1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
|
/*
* FITS muxer
* Copyright (c) 2017 Paras Chadha
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* FITS muxer.
*/
#include "internal.h"
typedef struct FITSContext {
int first_image;
} FITSContext;
static int fits_write_header(AVFormatContext *s)
{
FITSContext *fitsctx = s->priv_data;
fitsctx->first_image = 1;
return 0;
}
/**
* Write one header line comprising of keyword and value(int)
* @param s AVFormat Context
* @param keyword pointer to the char array in which keyword is stored
* @param value the value corresponding to the keyword
* @param lines_written to keep track of lines written so far
* @return 0
*/
static int write_keyword_value(AVFormatContext *s, const char *fmt,
const char *keyword, void *value, int *lines_written)
{
int len, ret;
uint8_t header[80];
len = strlen(keyword);
memset(header, ' ', sizeof(header));
memcpy(header, keyword, len);
header[8] = '=';
header[9] = ' ';
if (!strcmp(fmt, "%d")) {
ret = snprintf(header + 10, 70, fmt, *(int *)value);
} else {
ret = snprintf(header + 10, 70, fmt, *(float *)value);
}
memset(&header[ret + 10], ' ', sizeof(header) - (ret + 10));
avio_write(s->pb, header, sizeof(header));
*lines_written += 1;
return 0;
}
static int write_image_header(AVFormatContext *s)
{
AVStream *st = s->streams[0];
AVCodecParameters *encctx = st->codecpar;
FITSContext *fitsctx = s->priv_data;
uint8_t buffer[80];
int bitpix, naxis, naxis3 = 1, bzero = 0, rgb = 0, lines_written = 0, lines_left;
int pcount = 0, gcount = 1;
float datamax, datamin;
switch (encctx->format) {
case AV_PIX_FMT_GRAY8:
bitpix = 8;
naxis = 2;
datamin = 0;
datamax = 255;
break;
case AV_PIX_FMT_GRAY16BE:
bitpix = 16;
naxis = 2;
bzero = 32768;
datamin = 0;
datamax = 65535;
break;
case AV_PIX_FMT_GBRP:
case AV_PIX_FMT_GBRAP:
bitpix = 8;
naxis = 3;
rgb = 1;
if (encctx->format == AV_PIX_FMT_GBRP) {
naxis3 = 3;
} else {
naxis3 = 4;
}
datamin = 0;
datamax = 255;
break;
case AV_PIX_FMT_GBRP16BE:
case AV_PIX_FMT_GBRAP16BE:
bitpix = 16;
naxis = 3;
rgb = 1;
if (encctx->format == AV_PIX_FMT_GBRP16BE) {
naxis3 = 3;
} else {
naxis3 = 4;
}
bzero = 32768;
datamin = 0;
datamax = 65535;
break;
default:
return AVERROR(EINVAL);
}
if (fitsctx->first_image) {
memcpy(buffer, "SIMPLE = ", 10);
memset(buffer + 10, ' ', 70);
buffer[29] = 'T';
avio_write(s->pb, buffer, sizeof(buffer));
} else {
memcpy(buffer, "XTENSION= 'IMAGE '", 20);
memset(buffer + 20, ' ', 60);
avio_write(s->pb, buffer, sizeof(buffer));
}
lines_written++;
write_keyword_value(s, "%d", "BITPIX", &bitpix, &lines_written); // no of bits per pixel
write_keyword_value(s, "%d", "NAXIS", &naxis, &lines_written); // no of dimensions of image
write_keyword_value(s, "%d", "NAXIS1", &encctx->width, &lines_written); // first dimension i.e. width
write_keyword_value(s, "%d", "NAXIS2", &encctx->height, &lines_written); // second dimension i.e. height
if (rgb)
write_keyword_value(s, "%d", "NAXIS3", &naxis3, &lines_written); // third dimension to store RGBA planes
if (!fitsctx->first_image) {
write_keyword_value(s, "%d", "PCOUNT", &pcount, &lines_written);
write_keyword_value(s, "%d", "GCOUNT", &gcount, &lines_written);
} else {
fitsctx->first_image = 0;
}
write_keyword_value(s, "%g", "DATAMIN", &datamin, &lines_written);
write_keyword_value(s, "%g", "DATAMAX", &datamax, &lines_written);
/*
* Since FITS does not support unsigned 16 bit integers,
* BZERO = 32768 is used to store unsigned 16 bit integers as
* signed integers so that it can be read properly.
*/
if (bitpix == 16)
write_keyword_value(s, "%d", "BZERO", &bzero, &lines_written);
if (rgb) {
memcpy(buffer, "CTYPE3 = 'RGB '", 20);
memset(buffer + 20, ' ', 60);
avio_write(s->pb, buffer, sizeof(buffer));
lines_written++;
}
memcpy(buffer, "END", 3);
memset(buffer + 3, ' ', 77);
avio_write(s->pb, buffer, sizeof(buffer));
lines_written++;
lines_left = ((lines_written + 35) / 36) * 36 - lines_written;
memset(buffer, ' ', 80);
while (lines_left > 0) {
avio_write(s->pb, buffer, sizeof(buffer));
lines_left--;
}
return 0;
}
static int fits_write_packet(AVFormatContext *s, AVPacket *pkt)
{
int ret = write_image_header(s);
if (ret < 0)
return ret;
avio_write(s->pb, pkt->data, pkt->size);
return 0;
}
const AVOutputFormat ff_fits_muxer = {
.name = "fits",
.long_name = NULL_IF_CONFIG_SMALL("Flexible Image Transport System"),
.extensions = "fits",
.priv_data_size = sizeof(FITSContext),
.audio_codec = AV_CODEC_ID_NONE,
.video_codec = AV_CODEC_ID_FITS,
.write_header = fits_write_header,
.write_packet = fits_write_packet,
};
|
