3 * Copyright (c) 2017 Paras Chadha
5 * This file is part of FFmpeg.
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.
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.
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
27 #include "libavutil/intreadwrite.h"
29 #include "libavutil/opt.h"
30 #include "libavcodec/fits.h"
31 #include "libavutil/bprint.h"
33 #define FITS_BLOCK_SIZE 2880
35 typedef struct FITSContext {
42 static int fits_probe(AVProbeData *p)
44 const uint8_t *b = p->buf;
45 if (!memcmp(b, "SIMPLE = T", 30))
46 return AVPROBE_SCORE_MAX - 1;
50 static int fits_read_header(AVFormatContext *s)
53 FITSContext * fits = s->priv_data;
55 st = avformat_new_stream(s, NULL);
57 return AVERROR(ENOMEM);
59 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
60 st->codecpar->codec_id = AV_CODEC_ID_FITS;
62 avpriv_set_pts_info(st, 64, fits->framerate.den, fits->framerate.num);
64 fits->first_image = 1;
69 * Parses header and checks that the current HDU contains image or not
70 * It also stores the header in the avbuf and stores the size of data part in data_size
71 * @param s pointer to AVFormat Context
72 * @param fits pointer to FITSContext
73 * @param header pointer to FITSHeader
74 * @param avbuf pointer to AVBPrint to store the header
75 * @param data_size to store the size of data part
76 * @return 1 if image found, 0 if any other extension and AVERROR_INVALIDDATA otherwise
78 static int64_t is_image(AVFormatContext *s, FITSContext *fits, FITSHeader *header,
79 AVBPrint *avbuf, uint64_t *data_size)
81 int i, ret, image = 0;
82 char buf[FITS_BLOCK_SIZE] = { 0 };
83 int64_t buf_size = 0, size = 0, t;
86 ret = avio_read(s->pb, buf, FITS_BLOCK_SIZE);
89 } else if (ret < FITS_BLOCK_SIZE) {
90 return AVERROR_INVALIDDATA;
93 av_bprint_append_data(avbuf, buf, FITS_BLOCK_SIZE);
96 while(!ret && buf_size < FITS_BLOCK_SIZE) {
97 ret = avpriv_fits_header_parse_line(s, header, buf + buf_size, NULL);
104 image = fits->first_image || header->image_extension;
105 fits->first_image = 0;
107 if (header->groups) {
109 if (header->naxis > 1)
111 } else if (header->naxis) {
112 size = header->naxisn[0];
117 for (i = 1; i < header->naxis; i++) {
118 if(size && header->naxisn[i] > UINT64_MAX / size)
119 return AVERROR_INVALIDDATA;
120 size *= header->naxisn[i];
123 if(header->pcount > UINT64_MAX - size)
124 return AVERROR_INVALIDDATA;
125 size += header->pcount;
127 t = (abs(header->bitpix) >> 3) * ((int64_t) header->gcount);
128 if(size && t > UINT64_MAX / size)
129 return AVERROR_INVALIDDATA;
135 if(FITS_BLOCK_SIZE - 1 > UINT64_MAX - size)
136 return AVERROR_INVALIDDATA;
137 size = ((size + FITS_BLOCK_SIZE - 1) / FITS_BLOCK_SIZE) * FITS_BLOCK_SIZE;
143 static int fits_read_packet(AVFormatContext *s, AVPacket *pkt)
147 FITSContext *fits = s->priv_data;
152 if (fits->first_image) {
153 avpriv_fits_header_init(&header, STATE_SIMPLE);
155 avpriv_fits_header_init(&header, STATE_XTENSION);
158 av_bprint_init(&avbuf, FITS_BLOCK_SIZE, AV_BPRINT_SIZE_UNLIMITED);
159 while ((ret = is_image(s, fits, &header, &avbuf, &size)) == 0) {
160 pos = avio_skip(s->pb, size);
164 av_bprint_finalize(&avbuf, NULL);
165 av_bprint_init(&avbuf, FITS_BLOCK_SIZE, AV_BPRINT_SIZE_UNLIMITED);
166 avpriv_fits_header_init(&header, STATE_XTENSION);
171 if (!av_bprint_is_complete(&avbuf)) {
172 ret = AVERROR(ENOMEM);
176 // Header is sent with the first line removed...
177 ret = av_new_packet(pkt, avbuf.len - 80 + size);
181 pkt->stream_index = 0;
182 pkt->flags |= AV_PKT_FLAG_KEY;
184 ret = av_bprint_finalize(&avbuf, &buf);
186 av_packet_unref(pkt);
190 memcpy(pkt->data, buf + 80, avbuf.len - 80);
191 pkt->size = avbuf.len - 80;
193 ret = avio_read(s->pb, pkt->data + pkt->size, size);
195 av_packet_unref(pkt);
200 pkt->pts = fits->pts;
206 av_bprint_finalize(&avbuf, NULL);
210 static const AVOption fits_options[] = {
211 { "framerate", "set the framerate", offsetof(FITSContext, framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "1"}, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM},
215 static const AVClass fits_demuxer_class = {
216 .class_name = "FITS demuxer",
217 .item_name = av_default_item_name,
218 .option = fits_options,
219 .version = LIBAVUTIL_VERSION_INT,
222 AVInputFormat ff_fits_demuxer = {
224 .long_name = NULL_IF_CONFIG_SMALL("Flexible Image Transport System"),
225 .priv_data_size = sizeof(FITSContext),
226 .read_probe = fits_probe,
227 .read_header = fits_read_header,
228 .read_packet = fits_read_packet,
229 .priv_class = &fits_demuxer_class,
230 .raw_codec_id = AV_CODEC_ID_FITS,