FFmpeg
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 *fmt,
49  const char *keyword, void *value, int *lines_written)
50 {
51  int len, ret;
52  uint8_t header[80];
53 
54  len = strlen(keyword);
55  memset(header, ' ', sizeof(header));
56  memcpy(header, keyword, len);
57 
58  header[8] = '=';
59  header[9] = ' ';
60 
61  if (!strcmp(fmt, "%d")) {
62  ret = snprintf(header + 10, 70, fmt, *(int *)value);
63  } else {
64  ret = snprintf(header + 10, 70, fmt, *(float *)value);
65  }
66 
67  memset(&header[ret + 10], ' ', sizeof(header) - (ret + 10));
68 
69  avio_write(s->pb, header, sizeof(header));
70  *lines_written += 1;
71  return 0;
72 }
73 
75 {
76  AVStream *st = s->streams[0];
77  AVCodecParameters *encctx = st->codecpar;
78  FITSContext *fitsctx = s->priv_data;
79  uint8_t buffer[80];
80  int bitpix, naxis, naxis3 = 1, bzero = 0, rgb = 0, lines_written = 0, lines_left;
81  int pcount = 0, gcount = 1;
82  float datamax, datamin;
83 
84  switch (encctx->format) {
85  case AV_PIX_FMT_GRAY8:
86  bitpix = 8;
87  naxis = 2;
88  datamin = 0;
89  datamax = 255;
90  break;
92  bitpix = 16;
93  naxis = 2;
94  bzero = 32768;
95  datamin = 0;
96  datamax = 65535;
97  break;
98  case AV_PIX_FMT_GBRP:
99  case AV_PIX_FMT_GBRAP:
100  bitpix = 8;
101  naxis = 3;
102  rgb = 1;
103  if (encctx->format == AV_PIX_FMT_GBRP) {
104  naxis3 = 3;
105  } else {
106  naxis3 = 4;
107  }
108  datamin = 0;
109  datamax = 255;
110  break;
111  case AV_PIX_FMT_GBRP16BE:
113  bitpix = 16;
114  naxis = 3;
115  rgb = 1;
116  if (encctx->format == AV_PIX_FMT_GBRP16BE) {
117  naxis3 = 3;
118  } else {
119  naxis3 = 4;
120  }
121  bzero = 32768;
122  datamin = 0;
123  datamax = 65535;
124  break;
125  default:
126  return AVERROR(EINVAL);
127  }
128 
129  if (fitsctx->first_image) {
130  memcpy(buffer, "SIMPLE = ", 10);
131  memset(buffer + 10, ' ', 70);
132  buffer[29] = 'T';
133  avio_write(s->pb, buffer, sizeof(buffer));
134  } else {
135  memcpy(buffer, "XTENSION= 'IMAGE '", 20);
136  memset(buffer + 20, ' ', 60);
137  avio_write(s->pb, buffer, sizeof(buffer));
138  }
139  lines_written++;
140 
141  write_keyword_value(s, "%d", "BITPIX", &bitpix, &lines_written); // no of bits per pixel
142  write_keyword_value(s, "%d", "NAXIS", &naxis, &lines_written); // no of dimensions of image
143  write_keyword_value(s, "%d", "NAXIS1", &encctx->width, &lines_written); // first dimension i.e. width
144  write_keyword_value(s, "%d", "NAXIS2", &encctx->height, &lines_written); // second dimension i.e. height
145 
146  if (rgb)
147  write_keyword_value(s, "%d", "NAXIS3", &naxis3, &lines_written); // third dimension to store RGBA planes
148 
149  if (!fitsctx->first_image) {
150  write_keyword_value(s, "%d", "PCOUNT", &pcount, &lines_written);
151  write_keyword_value(s, "%d", "GCOUNT", &gcount, &lines_written);
152  } else {
153  fitsctx->first_image = 0;
154  }
155 
156  write_keyword_value(s, "%g", "DATAMIN", &datamin, &lines_written);
157  write_keyword_value(s, "%g", "DATAMAX", &datamax, &lines_written);
158 
159  /*
160  * Since FITS does not support unsigned 16 bit integers,
161  * BZERO = 32768 is used to store unsigned 16 bit integers as
162  * signed integers so that it can be read properly.
163  */
164  if (bitpix == 16)
165  write_keyword_value(s, "%d", "BZERO", &bzero, &lines_written);
166 
167  if (rgb) {
168  memcpy(buffer, "CTYPE3 = 'RGB '", 20);
169  memset(buffer + 20, ' ', 60);
170  avio_write(s->pb, buffer, sizeof(buffer));
171  lines_written++;
172  }
173 
174  memcpy(buffer, "END", 3);
175  memset(buffer + 3, ' ', 77);
176  avio_write(s->pb, buffer, sizeof(buffer));
177  lines_written++;
178 
179  lines_left = ((lines_written + 35) / 36) * 36 - lines_written;
180  memset(buffer, ' ', 80);
181  while (lines_left > 0) {
182  avio_write(s->pb, buffer, sizeof(buffer));
183  lines_left--;
184  }
185  return 0;
186 }
187 
189 {
190  int ret = write_image_header(s);
191  if (ret < 0)
192  return ret;
193  avio_write(s->pb, pkt->data, pkt->size);
194  return 0;
195 }
196 
198  .name = "fits",
199  .long_name = NULL_IF_CONFIG_SMALL("Flexible Image Transport System"),
200  .extensions = "fits",
201  .priv_data_size = sizeof(FITSContext),
202  .audio_codec = AV_CODEC_ID_NONE,
203  .video_codec = AV_CODEC_ID_FITS,
206 };
AVOutputFormat::name
const char * name
Definition: avformat.h:491
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
write_image_header
static int write_image_header(AVFormatContext *s)
Definition: fitsenc.c:74
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:52
AV_PIX_FMT_GBRP16BE
@ AV_PIX_FMT_GBRP16BE
planar GBR 4:4:4 48bpp, big-endian
Definition: pixfmt.h:164
FITSContext
Definition: fitsdec.c:42
AVPacket::data
uint8_t * data
Definition: packet.h:365
AV_PIX_FMT_GRAY16BE
@ AV_PIX_FMT_GRAY16BE
Y , 16bpp, big-endian.
Definition: pixfmt.h:97
rgb
Definition: rpzaenc.c:58
write_keyword_value
static int write_keyword_value(AVFormatContext *s, const char *fmt, const char *keyword, void *value, int *lines_written)
Write one header line comprising of keyword and value(int)
Definition: fitsenc.c:48
AV_PIX_FMT_GBRAP
@ AV_PIX_FMT_GBRAP
planar GBRA 4:4:4:4 32bpp
Definition: pixfmt.h:205
fits_write_packet
static int fits_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: fitsenc.c:188
pkt
AVPacket * pkt
Definition: movenc.c:59
AV_PIX_FMT_GBRAP16BE
@ AV_PIX_FMT_GBRAP16BE
planar GBRA 4:4:4:4 64bpp, big-endian
Definition: pixfmt.h:206
s
#define s(width, name)
Definition: cbs_vp9.c:257
AVCodecParameters::width
int width
Video only.
Definition: codec_par.h:126
AVFormatContext
Format I/O context.
Definition: avformat.h:1106
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:979
AV_CODEC_ID_FITS
@ AV_CODEC_ID_FITS
Definition: codec_id.h:284
AV_PIX_FMT_GRAY8
@ AV_PIX_FMT_GRAY8
Y , 8bpp.
Definition: pixfmt.h:74
AVPacket::size
int size
Definition: packet.h:366
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:117
header
static const uint8_t header[24]
Definition: sdr2.c:67
avio_write
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:215
write_packet
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost, int unqueue)
Definition: ffmpeg.c:729
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition: codec_id.h:47
AVOutputFormat
Definition: avformat.h:490
AVCodecParameters::height
int height
Definition: codec_par.h:127
value
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default value
Definition: writing_filters.txt:86
len
int len
Definition: vorbis_enc_data.h:426
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:832
FITSContext::first_image
int first_image
Definition: fitsdec.c:39
buffer
the frame and frame reference mechanism is intended to as much as expensive copies of that data while still allowing the filters to produce correct results The data is stored in buffers represented by AVFrame structures Several references can point to the same frame buffer
Definition: filter_design.txt:49
AV_PIX_FMT_GBRP
@ AV_PIX_FMT_GBRP
planar GBR 4:4:4 24bpp
Definition: pixfmt.h:158
fits_write_header
static int fits_write_header(AVFormatContext *s)
Definition: fitsenc.c:33
AVCodecParameters::format
int format
Definition: codec_par.h:84
AVPacket
This structure stores compressed data.
Definition: packet.h:342
ff_fits_muxer
const AVOutputFormat ff_fits_muxer
Definition: fitsenc.c:197
write_header
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:346
snprintf
#define snprintf
Definition: snprintf.h:34