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- #------------------------------------------------------------------------------
- # $File: jpeg,v 1.25 2015/01/02 16:56:50 christos Exp $
- # JPEG images
- # SunOS 5.5.1 had
- #
- # 0 string \377\330\377\340 JPEG file
- # 0 string \377\330\377\356 JPG file
- #
- # both of which turn into "JPEG image data" here.
- #
- 0 beshort 0xffd8 JPEG image data
- !:mime image/jpeg
- !:apple 8BIMJPEG
- !:strength +2
- >6 string JFIF \b, JFIF standard
- # The following added by Erik Rossen <rossen@freesurf.ch> 1999-09-06
- # in a vain attempt to add image size reporting for JFIF. Note that these
- # tests are not fool-proof since some perfectly valid JPEGs are currently
- # impossible to specify in magic(4) format.
- # First, a little JFIF version info:
- >>11 byte x \b %d.
- >>12 byte x \b%02d
- # Next, the resolution or aspect ratio of the image:
- >>13 byte 0 \b, aspect ratio
- >>13 byte 1 \b, resolution (DPI)
- >>13 byte 2 \b, resolution (DPCM)
- >>14 beshort x \b, density %dx
- >>16 beshort x \b%d
- >>4 beshort x \b, segment length %d
- # Next, show thumbnail info, if it exists:
- >>18 byte !0 \b, thumbnail %dx
- >>>19 byte x \b%d
- >6 string Exif \b, Exif standard: [
- >>12 indirect/r x
- >>12 string x \b]
- # Jump to the first segment
- >(4.S+4) use jpeg_segment
- # This uses recursion...
- 0 name jpeg_segment
- >0 beshort 0xFFFE
- # Recursion handled by FFE0
- #>>(2.S+2) use jpeg_segment
- >>2 pstring/HJ x \b, comment: "%s"
- >0 beshort 0xFFC0
- >>(2.S+2) use jpeg_segment
- >>4 byte x \b, baseline, precision %d
- >>7 beshort x \b, %dx
- >>5 beshort x \b%d
- >>9 byte x \b, frames %d
- >0 beshort 0xFFC1
- >>(2.S+2) use jpeg_segment
- >>4 byte x \b, extended sequential, precision %d
- >>7 beshort x \b, %dx
- >>5 beshort x \b%d
- >>9 byte x \b, frames %d
- >0 beshort 0xFFC2
- >>(2.S+2) use jpeg_segment
- >>4 byte x \b, progressive, precision %d
- >>7 beshort x \b, %dx
- >>5 beshort x \b%d
- >>9 byte x \b, frames %d
- # Define Huffman Tables
- >0 beshort 0xFFC4
- >>(2.S+2) use jpeg_segment
- >0 beshort 0xFFE1
- # Recursion handled by FFE0
- #>>(2.S+2) use jpeg_segment
- >>4 string Exif \b, Exif Standard: [
- >>>10 indirect/r x
- >>>10 string x \b]
- # Application specific markers
- >0 beshort&0xFFE0 =0xFFE0
- >>(2.S+2) use jpeg_segment
- # DB: Define Quantization tables
- # DD: Define Restart interval [XXX: wrong here, it is 4 bytes]
- # D8: Start of image
- # D9: End of image
- # Dn: Restart
- >0 beshort&0xFFD0 =0xFFD0
- >>0 beshort&0xFFE0 !0xFFE0
- >>>(2.S+2) use jpeg_segment
- #>0 beshort x unknown 0x%x
- #>>(2.S+2) use jpeg_segment
- # HSI is Handmade Software's proprietary JPEG encoding scheme
- 0 string hsi1 JPEG image data, HSI proprietary
- # From: David Santinoli <david@santinoli.com>
- 0 string \x00\x00\x00\x0C\x6A\x50\x20\x20\x0D\x0A\x87\x0A JPEG 2000
- # From: Johan van der Knijff <johan.vanderknijff@kb.nl>
- # Added sub-entries for JP2, JPX, JPM and MJ2 formats; added mimetypes
- # https://github.com/bitsgalore/jp2kMagic
- #
- # Now read value of 'Brand' field, which yields a few possibilities:
- >20 string \x6a\x70\x32\x20 Part 1 (JP2)
- !:mime image/jp2
- >20 string \x6a\x70\x78\x20 Part 2 (JPX)
- !:mime image/jpx
- >20 string \x6a\x70\x6d\x20 Part 6 (JPM)
- !:mime image/jpm
- >20 string \x6d\x6a\x70\x32 Part 3 (MJ2)
- !:mime video/mj2
- # Type: JPEG 2000 codesream
- # From: Mathieu Malaterre <mathieu.malaterre@gmail.com>
- 0 belong 0xff4fff51 JPEG 2000 codestream
- 45 beshort 0xff52
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