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fits.c
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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 "avcodec.h"
23 #include "libavutil/dict.h"
24 #include "fits.h"
25 
27 {
28  header->state = state;
29  header->naxis_index = 0;
30  header->blank_found = 0;
31  header->pcount = 0;
32  header->gcount = 1;
33  header->groups = 0;
34  header->rgb = 0;
35  header->image_extension = 0;
36  header->bscale = 1.0;
37  header->bzero = 0;
38  header->data_min_found = 0;
39  header->data_max_found = 0;
40  return 0;
41 }
42 
43 static int dict_set_if_not_null(AVDictionary ***metadata, char *keyword, char *value)
44 {
45  if (metadata)
46  av_dict_set(*metadata, keyword, value, 0);
47  return 0;
48 }
49 
50 /**
51  * Extract keyword and value from a header line (80 bytes) and store them in keyword and value strings respectively
52  * @param ptr8 pointer to the data
53  * @param keyword pointer to the char array in which keyword is to be stored
54  * @param value pointer to the char array in which value is to be stored
55  * @return 0 if calculated successfully otherwise AVERROR_INVALIDDATA
56  */
57 static int read_keyword_value(const uint8_t *ptr8, char *keyword, char *value)
58 {
59  int i;
60 
61  for (i = 0; i < 8 && ptr8[i] != ' '; i++) {
62  keyword[i] = ptr8[i];
63  }
64  keyword[i] = '\0';
65 
66  if (ptr8[8] == '=') {
67  i = 10;
68  while (i < 80 && ptr8[i] == ' ') {
69  i++;
70  }
71 
72  if (i < 80) {
73  *value++ = ptr8[i];
74  i++;
75  if (ptr8[i-1] == '\'') {
76  for (; i < 80 && ptr8[i] != '\''; i++) {
77  *value++ = ptr8[i];
78  }
79  *value++ = '\'';
80  } else if (ptr8[i-1] == '(') {
81  for (; i < 80 && ptr8[i] != ')'; i++) {
82  *value++ = ptr8[i];
83  }
84  *value++ = ')';
85  } else {
86  for (; i < 80 && ptr8[i] != ' ' && ptr8[i] != '/'; i++) {
87  *value++ = ptr8[i];
88  }
89  }
90  }
91  }
92  *value = '\0';
93  return 0;
94 }
95 
96 #define CHECK_KEYWORD(key) \
97  if (strcmp(keyword, key)) { \
98  av_log(avcl, AV_LOG_ERROR, "expected %s keyword, found %s = %s\n", key, keyword, value); \
99  return AVERROR_INVALIDDATA; \
100  }
101 
102 #define CHECK_VALUE(key, val) \
103  if (sscanf(value, "%d", &header->val) != 1) { \
104  av_log(avcl, AV_LOG_ERROR, "invalid value of %s keyword, %s = %s\n", key, keyword, value); \
105  return AVERROR_INVALIDDATA; \
106  }
107 
108 int avpriv_fits_header_parse_line(void *avcl, FITSHeader *header, const uint8_t line[80], AVDictionary ***metadata)
109 {
110  int dim_no, ret;
111  int64_t t;
112  double d;
113  char keyword[10], value[72], c;
114 
115  read_keyword_value(line, keyword, value);
116  switch (header->state) {
117  case STATE_SIMPLE:
118  CHECK_KEYWORD("SIMPLE");
119 
120  if (value[0] == 'F') {
121  av_log(avcl, AV_LOG_WARNING, "not a standard FITS file\n");
122  } else if (value[0] != 'T') {
123  av_log(avcl, AV_LOG_ERROR, "invalid value of SIMPLE keyword, SIMPLE = %c\n", value[0]);
124  return AVERROR_INVALIDDATA;
125  }
126 
127  header->state = STATE_BITPIX;
128  break;
129  case STATE_XTENSION:
130  CHECK_KEYWORD("XTENSION");
131 
132  if (!strcmp(value, "'IMAGE '")) {
133  header->image_extension = 1;
134  }
135 
136  header->state = STATE_BITPIX;
137  break;
138  case STATE_BITPIX:
139  CHECK_KEYWORD("BITPIX");
140  CHECK_VALUE("BITPIX", bitpix);
141  dict_set_if_not_null(metadata, keyword, value);
142 
143  header->state = STATE_NAXIS;
144  break;
145  case STATE_NAXIS:
146  CHECK_KEYWORD("NAXIS");
147  CHECK_VALUE("NAXIS", naxis);
148  dict_set_if_not_null(metadata, keyword, value);
149 
150  if (header->naxis) {
151  header->state = STATE_NAXIS_N;
152  } else {
153  header->state = STATE_REST;
154  }
155  break;
156  case STATE_NAXIS_N:
157  ret = sscanf(keyword, "NAXIS%d", &dim_no);
158  if (ret != 1 || dim_no != header->naxis_index + 1) {
159  av_log(avcl, AV_LOG_ERROR, "expected NAXIS%d keyword, found %s = %s\n", header->naxis_index + 1, keyword, value);
160  return AVERROR_INVALIDDATA;
161  }
162 
163  if (sscanf(value, "%d", &header->naxisn[header->naxis_index]) != 1) {
164  av_log(avcl, AV_LOG_ERROR, "invalid value of NAXIS%d keyword, %s = %s\n", header->naxis_index + 1, keyword, value);
165  return AVERROR_INVALIDDATA;
166  }
167 
168  dict_set_if_not_null(metadata, keyword, value);
169  header->naxis_index++;
170  if (header->naxis_index == header->naxis) {
171  header->state = STATE_REST;
172  }
173  break;
174  case STATE_REST:
175  if (!strcmp(keyword, "BLANK") && sscanf(value, "%"SCNd64"", &t) == 1) {
176  header->blank = t;
177  header->blank_found = 1;
178  } else if (!strcmp(keyword, "BSCALE") && sscanf(value, "%lf", &d) == 1) {
179  header->bscale = d;
180  } else if (!strcmp(keyword, "BZERO") && sscanf(value, "%lf", &d) == 1) {
181  header->bzero = d;
182  } else if (!strcmp(keyword, "CTYPE3") && !strncmp(value, "'RGB", 4)) {
183  header->rgb = 1;
184  } else if (!strcmp(keyword, "DATAMAX") && sscanf(value, "%lf", &d) == 1) {
185  header->data_max_found = 1;
186  header->data_max = d;
187  } else if (!strcmp(keyword, "DATAMIN") && sscanf(value, "%lf", &d) == 1) {
188  header->data_min_found = 1;
189  header->data_min = d;
190  } else if (!strcmp(keyword, "END")) {
191  return 1;
192  } else if (!strcmp(keyword, "GROUPS") && sscanf(value, "%c", &c) == 1) {
193  header->groups = (c == 'T');
194  } else if (!strcmp(keyword, "GCOUNT") && sscanf(value, "%"SCNd64"", &t) == 1) {
195  header->gcount = t;
196  } else if (!strcmp(keyword, "PCOUNT") && sscanf(value, "%"SCNd64"", &t) == 1) {
197  header->pcount = t;
198  }
199  dict_set_if_not_null(metadata, keyword, value);
200  break;
201  }
202  return 0;
203 }
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
int rgb
1 if file contains RGB image, 0 otherwise
Definition: fits.h:54
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
double data_max
Definition: fits.h:61
int image_extension
Definition: fits.h:55
FITSHeaderState
Definition: fits.h:29
double bscale
Definition: fits.h:56
Public dictionary API.
static int dict_set_if_not_null(AVDictionary ***metadata, char *keyword, char *value)
Definition: fits.c:43
FITSHeaderState state
Definition: fits.h:44
uint8_t
int naxis
Definition: fits.h:49
double bzero
Definition: fits.h:57
static struct @281 state
#define CHECK_KEYWORD(key)
Definition: fits.c:96
static const uint8_t header[24]
Definition: sdr2.c:67
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
Structure to store the header keywords in FITS file.
Definition: fits.h:43
Definition: graph2dot.c:48
int data_min_found
Definition: fits.h:58
double data_min
Definition: fits.h:59
int avpriv_fits_header_init(FITSHeader *header, FITSHeaderState state)
Initialize a single header line.
Definition: fits.c:26
GLsizei GLboolean const GLfloat * value
Definition: opengl_enc.c:109
Libavcodec external API header.
int avpriv_fits_header_parse_line(void *avcl, FITSHeader *header, const uint8_t line[80], AVDictionary ***metadata)
Parse a single header line.
Definition: fits.c:108
int naxisn[999]
Definition: fits.h:50
unsigned naxis_index
Definition: fits.h:45
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:70
int pcount
Definition: fits.h:51
int64_t blank
Definition: fits.h:47
#define CHECK_VALUE(key, val)
Definition: fits.c:102
static double c[64]
int data_max_found
Definition: fits.h:60
int groups
Definition: fits.h:53
int gcount
Definition: fits.h:52
int blank_found
Definition: fits.h:48
static int read_keyword_value(const uint8_t *ptr8, char *keyword, char *value)
Extract keyword and value from a header line (80 bytes) and store them in keyword and value strings r...
Definition: fits.c:57