKTABLE);
  38
  39         if(0 != spec_has_real_points)
  40                 *spec_has_real_points = false;
  41
  42         for(pt = spec, i = 0; pt && *pt; i++) {
  43                 const char *q = strchr(pt, ';');
  44                 FLAC__ASSERT(0 != q);
  45
  46                 if(q > pt) {
  47                         if(0 == strncmp(pt, "X;", 2)) { /* -S X */
  48                                 if(!FLAC__metadata_object_seektable_template_append_placeholders(seektable_template, 1))
  49                                         return false;
  50                         }
  51                         else if(q[-1] == 'x') { /* -S #x */
  52                                 if(total_samples_to_encode > 0) { /* we can only do these if we know the number of samples to encode up front */
  53                                         if(0 != spec_has_real_points)
  54                                                 *spec_has_real_points = true;
  55                                         if(!only_explicit_placeholders) {
  56                                                 const int n = (unsigned)atoi(pt);
  57                                                 if(n > 0)
  58                                                         if(!FLAC__metadata_object_seektable_template_append_spaced_points(seektable_template, (unsigned)n, total_samples_to_encode))
  59                                                                 return false;
  60                                         }
  61                                 }
  62                         }
  63                         else if(q[-1] == 's') { /* -S #s */
  64                                 if(total_samples_to_encode > 0) { /* we can only do these if we know the number of samples to encode up front */
  65                                         FLAC__ASSERT(sample_rate > 0);
  66                                         if(0 != spec_has_real_points)
  67                                                 *spec_has_real_points = true;
  68                                         if(!only_explicit_placeholders) {
  69                                                 const double sec = atof(pt);
  70                                                 if(sec > 0.0) {
  71                                                         unsigned samples = (unsigned)(sec * (double)sample_rate);
  72                                                         /* Restrict seekpoints to two per second of audio. */
  73                                                         samples = samples < sample_rate / 2 ? sample_rate / 2 : samples;
  74                                                         if(samples > 0) {
  75                                                                 /* +1 for the initial point at sample 0 */
  76                                                                 if(!FLAC__metadata_object_seektable_template_append_spaced_points_by_samples(seektable_template, samples, total_samples_to_encode))
  77                                                                         return false;
  78                                                         }
  79                                                 }
  80                                         }
  81                                 }
  82                         }
  83                         else { /* -S # */
  84                                 if(0 != spec_has_real_points)
  85                                         *spec_has_real_points = true;
  86                                 if(!only_explicit_placeholders) {
  87                                         char *endptr;
  88                                         const FLAC__int64 n = (FLAC__int64)strtoll(pt, &endptr, 10);
  89                                         if(
  90                                                 (n > 0 || (endptr > pt && *endptr == ';')) && /* is a valid number (extra check needed for "0") */
  91                                                 (total_samples_to_encode == 0 || (FLAC__uint64)n < total_samples_to_encode) /* number is not >= the known total_samples_to_encode */
  92                                         )
  93                                                 if(!FLAC__metadata_object_seektable_template_append_point(seektable_template, (FLAC__uint64)n))
  94                                                         return false;
  95                                 }
  96                         }
  97                 }
  98
  99                 pt = ++q;
 100         }
 101
 102         if(!FLAC__metadata_object_seektable_template_sort(seektable_template, /*compact=*/true))
 103                 return false;
 104
 105         return true;
 106 }