1 /* 2 * TIFF Common Routines 3 * Copyright (c) 2013 Thilo Borgmann <thilo.borgmann _at_ mail.de> 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 * TIFF Common Routines 25 * @author Thilo Borgmann <thilo.borgmann _at_ mail.de> 26 */ 27 28 #ifndef AVCODEC_TIFF_COMMON_H 29 #define AVCODEC_TIFF_COMMON_H 30 31 #include <stdint.h> 32 #include "libavutil/dict.h" 33 #include "bytestream.h" 34 35 /** data type identifiers for TIFF tags */ 36 enum TiffTypes { 37 TIFF_BYTE = 1, 38 TIFF_STRING, 39 TIFF_SHORT, 40 TIFF_LONG, 41 TIFF_RATIONAL, 42 TIFF_SBYTE, 43 TIFF_UNDEFINED, 44 TIFF_SSHORT, 45 TIFF_SLONG, 46 TIFF_SRATIONAL, 47 TIFF_FLOAT, 48 TIFF_DOUBLE, 49 TIFF_IFD 50 }; 51 52 /** sizes of various TIFF field types (string size = 100)*/ 53 static const uint8_t type_sizes[14] = { 54 0, 1, 100, 2, 4, 8, 1, 1, 2, 4, 8, 4, 8, 4 55 }; 56 57 static const uint16_t ifd_tags[] = { 58 0x8769, // EXIF IFD 59 0x8825, // GPS IFD 60 0xA005 // Interoperability IFD 61 }; 62 63 64 /** Returns a value > 0 if the tag is a known IFD-tag. 65 * The return value is the array index + 1 within ifd_tags[]. 66 */ 67 int ff_tis_ifd(unsigned tag); 68 69 /** Reads a short from the bytestream using given endianness. */ 70 unsigned ff_tget_short(GetByteContext *gb, int le); 71 72 /** Reads a long from the bytestream using given endianness. */ 73 unsigned ff_tget_long(GetByteContext *gb, int le); 74 75 /** Reads a double from the bytestream using given endianness. */ 76 double ff_tget_double(GetByteContext *gb, int le); 77 78 /** Reads a byte from the bytestream using given endianness. */ 79 unsigned ff_tget(GetByteContext *gb, int type, int le); 80 81 /** Adds count rationals converted to a string 82 * into the metadata dictionary. 83 */ 84 int ff_tadd_rational_metadata(int count, const char *name, const char *sep, 85 GetByteContext *gb, int le, AVDictionary **metadata); 86 87 /** Adds count longs converted to a string 88 * into the metadata dictionary. 89 */ 90 int ff_tadd_long_metadata(int count, const char *name, const char *sep, 91 GetByteContext *gb, int le, AVDictionary **metadata); 92 93 /** Adds count doubles converted to a string 94 * into the metadata dictionary. 95 */ 96 int ff_tadd_doubles_metadata(int count, const char *name, const char *sep, 97 GetByteContext *gb, int le, AVDictionary **metadata); 98 99 /** Adds count shorts converted to a string 100 * into the metadata dictionary. 101 */ 102 int ff_tadd_shorts_metadata(int count, const char *name, const char *sep, 103 GetByteContext *gb, int le, int is_signed, AVDictionary **metadata); 104 105 /** Adds count bytes converted to a string 106 * into the metadata dictionary. 107 */ 108 int ff_tadd_bytes_metadata(int count, const char *name, const char *sep, 109 GetByteContext *gb, int le, int is_signed, AVDictionary **metadata); 110 111 /** Adds a string of count characters 112 * into the metadata dictionary. 113 */ 114 int ff_tadd_string_metadata(int count, const char *name, 115 GetByteContext *gb, int le, AVDictionary **metadata); 116 117 /** Decodes a TIFF header from the input bytestream 118 * and sets the endianness in *le and the offset to 119 * the first IFD in *ifd_offset accordingly. 120 */ 121 int ff_tdecode_header(GetByteContext *gb, int *le, int *ifd_offset); 122 123 /** Reads the first 3 fields of a TIFF tag, which are 124 * the tag id, the tag type and the count of values for that tag. 125 * Afterwards the bytestream is located at the first value to read and 126 * *next holds the bytestream offset of the following tag. 127 */ 128 int ff_tread_tag(GetByteContext *gb, int le, unsigned *tag, unsigned *type, 129 unsigned *count, int *next); 130 131 #endif /* AVCODEC_TIFF_COMMON_H */ 132