/* * 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 "demux.h"#include "internal.h"#include "libavutil/opt.h"#include "libavcodec/fits.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 pkt pointer to AVPacket 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 code otherwise */static int is_image(AVFormatContext *s, FITSContext *fits, FITSHeader *header,                    AVPacket *pkt, uint64_t *data_size){    int i, ret, image = 0;    int64_t size = 0, t;     do {        const uint8_t *buf, *buf_end;        ret = av_append_packet(s->pb, pkt, FITS_BLOCK_SIZE);        if (ret < 0) {            return ret;        } else if (ret < FITS_BLOCK_SIZE) {            return AVERROR_INVALIDDATA;        }         ret = 0;        buf_end = pkt->data + pkt->size;        buf     = buf_end - FITS_BLOCK_SIZE;        while(!ret && buf < buf_end) {            ret = avpriv_fits_header_parse_line(s, header, buf, NULL);            buf += 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){    uint64_t size;    FITSContext *fits = s->priv_data;    FITSHeader header;    int ret;     if (fits->first_image) {        avpriv_fits_header_init(&header, STATE_SIMPLE);    } else {        avpriv_fits_header_init(&header, STATE_XTENSION);    }     while ((ret = is_image(s, fits, &header, pkt, &size)) == 0) {        int64_t pos = avio_skip(s->pb, size);        if (pos < 0)            return pos;         avpriv_fits_header_init(&header, STATE_XTENSION);        av_packet_unref(pkt);    }    if (ret < 0)        return ret;     pkt->stream_index = 0;    pkt->flags       |= AV_PKT_FLAG_KEY;    pkt->duration     = 1;    // Header is sent with the first line removed...    pkt->data        += 80;    pkt->size        -= 80;     if (size > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE - pkt->size)        return AVERROR(ERANGE);     ret = av_append_packet(s->pb, pkt, size);    if (ret < 0)        return ret;     return 0;} 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 FFInputFormat ff_fits_demuxer = {    .p.name         = "fits",    .p.long_name    = NULL_IF_CONFIG_SMALL("Flexible Image Transport System"),    .p.priv_class   = &fits_demuxer_class,    .p.flags        = AVFMT_NOTIMESTAMPS,    .priv_data_size = sizeof(FITSContext),    .read_probe     = fits_probe,    .read_header    = fits_read_header,    .read_packet    = fits_read_packet,};