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fitsdec.c
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1 /*
2  * FITS image decoder
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 /**
23  * @file
24  * FITS image decoder
25  *
26  * Specification: https://fits.gsfc.nasa.gov/fits_standard.html Version 3.0
27  *
28  * Support all 2d images alongwith, bzero, bscale and blank keywords.
29  * RGBA images are supported as NAXIS3 = 3 or 4 i.e. Planes in RGBA order. Also CTYPE = 'RGB ' should be present.
30  * Also to interpret data, values are linearly scaled using min-max scaling but not RGB images.
31  */
32 
33 #include "avcodec.h"
34 #include "internal.h"
35 #include <float.h>
36 #include "libavutil/intreadwrite.h"
37 #include "libavutil/intfloat.h"
38 #include "libavutil/dict.h"
39 #include "libavutil/opt.h"
40 #include "fits.h"
41 
42 typedef struct FITSContext {
43  const AVClass *class;
44  int blank_val;
45 } FITSContext;
46 
47 /**
48  * Calculate the data_min and data_max values from the data.
49  * This is called if the values are not present in the header.
50  * @param ptr8 pointer to the data
51  * @param header pointer to the header
52  * @param end pointer to end of packet
53  * @return 0 if calculated successfully otherwise AVERROR_INVALIDDATA
54  */
55 static int fill_data_min_max(const uint8_t *ptr8, FITSHeader *header, const uint8_t *end)
56 {
57  uint8_t t8;
58  int16_t t16;
59  int32_t t32;
60  int64_t t64;
61  float tflt;
62  double tdbl;
63  int i, j;
64 
65  header->data_min = DBL_MAX;
66  header->data_max = DBL_MIN;
67  switch (header->bitpix) {
68 #define CASE_N(a, t, rd) \
69  case a: \
70  for (i = 0; i < header->naxisn[1]; i++) { \
71  for (j = 0; j < header->naxisn[0]; j++) { \
72  t = rd; \
73  if (!header->blank_found || t != header->blank) { \
74  if (t > header->data_max) \
75  header->data_max = t; \
76  if (t < header->data_min) \
77  header->data_min = t; \
78  } \
79  ptr8 += abs(a) >> 3; \
80  } \
81  } \
82  break
83 
84  CASE_N(-64, tdbl, av_int2double(AV_RB64(ptr8)));
85  CASE_N(-32, tflt, av_int2float(AV_RB32(ptr8)));
86  CASE_N(8, t8, ptr8[0]);
87  CASE_N(16, t16, AV_RB16(ptr8));
88  CASE_N(32, t32, AV_RB32(ptr8));
89  CASE_N(64, t64, AV_RB64(ptr8));
90  default:
91  return AVERROR_INVALIDDATA;
92  }
93  return 0;
94 }
95 
96 /**
97  * Read the fits header and store the values in FITSHeader pointed by header
98  * @param avctx AVCodec context
99  * @param ptr pointer to pointer to the data
100  * @param header pointer to the FITSHeader
101  * @param end pointer to end of packet
102  * @param metadata pointer to pointer to AVDictionary to store metadata
103  * @return 0 if calculated successfully otherwise AVERROR_INVALIDDATA
104  */
105 static int fits_read_header(AVCodecContext *avctx, const uint8_t **ptr, FITSHeader *header,
106  const uint8_t *end, AVDictionary **metadata)
107 {
108  const uint8_t *ptr8 = *ptr;
109  int lines_read, bytes_left, i, ret;
110  size_t size;
111 
112  lines_read = 1; // to account for first header line, SIMPLE or XTENSION which is not included in packet...
114  do {
115  if (end - ptr8 < 80)
116  return AVERROR_INVALIDDATA;
117  ret = avpriv_fits_header_parse_line(avctx, header, ptr8, &metadata);
118  ptr8 += 80;
119  lines_read++;
120  } while (!ret);
121  if (ret < 0)
122  return ret;
123 
124  bytes_left = (((lines_read + 35) / 36) * 36 - lines_read) * 80;
125  if (end - ptr8 < bytes_left)
126  return AVERROR_INVALIDDATA;
127  ptr8 += bytes_left;
128 
129  if (header->rgb && (header->naxis != 3 || (header->naxisn[2] != 3 && header->naxisn[2] != 4))) {
130  av_log(avctx, AV_LOG_ERROR, "File contains RGB image but NAXIS = %d and NAXIS3 = %d\n", header->naxis, header->naxisn[2]);
131  return AVERROR_INVALIDDATA;
132  }
133 
134  if (!header->rgb && header->naxis != 2) {
135  av_log(avctx, AV_LOG_ERROR, "unsupported number of dimensions, NAXIS = %d\n", header->naxis);
136  return AVERROR_INVALIDDATA;
137  }
138 
139  if (header->blank_found && (header->bitpix == -32 || header->bitpix == -64)) {
140  av_log(avctx, AV_LOG_WARNING, "BLANK keyword found but BITPIX = %d\n. Ignoring BLANK", header->bitpix);
141  header->blank_found = 0;
142  }
143 
144  size = abs(header->bitpix) >> 3;
145  for (i = 0; i < header->naxis; i++) {
146  if (header->naxisn[i] > SIZE_MAX / size) {
147  av_log(avctx, AV_LOG_ERROR, "unsupported size of FITS image");
148  return AVERROR_INVALIDDATA;
149  }
150  size *= header->naxisn[i];
151  }
152 
153  if (end - ptr8 < size)
154  return AVERROR_INVALIDDATA;
155  *ptr = ptr8;
156 
157  if (!header->rgb && (!header->data_min_found || !header->data_max_found)) {
158  ret = fill_data_min_max(ptr8, header, end);
159  if (ret < 0) {
160  av_log(avctx, AV_LOG_ERROR, "invalid BITPIX, %d\n", header->bitpix);
161  return ret;
162  }
163  } else {
164  /*
165  * instead of applying bscale and bzero to every element,
166  * we can do inverse transformation on data_min and data_max
167  */
168  header->data_min = (header->data_min - header->bzero) / header->bscale;
169  header->data_max = (header->data_max - header->bzero) / header->bscale;
170  }
171 
172  return 0;
173 }
174 
175 static int fits_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
176 {
177  AVFrame *p=data;
178  const uint8_t *ptr8 = avpkt->data, *end;
179  uint8_t t8;
180  int16_t t16;
181  int32_t t32;
182  int64_t t64;
183  float tflt;
184  double tdbl;
185  int ret, i, j, k;
186  const int map[] = {2, 0, 1, 3}; // mapping from GBRA -> RGBA as RGBA is to be stored in FITS file..
187  uint8_t *dst8;
188  uint16_t *dst16;
189  uint64_t t;
191  FITSContext * fitsctx = avctx->priv_data;
192 
193  end = ptr8 + avpkt->size;
194  p->metadata = NULL;
195  ret = fits_read_header(avctx, &ptr8, &header, end, &p->metadata);
196  if (ret < 0)
197  return ret;
198 
199  if (header.rgb) {
200  if (header.bitpix == 8) {
201  if (header.naxisn[2] == 3) {
202  avctx->pix_fmt = AV_PIX_FMT_GBRP;
203  } else {
204  avctx->pix_fmt = AV_PIX_FMT_GBRAP;
205  }
206  } else if (header.bitpix == 16) {
207  if (header.naxisn[2] == 3) {
208  avctx->pix_fmt = AV_PIX_FMT_GBRP16;
209  } else {
210  avctx->pix_fmt = AV_PIX_FMT_GBRAP16;
211  }
212  } else {
213  av_log(avctx, AV_LOG_ERROR, "unsupported BITPIX = %d\n", header.bitpix);
214  return AVERROR_INVALIDDATA;
215  }
216  } else {
217  if (header.bitpix == 8) {
218  avctx->pix_fmt = AV_PIX_FMT_GRAY8;
219  } else {
220  avctx->pix_fmt = AV_PIX_FMT_GRAY16;
221  }
222  }
223 
224  if ((ret = ff_set_dimensions(avctx, header.naxisn[0], header.naxisn[1])) < 0)
225  return ret;
226 
227  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
228  return ret;
229 
230  /*
231  * FITS stores images with bottom row first. Therefore we have
232  * to fill the image from bottom to top.
233  */
234  if (header.rgb) {
235  switch(header.bitpix) {
236 #define CASE_RGB(cas, dst, type, dref) \
237  case cas: \
238  for (k = 0; k < header.naxisn[2]; k++) { \
239  for (i = 0; i < avctx->height; i++) { \
240  dst = (type *) (p->data[map[k]] + (avctx->height - i - 1) * p->linesize[map[k]]); \
241  for (j = 0; j < avctx->width; j++) { \
242  t32 = dref(ptr8); \
243  if (!header.blank_found || t32 != header.blank) { \
244  t = t32 * header.bscale + header.bzero; \
245  } else { \
246  t = fitsctx->blank_val; \
247  } \
248  *dst++ = (type) t; \
249  ptr8 += cas >> 3; \
250  } \
251  } \
252  } \
253  break
254 
255  CASE_RGB(8, dst8, uint8_t, *);
256  CASE_RGB(16, dst16, uint16_t, AV_RB16);
257  }
258  } else {
259  switch (header.bitpix) {
260 #define CASE_GRAY(cas, dst, type, t, rd) \
261  case cas: \
262  for (i = 0; i < avctx->height; i++) { \
263  dst = (type *) (p->data[0] + (avctx->height-i-1)* p->linesize[0]); \
264  for (j = 0; j < avctx->width; j++) { \
265  t = rd; \
266  if (!header.blank_found || t != header.blank) { \
267  *dst++ = ((t - header.data_min) * ((1 << (sizeof(type) * 8)) - 1)) / (header.data_max - header.data_min); \
268  } else { \
269  *dst++ = fitsctx->blank_val; \
270  } \
271  ptr8 += abs(cas) >> 3; \
272  } \
273  } \
274  break
275 
276  CASE_GRAY(-64, dst16, uint16_t, tdbl, av_int2double(AV_RB64(ptr8)));
277  CASE_GRAY(-32, dst16, uint16_t, tflt, av_int2float(AV_RB32(ptr8)));
278  CASE_GRAY(8, dst8, uint8_t, t8, ptr8[0]);
279  CASE_GRAY(16, dst16, uint16_t, t16, AV_RB16(ptr8));
280  CASE_GRAY(32, dst16, uint16_t, t32, AV_RB32(ptr8));
281  CASE_GRAY(64, dst16, uint16_t, t64, AV_RB64(ptr8));
282  default:
283  av_log(avctx, AV_LOG_ERROR, "invalid BITPIX, %d\n", header.bitpix);
284  return AVERROR_INVALIDDATA;
285  }
286  }
287 
288  p->key_frame = 1;
290 
291  *got_frame = 1;
292 
293  return avpkt->size;
294 }
295 
296 static const AVOption fits_options[] = {
297  { "blank_value", "value that is used to replace BLANK pixels in data array", offsetof(FITSContext, blank_val), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 65535, AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_VIDEO_PARAM},
298  { NULL },
299 };
300 
301 static const AVClass fits_decoder_class = {
302  .class_name = "FITS decoder",
303  .item_name = av_default_item_name,
304  .option = fits_options,
305  .version = LIBAVUTIL_VERSION_INT,
306 };
307 
309  .name = "fits",
310  .type = AVMEDIA_TYPE_VIDEO,
311  .id = AV_CODEC_ID_FITS,
312  .priv_data_size = sizeof(FITSContext),
314  .capabilities = AV_CODEC_CAP_DR1,
315  .long_name = NULL_IF_CONFIG_SMALL("Flexible Image Transport System"),
316  .priv_class = &fits_decoder_class
317 };
#define NULL
Definition: coverity.c:32
#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
This structure describes decoded (raw) audio or video data.
Definition: frame.h:201
AVOption.
Definition: opt.h:246
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
int ff_set_dimensions(AVCodecContext *s, int width, int height)
Check that the provided frame dimensions are valid and set them on the codec context.
Definition: utils.c:196
AVCodec ff_fits_decoder
Definition: fitsdec.c:308
static av_always_inline float av_int2float(uint32_t i)
Reinterpret a 32-bit integer as a float.
Definition: intfloat.h:40
planar GBR 4:4:4 24bpp
Definition: pixfmt.h:164
int size
Definition: avcodec.h:1401
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:193
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1697
double data_max
Definition: fits.h:61
#define t8
Definition: regdef.h:53
static int fits_read_header(AVCodecContext *avctx, const uint8_t **ptr, FITSHeader *header, const uint8_t *end, AVDictionary **metadata)
Read the fits header and store the values in FITSHeader pointed by header.
Definition: fitsdec.c:105
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:87
AVCodec.
Definition: avcodec.h:3351
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:42
#define CASE_GRAY(cas, dst, type, t, rd)
double bscale
Definition: fits.h:56
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
Public dictionary API.
static av_always_inline double av_int2double(uint64_t i)
Reinterpret a 64-bit integer as a double.
Definition: intfloat.h:60
uint8_t
int naxis
Definition: fits.h:49
double bzero
Definition: fits.h:57
#define CASE_RGB(cas, dst, type, dref)
AVOptions.
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
Definition: bytestream.h:87
uint8_t * data
Definition: avcodec.h:1400
AVDictionary * metadata
metadata.
Definition: frame.h:488
ptrdiff_t size
Definition: opengl_enc.c:101
static const uint8_t header[24]
Definition: sdr2.c:67
#define av_log(a,...)
int blank_val
Definition: fitsdec.c:44
static int fits_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: fitsdec.c:175
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
static int fill_data_min_max(const uint8_t *ptr8, FITSHeader *header, const uint8_t *end)
Calculate the data_min and data_max values from the data.
Definition: fitsdec.c:55
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
Structure to store the header keywords in FITS file.
Definition: fits.h:43
int data_min_found
Definition: fits.h:58
const char * name
Name of the codec implementation.
Definition: avcodec.h:3358
double data_min
Definition: fits.h:59
#define AV_PIX_FMT_GBRAP16
Definition: pixfmt.h:390
int avpriv_fits_header_init(FITSHeader *header, FITSHeaderState state)
Initialize a single header line.
Definition: fits.c:26
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:284
#define AV_PIX_FMT_GBRP16
Definition: pixfmt.h:387
#define AV_PIX_FMT_GRAY16
Definition: pixfmt.h:352
int32_t
int bitpix
Definition: fits.h:46
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
#define AV_OPT_FLAG_VIDEO_PARAM
Definition: opt.h:279
main external API structure.
Definition: avcodec.h:1488
int naxisn[999]
Definition: fits.h:50
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1886
Describe the class of an AVClass context structure.
Definition: log.h:67
#define AV_OPT_FLAG_DECODING_PARAM
a generic parameter which can be set by the user for demuxing or decoding
Definition: opt.h:277
const VDPAUPixFmtMap * map
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_RB64
Definition: bytestream.h:87
Y , 8bpp.
Definition: pixfmt.h:70
common internal api header.
static const AVClass fits_decoder_class
Definition: fitsdec.c:301
planar GBRA 4:4:4:4 32bpp
Definition: pixfmt.h:211
void * priv_data
Definition: avcodec.h:1515
int data_max_found
Definition: fits.h:60
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:279
#define CASE_N(a, t, rd)
static const AVOption fits_options[]
Definition: fitsdec.c:296
int blank_found
Definition: fits.h:48
This structure stores compressed data.
Definition: avcodec.h:1377
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:956