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 
grabbag__seektable_convert_specification_to_template(const char * spec,FLAC__bool only_explicit_placeholders,FLAC__uint64 total_samples_to_encode,uint32_t sample_rate,FLAC__StreamMetadata * seektable_template,FLAC__bool * spec_has_real_points)30 FLAC__bool grabbag__seektable_convert_specification_to_template(const char *spec, FLAC__bool only_explicit_placeholders, FLAC__uint64 total_samples_to_encode, uint32_t sample_rate, FLAC__StreamMetadata *seektable_template, FLAC__bool *spec_has_real_points)
31 {
32 	uint32_t 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 = (uint32_t)atoi(pt);
57 						if(n > 0)
58 							if(!FLAC__metadata_object_seektable_template_append_spaced_points(seektable_template, (uint32_t)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 							uint32_t samples = (uint32_t)(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 }
107