FFmpeg
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 "codec_internal.h"
35 #include "internal.h"
36 #include <float.h>
37 #include "libavutil/intreadwrite.h"
38 #include "libavutil/intfloat.h"
39 #include "libavutil/dict.h"
40 #include "libavutil/opt.h"
41 #include "fits.h"
42 
43 typedef struct FITSContext {
44  const AVClass *class;
45  int blank_val;
46 } FITSContext;
47 
48 /**
49  * Calculate the data_min and data_max values from the data.
50  * This is called if the values are not present in the header.
51  * @param ptr8 pointer to the data
52  * @param header pointer to the header
53  * @param end pointer to end of packet
54  * @return 0 if calculated successfully otherwise AVERROR_INVALIDDATA
55  */
56 static int fill_data_min_max(const uint8_t *ptr8, FITSHeader *header, const uint8_t *end)
57 {
58  uint8_t t8;
59  int16_t t16;
60  int32_t t32;
61  int64_t t64;
62  float tflt;
63  double tdbl;
64  int i, j;
65 
66  header->data_min = DBL_MAX;
67  header->data_max = -DBL_MAX;
68  switch (header->bitpix) {
69 #define CASE_N(a, t, rd) \
70  case a: \
71  for (i = 0; i < header->naxisn[1]; i++) { \
72  for (j = 0; j < header->naxisn[0]; j++) { \
73  t = rd; \
74  if (!header->blank_found || t != header->blank) { \
75  if (t > header->data_max) \
76  header->data_max = t; \
77  if (t < header->data_min) \
78  header->data_min = t; \
79  } \
80  ptr8 += abs(a) >> 3; \
81  } \
82  } \
83  break
84 
85  CASE_N(-64, tdbl, av_int2double(AV_RB64(ptr8)));
86  CASE_N(-32, tflt, av_int2float(AV_RB32(ptr8)));
87  CASE_N(8, t8, ptr8[0]);
88  CASE_N(16, t16, AV_RB16(ptr8));
89  CASE_N(32, t32, AV_RB32(ptr8));
90  CASE_N(64, t64, AV_RB64(ptr8));
91  default:
92  return AVERROR_INVALIDDATA;
93  }
94  return 0;
95 }
96 
97 /**
98  * Read the fits header and store the values in FITSHeader pointed by header
99  * @param avctx AVCodec context
100  * @param ptr pointer to pointer to the data
101  * @param header pointer to the FITSHeader
102  * @param end pointer to end of packet
103  * @param metadata pointer to pointer to AVDictionary to store metadata
104  * @return 0 if calculated successfully otherwise AVERROR_INVALIDDATA
105  */
106 static int fits_read_header(AVCodecContext *avctx, const uint8_t **ptr, FITSHeader *header,
107  const uint8_t *end, AVDictionary **metadata)
108 {
109  const uint8_t *ptr8 = *ptr;
110  int lines_read, bytes_left, i, ret;
111  size_t size;
112 
113  lines_read = 1; // to account for first header line, SIMPLE or XTENSION which is not included in packet...
115  do {
116  if (end - ptr8 < 80)
117  return AVERROR_INVALIDDATA;
118  ret = avpriv_fits_header_parse_line(avctx, header, ptr8, &metadata);
119  ptr8 += 80;
120  lines_read++;
121  } while (!ret);
122  if (ret < 0)
123  return ret;
124 
125  bytes_left = (((lines_read + 35) / 36) * 36 - lines_read) * 80;
126  if (end - ptr8 < bytes_left)
127  return AVERROR_INVALIDDATA;
128  ptr8 += bytes_left;
129 
130  if (header->rgb && (header->naxis != 3 || (header->naxisn[2] != 3 && header->naxisn[2] != 4))) {
131  av_log(avctx, AV_LOG_ERROR, "File contains RGB image but NAXIS = %d and NAXIS3 = %d\n", header->naxis, header->naxisn[2]);
132  return AVERROR_INVALIDDATA;
133  }
134 
135  if (!header->rgb && header->naxis != 2) {
136  av_log(avctx, AV_LOG_ERROR, "unsupported number of dimensions, NAXIS = %d\n", header->naxis);
137  return AVERROR_INVALIDDATA;
138  }
139 
140  if (header->blank_found && (header->bitpix == -32 || header->bitpix == -64)) {
141  av_log(avctx, AV_LOG_WARNING, "BLANK keyword found but BITPIX = %d\n. Ignoring BLANK", header->bitpix);
142  header->blank_found = 0;
143  }
144 
145  size = abs(header->bitpix) >> 3;
146  for (i = 0; i < header->naxis; i++) {
147  if (size == 0 || header->naxisn[i] > SIZE_MAX / size) {
148  av_log(avctx, AV_LOG_ERROR, "unsupported size of FITS image");
149  return AVERROR_INVALIDDATA;
150  }
151  size *= header->naxisn[i];
152  }
153 
154  if (end - ptr8 < size)
155  return AVERROR_INVALIDDATA;
156  *ptr = ptr8;
157 
158  if (!header->rgb && (!header->data_min_found || !header->data_max_found)) {
159  ret = fill_data_min_max(ptr8, header, end);
160  if (ret < 0) {
161  av_log(avctx, AV_LOG_ERROR, "invalid BITPIX, %d\n", header->bitpix);
162  return ret;
163  }
164  } else {
165  /*
166  * instead of applying bscale and bzero to every element,
167  * we can do inverse transformation on data_min and data_max
168  */
169  header->data_min = (header->data_min - header->bzero) / header->bscale;
170  header->data_max = (header->data_max - header->bzero) / header->bscale;
171  }
172  if (!header->rgb && header->data_min >= header->data_max) {
173  if (header->data_min > header->data_max) {
174  av_log(avctx, AV_LOG_ERROR, "data min/max (%g %g) is invalid\n", header->data_min, header->data_max);
175  return AVERROR_INVALIDDATA;
176  }
177  av_log(avctx, AV_LOG_WARNING, "data min/max indicates a blank image\n");
178  header->data_max ++;
179  }
180 
181  return 0;
182 }
183 
185  int *got_frame, AVPacket *avpkt)
186 {
187  const uint8_t *ptr8 = avpkt->data, *end;
188  uint8_t t8;
189  int16_t t16;
190  int32_t t32;
191  int64_t t64;
192  float tflt;
193  double tdbl;
194  int ret, i, j, k;
195  const int map[] = {2, 0, 1, 3}; // mapping from GBRA -> RGBA as RGBA is to be stored in FITS file..
196  uint8_t *dst8;
197  uint16_t *dst16;
198  uint64_t t;
200  FITSContext * fitsctx = avctx->priv_data;
201 
202  end = ptr8 + avpkt->size;
203  p->metadata = NULL;
204  ret = fits_read_header(avctx, &ptr8, &header, end, &p->metadata);
205  if (ret < 0)
206  return ret;
207 
208  if (header.rgb) {
209  if (header.bitpix == 8) {
210  if (header.naxisn[2] == 3) {
211  avctx->pix_fmt = AV_PIX_FMT_GBRP;
212  } else {
213  avctx->pix_fmt = AV_PIX_FMT_GBRAP;
214  }
215  } else if (header.bitpix == 16) {
216  if (header.naxisn[2] == 3) {
217  avctx->pix_fmt = AV_PIX_FMT_GBRP16;
218  } else {
219  avctx->pix_fmt = AV_PIX_FMT_GBRAP16;
220  }
221  } else {
222  av_log(avctx, AV_LOG_ERROR, "unsupported BITPIX = %d\n", header.bitpix);
223  return AVERROR_INVALIDDATA;
224  }
225  } else {
226  if (header.bitpix == 8) {
227  avctx->pix_fmt = AV_PIX_FMT_GRAY8;
228  } else {
229  avctx->pix_fmt = AV_PIX_FMT_GRAY16;
230  }
231  }
232 
233  if ((ret = ff_set_dimensions(avctx, header.naxisn[0], header.naxisn[1])) < 0)
234  return ret;
235 
236  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
237  return ret;
238 
239  /*
240  * FITS stores images with bottom row first. Therefore we have
241  * to fill the image from bottom to top.
242  */
243  if (header.rgb) {
244  switch(header.bitpix) {
245 #define CASE_RGB(cas, dst, type, dref) \
246  case cas: \
247  for (k = 0; k < header.naxisn[2]; k++) { \
248  for (i = 0; i < avctx->height; i++) { \
249  dst = (type *) (p->data[map[k]] + (avctx->height - i - 1) * p->linesize[map[k]]); \
250  for (j = 0; j < avctx->width; j++) { \
251  t32 = dref(ptr8); \
252  if (!header.blank_found || t32 != header.blank) { \
253  t = t32 * header.bscale + header.bzero; \
254  } else { \
255  t = fitsctx->blank_val; \
256  } \
257  *dst++ = (type) t; \
258  ptr8 += cas >> 3; \
259  } \
260  } \
261  } \
262  break
263 
264  CASE_RGB(8, dst8, uint8_t, *);
265  CASE_RGB(16, dst16, uint16_t, AV_RB16);
266  }
267  } else {
268  double scale = header.data_max - header.data_min;
269 
270  if (scale <= 0 || !isfinite(scale)) {
271  scale = 1;
272  }
273  scale = 1/scale;
274 
275  switch (header.bitpix) {
276 #define CASE_GRAY(cas, dst, type, t, rd) \
277  case cas: \
278  for (i = 0; i < avctx->height; i++) { \
279  dst = (type *) (p->data[0] + (avctx->height-i-1)* p->linesize[0]); \
280  for (j = 0; j < avctx->width; j++) { \
281  t = rd; \
282  if (!header.blank_found || t != header.blank) { \
283  *dst++ = lrint(((t - header.data_min) * ((1 << (sizeof(type) * 8)) - 1)) * scale); \
284  } else { \
285  *dst++ = fitsctx->blank_val; \
286  } \
287  ptr8 += abs(cas) >> 3; \
288  } \
289  } \
290  break
291 
292  CASE_GRAY(-64, dst16, uint16_t, tdbl, av_int2double(AV_RB64(ptr8)));
293  CASE_GRAY(-32, dst16, uint16_t, tflt, av_int2float(AV_RB32(ptr8)));
294  CASE_GRAY(8, dst8, uint8_t, t8, ptr8[0]);
295  CASE_GRAY(16, dst16, uint16_t, t16, AV_RB16(ptr8));
296  CASE_GRAY(32, dst16, uint16_t, t32, AV_RB32(ptr8));
297  CASE_GRAY(64, dst16, uint16_t, t64, AV_RB64(ptr8));
298  default:
299  av_log(avctx, AV_LOG_ERROR, "invalid BITPIX, %d\n", header.bitpix);
300  return AVERROR_INVALIDDATA;
301  }
302  }
303 
304  p->key_frame = 1;
306 
307  *got_frame = 1;
308 
309  return avpkt->size;
310 }
311 
312 static const AVOption fits_options[] = {
313  { "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},
314  { NULL },
315 };
316 
317 static const AVClass fits_decoder_class = {
318  .class_name = "FITS decoder",
319  .item_name = av_default_item_name,
320  .option = fits_options,
321  .version = LIBAVUTIL_VERSION_INT,
322 };
323 
325  .p.name = "fits",
326  .p.type = AVMEDIA_TYPE_VIDEO,
327  .p.id = AV_CODEC_ID_FITS,
328  .p.capabilities = AV_CODEC_CAP_DR1,
329  .p.long_name = NULL_IF_CONFIG_SMALL("Flexible Image Transport System"),
330  .p.priv_class = &fits_decoder_class,
331  .priv_data_size = sizeof(FITSContext),
333 };
AV_PIX_FMT_GBRAP16
#define AV_PIX_FMT_GBRAP16
Definition: pixfmt.h:428
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
opt.h
AV_OPT_FLAG_VIDEO_PARAM
#define AV_OPT_FLAG_VIDEO_PARAM
Definition: opt.h:284
av_int2double
static av_always_inline double av_int2double(uint64_t i)
Reinterpret a 64-bit integer as a double.
Definition: intfloat.h:60
FITSContext
Definition: fitsdec.c:43
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:374
AVOption
AVOption.
Definition: opt.h:251
FFCodec
Definition: codec_internal.h:112
float.h
AVDictionary
Definition: dict.c:30
intfloat.h
CASE_RGB
#define CASE_RGB(cas, dst, type, dref)
fits.h
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:116
AV_PIX_FMT_GBRAP
@ AV_PIX_FMT_GBRAP
planar GBRA 4:4:4:4 32bpp
Definition: pixfmt.h:205
av_int2float
static av_always_inline float av_int2float(uint32_t i)
Reinterpret a 32-bit integer as a float.
Definition: intfloat.h:40
avpriv_fits_header_parse_line
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:113
AVFrame::key_frame
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:417
scale
static av_always_inline float scale(float x, float s)
Definition: vf_v360.c:1388
AV_PIX_FMT_GRAY16
#define AV_PIX_FMT_GRAY16
Definition: pixfmt.h:390
fits_read_header
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:106
fill_data_min_max
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:56
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
CASE_GRAY
#define CASE_GRAY(cas, dst, type, t, rd)
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:254
intreadwrite.h
isfinite
#define isfinite(x)
Definition: libm.h:359
AV_PIX_FMT_GBRP16
#define AV_PIX_FMT_GBRP16
Definition: pixfmt.h:425
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
AV_CODEC_ID_FITS
@ AV_CODEC_ID_FITS
Definition: codec_id.h:285
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:237
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
FITSContext::blank_val
int blank_val
Definition: fitsdec.c:45
abs
#define abs(x)
Definition: cuda_runtime.h:35
AV_PIX_FMT_GRAY8
@ AV_PIX_FMT_GRAY8
Y , 8bpp.
Definition: pixfmt.h:74
AVFrame::pict_type
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:422
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1403
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:375
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:116
codec_internal.h
size
int size
Definition: twinvq_data.h:10344
AV_RB32
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:96
t8
#define t8
Definition: regdef.h:53
header
static const uint8_t header[24]
Definition: sdr2.c:67
avpriv_fits_header_init
int avpriv_fits_header_init(FITSHeader *header, FITSHeaderState state)
Initialize a single header line.
Definition: fits.c:31
STATE_BITPIX
@ STATE_BITPIX
Definition: fits.h:32
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
AV_OPT_FLAG_DECODING_PARAM
#define AV_OPT_FLAG_DECODING_PARAM
a generic parameter which can be set by the user for demuxing or decoding
Definition: opt.h:282
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:203
CASE_N
#define CASE_N(a, t, rd)
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:599
avcodec.h
ret
ret
Definition: filter_design.txt:187
AVClass::class_name
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:71
dict.h
AVCodecContext
main external API structure.
Definition: avcodec.h:389
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:225
AVFrame::metadata
AVDictionary * metadata
metadata.
Definition: frame.h:620
FITSHeader
Structure to store the header keywords in FITS file.
Definition: fits.h:43
fits_decoder_class
static const AVClass fits_decoder_class
Definition: fitsdec.c:317
AV_PIX_FMT_GBRP
@ AV_PIX_FMT_GBRP
planar GBR 4:4:4 24bpp
Definition: pixfmt.h:158
ff_fits_decoder
const FFCodec ff_fits_decoder
Definition: fitsdec.c:324
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
ff_set_dimensions
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:90
map
const VDPAUPixFmtMap * map
Definition: hwcontext_vdpau.c:71
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:416
AVPacket
This structure stores compressed data.
Definition: packet.h:351
int32_t
int32_t
Definition: audioconvert.c:56
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
fits_decode_frame
static int fits_decode_frame(AVCodecContext *avctx, AVFrame *p, int *got_frame, AVPacket *avpkt)
Definition: fitsdec.c:184
AV_RB64
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:95
fits_options
static const AVOption fits_options[]
Definition: fitsdec.c:312
AV_RB16
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:98