| /* |
| * 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 (size == 0 || 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; |
| } |
| if (!header->rgb && header->data_min >= header->data_max) { |
| if (header->data_min > header->data_max) { |
| av_log(avctx, AV_LOG_ERROR, "data min/max (%g %g) is invalid\n", header->data_min, header->data_max); |
| return AVERROR_INVALIDDATA; |
| } |
| av_log(avctx, AV_LOG_WARNING, "data min/max indicates a blank image\n"); |
| header->data_max ++; |
| } |
| |
| 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 { |
| double scale = header.data_max - header.data_min; |
| |
| if (scale <= 0 || !isfinite(scale)) { |
| scale = 1; |
| } |
| scale = 1/scale; |
| |
| 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) { \ |
| *dst++ = lrint(((t - header.data_min) * ((1 << (sizeof(type) * 8)) - 1)) * scale); \ |
| } else { \ |
| *dst++ = fitsctx->blank_val; \ |
| } \ |
| 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 |
| }; |
