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 "avio_internal.h"
28 #include "internal.h"
29 #include "mux.h"
30 
31 typedef struct FITSContext {
32  int first_image;
33 } FITSContext;
34 
36 {
37  FITSContext *fitsctx = s->priv_data;
38  fitsctx->first_image = 1;
39  return 0;
40 }
41 
42 /**
43  * Write one header line comprising of keyword and value(int)
44  * @param s AVFormat Context
45  * @param keyword pointer to the char array in which keyword is stored
46  * @param value the value corresponding to the keyword
47  * @param lines_written to keep track of lines written so far
48  * @return 0
49  */
50 static int write_keyword_value(AVFormatContext *s, const char *fmt,
51  const char *keyword, void *value, int *lines_written)
52 {
53  int len, ret;
54  uint8_t header[80];
55 
56  len = strlen(keyword);
57  memset(header, ' ', sizeof(header));
58  memcpy(header, keyword, len);
59 
60  header[8] = '=';
61  header[9] = ' ';
62 
63  if (!strcmp(fmt, "%d")) {
64  ret = snprintf(header + 10, 70, fmt, *(int *)value);
65  } else {
66  ret = snprintf(header + 10, 70, fmt, *(float *)value);
67  }
68 
69  memset(&header[ret + 10], ' ', sizeof(header) - (ret + 10));
70 
71  avio_write(s->pb, header, sizeof(header));
72  *lines_written += 1;
73  return 0;
74 }
75 
77 {
78  AVStream *st = s->streams[0];
79  AVCodecParameters *encctx = st->codecpar;
80  FITSContext *fitsctx = s->priv_data;
81  uint8_t buffer[80];
82  int bitpix, naxis, naxis3 = 1, bzero = 0, rgb = 0, lines_written = 0, lines_left;
83  int pcount = 0, gcount = 1;
84  float datamax, datamin;
85 
86  switch (encctx->format) {
87  case AV_PIX_FMT_GRAY8:
88  bitpix = 8;
89  naxis = 2;
90  datamin = 0;
91  datamax = 255;
92  break;
94  bitpix = 16;
95  naxis = 2;
96  bzero = 32768;
97  datamin = 0;
98  datamax = 65535;
99  break;
100  case AV_PIX_FMT_GBRP:
101  case AV_PIX_FMT_GBRAP:
102  bitpix = 8;
103  naxis = 3;
104  rgb = 1;
105  if (encctx->format == AV_PIX_FMT_GBRP) {
106  naxis3 = 3;
107  } else {
108  naxis3 = 4;
109  }
110  datamin = 0;
111  datamax = 255;
112  break;
113  case AV_PIX_FMT_GBRP16BE:
115  bitpix = 16;
116  naxis = 3;
117  rgb = 1;
118  if (encctx->format == AV_PIX_FMT_GBRP16BE) {
119  naxis3 = 3;
120  } else {
121  naxis3 = 4;
122  }
123  bzero = 32768;
124  datamin = 0;
125  datamax = 65535;
126  break;
127  default:
128  return AVERROR(EINVAL);
129  }
130 
131  if (fitsctx->first_image) {
132  memcpy(buffer, "SIMPLE = ", 10);
133  memset(buffer + 10, ' ', 70);
134  buffer[29] = 'T';
135  avio_write(s->pb, buffer, sizeof(buffer));
136  } else {
137  memcpy(buffer, "XTENSION= 'IMAGE '", 20);
138  memset(buffer + 20, ' ', 60);
139  avio_write(s->pb, buffer, sizeof(buffer));
140  }
141  lines_written++;
142 
143  write_keyword_value(s, "%d", "BITPIX", &bitpix, &lines_written); // no of bits per pixel
144  write_keyword_value(s, "%d", "NAXIS", &naxis, &lines_written); // no of dimensions of image
145  write_keyword_value(s, "%d", "NAXIS1", &encctx->width, &lines_written); // first dimension i.e. width
146  write_keyword_value(s, "%d", "NAXIS2", &encctx->height, &lines_written); // second dimension i.e. height
147 
148  if (rgb)
149  write_keyword_value(s, "%d", "NAXIS3", &naxis3, &lines_written); // third dimension to store RGBA planes
150 
151  if (!fitsctx->first_image) {
152  write_keyword_value(s, "%d", "PCOUNT", &pcount, &lines_written);
153  write_keyword_value(s, "%d", "GCOUNT", &gcount, &lines_written);
154  } else {
155  fitsctx->first_image = 0;
156  }
157 
158  write_keyword_value(s, "%g", "DATAMIN", &datamin, &lines_written);
159  write_keyword_value(s, "%g", "DATAMAX", &datamax, &lines_written);
160 
161  /*
162  * Since FITS does not support unsigned 16 bit integers,
163  * BZERO = 32768 is used to store unsigned 16 bit integers as
164  * signed integers so that it can be read properly.
165  */
166  if (bitpix == 16)
167  write_keyword_value(s, "%d", "BZERO", &bzero, &lines_written);
168 
169  if (rgb) {
170  memcpy(buffer, "CTYPE3 = 'RGB '", 20);
171  memset(buffer + 20, ' ', 60);
172  avio_write(s->pb, buffer, sizeof(buffer));
173  lines_written++;
174  }
175 
176  memcpy(buffer, "END", 3);
177  memset(buffer + 3, ' ', 77);
178  avio_write(s->pb, buffer, sizeof(buffer));
179  lines_written++;
180 
181  lines_left = ((lines_written + 35) / 36) * 36 - lines_written;
182  ffio_fill(s->pb, ' ', sizeof(buffer) * lines_left);
183  return 0;
184 }
185 
187 {
188  int ret = write_image_header(s);
189  if (ret < 0)
190  return ret;
191  avio_write(s->pb, pkt->data, pkt->size);
192  return 0;
193 }
194 
196  .p.name = "fits",
197  .p.long_name = NULL_IF_CONFIG_SMALL("Flexible Image Transport System"),
198  .p.extensions = "fits",
199  .p.audio_codec = AV_CODEC_ID_NONE,
200  .p.video_codec = AV_CODEC_ID_FITS,
201  .priv_data_size = sizeof(FITSContext),
204  .p.flags = AVFMT_NOTIMESTAMPS,
205 };
AVOutputFormat::name
const char * name
Definition: avformat.h:511
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:76
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:47
AV_PIX_FMT_GBRP16BE
@ AV_PIX_FMT_GBRP16BE
planar GBR 4:4:4 48bpp, big-endian
Definition: pixfmt.h:171
AVFMT_NOTIMESTAMPS
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:480
FITSContext
Definition: fitsdec.c:43
AVPacket::data
uint8_t * data
Definition: packet.h:522
FFOutputFormat::p
AVOutputFormat p
The public AVOutputFormat.
Definition: mux.h:36
AV_PIX_FMT_GRAY16BE
@ AV_PIX_FMT_GRAY16BE
Y , 16bpp, big-endian.
Definition: pixfmt.h:104
rgb
Definition: rpzaenc.c:60
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:50
AV_PIX_FMT_GBRAP
@ AV_PIX_FMT_GBRAP
planar GBRA 4:4:4:4 32bpp
Definition: pixfmt.h:212
ff_fits_muxer
const FFOutputFormat ff_fits_muxer
Definition: fitsenc.c:195
fits_write_packet
static int fits_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: fitsenc.c:186
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:213
s
#define s(width, name)
Definition: cbs_vp9.c:198
AVCodecParameters::width
int width
Video only.
Definition: codec_par.h:121
AVFormatContext
Format I/O context.
Definition: avformat.h:1363
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:864
AV_CODEC_ID_FITS
@ AV_CODEC_ID_FITS
Definition: codec_id.h:289
FFOutputFormat
Definition: mux.h:32
ffio_fill
void ffio_fill(AVIOContext *s, int b, int64_t count)
Definition: aviobuf.c:234
AV_PIX_FMT_GRAY8
@ AV_PIX_FMT_GRAY8
Y , 8bpp.
Definition: pixfmt.h:81
AVPacket::size
int size
Definition: packet.h:523
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:106
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:248
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition: codec_id.h:50
avio_internal.h
AVCodecParameters::height
int height
Definition: codec_par.h:122
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
write_packet
static int write_packet(Muxer *mux, OutputStream *ost, AVPacket *pkt)
Definition: ffmpeg_mux.c:209
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:841
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:165
fits_write_header
static int fits_write_header(AVFormatContext *s)
Definition: fitsenc.c:35
AVCodecParameters::format
int format
Definition: codec_par.h:79
AVPacket
This structure stores compressed data.
Definition: packet.h:499
write_header
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:346
snprintf
#define snprintf
Definition: snprintf.h:34
mux.h