mirror of https://github.com/FFmpeg/FFmpeg.git
Paras Chadha
8 years ago
committed by
Paul B Mahol
parent
61e4db4bb7
commit
207f0cff2a
4 changed files with 234 additions and 1 deletions
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/*
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* FITS demuxer |
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* Copyright (c) 2017 Paras Chadha |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/**
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* @file |
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* FITS demuxer. |
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*/ |
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#include "libavutil/intreadwrite.h" |
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#include "internal.h" |
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#include "libavutil/opt.h" |
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#include "libavcodec/fits.h" |
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#include "libavutil/bprint.h" |
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#define FITS_BLOCK_SIZE 2880 |
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typedef struct FITSContext { |
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const AVClass *class; |
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AVRational framerate; |
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int first_image; |
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int64_t pts; |
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} FITSContext; |
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static int fits_probe(AVProbeData *p) |
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{ |
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const uint8_t *b = p->buf; |
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if (!memcmp(b, "SIMPLE = T", 30)) |
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return AVPROBE_SCORE_MAX - 1; |
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return 0; |
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} |
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static int fits_read_header(AVFormatContext *s) |
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{ |
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AVStream *st; |
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FITSContext * fits = s->priv_data; |
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st = avformat_new_stream(s, NULL); |
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if (!st) |
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return AVERROR(ENOMEM); |
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st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
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st->codecpar->codec_id = AV_CODEC_ID_FITS; |
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avpriv_set_pts_info(st, 64, fits->framerate.den, fits->framerate.num); |
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fits->pts = 0; |
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fits->first_image = 1; |
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return 0; |
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} |
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/**
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* Parses header and checks that the current HDU contains image or not |
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* It also stores the header in the avbuf and stores the size of data part in data_size |
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* @param s pointer to AVFormat Context |
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* @param fits pointer to FITSContext |
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* @param header pointer to FITSHeader |
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* @param avbuf pointer to AVBPrint to store the header |
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* @param data_size to store the size of data part |
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* @return 1 if image found, 0 if any other extension and AVERROR_INVALIDDATA otherwise |
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*/ |
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static int64_t is_image(AVFormatContext *s, FITSContext *fits, FITSHeader *header, |
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AVBPrint *avbuf, uint64_t *data_size) |
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{ |
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int i, ret, image = 0; |
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char buf[FITS_BLOCK_SIZE] = { 0 }; |
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int64_t buf_size = 0, size = 0, t; |
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do { |
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ret = avio_read(s->pb, buf, FITS_BLOCK_SIZE); |
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if (ret < 0) { |
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return ret; |
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} else if (ret < FITS_BLOCK_SIZE) { |
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return AVERROR_INVALIDDATA; |
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} |
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av_bprint_append_data(avbuf, buf, FITS_BLOCK_SIZE); |
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ret = 0; |
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buf_size = 0; |
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while(!ret && buf_size < FITS_BLOCK_SIZE) { |
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ret = avpriv_fits_header_parse_line(s, header, buf + buf_size, NULL); |
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buf_size += 80; |
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} |
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} while (!ret); |
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if (ret < 0) |
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return ret; |
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image = fits->first_image || header->image_extension; |
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fits->first_image = 0; |
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if (header->groups) { |
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image = 0; |
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if (header->naxis > 1) |
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size = 1; |
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} else if (header->naxis) { |
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size = header->naxisn[0]; |
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} else { |
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image = 0; |
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} |
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for (i = 1; i < header->naxis; i++) { |
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if(size && header->naxisn[i] > UINT64_MAX / size) |
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return AVERROR_INVALIDDATA; |
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size *= header->naxisn[i]; |
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} |
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if(header->pcount > UINT64_MAX - size) |
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return AVERROR_INVALIDDATA; |
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size += header->pcount; |
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t = (abs(header->bitpix) >> 3) * ((int64_t) header->gcount); |
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if(size && t > UINT64_MAX / size) |
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return AVERROR_INVALIDDATA; |
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size *= t; |
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if (!size) { |
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image = 0; |
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} else { |
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if(FITS_BLOCK_SIZE - 1 > UINT64_MAX - size) |
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return AVERROR_INVALIDDATA; |
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size = ((size + FITS_BLOCK_SIZE - 1) / FITS_BLOCK_SIZE) * FITS_BLOCK_SIZE; |
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} |
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*data_size = size; |
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return image; |
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} |
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static int fits_read_packet(AVFormatContext *s, AVPacket *pkt) |
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{ |
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int64_t pos, ret; |
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uint64_t size; |
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FITSContext *fits = s->priv_data; |
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FITSHeader header; |
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AVBPrint avbuf; |
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char *buf; |
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if (fits->first_image) { |
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avpriv_fits_header_init(&header, STATE_SIMPLE); |
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} else { |
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avpriv_fits_header_init(&header, STATE_XTENSION); |
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} |
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av_bprint_init(&avbuf, FITS_BLOCK_SIZE, AV_BPRINT_SIZE_UNLIMITED); |
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while ((ret = is_image(s, fits, &header, &avbuf, &size)) == 0) { |
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pos = avio_skip(s->pb, size); |
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if (pos < 0) |
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return pos; |
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av_bprint_finalize(&avbuf, NULL); |
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av_bprint_init(&avbuf, FITS_BLOCK_SIZE, AV_BPRINT_SIZE_UNLIMITED); |
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avpriv_fits_header_init(&header, STATE_XTENSION); |
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} |
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if (ret < 0) |
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goto fail; |
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if (!av_bprint_is_complete(&avbuf)) { |
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ret = AVERROR(ENOMEM); |
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goto fail; |
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} |
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// Header is sent with the first line removed...
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ret = av_new_packet(pkt, avbuf.len - 80 + size); |
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if (ret < 0) |
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goto fail; |
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pkt->stream_index = 0; |
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pkt->flags |= AV_PKT_FLAG_KEY; |
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ret = av_bprint_finalize(&avbuf, &buf); |
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if (ret < 0) { |
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av_packet_unref(pkt); |
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return ret; |
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} |
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memcpy(pkt->data, buf + 80, avbuf.len - 80); |
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pkt->size = avbuf.len - 80; |
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av_freep(&buf); |
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ret = avio_read(s->pb, pkt->data + pkt->size, size); |
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if (ret < 0) { |
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av_packet_unref(pkt); |
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return ret; |
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} |
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pkt->size += ret; |
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pkt->pts = fits->pts; |
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fits->pts++; |
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return 0; |
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fail: |
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av_bprint_finalize(&avbuf, NULL); |
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return ret; |
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} |
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static const AVOption fits_options[] = { |
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{ "framerate", "set the framerate", offsetof(FITSContext, framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "1"}, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM}, |
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{ NULL }, |
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}; |
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static const AVClass fits_demuxer_class = { |
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.class_name = "FITS demuxer", |
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.item_name = av_default_item_name, |
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.option = fits_options, |
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.version = LIBAVUTIL_VERSION_INT, |
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}; |
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AVInputFormat ff_fits_demuxer = { |
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.name = "fits", |
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.long_name = NULL_IF_CONFIG_SMALL("Flexible Image Transport System"), |
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.priv_data_size = sizeof(FITSContext), |
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.read_probe = fits_probe, |
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.read_header = fits_read_header, |
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.read_packet = fits_read_packet, |
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.priv_class = &fits_demuxer_class, |
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.raw_codec_id = AV_CODEC_ID_FITS, |
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}; |
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