FFmpeg
fitsenc.c
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1 /*
2  * FITS image encoder
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 encoder
25  *
26  * Specification: https://fits.gsfc.nasa.gov/fits_standard.html Version 3.0
27  *
28  * RGBA images are encoded as planes in RGBA order. So, NAXIS3 is 3 or 4 for them.
29  * Also CTYPE3 = 'RGB ' is added to the header to distinguish them from 3d images.
30  */
31 
32 #include "libavutil/intreadwrite.h"
33 #include "avcodec.h"
34 #include "bytestream.h"
35 #include "internal.h"
36 
38  const AVFrame *pict, int *got_packet)
39 {
40  AVFrame * const p = (AVFrame *)pict;
41  uint8_t *bytestream, *bytestream_start, *ptr;
42  const uint16_t flip = (1 << 15);
43  uint64_t data_size = 0, padded_data_size = 0;
44  int ret, bitpix, naxis3 = 1, i, j, k, bytes_left;
45  int map[] = {2, 0, 1, 3}; // mapping from GBRA -> RGBA as RGBA is to be stored in FITS file..
46 
47  switch (avctx->pix_fmt) {
48  case AV_PIX_FMT_GRAY8:
50  map[0] = 0; // grayscale images should be directly mapped
51  if (avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
52  bitpix = 8;
53  } else {
54  bitpix = 16;
55  }
56  break;
57  case AV_PIX_FMT_GBRP:
58  case AV_PIX_FMT_GBRAP:
59  bitpix = 8;
60  if (avctx->pix_fmt == AV_PIX_FMT_GBRP) {
61  naxis3 = 3;
62  } else {
63  naxis3 = 4;
64  }
65  break;
68  bitpix = 16;
69  if (avctx->pix_fmt == AV_PIX_FMT_GBRP16BE) {
70  naxis3 = 3;
71  } else {
72  naxis3 = 4;
73  }
74  break;
75  default:
76  av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n");
77  return AVERROR(EINVAL);
78  }
79 
80  data_size = (bitpix >> 3) * avctx->height * avctx->width * naxis3;
81  padded_data_size = ((data_size + 2879) / 2880 ) * 2880;
82 
83  if ((ret = ff_alloc_packet2(avctx, pkt, padded_data_size, 0)) < 0)
84  return ret;
85 
86  bytestream_start =
87  bytestream = pkt->data;
88 
89  for (k = 0; k < naxis3; k++) {
90  for (i = 0; i < avctx->height; i++) {
91  ptr = p->data[map[k]] + (avctx->height - i - 1) * p->linesize[map[k]];
92  if (bitpix == 16) {
93  for (j = 0; j < avctx->width; j++) {
94  // subtracting bzero is equivalent to first bit flip
95  bytestream_put_be16(&bytestream, AV_RB16(ptr) ^ flip);
96  ptr += 2;
97  }
98  } else {
99  memcpy(bytestream, ptr, avctx->width);
100  bytestream += avctx->width;
101  }
102  }
103  }
104 
105  bytes_left = padded_data_size - data_size;
106  memset(bytestream, 0, bytes_left);
107  bytestream += bytes_left;
108 
109  pkt->size = bytestream - bytestream_start;
110  pkt->flags |= AV_PKT_FLAG_KEY;
111  *got_packet = 1;
112 
113  return 0;
114 }
115 
117  .name = "fits",
118  .long_name = NULL_IF_CONFIG_SMALL("Flexible Image Transport System"),
119  .type = AVMEDIA_TYPE_VIDEO,
120  .id = AV_CODEC_ID_FITS,
121  .encode2 = fits_encode_frame,
122  .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_GBRAP16BE,
128  AV_PIX_FMT_NONE },
129 };
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
planar GBR 4:4:4 24bpp
Definition: pixfmt.h:168
int size
Definition: avcodec.h:1481
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1778
static AVPacket pkt
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:87
AVCodec.
Definition: avcodec.h:3484
planar GBRA 4:4:4:4 64bpp, big-endian
Definition: pixfmt.h:216
int ff_alloc_packet2(AVCodecContext *avctx, AVPacket *avpkt, int64_t size, int64_t min_size)
Check AVPacket size and/or allocate data.
Definition: encode.c:32
uint8_t
uint8_t * data
Definition: avcodec.h:1480
planar GBR 4:4:4 48bpp, big-endian
Definition: pixfmt.h:174
#define av_log(a,...)
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1512
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
static void flip(AVCodecContext *avctx, AVFrame *frame)
Definition: rawdec.c:136
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
const char * name
Name of the codec implementation.
Definition: avcodec.h:3491
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1486
int width
picture width / height.
Definition: avcodec.h:1741
AVCodec ff_fits_encoder
Definition: fitsenc.c:116
static int fits_encode_frame(AVCodecContext *avctx, AVPacket *pkt, const AVFrame *pict, int *got_packet)
Definition: fitsenc.c:37
if(ret)
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:326
main external API structure.
Definition: avcodec.h:1568
Y , 16bpp, big-endian.
Definition: pixfmt.h:97
const VDPAUPixFmtMap * map
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:309
Y , 8bpp.
Definition: pixfmt.h:74
common internal api header.
planar GBRA 4:4:4:4 32bpp
Definition: pixfmt.h:215
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
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
This structure stores compressed data.
Definition: avcodec.h:1457