| /* |
| * FITS demuxer |
| * 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 demuxer. |
| */ |
| |
| #include "libavutil/intreadwrite.h" |
| #include "internal.h" |
| #include "libavutil/opt.h" |
| #include "libavcodec/fits.h" |
| #include "libavutil/bprint.h" |
| |
| #define FITS_BLOCK_SIZE 2880 |
| |
| typedef struct FITSContext { |
| const AVClass *class; |
| AVRational framerate; |
| int first_image; |
| int64_t pts; |
| } FITSContext; |
| |
| static int fits_probe(const AVProbeData *p) |
| { |
| const uint8_t *b = p->buf; |
| if (!memcmp(b, "SIMPLE = T", 30)) |
| return AVPROBE_SCORE_MAX - 1; |
| return 0; |
| } |
| |
| static int fits_read_header(AVFormatContext *s) |
| { |
| AVStream *st; |
| FITSContext * fits = s->priv_data; |
| |
| st = avformat_new_stream(s, NULL); |
| if (!st) |
| return AVERROR(ENOMEM); |
| |
| st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
| st->codecpar->codec_id = AV_CODEC_ID_FITS; |
| |
| avpriv_set_pts_info(st, 64, fits->framerate.den, fits->framerate.num); |
| fits->pts = 0; |
| fits->first_image = 1; |
| return 0; |
| } |
| |
| /** |
| * Parses header and checks that the current HDU contains image or not |
| * It also stores the header in the avbuf and stores the size of data part in data_size |
| * @param s pointer to AVFormat Context |
| * @param fits pointer to FITSContext |
| * @param header pointer to FITSHeader |
| * @param avbuf pointer to AVBPrint to store the header |
| * @param data_size to store the size of data part |
| * @return 1 if image found, 0 if any other extension and AVERROR_INVALIDDATA otherwise |
| */ |
| static int64_t is_image(AVFormatContext *s, FITSContext *fits, FITSHeader *header, |
| AVBPrint *avbuf, uint64_t *data_size) |
| { |
| int i, ret, image = 0; |
| char buf[FITS_BLOCK_SIZE] = { 0 }; |
| int64_t buf_size = 0, size = 0, t; |
| |
| do { |
| ret = avio_read(s->pb, buf, FITS_BLOCK_SIZE); |
| if (ret < 0) { |
| return ret; |
| } else if (ret < FITS_BLOCK_SIZE) { |
| return AVERROR_INVALIDDATA; |
| } |
| |
| av_bprint_append_data(avbuf, buf, FITS_BLOCK_SIZE); |
| ret = 0; |
| buf_size = 0; |
| while(!ret && buf_size < FITS_BLOCK_SIZE) { |
| ret = avpriv_fits_header_parse_line(s, header, buf + buf_size, NULL); |
| buf_size += 80; |
| } |
| } while (!ret); |
| if (ret < 0) |
| return ret; |
| |
| image = fits->first_image || header->image_extension; |
| fits->first_image = 0; |
| |
| if (header->groups) { |
| image = 0; |
| if (header->naxis > 1) |
| size = 1; |
| } else if (header->naxis) { |
| size = header->naxisn[0]; |
| } else { |
| image = 0; |
| } |
| |
| for (i = 1; i < header->naxis; i++) { |
| if(size && header->naxisn[i] > UINT64_MAX / size) |
| return AVERROR_INVALIDDATA; |
| size *= header->naxisn[i]; |
| } |
| |
| if(header->pcount > UINT64_MAX - size) |
| return AVERROR_INVALIDDATA; |
| size += header->pcount; |
| |
| t = (abs(header->bitpix) >> 3) * ((int64_t) header->gcount); |
| if(size && t > UINT64_MAX / size) |
| return AVERROR_INVALIDDATA; |
| size *= t; |
| |
| if (!size) { |
| image = 0; |
| } else { |
| if(FITS_BLOCK_SIZE - 1 > UINT64_MAX - size) |
| return AVERROR_INVALIDDATA; |
| size = ((size + FITS_BLOCK_SIZE - 1) / FITS_BLOCK_SIZE) * FITS_BLOCK_SIZE; |
| } |
| *data_size = size; |
| return image; |
| } |
| |
| static int fits_read_packet(AVFormatContext *s, AVPacket *pkt) |
| { |
| int64_t pos, ret; |
| uint64_t size; |
| FITSContext *fits = s->priv_data; |
| FITSHeader header; |
| AVBPrint avbuf; |
| char *buf; |
| |
| if (fits->first_image) { |
| avpriv_fits_header_init(&header, STATE_SIMPLE); |
| } else { |
| avpriv_fits_header_init(&header, STATE_XTENSION); |
| } |
| |
| av_bprint_init(&avbuf, FITS_BLOCK_SIZE, AV_BPRINT_SIZE_UNLIMITED); |
| while ((ret = is_image(s, fits, &header, &avbuf, &size)) == 0) { |
| av_bprint_finalize(&avbuf, NULL); |
| pos = avio_skip(s->pb, size); |
| if (pos < 0) |
| return pos; |
| |
| av_bprint_init(&avbuf, FITS_BLOCK_SIZE, AV_BPRINT_SIZE_UNLIMITED); |
| avpriv_fits_header_init(&header, STATE_XTENSION); |
| } |
| if (ret < 0) |
| goto fail; |
| |
| if (!av_bprint_is_complete(&avbuf)) { |
| ret = AVERROR(ENOMEM); |
| goto fail; |
| } |
| |
| // Header is sent with the first line removed... |
| ret = av_new_packet(pkt, avbuf.len - 80 + size); |
| if (ret < 0) |
| goto fail; |
| |
| pkt->stream_index = 0; |
| pkt->flags |= AV_PKT_FLAG_KEY; |
| |
| ret = av_bprint_finalize(&avbuf, &buf); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| memcpy(pkt->data, buf + 80, avbuf.len - 80); |
| pkt->size = avbuf.len - 80; |
| av_freep(&buf); |
| ret = avio_read(s->pb, pkt->data + pkt->size, size); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| pkt->size += ret; |
| pkt->pts = fits->pts; |
| fits->pts++; |
| |
| return 0; |
| |
| fail: |
| av_bprint_finalize(&avbuf, NULL); |
| return ret; |
| } |
| |
| static const AVOption fits_options[] = { |
| { "framerate", "set the framerate", offsetof(FITSContext, framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "1"}, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM}, |
| { NULL }, |
| }; |
| |
| static const AVClass fits_demuxer_class = { |
| .class_name = "FITS demuxer", |
| .item_name = av_default_item_name, |
| .option = fits_options, |
| .version = LIBAVUTIL_VERSION_INT, |
| }; |
| |
| AVInputFormat ff_fits_demuxer = { |
| .name = "fits", |
| .long_name = NULL_IF_CONFIG_SMALL("Flexible Image Transport System"), |
| .priv_data_size = sizeof(FITSContext), |
| .read_probe = fits_probe, |
| .read_header = fits_read_header, |
| .read_packet = fits_read_packet, |
| .priv_class = &fits_demuxer_class, |
| .raw_codec_id = AV_CODEC_ID_FITS, |
| }; |