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fitsenc.c
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1 /*
2  * FITS muxer
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 muxer.
25  */
26 
27 #include "internal.h"
28 
29 typedef struct FITSContext {
30  int first_image;
31 } FITSContext;
32 
34 {
35  FITSContext *fitsctx = s->priv_data;
36  fitsctx->first_image = 1;
37  return 0;
38 }
39 
40 /**
41  * Write one header line comprising of keyword and value(int)
42  * @param s AVFormat Context
43  * @param keyword pointer to the char array in which keyword is stored
44  * @param value the value corresponding to the keyword
45  * @param lines_written to keep track of lines written so far
46  * @return 0
47  */
48 static int write_keyword_value(AVFormatContext *s, const char *keyword, int value, int *lines_written)
49 {
50  int len, ret;
51  uint8_t header[80];
52 
53  len = strlen(keyword);
54  memset(header, ' ', sizeof(header));
55  memcpy(header, keyword, len);
56 
57  header[8] = '=';
58  header[9] = ' ';
59 
60  ret = snprintf(header + 10, 70, "%d", value);
61  memset(&header[ret + 10], ' ', sizeof(header) - (ret + 10));
62 
63  avio_write(s->pb, header, sizeof(header));
64  *lines_written += 1;
65  return 0;
66 }
67 
69 {
70  AVStream *st = s->streams[0];
71  AVCodecParameters *encctx = st->codecpar;
72  FITSContext *fitsctx = s->priv_data;
73  uint8_t buffer[80];
74  int bitpix, naxis, naxis3 = 1, bzero = 0, rgb = 0, lines_written = 0, lines_left;
75 
76  switch (encctx->format) {
77  case AV_PIX_FMT_GRAY8:
78  bitpix = 8;
79  naxis = 2;
80  break;
82  bitpix = 16;
83  naxis = 2;
84  bzero = 32768;
85  break;
86  case AV_PIX_FMT_GBRP:
87  case AV_PIX_FMT_GBRAP:
88  bitpix = 8;
89  naxis = 3;
90  rgb = 1;
91  if (encctx->format == AV_PIX_FMT_GBRP) {
92  naxis3 = 3;
93  } else {
94  naxis3 = 4;
95  }
96  break;
99  bitpix = 16;
100  naxis = 3;
101  rgb = 1;
102  if (encctx->format == AV_PIX_FMT_GBRP16BE) {
103  naxis3 = 3;
104  } else {
105  naxis3 = 4;
106  }
107  bzero = 32768;
108  break;
109  default:
110  return AVERROR(EINVAL);
111  }
112 
113  if (fitsctx->first_image) {
114  memcpy(buffer, "SIMPLE = ", 10);
115  memset(buffer + 10, ' ', 70);
116  buffer[29] = 'T';
117  avio_write(s->pb, buffer, sizeof(buffer));
118  } else {
119  memcpy(buffer, "XTENSION= 'IMAGE '", 20);
120  memset(buffer + 20, ' ', 60);
121  avio_write(s->pb, buffer, sizeof(buffer));
122  }
123  lines_written++;
124 
125  write_keyword_value(s, "BITPIX", bitpix, &lines_written); // no of bits per pixel
126  write_keyword_value(s, "NAXIS", naxis, &lines_written); // no of dimensions of image
127  write_keyword_value(s, "NAXIS1", encctx->width, &lines_written); // first dimension i.e. width
128  write_keyword_value(s, "NAXIS2", encctx->height, &lines_written); // second dimension i.e. height
129 
130  if (rgb)
131  write_keyword_value(s, "NAXIS3", naxis3, &lines_written); // third dimension to store RGBA planes
132 
133  if (!fitsctx->first_image) {
134  write_keyword_value(s, "PCOUNT", 0, &lines_written);
135  write_keyword_value(s, "GCOUNT", 1, &lines_written);
136  } else {
137  fitsctx->first_image = 0;
138  }
139 
140  /*
141  * Since FITS does not support unsigned 16 bit integers,
142  * BZERO = 32768 is used to store unsigned 16 bit integers as
143  * signed integers so that it can be read properly.
144  */
145  if (bitpix == 16)
146  write_keyword_value(s, "BZERO", bzero, &lines_written);
147 
148  if (rgb) {
149  memcpy(buffer, "CTYPE3 = 'RGB '", 20);
150  memset(buffer + 20, ' ', 60);
151  avio_write(s->pb, buffer, sizeof(buffer));
152  lines_written++;
153  }
154 
155  memcpy(buffer, "END", 3);
156  memset(buffer + 3, ' ', 77);
157  avio_write(s->pb, buffer, sizeof(buffer));
158  lines_written++;
159 
160  lines_left = ((lines_written + 35) / 36) * 36 - lines_written;
161  memset(buffer, ' ', 80);
162  while (lines_left > 0) {
163  avio_write(s->pb, buffer, sizeof(buffer));
164  lines_left--;
165  }
166  return 0;
167 }
168 
170 {
171  int ret = write_image_header(s);
172  if (ret < 0)
173  return ret;
174  avio_write(s->pb, pkt->data, pkt->size);
175  return 0;
176 }
177 
179  .name = "fits",
180  .long_name = NULL_IF_CONFIG_SMALL("Flexible Image Transport System"),
181  .extensions = "fits",
182  .priv_data_size = sizeof(FITSContext),
183  .audio_codec = AV_CODEC_ID_NONE,
184  .video_codec = AV_CODEC_ID_FITS,
187 };
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost, int unqueue)
Definition: ffmpeg.c:689
static int write_image_header(AVFormatContext *s)
Definition: fitsenc.c:68
planar GBR 4:4:4 24bpp
Definition: pixfmt.h:168
int size
Definition: avcodec.h:1446
static int fits_write_header(AVFormatContext *s)
Definition: fitsenc.c:33
static AVPacket pkt
This struct describes the properties of an encoded stream.
Definition: avcodec.h:3892
Format I/O context.
Definition: avformat.h:1351
planar GBRA 4:4:4:4 64bpp, big-endian
Definition: pixfmt.h:216
uint8_t
int width
Video only.
Definition: avcodec.h:3966
int first_image
Definition: fitsdec.c:38
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1419
uint8_t * data
Definition: avcodec.h:1445
planar GBR 4:4:4 48bpp, big-endian
Definition: pixfmt.h:174
static const uint8_t header[24]
Definition: sdr2.c:67
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:218
static int write_keyword_value(AVFormatContext *s, const char *keyword, int value, int *lines_written)
Write one header line comprising of keyword and value(int)
Definition: fitsenc.c:48
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
AVOutputFormat ff_fits_muxer
Definition: fitsenc.c:178
GLsizei GLboolean const GLfloat * value
Definition: opengl_enc.c:109
const char * name
Definition: avformat.h:507
#define s(width, name)
Definition: cbs_vp9.c:257
Stream structure.
Definition: avformat.h:874
AVIOContext * pb
I/O context.
Definition: avformat.h:1393
Y , 16bpp, big-endian.
Definition: pixfmt.h:97
#define snprintf
Definition: snprintf.h:34
static int fits_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: fitsenc.c:169
Y , 8bpp.
Definition: pixfmt.h:74
planar GBRA 4:4:4:4 32bpp
Definition: pixfmt.h:215
int len
void * priv_data
Format private data.
Definition: avformat.h:1379
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:337
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1021
This structure stores compressed data.
Definition: avcodec.h:1422
GLuint buffer
Definition: opengl_enc.c:102