diff options
Diffstat (limited to 'libavcodec/exif.c')
| -rw-r--r-- | libavcodec/exif.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/libavcodec/exif.c b/libavcodec/exif.c new file mode 100644 index 0000000..fa30f05 --- /dev/null +++ b/libavcodec/exif.c @@ -0,0 +1,142 @@ +/* + * EXIF metadata parser + * Copyright (c) 2013 Thilo Borgmann <thilo.borgmann _at_ mail.de> + * + * 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 + * EXIF metadata parser + * @author Thilo Borgmann <thilo.borgmann _at_ mail.de> + */ + +#include "exif.h" + + +static const char *exif_get_tag_name(uint16_t id) +{ + int i; + + for (i = 0; i < FF_ARRAY_ELEMS(tag_list); i++) { + if (tag_list[i].id == id) + return tag_list[i].name; + } + + return NULL; +} + + +static int exif_add_metadata(AVCodecContext *avctx, int count, int type, + const char *name, const char *sep, + GetByteContext *gb, int le, + AVDictionary **metadata) +{ + switch(type) { + case 0: + av_log(avctx, AV_LOG_WARNING, + "Invalid TIFF tag type 0 found for %s with size %d\n", + name, count); + return 0; + case TIFF_DOUBLE : return ff_tadd_doubles_metadata(count, name, sep, gb, le, metadata); + case TIFF_SSHORT : return ff_tadd_shorts_metadata(count, name, sep, gb, le, 1, metadata); + case TIFF_SHORT : return ff_tadd_shorts_metadata(count, name, sep, gb, le, 0, metadata); + case TIFF_SBYTE : return ff_tadd_bytes_metadata(count, name, sep, gb, le, 1, metadata); + case TIFF_BYTE : + case TIFF_UNDEFINED: return ff_tadd_bytes_metadata(count, name, sep, gb, le, 0, metadata); + case TIFF_STRING : return ff_tadd_string_metadata(count, name, gb, le, metadata); + case TIFF_SRATIONAL: + case TIFF_RATIONAL : return ff_tadd_rational_metadata(count, name, sep, gb, le, metadata); + case TIFF_SLONG : + case TIFF_LONG : return ff_tadd_long_metadata(count, name, sep, gb, le, metadata); + default: + avpriv_request_sample(avctx, "TIFF tag type (%u)", type); + return 0; + }; +} + + +static int exif_decode_tag(AVCodecContext *avctx, GetByteContext *gbytes, int le, + int depth, AVDictionary **metadata) +{ + int ret, cur_pos; + unsigned id, count; + enum TiffTypes type; + + if (depth > 2) { + return 0; + } + + ff_tread_tag(gbytes, le, &id, &type, &count, &cur_pos); + + if (!bytestream2_tell(gbytes)) { + bytestream2_seek(gbytes, cur_pos, SEEK_SET); + return 0; + } + + // read count values and add it metadata + // store metadata or proceed with next IFD + ret = ff_tis_ifd(id); + if (ret) { + ret = avpriv_exif_decode_ifd(avctx, gbytes, le, depth + 1, metadata); + } else { + const char *name = exif_get_tag_name(id); + char *use_name = (char*) name; + + if (!use_name) { + use_name = av_malloc(7); + if (!use_name) { + return AVERROR(ENOMEM); + } + snprintf(use_name, 7, "0x%04X", id); + } + + ret = exif_add_metadata(avctx, count, type, use_name, NULL, + gbytes, le, metadata); + + if (!name) { + av_freep(&use_name); + } + } + + bytestream2_seek(gbytes, cur_pos, SEEK_SET); + + return ret; +} + + +int avpriv_exif_decode_ifd(AVCodecContext *avctx, GetByteContext *gbytes, int le, + int depth, AVDictionary **metadata) +{ + int i, ret; + int entries; + + entries = ff_tget_short(gbytes, le); + + if (bytestream2_get_bytes_left(gbytes) < entries * 12) { + return AVERROR_INVALIDDATA; + } + + for (i = 0; i < entries; i++) { + if ((ret = exif_decode_tag(avctx, gbytes, le, depth, metadata)) < 0) { + return ret; + } + } + + // return next IDF offset or 0x000000000 or a value < 0 for failure + return ff_tget_long(gbytes, le); +} |
