/* * 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/avassert.h" #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; } 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->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 > INT64_MAX / size) return AVERROR_INVALIDDATA; size *= t; if (!size) { image = 0; } else { if(FITS_BLOCK_SIZE - 1 > INT64_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; } av_assert0(avbuf.len <= INT64_MAX && size <= INT64_MAX); if (avbuf.len + size > INT_MAX - 80) { ret = AVERROR_INVALIDDATA; 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->duration = 1; 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, .category = AV_CLASS_CATEGORY_DEMUXER, }; const 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, };