CDR is a File format used by CorelDRAW vector graphics editor since 1989 until today. Authors did not release any public description of the format. This is the "unofficial" specification.
Several groups have claimed, that they have parsed the CDR format (libcdr, sK1 Project). However, instead of publishing a clear description, they force users into utilizing their software tools, which they created. This is the first human-readable description of the CDR format.
There are two categories of CDR files:
- Start with
WL: Old Format - used before 1992 - Start with
RIFF: RIFF Format - used after 1992
- starts with ASCII bytes
WL
The file structure corresponds to the RIFF format. Some "LIST" chunks contain data, which can not be interpreted as subchunks.
Each CRD file has a version V associated with it. The structure of some parts of the file may depend on V.
The file is a sequence of bytes. Following data types are used in this document:
asci4- four bytes, interpreted as a four-byte ASCII stringuint2- two bytes, interpreted as a 16-bit unsigned integer in Little Endianuint4- four bytes, interpreted as a 32-bit unsigned integer in Little Endiansint2- two bytes, interpreted as a 16-bit signed integer in Little Endiansint4- four bytes, interpreted as a 32-bit signed integer in Little Endiandoubl- 64-bit floating point number in Little Endiancoord- if V<600, the value is sint2 / 1000, otherwise sint4 / 254 000string- the sequence of non-zero bytes, ended with a zero byte, represents an ASCII text
Size Type Value
4 asci4 "RIFF"
4 uint4 The length of the following data (file size - 8)
4 asci4 "CDR" + a byte, identifying the format version
* CHUNKS The sequence of chunks
A chunk is a sequence of bytes in the following format
Size Type Value
4 asci4 Identifier of the chunk
4 uint4 N : the size of the chunk content
N bytes The content of the chunk
When N is odd, there is a one-byte padding before the next chunk.
When the chunk identifier is "LIST", the content starts with asci4, which is called a list-type.
The CDR file usually consists of six chunks (starting at byte 12):
ID Size list-type
vrsn 2
DISP *
LIST 24 INFO
LIST 52 cmpr
LIST * cmpr
sumi 60
The main data is in the second "LIST cmpr" chunk. The content of important chunk types is described below.
Contains a version (below as V) of the file
Size Type Value
2 uint2 Version of the file
Contains a raster image: a thumbnail of the CDR file.
Size Type Value
8 bytes unknown
4 uint4 W: width
4 uint4 H: height
28 bytes unknown
1024 bytes Palette for the image (256 samples * 4 bytes per sample)
W*H bytes Indices to the palette for each pixel
Contains subchunks.
Size Type Value
4 asci4 list-type
* CHUNKS The sequence of chunks
Contains compressed subchunks.
Size Type Value
4 asci4 "cmpr"
4 uint4 C1 - the size of Part1 compressed
4 uint4 U1 - the size of Part1 uncompressed
4 uint4 C2 - the size of Part2 compressed
4 uint4 U2 - the size of Part2 uncompressed
4 asci4 "CPng"
4 bytes 0x01, 0x00, 0x04, 0x00
C1-8 bytes Part1 compressed with ZLIB
4 asci4 "CPng"
4 bytes 0x01, 0x00, 0x04, 0x00
C2-8 bytes Part2 compressed with ZLIB
This chunk contains two (decompressed) byte sequences: Part1 and Part2. Part2 is a list of uint4 numbers.
Part1 is CHUNKS: a sequence of chunks with a small difference: the Size of each chunk is not the actual size, but the index into Part2, where the true Size is stored.
STyLes of Text
Size Type Value
4 asci4 "stlt"
4 uint4 Number of Records (NOR)
* Map12 Fill IDs
* Map12 Outline IDs
4 uint4 Number of Fonts (NOF)
// repeated NOF times
4 uint4 Font Style ID
* bytes unknown. Size: V<1000 ? 12 : 20
4 uint4 Font ID
4 uint4 Font Encoding
8 bytes unknown
* coord Font Size
* bytes unknown. Size: V<1000 ? 12 : 20
// end repeat
* Map12 Align IDs
4 uint4 Number of Intervals (NOI)
52*NOI unknown
4 uint4 Number of Set5 (NOS)
152*NOS unknown
4 uint4 Number of Tabs (NOT)
784*NOT unknown
4 uint4 Number of Bullets (NOB)
// repeat NOB times
40 byets unknown
4 uint4 unknown (only when V>1300)
// if V>=1300
4 uint4 X
68 bytes unknown (if X not 0)
12 bytes unknown (if X == 0)
// else
20 bytes unknown
8 bytes unknown (if V>=1000)
4 uint4 X
8 bytes unknown (if X not 0)
8 bytes unknown
// end if
// end repeat
4 uint4 Number of Indents (NOI)
// repeat NOI times
4 uint4 Indent ID
12 bytes unknown
* coord right indent
* coord first indent
* coord left indent
// end repeat
4 uint4 Number of Hypens (NOH)
// repeat NOH times
32 bytes unknown
4 bytes unknown (if V>=1300)
// end repeat
4 uint4 Number of Dropcaps (NOD)
28*NOD unknown
4 uint4 Number of Set11 (NOS, if V>800)
12*NOS unknown (if V>800)
// repeat NOR times
4 uint4 NUM
4 uint4 Style ID
4 uint4 Parent ID
4 uint4 NL
NL bytes unknown
NL bytes unknown (if V>=1200)
4 uint4 Fill ID
4 uint4 Outline ID
// if NUM > 1
4 uint4 Font Rec ID
4 uint4 Align ID
4 uint4 Interval ID
4 uint4 Set5 ID
4 uint4 Set11 ID (if V>800)
// end if
// if NUM > 2
4 uint4 Tab ID
4 uint4 Bullet ID
4 uint4 Indent ID
4 uint4 Hyphen ID
4 uint4 Drop Cap ID
// end if
Map12 has a following structure:
4 uint4 Number of Values (NOV)
// repeated NOV times:
4 uint4 ID
4 uint4 unknown
4 uint4 Value
48 bytes unknown data (only for Fill IDs, when V>=1300)
Data of a single font
4 uint2 Font ID
4 uint2 Encoding ID
14 bytes unknown
* string Font name
Configuration
* bytes unknown. Size (if V>=1300 : 12, else if V>=900 : 4, else if 700>V>=600 : 28)
* coord Default page width
* coord Default page height
Shape data (geometry + fills + outlines)
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