1 /*
2 * FITS implementation of common functions
3 * Copyright (c) 2017 Paras Chadha
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include <inttypes.h>
23 #include <limits.h>
24 #include <stdio.h>
25 #include <string.h>
26 #include "libavutil/dict.h"
27 #include "libavutil/error.h"
28 #include "libavutil/log.h"
29 #include "fits.h"
30
avpriv_fits_header_init(FITSHeader * header,FITSHeaderState state)31 int avpriv_fits_header_init(FITSHeader *header, FITSHeaderState state)
32 {
33 header->state = state;
34 header->naxis_index = 0;
35 header->blank_found = 0;
36 header->pcount = 0;
37 header->gcount = 1;
38 header->groups = 0;
39 header->rgb = 0;
40 header->image_extension = 0;
41 header->bscale = 1.0;
42 header->bzero = 0;
43 header->data_min_found = 0;
44 header->data_max_found = 0;
45 return 0;
46 }
47
dict_set_if_not_null(AVDictionary *** metadata,char * keyword,char * value)48 static int dict_set_if_not_null(AVDictionary ***metadata, char *keyword, char *value)
49 {
50 if (metadata)
51 av_dict_set(*metadata, keyword, value, 0);
52 return 0;
53 }
54
55 /**
56 * Extract keyword and value from a header line (80 bytes) and store them in keyword and value strings respectively
57 * @param ptr8 pointer to the data
58 * @param keyword pointer to the char array in which keyword is to be stored
59 * @param value pointer to the char array in which value is to be stored
60 * @return 0 if calculated successfully otherwise AVERROR_INVALIDDATA
61 */
read_keyword_value(const uint8_t * ptr8,char * keyword,char * value)62 static int read_keyword_value(const uint8_t *ptr8, char *keyword, char *value)
63 {
64 int i;
65
66 for (i = 0; i < 8 && ptr8[i] != ' '; i++) {
67 keyword[i] = ptr8[i];
68 }
69 keyword[i] = '\0';
70
71 if (ptr8[8] == '=') {
72 i = 10;
73 while (i < 80 && ptr8[i] == ' ') {
74 i++;
75 }
76
77 if (i < 80) {
78 *value++ = ptr8[i];
79 i++;
80 if (ptr8[i-1] == '\'') {
81 for (; i < 80 && ptr8[i] != '\''; i++) {
82 *value++ = ptr8[i];
83 }
84 *value++ = '\'';
85 } else if (ptr8[i-1] == '(') {
86 for (; i < 80 && ptr8[i] != ')'; i++) {
87 *value++ = ptr8[i];
88 }
89 *value++ = ')';
90 } else {
91 for (; i < 80 && ptr8[i] != ' ' && ptr8[i] != '/'; i++) {
92 *value++ = ptr8[i];
93 }
94 }
95 }
96 }
97 *value = '\0';
98 return 0;
99 }
100
101 #define CHECK_KEYWORD(key) \
102 if (strcmp(keyword, key)) { \
103 av_log(avcl, AV_LOG_ERROR, "expected %s keyword, found %s = %s\n", key, keyword, value); \
104 return AVERROR_INVALIDDATA; \
105 }
106
107 #define CHECK_VALUE(key, val) \
108 if (sscanf(value, "%d", &header->val) != 1) { \
109 av_log(avcl, AV_LOG_ERROR, "invalid value of %s keyword, %s = %s\n", key, keyword, value); \
110 return AVERROR_INVALIDDATA; \
111 }
112
avpriv_fits_header_parse_line(void * avcl,FITSHeader * header,const uint8_t line[80],AVDictionary *** metadata)113 int avpriv_fits_header_parse_line(void *avcl, FITSHeader *header, const uint8_t line[80], AVDictionary ***metadata)
114 {
115 int dim_no, ret;
116 int64_t t;
117 double d;
118 char keyword[10], value[72], c;
119
120 read_keyword_value(line, keyword, value);
121 switch (header->state) {
122 case STATE_SIMPLE:
123 CHECK_KEYWORD("SIMPLE");
124
125 if (value[0] == 'F') {
126 av_log(avcl, AV_LOG_WARNING, "not a standard FITS file\n");
127 } else if (value[0] != 'T') {
128 av_log(avcl, AV_LOG_ERROR, "invalid value of SIMPLE keyword, SIMPLE = %c\n", value[0]);
129 return AVERROR_INVALIDDATA;
130 }
131
132 header->state = STATE_BITPIX;
133 break;
134 case STATE_XTENSION:
135 CHECK_KEYWORD("XTENSION");
136
137 if (!strcmp(value, "'IMAGE '")) {
138 header->image_extension = 1;
139 }
140
141 header->state = STATE_BITPIX;
142 break;
143 case STATE_BITPIX:
144 CHECK_KEYWORD("BITPIX");
145 CHECK_VALUE("BITPIX", bitpix);
146
147 switch(header->bitpix) {
148 case 8:
149 case 16:
150 case 32: case -32:
151 case 64: case -64: break;
152 default:
153 av_log(avcl, AV_LOG_ERROR, "invalid value of BITPIX %d\n", header->bitpix); \
154 return AVERROR_INVALIDDATA;
155 }
156
157 dict_set_if_not_null(metadata, keyword, value);
158
159 header->state = STATE_NAXIS;
160 break;
161 case STATE_NAXIS:
162 CHECK_KEYWORD("NAXIS");
163 CHECK_VALUE("NAXIS", naxis);
164 dict_set_if_not_null(metadata, keyword, value);
165
166 if (header->naxis) {
167 header->state = STATE_NAXIS_N;
168 } else {
169 header->state = STATE_REST;
170 }
171 break;
172 case STATE_NAXIS_N:
173 ret = sscanf(keyword, "NAXIS%d", &dim_no);
174 if (ret != 1 || dim_no != header->naxis_index + 1) {
175 av_log(avcl, AV_LOG_ERROR, "expected NAXIS%d keyword, found %s = %s\n", header->naxis_index + 1, keyword, value);
176 return AVERROR_INVALIDDATA;
177 }
178
179 if (sscanf(value, "%d", &header->naxisn[header->naxis_index]) != 1) {
180 av_log(avcl, AV_LOG_ERROR, "invalid value of NAXIS%d keyword, %s = %s\n", header->naxis_index + 1, keyword, value);
181 return AVERROR_INVALIDDATA;
182 }
183
184 dict_set_if_not_null(metadata, keyword, value);
185 header->naxis_index++;
186 if (header->naxis_index == header->naxis) {
187 header->state = STATE_REST;
188 }
189 break;
190 case STATE_REST:
191 if (!strcmp(keyword, "BLANK") && sscanf(value, "%"SCNd64"", &t) == 1) {
192 header->blank = t;
193 header->blank_found = 1;
194 } else if (!strcmp(keyword, "BSCALE") && sscanf(value, "%lf", &d) == 1) {
195 if (d <= 0)
196 return AVERROR_INVALIDDATA;
197 header->bscale = d;
198 } else if (!strcmp(keyword, "BZERO") && sscanf(value, "%lf", &d) == 1) {
199 header->bzero = d;
200 } else if (!strcmp(keyword, "CTYPE3") && !strncmp(value, "'RGB", 4)) {
201 header->rgb = 1;
202 } else if (!strcmp(keyword, "DATAMAX") && sscanf(value, "%lf", &d) == 1) {
203 header->data_max_found = 1;
204 header->data_max = d;
205 } else if (!strcmp(keyword, "DATAMIN") && sscanf(value, "%lf", &d) == 1) {
206 header->data_min_found = 1;
207 header->data_min = d;
208 } else if (!strcmp(keyword, "END")) {
209 return 1;
210 } else if (!strcmp(keyword, "GROUPS") && sscanf(value, "%c", &c) == 1) {
211 header->groups = (c == 'T');
212 } else if (!strcmp(keyword, "GCOUNT") && sscanf(value, "%"SCNd64"", &t) == 1) {
213 if (t < 0 || t > INT_MAX)
214 return AVERROR_INVALIDDATA;
215 header->gcount = t;
216 } else if (!strcmp(keyword, "PCOUNT") && sscanf(value, "%"SCNd64"", &t) == 1) {
217 if (t < 0 || t > INT_MAX)
218 return AVERROR_INVALIDDATA;
219 header->pcount = t;
220 }
221 dict_set_if_not_null(metadata, keyword, value);
222 break;
223 }
224 return 0;
225 }
226