avcodec/tiff: Refactor TIFF tag related functions to share the code.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 146 insertions, 0 deletions

diff --git a/libavcodec/tiff_common.h b/libavcodec/tiff_common.h
new file mode 100644
index 0000000000..15eeb76df6
--- /dev/null
+++ b/libavcodec/tiff_common.h
@@ -0,0 +1,146 @@
+/*
+ * TIFF Common Routines
+ * Copyright (c) 2013 Thilo Borgmann <thilo.borgmann _at_ googlemail.com>
+ *
+ * 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
+ * TIFF Common Routines
+ * @author Thilo Borgmann <thilo.borgmann _at_ googlemail.com>
+ */
+
+#ifndef AVCODEC_TIFF_COMMON_H
+#define AVCODEC_TIFF_COMMON_H
+
+#include "avcodec.h"
+#include "tiff.h"
+#include "bytestream.h"
+#include "libavutil/bprint.h"
+
+/** data type identifiers for TIFF tags */
+enum TiffTypes {
+    TIFF_BYTE = 1,
+    TIFF_STRING,
+    TIFF_SHORT,
+    TIFF_LONG,
+    TIFF_RATIONAL,
+    TIFF_SBYTE,
+    TIFF_UNDEFINED,
+    TIFF_SSHORT,
+    TIFF_SLONG,
+    TIFF_SRATIONAL,
+    TIFF_FLOAT,
+    TIFF_DOUBLE,
+    TIFF_IFD
+};
+
+/** sizes of various TIFF field types (string size = 100)*/
+static const uint8_t type_sizes[14] = {
+    0, 1, 100, 2, 4, 8, 1, 1, 2, 4, 8, 4, 8, 4
+};
+
+static const uint16_t ifd_tags[] = {
+    0x8769, // EXIF IFD
+    0x8825, // GPS IFD
+    0xA005  // Interoperability IFD
+};
+
+
+/** Returns a value > 0 if the tag is a known IFD-tag.
+ *  The return value is the array index + 1 within ifd_tags[].
+ */
+int ff_tis_ifd(unsigned tag);
+
+/** Reads a short from the bytestream using given endianess. */
+unsigned ff_tget_short(GetByteContext *gb, int le);
+
+/** Reads a long from the bytestream using given endianess. */
+unsigned ff_tget_long(GetByteContext *gb, int le);
+
+/** Reads a double from the bytestream using given endianess. */
+double   ff_tget_double(GetByteContext *gb, int le);
+
+/** Reads a byte from the bytestream using given endianess. */
+unsigned ff_tget(GetByteContext *gb, int type, int le);
+
+/** Returns an allocated string containing count
+ *  rational values using the given seperator.
+ */
+char *ff_trationals2str(int *rp, int count, const char *sep);
+
+/** Returns an allocated string containing count
+ *  long values using the given seperator.
+ */
+char *ff_tlongs2str(int32_t *lp, int count, const char *sep);
+
+/** Returns an allocated string containing count
+ *  double values using the given seperator.
+ */
+char *ff_tdoubles2str(double *dp, int count, const char *sep);
+
+/** Returns an allocated string containing count
+ *  short values using the given seperator.
+ */
+char *ff_tshorts2str(int16_t *sp, int count, const char *sep);
+
+/** Adds count rationals converted to a string
+ *  into the metadata dictionary.
+ */
+int ff_tadd_rational_metadata(int count, const char *name, const char *sep,
+                              GetByteContext *gb, int le, AVDictionary **metadata);
+
+/** Adds count longs converted to a string
+ *  into the metadata dictionary.
+ */
+int ff_tadd_long_metadata(int count, const char *name, const char *sep,
+                          GetByteContext *gb, int le, AVDictionary **metadata);
+
+/** Adds count doubles converted to a string
+ *  into the metadata dictionary.
+ */
+int ff_tadd_doubles_metadata(int count, const char *name, const char *sep,
+                             GetByteContext *gb, int le, AVDictionary **metadata);
+
+/** Adds count shorts converted to a string
+ *  into the metadata dictionary.
+ */
+int ff_tadd_shorts_metadata(int count, const char *name, const char *sep,
+                            GetByteContext *gb, int le, AVDictionary **metadata);
+
+/** Adds a string of count characters
+ *  into the metadata dictionary.
+ */
+int ff_tadd_string_metadata(int count, const char *name,
+                            GetByteContext *gb, int le, AVDictionary **metadata);
+
+/** Decodes a TIFF header from the input bytestream
+ *  and sets the endianess in *le and the offset to
+ *  the first IFD in *ifd_offset accordingly.
+ */
+int ff_tdecode_header(GetByteContext *gb, int *le, int *ifd_offset);
+
+/** Reads the first 3 fields of a TIFF tag, which are
+ *  the tag id, the tag type and the count of values for that tag.
+ *  Afterwards the bytestream is located at the first value to read and
+ *  *next holds the bytestream offset of the following tag.
+ */
+int ff_tread_tag(GetByteContext *gb, int le, unsigned *tag, unsigned *type,
+                 unsigned *count, int *next);
+
+#endif /* AVCODEC_TIFF_COMMON_H */