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Diffstat (limited to 'libavcodec/fitsenc.c')
-rw-r--r-- | libavcodec/fitsenc.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/libavcodec/fitsenc.c b/libavcodec/fitsenc.c new file mode 100644 index 0000000..b44507e --- /dev/null +++ b/libavcodec/fitsenc.c @@ -0,0 +1,129 @@ +/* + * FITS image encoder + * 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 image encoder + * + * Specification: https://fits.gsfc.nasa.gov/fits_standard.html Version 3.0 + * + * RGBA images are encoded as planes in RGBA order. So, NAXIS3 is 3 or 4 for them. + * Also CTYPE3 = 'RGB ' is added to the header to distinguish them from 3d images. + */ + +#include "libavutil/intreadwrite.h" +#include "avcodec.h" +#include "bytestream.h" +#include "internal.h" + +static int fits_encode_frame(AVCodecContext *avctx, AVPacket *pkt, + const AVFrame *pict, int *got_packet) +{ + AVFrame * const p = (AVFrame *)pict; + uint8_t *bytestream, *bytestream_start, *ptr; + const uint16_t flip = (1 << 15); + uint64_t data_size = 0, padded_data_size = 0; + int ret, bitpix, naxis3 = 1, i, j, k, bytes_left; + int map[] = {2, 0, 1, 3}; // mapping from GBRA -> RGBA as RGBA is to be stored in FITS file.. + + switch (avctx->pix_fmt) { + case AV_PIX_FMT_GRAY8: + case AV_PIX_FMT_GRAY16BE: + map[0] = 0; // grayscale images should be directly mapped + if (avctx->pix_fmt == AV_PIX_FMT_GRAY8) { + bitpix = 8; + } else { + bitpix = 16; + } + break; + case AV_PIX_FMT_GBRP: + case AV_PIX_FMT_GBRAP: + bitpix = 8; + if (avctx->pix_fmt == AV_PIX_FMT_GBRP) { + naxis3 = 3; + } else { + naxis3 = 4; + } + break; + case AV_PIX_FMT_GBRP16BE: + case AV_PIX_FMT_GBRAP16BE: + bitpix = 16; + if (avctx->pix_fmt == AV_PIX_FMT_GBRP16BE) { + naxis3 = 3; + } else { + naxis3 = 4; + } + break; + default: + av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n"); + return AVERROR(EINVAL); + } + + data_size = (bitpix >> 3) * avctx->height * avctx->width * naxis3; + padded_data_size = ((data_size + 2879) / 2880 ) * 2880; + + if ((ret = ff_alloc_packet2(avctx, pkt, padded_data_size, 0)) < 0) + return ret; + + bytestream_start = + bytestream = pkt->data; + + for (k = 0; k < naxis3; k++) { + for (i = 0; i < avctx->height; i++) { + ptr = p->data[map[k]] + (avctx->height - i - 1) * p->linesize[map[k]]; + if (bitpix == 16) { + for (j = 0; j < avctx->width; j++) { + // subtracting bzero is equivalent to first bit flip + bytestream_put_be16(&bytestream, AV_RB16(ptr) ^ flip); + ptr += 2; + } + } else { + memcpy(bytestream, ptr, avctx->width); + bytestream += avctx->width; + } + } + } + + bytes_left = padded_data_size - data_size; + memset(bytestream, 0, bytes_left); + bytestream += bytes_left; + + pkt->size = bytestream - bytestream_start; + pkt->flags |= AV_PKT_FLAG_KEY; + *got_packet = 1; + + return 0; +} + +AVCodec ff_fits_encoder = { + .name = "fits", + .long_name = NULL_IF_CONFIG_SMALL("Flexible Image Transport System"), + .type = AVMEDIA_TYPE_VIDEO, + .id = AV_CODEC_ID_FITS, + .encode2 = fits_encode_frame, + .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_GBRAP16BE, + AV_PIX_FMT_GBRP16BE, + AV_PIX_FMT_GBRP, + AV_PIX_FMT_GBRAP, + AV_PIX_FMT_GRAY16BE, + AV_PIX_FMT_GRAY8, + AV_PIX_FMT_NONE }, +}; |