1/* 2 * FITS image encoder 3 * Copyright (c) 2017 Paras Chadha 4 * 5 * This file is part of FFmpeg. 6 * 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. 11 * 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. 16 * 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 20 */ 21 22/** 23 * @file 24 * FITS image encoder 25 * 26 * Specification: https://fits.gsfc.nasa.gov/fits_standard.html Version 3.0 27 * 28 * RGBA images are encoded as planes in RGBA order. So, NAXIS3 is 3 or 4 for them. 29 * Also CTYPE3 = 'RGB ' is added to the header to distinguish them from 3d images. 30 */ 31 32#include "libavutil/intreadwrite.h" 33#include "avcodec.h" 34#include "bytestream.h" 35#include "codec_internal.h" 36#include "encode.h" 37 38static int fits_encode_frame(AVCodecContext *avctx, AVPacket *pkt, 39 const AVFrame *pict, int *got_packet) 40{ 41 AVFrame * const p = (AVFrame *)pict; 42 uint8_t *bytestream, *ptr; 43 const uint16_t flip = (1 << 15); 44 uint64_t data_size = 0, padded_data_size = 0; 45 int ret, bitpix, naxis3 = 1, i, j, k, bytes_left; 46 int map[] = {2, 0, 1, 3}; // mapping from GBRA -> RGBA as RGBA is to be stored in FITS file.. 47 48 switch (avctx->pix_fmt) { 49 case AV_PIX_FMT_GRAY8: 50 case AV_PIX_FMT_GRAY16BE: 51 map[0] = 0; // grayscale images should be directly mapped 52 if (avctx->pix_fmt == AV_PIX_FMT_GRAY8) { 53 bitpix = 8; 54 } else { 55 bitpix = 16; 56 } 57 break; 58 case AV_PIX_FMT_GBRP: 59 case AV_PIX_FMT_GBRAP: 60 bitpix = 8; 61 if (avctx->pix_fmt == AV_PIX_FMT_GBRP) { 62 naxis3 = 3; 63 } else { 64 naxis3 = 4; 65 } 66 break; 67 case AV_PIX_FMT_GBRP16BE: 68 case AV_PIX_FMT_GBRAP16BE: 69 bitpix = 16; 70 if (avctx->pix_fmt == AV_PIX_FMT_GBRP16BE) { 71 naxis3 = 3; 72 } else { 73 naxis3 = 4; 74 } 75 break; 76 default: 77 av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n"); 78 return AVERROR(EINVAL); 79 } 80 81 data_size = (bitpix >> 3) * avctx->height * avctx->width * naxis3; 82 padded_data_size = ((data_size + 2879) / 2880 ) * 2880; 83 84 if ((ret = ff_get_encode_buffer(avctx, pkt, padded_data_size, 0)) < 0) 85 return ret; 86 87 bytestream = pkt->data; 88 89 for (k = 0; k < naxis3; k++) { 90 for (i = 0; i < avctx->height; i++) { 91 ptr = p->data[map[k]] + (avctx->height - i - 1) * p->linesize[map[k]]; 92 if (bitpix == 16) { 93 for (j = 0; j < avctx->width; j++) { 94 // subtracting bzero is equivalent to first bit flip 95 bytestream_put_be16(&bytestream, AV_RB16(ptr) ^ flip); 96 ptr += 2; 97 } 98 } else { 99 memcpy(bytestream, ptr, avctx->width); 100 bytestream += avctx->width; 101 } 102 } 103 } 104 105 bytes_left = padded_data_size - data_size; 106 memset(bytestream, 0, bytes_left); 107 108 *got_packet = 1; 109 110 return 0; 111} 112 113const FFCodec ff_fits_encoder = { 114 .p.name = "fits", 115 .p.long_name = NULL_IF_CONFIG_SMALL("Flexible Image Transport System"), 116 .p.type = AVMEDIA_TYPE_VIDEO, 117 .p.id = AV_CODEC_ID_FITS, 118 .p.capabilities = AV_CODEC_CAP_DR1, 119 FF_CODEC_ENCODE_CB(fits_encode_frame), 120 .p.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_GBRAP16BE, 121 AV_PIX_FMT_GBRP16BE, 122 AV_PIX_FMT_GBRP, 123 AV_PIX_FMT_GBRAP, 124 AV_PIX_FMT_GRAY16BE, 125 AV_PIX_FMT_GRAY8, 126 AV_PIX_FMT_NONE }, 127}; 128