diff options
author | Paras Chadha <paraschadha18@gmail.com> | 2017-08-29 20:16:44 +0300 |
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committer | Paul B Mahol <onemda@gmail.com> | 2017-08-30 13:13:01 +0300 |
commit | 61e4db4bb730409798dff8d87d83459cb888786e (patch) | |
tree | b4a6f7ffadd4f3ece2176f42cc952b7e9106a972 /libavcodec/fitsdec.c | |
parent | 7fbc0825773eb597c5a3f5679a8d58ced0d9456f (diff) |
Add FITS Decoder
Signed-off-by: Paras Chadha <paraschadha18@gmail.com>
Diffstat (limited to 'libavcodec/fitsdec.c')
-rw-r--r-- | libavcodec/fitsdec.c | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/libavcodec/fitsdec.c b/libavcodec/fitsdec.c new file mode 100644 index 0000000000..8ede0bcbfa --- /dev/null +++ b/libavcodec/fitsdec.c @@ -0,0 +1,318 @@ +/* + * FITS image decoder + * 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 decoder + * + * Specification: https://fits.gsfc.nasa.gov/fits_standard.html Version 3.0 + * + * Support all 2d images alongwith, bzero, bscale and blank keywords. + * RGBA images are supported as NAXIS3 = 3 or 4 i.e. Planes in RGBA order. Also CTYPE = 'RGB ' should be present. + * Also to interpret data, values are linearly scaled using min-max scaling but not RGB images. + */ + +#include "avcodec.h" +#include "internal.h" +#include <float.h> +#include "libavutil/intreadwrite.h" +#include "libavutil/intfloat.h" +#include "libavutil/dict.h" +#include "libavutil/opt.h" +#include "fits.h" + +typedef struct FITSContext { + const AVClass *class; + int blank_val; +} FITSContext; + +/** + * Calculate the data_min and data_max values from the data. + * This is called if the values are not present in the header. + * @param ptr8 pointer to the data + * @param header pointer to the header + * @param end pointer to end of packet + * @return 0 if calculated successfully otherwise AVERROR_INVALIDDATA + */ +static int fill_data_min_max(const uint8_t *ptr8, FITSHeader *header, const uint8_t *end) +{ + uint8_t t8; + int16_t t16; + int32_t t32; + int64_t t64; + float tflt; + double tdbl; + int i, j; + + header->data_min = DBL_MAX; + header->data_max = DBL_MIN; + switch (header->bitpix) { +#define CASE_N(a, t, rd) \ + case a: \ + for (i = 0; i < header->naxisn[1]; i++) { \ + for (j = 0; j < header->naxisn[0]; j++) { \ + t = rd; \ + if (!header->blank_found || t != header->blank) { \ + if (t > header->data_max) \ + header->data_max = t; \ + if (t < header->data_min) \ + header->data_min = t; \ + } \ + ptr8 += abs(a) >> 3; \ + } \ + } \ + break + + CASE_N(-64, tdbl, av_int2double(AV_RB64(ptr8))); + CASE_N(-32, tflt, av_int2float(AV_RB32(ptr8))); + CASE_N(8, t8, ptr8[0]); + CASE_N(16, t16, AV_RB16(ptr8)); + CASE_N(32, t32, AV_RB32(ptr8)); + CASE_N(64, t64, AV_RB64(ptr8)); + default: + return AVERROR_INVALIDDATA; + } + return 0; +} + +/** + * Read the fits header and store the values in FITSHeader pointed by header + * @param avctx AVCodec context + * @param ptr pointer to pointer to the data + * @param header pointer to the FITSHeader + * @param end pointer to end of packet + * @param metadata pointer to pointer to AVDictionary to store metadata + * @return 0 if calculated successfully otherwise AVERROR_INVALIDDATA + */ +static int fits_read_header(AVCodecContext *avctx, const uint8_t **ptr, FITSHeader *header, + const uint8_t *end, AVDictionary **metadata) +{ + const uint8_t *ptr8 = *ptr; + int lines_read, bytes_left, i, ret; + size_t size; + + lines_read = 1; // to account for first header line, SIMPLE or XTENSION which is not included in packet... + avpriv_fits_header_init(header, STATE_BITPIX); + do { + if (end - ptr8 < 80) + return AVERROR_INVALIDDATA; + ret = avpriv_fits_header_parse_line(avctx, header, ptr8, &metadata); + ptr8 += 80; + lines_read++; + } while (!ret); + if (ret < 0) + return ret; + + bytes_left = (((lines_read + 35) / 36) * 36 - lines_read) * 80; + if (end - ptr8 < bytes_left) + return AVERROR_INVALIDDATA; + ptr8 += bytes_left; + + if (header->rgb && (header->naxis != 3 || (header->naxisn[2] != 3 && header->naxisn[2] != 4))) { + av_log(avctx, AV_LOG_ERROR, "File contains RGB image but NAXIS = %d and NAXIS3 = %d\n", header->naxis, header->naxisn[2]); + return AVERROR_INVALIDDATA; + } + + if (!header->rgb && header->naxis != 2) { + av_log(avctx, AV_LOG_ERROR, "unsupported number of dimensions, NAXIS = %d\n", header->naxis); + return AVERROR_INVALIDDATA; + } + + if (header->blank_found && (header->bitpix == -32 || header->bitpix == -64)) { + av_log(avctx, AV_LOG_WARNING, "BLANK keyword found but BITPIX = %d\n. Ignoring BLANK", header->bitpix); + header->blank_found = 0; + } + + size = abs(header->bitpix) >> 3; + for (i = 0; i < header->naxis; i++) { + if (header->naxisn[i] > SIZE_MAX / size) { + av_log(avctx, AV_LOG_ERROR, "unsupported size of FITS image"); + return AVERROR_INVALIDDATA; + } + size *= header->naxisn[i]; + } + + if (end - ptr8 < size) + return AVERROR_INVALIDDATA; + *ptr = ptr8; + + if (!header->rgb && (!header->data_min_found || !header->data_max_found)) { + ret = fill_data_min_max(ptr8, header, end); + if (ret < 0) { + av_log(avctx, AV_LOG_ERROR, "invalid BITPIX, %d\n", header->bitpix); + return ret; + } + } else { + /* + * instead of applying bscale and bzero to every element, + * we can do inverse transformation on data_min and data_max + */ + header->data_min = (header->data_min - header->bzero) / header->bscale; + header->data_max = (header->data_max - header->bzero) / header->bscale; + } + + return 0; +} + +static int fits_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) +{ + AVFrame *p=data; + const uint8_t *ptr8 = avpkt->data, *end; + uint8_t t8; + int16_t t16; + int32_t t32; + int64_t t64; + float tflt; + double tdbl; + int ret, i, j, k; + const int map[] = {2, 0, 1, 3}; // mapping from GBRA -> RGBA as RGBA is to be stored in FITS file.. + uint8_t *dst8; + uint16_t *dst16; + uint64_t t; + FITSHeader header; + FITSContext * fitsctx = avctx->priv_data; + + end = ptr8 + avpkt->size; + p->metadata = NULL; + ret = fits_read_header(avctx, &ptr8, &header, end, &p->metadata); + if (ret < 0) + return ret; + + if (header.rgb) { + if (header.bitpix == 8) { + if (header.naxisn[2] == 3) { + avctx->pix_fmt = AV_PIX_FMT_GBRP; + } else { + avctx->pix_fmt = AV_PIX_FMT_GBRAP; + } + } else if (header.bitpix == 16) { + if (header.naxisn[2] == 3) { + avctx->pix_fmt = AV_PIX_FMT_GBRP16; + } else { + avctx->pix_fmt = AV_PIX_FMT_GBRAP16; + } + } else { + av_log(avctx, AV_LOG_ERROR, "unsupported BITPIX = %d\n", header.bitpix); + return AVERROR_INVALIDDATA; + } + } else { + if (header.bitpix == 8) { + avctx->pix_fmt = AV_PIX_FMT_GRAY8; + } else { + avctx->pix_fmt = AV_PIX_FMT_GRAY16; + } + } + + if ((ret = ff_set_dimensions(avctx, header.naxisn[0], header.naxisn[1])) < 0) + return ret; + + if ((ret = ff_get_buffer(avctx, p, 0)) < 0) + return ret; + + /* + * FITS stores images with bottom row first. Therefore we have + * to fill the image from bottom to top. + */ + if (header.rgb) { + switch(header.bitpix) { +#define CASE_RGB(cas, dst, type, dref) \ + case cas: \ + for (k = 0; k < header.naxisn[2]; k++) { \ + for (i = 0; i < avctx->height; i++) { \ + dst = (type *) (p->data[map[k]] + (avctx->height - i - 1) * p->linesize[map[k]]); \ + for (j = 0; j < avctx->width; j++) { \ + t32 = dref(ptr8); \ + if (!header.blank_found || t32 != header.blank) { \ + t = t32 * header.bscale + header.bzero; \ + } else { \ + t = fitsctx->blank_val; \ + } \ + *dst++ = (type) t; \ + ptr8 += cas >> 3; \ + } \ + } \ + } \ + break + + CASE_RGB(8, dst8, uint8_t, *); + CASE_RGB(16, dst16, uint16_t, AV_RB16); + } + } else { + switch (header.bitpix) { +#define CASE_GRAY(cas, dst, type, t, rd) \ + case cas: \ + for (i = 0; i < avctx->height; i++) { \ + dst = (type *) (p->data[0] + (avctx->height-i-1)* p->linesize[0]); \ + for (j = 0; j < avctx->width; j++) { \ + t = rd; \ + if (!header.blank_found || t != header.blank) { \ + t = ((t - header.data_min) * ((1 << (sizeof(type) * 8)) - 1)) / (header.data_max - header.data_min); \ + } else { \ + t = fitsctx->blank_val; \ + } \ + *dst++ = (type) t; \ + ptr8 += abs(cas) >> 3; \ + } \ + } \ + break + + CASE_GRAY(-64, dst16, uint16_t, tdbl, av_int2double(AV_RB64(ptr8))); + CASE_GRAY(-32, dst16, uint16_t, tflt, av_int2float(AV_RB32(ptr8))); + CASE_GRAY(8, dst8, uint8_t, t8, ptr8[0]); + CASE_GRAY(16, dst16, uint16_t, t16, AV_RB16(ptr8)); + CASE_GRAY(32, dst16, uint16_t, t32, AV_RB32(ptr8)); + CASE_GRAY(64, dst16, uint16_t, t64, AV_RB64(ptr8)); + default: + av_log(avctx, AV_LOG_ERROR, "invalid BITPIX, %d\n", header.bitpix); + return AVERROR_INVALIDDATA; + } + } + + p->key_frame = 1; + p->pict_type = AV_PICTURE_TYPE_I; + + *got_frame = 1; + + return avpkt->size; +} + +static const AVOption fits_options[] = { + { "blank_value", "value that is used to replace BLANK pixels in data array", offsetof(FITSContext, blank_val), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 65535, AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_VIDEO_PARAM}, + { NULL }, +}; + +static const AVClass fits_decoder_class = { + .class_name = "FITS decoder", + .item_name = av_default_item_name, + .option = fits_options, + .version = LIBAVUTIL_VERSION_INT, +}; + +AVCodec ff_fits_decoder = { + .name = "fits", + .type = AVMEDIA_TYPE_VIDEO, + .id = AV_CODEC_ID_FITS, + .priv_data_size = sizeof(FITSContext), + .decode = fits_decode_frame, + .capabilities = AV_CODEC_CAP_DR1, + .long_name = NULL_IF_CONFIG_SMALL("Flexible Image Transport System"), + .priv_class = &fits_decoder_class +}; |