File Coverage

blib/lib/Image/ExifTool/CanonVRD.pm

Criterion	Covered	Total	%
statement	373	464	80.3
branch	211	324	65.1
condition	66	129	51.1
subroutine	13	16	81.2
pod	0	12	0.0
total	663	945	70.1

#------------------------------------------------------------------------------
# File:         CanonVRD.pm
#
# Description:  Read/write Canon VRD and DR4 information
#
# Revisions:    2006/10/30 - P. Harvey Created
#               2007/10/23 - PH Added new VRD 3.0 tags
#               2008/08/29 - PH Added new VRD 3.4 tags
#               2008/12/02 - PH Added new VRD 3.5 tags
#               2010/06/18 - PH Support variable-length CustomPictureStyle data
#               2010/09/14 - PH Added r/w support for XMP in VRD
#               2015/05/16 - PH Added DR4 support (DPP 4.1.50.0)
#               2018/03/13 - PH Update to DPP 4.8.20
#
# References:   1) Bogdan private communication (Canon DPP v3.4.1.1)
#               2) Gert Kello private communication (DPP 3.8)
#------------------------------------------------------------------------------

package Image::ExifTool::CanonVRD;

use strict;
use vars qw($VERSION);
use Image::ExifTool qw(:DataAccess :Utils);
use Image::ExifTool::Canon;

$VERSION = '1.33';

sub ProcessCanonVRD($$;$);
sub WriteCanonVRD($$;$);
sub ProcessEditData($$$);
sub ProcessIHL($$$);
sub ProcessIHLExif($$$);
sub ProcessDR4($$;$);
sub SortDR4($$);

# map for adding directories to VRD
my %vrdMap = (
    XMP      => 'CanonVRD',
    CanonVRD => 'VRD',
);

my %noYes = (
    PrintConvColumns => 2,
    PrintConv => { 0 => 'No', 1 => 'Yes' },
);

# DR4 format codes
my %vrdFormat = (
    1 => 'int32u',
    2 => 'string',
    8 => 'int32u',
    9 => 'int32s',
    13 => 'double',
    33 => 'int32u', # (array)
    38 => 'double', # (array)
    # 254 => 'undef', ?
    255 => 'undef',
);

# empty VRD header/footer for creating VRD from scratch
my $blankHeader = "CANON OPTIONAL DATA\0\0\x01\0\0\0\0\0\0";
my $blankFooter = "CANON OPTIONAL DATA\0" . ("\0" x 42) . "\xff\xd9";

# main tag table blocks in CanonVRD trailer (ref PH)
%Image::ExifTool::CanonVRD::Main = (
    WRITE_PROC => \&WriteCanonVRD,
    PROCESS_PROC => \&ProcessCanonVRD,
    NOTES => q{
        Canon Digital Photo Professional writes VRD (Recipe Data) information as a
        trailer record to JPEG, TIFF, CRW and CR2 images, or as stand-alone VRD or
        DR4 files.  The tags listed below represent information found in these
        records.  The complete VRD/DR4 data record may be accessed as a block using
        the Extra 'CanonVRD' or 'CanonDR4' tag, but this tag is not extracted or
        copied unless specified explicitly.
    },
    0xffff00f4 => {
        Name => 'EditData',
        SubDirectory => { TagTable => 'Image::ExifTool::CanonVRD::Edit' },
    },
    0xffff00f5 => {
        Name => 'IHLData',
        SubDirectory => { TagTable => 'Image::ExifTool::CanonVRD::IHL' },
    },
    0xffff00f6 => {
        Name => 'XMP',
        Flags => [ 'Binary', 'Protected' ],
        Writable => 'undef',    # allow writing/deleting as a block
        SubDirectory => {
            DirName => 'XMP',
            TagTable => 'Image::ExifTool::XMP::Main',
        },
    },
    0xffff00f7 => {
        Name => 'Edit4Data',
        SubDirectory => { TagTable => 'Image::ExifTool::CanonVRD::Edit4' },
    },
);

# the VRD edit information is divided into sections
%Image::ExifTool::CanonVRD::Edit = (
    WRITE_PROC => \&ProcessEditData,
    PROCESS_PROC => \&ProcessEditData,
    VARS => { ID_LABEL => 'Index' }, # change TagID label in documentation
    NOTES => 'Canon VRD edit information.',
    0 => {
        Name => 'VRD1',
        Size => 0x272,  # size of version 1.0 edit information in bytes
        SubDirectory => { TagTable => 'Image::ExifTool::CanonVRD::Ver1' },
    },
    1 => {
        Name => 'VRDStampTool',
        Size => 0,      # size is variable, and obtained from int32u at directory start
        SubDirectory => { TagTable => 'Image::ExifTool::CanonVRD::StampTool' },
    },
    2 => {
        Name => 'VRD2',
        Size => undef,  # size is the remaining edit data
        SubDirectory => { TagTable => 'Image::ExifTool::CanonVRD::Ver2' },
    },
);

# Canon DPP version 4 edit information
%Image::ExifTool::CanonVRD::Edit4 = (
    WRITE_PROC => \&ProcessEditData,
    PROCESS_PROC => \&ProcessEditData,
    VARS => { ID_LABEL => 'Index' }, # change TagID label in documentation
    NOTES => 'Canon DPP version 4 edit information.',
    0 => {
        Name => 'DR4',
        Size => undef,  # size is the remaining edit data
        SubDirectory => { TagTable => 'Image::ExifTool::CanonVRD::DR4' },
    },
);

# "IHL Created Optional Item Data" tags (not yet writable)
%Image::ExifTool::CanonVRD::IHL = (
    PROCESS_PROC => \&ProcessIHL,
    TAG_PREFIX => 'VRD_IHL',
    GROUPS => { 2 => 'Image' },
    1 => [
        # this contains edited TIFF-format data, with an original IFD at 0x0008
        # and an edited IFD with offset given in the TIFF header.
        {
            Name => 'IHL_EXIF',
            Condition => '$self->Options("ExtractEmbedded")',
            SubDirectory => {
                TagTable => 'Image::ExifTool::Exif::Main',
                ProcessProc => \&ProcessIHLExif,
            },
        },{
            Name => 'IHL_EXIF',
            Notes => q{
                extracted as a block if the L option is used, or processed as the
                first sub-document with the L option
            },
            Binary => 1,
            Unknown => 1,
        },
    ],
    # 2 - written by DPP 3.0.2.6, and it looks something like edit data,
    #     but I haven't decoded it yet - PH
    3 => {
        # (same size as the PreviewImage with DPP 3.0.2.6)
        Name => 'ThumbnailImage',
        Groups => { 2 => 'Preview' },
        Binary => 1,
    },
    4 => {
        Name => 'PreviewImage',
        Groups => { 2 => 'Preview' },
        Binary => 1,
    },
    5 => {
        Name => 'RawCodecVersion',
        ValueConv => '$val =~ s/\0.*//s; $val',  # truncate string at null
    },
    6 => {
        Name => 'CRCDevelParams',
        Binary => 1,
        Unknown => 1,
    },
);

# VRD version 1 tags (ref PH)
%Image::ExifTool::CanonVRD::Ver1 = (
    PROCESS_PROC => \&Image::ExifTool::ProcessBinaryData,
    WRITE_PROC => \&Image::ExifTool::WriteBinaryData,
    CHECK_PROC => \&Image::ExifTool::CheckBinaryData,
    WRITABLE => 1,
    FIRST_ENTRY => 0,
    GROUPS => { 2 => 'Image' },
    DATAMEMBER => [ 0x002 ],   # necessary for writing
#
# RAW image adjustment
#
    0x002 => {
        Name => 'VRDVersion',
        Format => 'int16u',
        Writable => 0,
        DataMember => 'VRDVersion',
        RawConv => '$$self{VRDVersion} = $val',
        PrintConv => '$val =~ s/^(\d)(\d*)(\d)$/$1.$2.$3/; $val',
    },
    0x006 => {
        Name => 'WBAdjRGGBLevels',
        Format => 'int16u[4]',
    },
    0x018 => {
        Name => 'WhiteBalanceAdj',
        Format => 'int16u',
        PrintConvColumns => 2,
        PrintConv => {
            0 => 'Auto',
            1 => 'Daylight',
            2 => 'Cloudy',
            3 => 'Tungsten',
            4 => 'Fluorescent',
            5 => 'Flash',
            8 => 'Shade',
            9 => 'Kelvin',
            30 => 'Manual (Click)',
            31 => 'Shot Settings',
        },
    },
    0x01a => {
        Name => 'WBAdjColorTemp',
        Format => 'int16u',
    },
    # 0x01c similar to 0x006
    0x024 => {
        Name => 'WBFineTuneActive',
        Format => 'int16u',
        %noYes,
    },
    0x028 => {
        Name => 'WBFineTuneSaturation',
        Format => 'int16u',
    },
    0x02c => {
        Name => 'WBFineTuneTone',
        Format => 'int16u',
    },
    0x02e => {
        Name => 'RawColorAdj',
        Format => 'int16u',
        PrintConv => {
            0 => 'Shot Settings',
            1 => 'Faithful',
            2 => 'Custom',
        },
    },
    0x030 => {
        Name => 'RawCustomSaturation',
        Format => 'int32s',
    },
    0x034 => {
        Name => 'RawCustomTone',
        Format => 'int32s',
    },
    0x038 => {
        Name => 'RawBrightnessAdj',
        Format => 'int32s',
        ValueConv => '$val / 6000',
        ValueConvInv => 'int($val * 6000 + ($val < 0 ? -0.5 : 0.5))',
        PrintConv => 'sprintf("%.2f",$val)',
        PrintConvInv => '$val',
    },
    0x03c => {
        Name => 'ToneCurveProperty',
        Format => 'int16u',
        PrintConvColumns => 2,
        PrintConv => {
            0 => 'Shot Settings',
            1 => 'Linear',
            2 => 'Custom 1',
            3 => 'Custom 2',
            4 => 'Custom 3',
            5 => 'Custom 4',
            6 => 'Custom 5',
        },
    },
    # 0x040 usually "10 9 2"
    0x07a => {
        Name => 'DynamicRangeMin',
        Format => 'int16u',
    },
    0x07c => {
        Name => 'DynamicRangeMax',
        Format => 'int16u',
    },
    # 0x0c6 usually "10 9 2"
#
# RGB image adjustment
#
    0x110 => {
        Name => 'ToneCurveActive',
        Format => 'int16u',
        %noYes,
    },
    0x113 => {
        Name => 'ToneCurveMode',
        PrintConv => { 0 => 'RGB', 1 => 'Luminance' },
    },
    0x114 => {
        Name => 'BrightnessAdj',
        Format => 'int8s',
    },
    0x115 => {
        Name => 'ContrastAdj',
        Format => 'int8s',
    },
    0x116 => {
        Name => 'SaturationAdj',
        Format => 'int16s',
    },
    0x11e => {
        Name => 'ColorToneAdj',
        Notes => 'in degrees, so -1 is the same as 359',
        Format => 'int32s',
    },
    0x126 => {
        Name => 'LuminanceCurvePoints',
        Format => 'int16u[21]',
        PrintConv => 'Image::ExifTool::CanonVRD::ToneCurvePrint($val)',
        PrintConvInv => 'Image::ExifTool::CanonVRD::ToneCurvePrintInv($val)',
    },
    0x150 => {
        Name => 'LuminanceCurveLimits',
        Notes => '4 numbers: input and output highlight and shadow points',
        Format => 'int16u[4]',
    },
    0x159 => {
        Name => 'ToneCurveInterpolation',
        PrintConv => { 0 => 'Curve', 1 => 'Straight' },
    },
    0x160 => {
        Name => 'RedCurvePoints',
        Format => 'int16u[21]',
        PrintConv => 'Image::ExifTool::CanonVRD::ToneCurvePrint($val)',
        PrintConvInv => 'Image::ExifTool::CanonVRD::ToneCurvePrintInv($val)',
    },
    # 0x193 same as 0x159
    0x19a => {
        Name => 'GreenCurvePoints',
        Format => 'int16u[21]',
        PrintConv => 'Image::ExifTool::CanonVRD::ToneCurvePrint($val)',
        PrintConvInv => 'Image::ExifTool::CanonVRD::ToneCurvePrintInv($val)',
    },
    # 0x1cd same as 0x159
    0x1d4 => {
        Name => 'BlueCurvePoints',
        Format => 'int16u[21]',
        PrintConv => 'Image::ExifTool::CanonVRD::ToneCurvePrint($val)',
        PrintConvInv => 'Image::ExifTool::CanonVRD::ToneCurvePrintInv($val)',
    },
    0x18a => {
        Name => 'RedCurveLimits',
        Format => 'int16u[4]',
    },
    0x1c4 => {
        Name => 'GreenCurveLimits',
        Format => 'int16u[4]',
    },
    0x1fe => {
        Name => 'BlueCurveLimits',
        Format => 'int16u[4]',
    },
    # 0x207 same as 0x159
    0x20e => {
        Name => 'RGBCurvePoints',
        Format => 'int16u[21]',
        PrintConv => 'Image::ExifTool::CanonVRD::ToneCurvePrint($val)',
        PrintConvInv => 'Image::ExifTool::CanonVRD::ToneCurvePrintInv($val)',
    },
    0x238 => {
        Name => 'RGBCurveLimits',
        Format => 'int16u[4]',
    },
    # 0x241 same as 0x159
    0x244 => {
        Name => 'CropActive',
        Format => 'int16u',
        %noYes,
    },
    0x246 => {
        Name => 'CropLeft',
        Notes => 'crop coordinates in original unrotated image',
        Format => 'int16u',
    },
    0x248 => {
        Name => 'CropTop',
        Format => 'int16u',
    },
    0x24a => {
        Name => 'CropWidth',
        Format => 'int16u',
    },
    0x24c => {
        Name => 'CropHeight',
        Format => 'int16u',
    },
    0x25a => {
        Name => 'SharpnessAdj',
        Format => 'int16u',
    },
    0x260 => {
        Name => 'CropAspectRatio',
        Format => 'int16u',
        PrintConv => {
            0 => 'Free',
            1 => '3:2',
            2 => '2:3',
            3 => '4:3',
            4 => '3:4',
            5 => 'A-size Landscape',
            6 => 'A-size Portrait',
            7 => 'Letter-size Landscape',
            8 => 'Letter-size Portrait',
            9 => '4:5',
            10 => '5:4',
            11 => '1:1',
            12 => 'Circle',
            65535 => 'Custom',
        },
    },
    0x262 => {
        Name => 'ConstrainedCropWidth',
        Format => 'float',
        PrintConv => 'sprintf("%.7g",$val)',
        PrintConvInv => '$val',
    },
    0x266 => {
        Name => 'ConstrainedCropHeight',
        Format => 'float',
        PrintConv => 'sprintf("%.7g",$val)',
        PrintConvInv => '$val',
    },
    0x26a => {
        Name => 'CheckMark',
        Format => 'int16u',
        PrintConv => {
            0 => 'Clear',
            1 => 1,
            2 => 2,
            3 => 3,
        },
    },
    0x26e => {
        Name => 'Rotation',
        Format => 'int16u',
        PrintConv => {
            0 => 0,
            1 => 90,
            2 => 180,
            3 => 270,
        },
    },
    0x270 => {
        Name => 'WorkColorSpace',
        Format => 'int16u',
        PrintConv => {
            0 => 'sRGB',
            1 => 'Adobe RGB',
            2 => 'Wide Gamut RGB',
            3 => 'Apple RGB',
            4 => 'ColorMatch RGB',
        },
    },
    # (VRD 1.0.0 edit data ends here -- 0x272 bytes)
);

# VRD Stamp Tool tags (ref PH)
%Image::ExifTool::CanonVRD::StampTool = (
    PROCESS_PROC => \&Image::ExifTool::ProcessBinaryData,
    GROUPS => { 2 => 'Image' },
    0x00 => {
        Name => 'StampToolCount',
        Format => 'int32u',
    },
);

# VRD version 2 and 3 tags (ref PH)
%Image::ExifTool::CanonVRD::Ver2 = (
    PROCESS_PROC => \&Image::ExifTool::ProcessBinaryData,
    WRITE_PROC => \&Image::ExifTool::WriteBinaryData,
    CHECK_PROC => \&Image::ExifTool::CheckBinaryData,
    WRITABLE => 1,
    FIRST_ENTRY => 0,
    FORMAT => 'int16s',
    DATAMEMBER => [ 0x58, 0xdc, 0xdf, 0xe0 ], # (required for DataMember and var-format tags)
    IS_SUBDIR => [ 0xe0 ],
    GROUPS => { 2 => 'Image' },
    NOTES => 'Tags added in DPP version 2.0 and later.',
    0x02 => {
        Name => 'PictureStyle',
        PrintConvColumns => 2,
        PrintConv => {
            0 => 'Standard',
            1 => 'Portrait',
            2 => 'Landscape',
            3 => 'Neutral',
            4 => 'Faithful',
            5 => 'Monochrome',
            6 => 'Unknown?', # PH (maybe in-camera custom picture style?)
            7 => 'Custom',
        },
    },
    0x03 => { Name => 'IsCustomPictureStyle', %noYes },
    # 0x08: 3
    # 0x09: 4095
    # 0x0a: 0
    # 0x0b: 4095
    # 0x0c: 0
    0x0d => 'StandardRawColorTone',
    0x0e => 'StandardRawSaturation',
    0x0f => 'StandardRawContrast',
    0x10 => { Name => 'StandardRawLinear', %noYes },
    0x11 => 'StandardRawSharpness',
    0x12 => 'StandardRawHighlightPoint',
    0x13 => 'StandardRawShadowPoint',
    0x14 => 'StandardOutputHighlightPoint', #2
    0x15 => 'StandardOutputShadowPoint', #2
    0x16 => 'PortraitRawColorTone',
    0x17 => 'PortraitRawSaturation',
    0x18 => 'PortraitRawContrast',
    0x19 => { Name => 'PortraitRawLinear', %noYes },
    0x1a => 'PortraitRawSharpness',
    0x1b => 'PortraitRawHighlightPoint',
    0x1c => 'PortraitRawShadowPoint',
    0x1d => 'PortraitOutputHighlightPoint',
    0x1e => 'PortraitOutputShadowPoint',
    0x1f => 'LandscapeRawColorTone',
    0x20 => 'LandscapeRawSaturation',
    0x21 => 'LandscapeRawContrast',
    0x22 => { Name => 'LandscapeRawLinear', %noYes },
    0x23 => 'LandscapeRawSharpness',
    0x24 => 'LandscapeRawHighlightPoint',
    0x25 => 'LandscapeRawShadowPoint',
    0x26 => 'LandscapeOutputHighlightPoint',
    0x27 => 'LandscapeOutputShadowPoint',
    0x28 => 'NeutralRawColorTone',
    0x29 => 'NeutralRawSaturation',
    0x2a => 'NeutralRawContrast',
    0x2b => { Name => 'NeutralRawLinear', %noYes },
    0x2c => 'NeutralRawSharpness',
    0x2d => 'NeutralRawHighlightPoint',
    0x2e => 'NeutralRawShadowPoint',
    0x2f => 'NeutralOutputHighlightPoint',
    0x30 => 'NeutralOutputShadowPoint',
    0x31 => 'FaithfulRawColorTone',
    0x32 => 'FaithfulRawSaturation',
    0x33 => 'FaithfulRawContrast',
    0x34 => { Name => 'FaithfulRawLinear', %noYes },
    0x35 => 'FaithfulRawSharpness',
    0x36 => 'FaithfulRawHighlightPoint',
    0x37 => 'FaithfulRawShadowPoint',
    0x38 => 'FaithfulOutputHighlightPoint',
    0x39 => 'FaithfulOutputShadowPoint',
    0x3a => {
        Name => 'MonochromeFilterEffect',
        PrintConv => {
            -2 => 'None',
            -1 => 'Yellow',
            0 => 'Orange',
            1 => 'Red',
            2 => 'Green',
        },
    },
    0x3b => {
        Name => 'MonochromeToningEffect',
        PrintConv => {
            -2 => 'None',
            -1 => 'Sepia',
            0 => 'Blue',
            1 => 'Purple',
            2 => 'Green',
        },
    },
    0x3c => 'MonochromeContrast',
    0x3d => { Name => 'MonochromeLinear', %noYes },
    0x3e => 'MonochromeSharpness',
    0x3f => 'MonochromeRawHighlightPoint',
    0x40 => 'MonochromeRawShadowPoint',
    0x41 => 'MonochromeOutputHighlightPoint',
    0x42 => 'MonochromeOutputShadowPoint',
    0x45 => { Name => 'UnknownContrast',            Unknown => 1 },
    0x46 => { Name => 'UnknownLinear', %noYes,      Unknown => 1 },
    0x47 => { Name => 'UnknownSharpness',           Unknown => 1 },
    0x48 => { Name => 'UnknownRawHighlightPoint',   Unknown => 1 },
    0x49 => { Name => 'UnknownRawShadowPoint',      Unknown => 1 },
    0x4a => { Name => 'UnknownOutputHighlightPoint',Unknown => 1 },
    0x4b => { Name => 'UnknownOutputShadowPoint',   Unknown => 1 },
    0x4c => 'CustomColorTone',
    0x4d => 'CustomSaturation',
    0x4e => 'CustomContrast',
    0x4f => { Name => 'CustomLinear', %noYes },
    0x50 => 'CustomSharpness',
    0x51 => 'CustomRawHighlightPoint',
    0x52 => 'CustomRawShadowPoint',
    0x53 => 'CustomOutputHighlightPoint',
    0x54 => 'CustomOutputShadowPoint',
    0x58 => {
        Name => 'CustomPictureStyleData',
        Format => 'var_int16u',
        Binary => 1,
        Notes => 'variable-length data structure',
        Writable => 0,
        RawConv => 'length($val) == 2 ? undef : $val', # ignore if no data
    },
    # (VRD 2.0.0 edit data ends here: 178 bytes, index 0x59)
    0x5e => [{
        Name => 'ChrominanceNoiseReduction',
        Condition => '$$self{VRDVersion} < 330',
        Notes => 'VRDVersion prior to 3.3.0',
        PrintConv => {
            0   => 'Off',
            58  => 'Low',
            100 => 'High',
        },
    },{ #1
        Name => 'ChrominanceNoiseReduction',
        Notes => 'VRDVersion 3.3.0 or later',
        PrintHex => 1,
        PrintConvColumns => 4,
        PrintConv => {
            0x00 => 0,
            0x10 => 1,
            0x21 => 2,
            0x32 => 3,
            0x42 => 4,
            0x53 => 5,
            0x64 => 6,
            0x74 => 7,
            0x85 => 8,
            0x96 => 9,
            0xa6 => 10,
            0xa7 => 11,
            0xa8 => 12,
            0xa9 => 13,
            0xaa => 14,
            0xab => 15,
            0xac => 16,
            0xad => 17,
            0xae => 18,
            0xaf => 19,
            0xb0 => 20,
        },
    }],
    0x5f => [{
        Name => 'LuminanceNoiseReduction',
        Condition => '$$self{VRDVersion} < 330',
        Notes => 'VRDVersion prior to 3.3.0',
        PrintConv => {
            0   => 'Off',
            65  => 'Low',
            100 => 'High',
        },
    },{ #1
        Name => 'LuminanceNoiseReduction',
        Notes => 'VRDVersion 3.3.0 or later',
        PrintHex => 1,
        PrintConvColumns => 4,
        PrintConv => {
            0x00 => 0,
            0x41 => 1,
            0x64 => 2,
            0x6e => 3,
            0x78 => 4,
            0x82 => 5,
            0x8c => 6,
            0x96 => 7,
            0xa0 => 8,
            0xaa => 9,
            0xb4 => 10,
            0xb5 => 11,
            0xb6 => 12,
            0xb7 => 13,
            0xb8 => 14,
            0xb9 => 15,
            0xba => 16,
            0xbb => 17,
            0xbc => 18,
            0xbd => 19,
            0xbe => 20,
        },
    }],
    0x60 => [{
        Name => 'ChrominanceNR_TIFF_JPEG',
        Condition => '$$self{VRDVersion} < 330',
        Notes => 'VRDVersion prior to 3.3.0',
        PrintConv => {
            0   => 'Off',
            33  => 'Low',
            100 => 'High',
        },
    },{ #1
        Name => 'ChrominanceNR_TIFF_JPEG',
        Notes => 'VRDVersion 3.3.0 or later',
        PrintHex => 1,
        PrintConvColumns => 4,
        PrintConv => {
            0x00 => 0,
            0x10 => 1,
            0x21 => 2,
            0x32 => 3,
            0x42 => 4,
            0x53 => 5,
            0x64 => 6,
            0x74 => 7,
            0x85 => 8,
            0x96 => 9,
            0xa6 => 10,
            0xa7 => 11,
            0xa8 => 12,
            0xa9 => 13,
            0xaa => 14,
            0xab => 15,
            0xac => 16,
            0xad => 17,
            0xae => 18,
            0xaf => 19,
            0xb0 => 20,
        },
    }],
    # 0x61: 1
    # (VRD 3.0.0 edit data ends here: 196 bytes, index 0x62)
    0x62 => { Name => 'ChromaticAberrationOn',      %noYes },
    0x63 => { Name => 'DistortionCorrectionOn',     %noYes },
    0x64 => { Name => 'PeripheralIlluminationOn',   %noYes },
    0x65 => { Name => 'ColorBlur',                  %noYes },
    0x66 => {
        Name => 'ChromaticAberration',
        ValueConv => '$val / 0x400',
        ValueConvInv => 'int($val * 0x400 + 0.5)',
        PrintConv => 'sprintf("%.0f%%", $val * 100)',
        PrintConvInv => 'ToFloat($val) / 100',
    },
    0x67 => {
        Name => 'DistortionCorrection',
        ValueConv => '$val / 0x400',
        ValueConvInv => 'int($val * 0x400 + 0.5)',
        PrintConv => 'sprintf("%.0f%%", $val * 100)',
        PrintConvInv => 'ToFloat($val) / 100',
    },
    0x68 => {
        Name => 'PeripheralIllumination',
        ValueConv => '$val / 0x400',
        ValueConvInv => 'int($val * 0x400 + 0.5)',
        PrintConv => 'sprintf("%.0f%%", $val * 100)',
        PrintConvInv => 'ToFloat($val) / 100',
    },
    0x69 => {
        Name => 'AberrationCorrectionDistance',
        Notes => '100% = infinity',
        RawConv => '$val == 0x7fff ? undef : $val',
        ValueConv => '1 - $val / 0x400',
        ValueConvInv => 'int((1 - $val) * 0x400 + 0.5)',
        PrintConv => 'sprintf("%.0f%%", $val * 100)',
        PrintConvInv => 'ToFloat($val) / 100',
    },
    0x6a => 'ChromaticAberrationRed',
    0x6b => 'ChromaticAberrationBlue',
    0x6d => { #1
        Name => 'LuminanceNR_TIFF_JPEG',
        Notes => 'val = raw / 10',
        ValueConv => '$val / 10',
        ValueConvInv => 'int($val * 10 + 0.5)',
    },
    # (VRD 3.4.0 edit data ends here: 220 bytes, index 0x6e)
    0x6e => { Name => 'AutoLightingOptimizerOn', %noYes },
    0x6f => {
        Name => 'AutoLightingOptimizer',
        PrintConv => {
            100 => 'Low',
            200 => 'Standard',
            300 => 'Strong',
            0x7fff => 'n/a', #1
        },
    },
    # 0x71: 200
    # 0x73: 100
    # (VRD 3.5.0 edit data ends here: 232 bytes, index 0x74)
    0x75 => {
        Name => 'StandardRawHighlight',
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x76 => {
        Name => 'PortraitRawHighlight',
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x77 => {
        Name => 'LandscapeRawHighlight',
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x78 => {
        Name => 'NeutralRawHighlight',
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x79 => {
        Name => 'FaithfulRawHighlight',
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x7a => {
        Name => 'MonochromeRawHighlight',
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x7b => {
        Name => 'UnknownRawHighlight',
        Unknown => 1,
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x7c => {
        Name => 'CustomRawHighlight',
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x7e => {
        Name => 'StandardRawShadow',
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x7f => {
        Name => 'PortraitRawShadow',
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x80 => {
        Name => 'LandscapeRawShadow',
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x81 => {
        Name => 'NeutralRawShadow',
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x82 => {
        Name => 'FaithfulRawShadow',
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x83 => {
        Name => 'MonochromeRawShadow',
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x84 => {
        Name => 'UnknownRawShadow',
        Unknown => 1,
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x85 => {
        Name => 'CustomRawShadow',
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
    },
    0x8b => { #2
        Name => 'AngleAdj',
        Format => 'int32s',
        ValueConv => '$val / 100',
        ValueConvInv => '$val * 100',
    },
    0x8e => {
        Name => 'CheckMark2',
        Format => 'int16u',
        PrintConvColumns => 2,
        PrintConv => {
            0 => 'Clear',
            1 => 1,
            2 => 2,
            3 => 3,
            4 => 4,
            5 => 5,
        },
    },
    # (VRD 3.8.0 edit data ends here: 286 bytes, index 0x8f)
    0x90 => {
        Name => 'UnsharpMask',
        PrintConv => { 0 => 'Off', 1 => 'On' },
    },
    0x92 => 'StandardUnsharpMaskStrength',
    0x94 => 'StandardUnsharpMaskFineness',
    0x96 => 'StandardUnsharpMaskThreshold',
    0x98 => 'PortraitUnsharpMaskStrength',
    0x9a => 'PortraitUnsharpMaskFineness',
    0x9c => 'PortraitUnsharpMaskThreshold',
    0x9e => 'LandscapeUnsharpMaskStrength',
    0xa0 => 'LandscapeUnsharpMaskFineness',
    0xa2 => 'LandscapeUnsharpMaskThreshold',
    0xa4 => 'NeutraUnsharpMaskStrength',
    0xa6 => 'NeutralUnsharpMaskFineness',
    0xa8 => 'NeutralUnsharpMaskThreshold',
    0xaa => 'FaithfulUnsharpMaskStrength',
    0xac => 'FaithfulUnsharpMaskFineness',
    0xae => 'FaithfulUnsharpMaskThreshold',
    0xb0 => 'MonochromeUnsharpMaskStrength',
    0xb2 => 'MonochromeUnsharpMaskFineness',
    0xb4 => 'MonochromeUnsharpMaskThreshold',
    0xb6 => 'CustomUnsharpMaskStrength',
    0xb8 => 'CustomUnsharpMaskFineness',
    0xba => 'CustomUnsharpMaskThreshold',
    0xbc => 'CustomDefaultUnsharpStrength',
    0xbe => 'CustomDefaultUnsharpFineness',
    0xc0 => 'CustomDefaultUnsharpThreshold',
    # (VRD 3.9.1 edit data ends here: 392 bytes, index 0xc4)
    # 0xc9: 3    - some RawSharpness
    # 0xca: 4095 - some RawHighlightPoint
    # 0xcb: 0    - some RawShadowPoint
    # 0xcc: 4095 - some OutputHighlightPoint
    # 0xcd: 0    - some OutputShadowPoint
    # 0xd1: 3    - some UnsharpMaskStrength
    # 0xd3: 7    - some UnsharpMaskFineness
    # 0xd5: 3,4  - some UnsharpMaskThreshold
    0xd6 => { Name => 'CropCircleActive', %noYes },
    0xd7 => 'CropCircleX',
    0xd8 => 'CropCircleY',
    0xd9 => 'CropCircleRadius',
    # 0xda: 0, 1
    # 0xdb: 100
    0xdc => {
        Name => 'DLOOn',
        DataMember => 'DLOOn',
        RawConv => '$$self{DLOOn} = $val',
        %noYes,
    },
    0xdd => 'DLOSetting',
    # (VRD 3.11.0 edit data ends here: 444 bytes, index 0xde)
    0xde => {
        Name => 'DLOShootingDistance',
        Notes => '100% = infinity',
        RawConv => '$val == 0x7fff ? undef : $val',
        ValueConv => '1 - $val / 0x400',
        ValueConvInv => 'int((1 - $val) * 0x400 + 0.5)',
        PrintConv => 'sprintf("%.0f%%", $val * 100)',
        PrintConvInv => 'ToFloat($val) / 100',
    },
    0xdf => {
        Name => 'DLODataLength',
        DataMember => 'DLODataLength',
        Format => 'int32u',
        Writable => 0,
        RawConv => '$$self{DLODataLength} = $val',
    },
    0xe0 => { # (yes, this overlaps DLODataLength)
        Name => 'DLOInfo',
        # - have seen DLODataLengths of 65536,64869 when DLO is Off, so must test DLOOn flag
        Condition => '$$self{DLOOn}',
        SubDirectory => { TagTable => 'Image::ExifTool::CanonVRD::DLOInfo' },
        Hook => '$varSize += $$self{DLODataLength} + 0x16',
    },
    0xe1 => 'CameraRawColorTone',
    # (VRD 3.11.2 edit data ends here: 452 bytes, index 0xe2, unless DLO is on)
    0xe2 => 'CameraRawSaturation',
    0xe3 => 'CameraRawContrast',
    0xe4 => { Name => 'CameraRawLinear', %noYes },
    0xe5 => 'CameraRawSharpness',
    0xe6 => 'CameraRawHighlightPoint',
    0xe7 => 'CameraRawShadowPoint',
    0xe8 => 'CameraRawOutputHighlightPoint',
    0xe9 => 'CameraRawOutputShadowPoint',
);

# DLO tags (ref PH)
%Image::ExifTool::CanonVRD::DLOInfo = (
    PROCESS_PROC => \&Image::ExifTool::ProcessBinaryData,
    WRITE_PROC => \&Image::ExifTool::WriteBinaryData,
    CHECK_PROC => \&Image::ExifTool::CheckBinaryData,
    WRITABLE => 1,
    FIRST_ENTRY => 1,
    FORMAT => 'int16s',
    GROUPS => { 2 => 'Image' },
    NOTES => 'Tags added when DLO (Digital Lens Optimizer) is on.',
    # 0x01 - seen 3112,3140
    0x04 => 'DLOSettingApplied',
    0x05 => {
        Name => 'DLOVersion', #(NC)
        Format => 'string[10]',
    },
    0x0a => {
        Name => 'DLOData',
        LargeTag => 1, # large tag, so avoid storing unnecessarily
        Notes => 'variable-length Digital Lens Optimizer data, stored in JPEG-like format',
        Format => 'undef[$$self{DLODataLength}]',
        Writable => 0,
        Binary => 1,
    },
);

# VRD version 4 tags (ref PH)
%Image::ExifTool::CanonVRD::DR4 = (
    PROCESS_PROC => \&ProcessDR4,
    WRITE_PROC => \&ProcessDR4,
    WRITABLE => 1,
    GROUPS => { 2 => 'Image' },
    VARS => { HEX_ID => 1, SORT_PROC => \&SortDR4 },
    NOTES => q{
        Tags written by Canon DPP version 4 in CanonVRD trailers and DR4 files. Each
        tag has three associated flag words which are stored with the directory
        entry, some of which are extracted as a separate tag, indicated in the table
        below by a decimal appended to the tag ID (.0, .1 or .2).
    },
    header => {
        Name => 'DR4Header',
        SubDirectory => { TagTable => 'Image::ExifTool::CanonVRD::DR4Header' },
    },
    0x10002 => 'Rotation', # left/right rotation 90,180,270
    0x10003 => 'AngleAdj', # crop angle
    # 0x10018 - fmt=8: 0
    # 0x10020 - fmt=2: ''
    0x10021 => 'CustomPictureStyle', # (string)
    0x10101 => {
        Name => 'CheckMark',
        PrintConv => {
            0 => 'Clear',
            1 => 1,
            2 => 2,
            3 => 3,
            4 => 4,
            5 => 5,
        },
    },
    0x10200 => {
        Name => 'WorkColorSpace',
        PrintConv => {
            1 => 'sRGB',
            2 => 'Adobe RGB',
            3 => 'Wide Gamut RGB',
            4 => 'Apple RGB',
            5 => 'ColorMatch RGB',
        },
    },
    # 0x10201 - fmt=9: 0
    # 0x10f20 - fmt=9: 350
    0x20001 => 'RawBrightnessAdj',
    0x20101 => {
        Name => 'WhiteBalanceAdj',
        PrintConvColumns => 2,
        PrintConv => {
            -1 => 'Manual (Click)',
            0 => 'Auto',
            1 => 'Daylight',
            2 => 'Cloudy',
            3 => 'Tungsten',
            4 => 'Fluorescent',
            5 => 'Flash',
            8 => 'Shade',
            9 => 'Kelvin',
            255 => 'Shot Settings',
        },
    },
    0x20102 => 'WBAdjColorTemp',
    0x20105 => 'WBAdjMagentaGreen',
    0x20106 => 'WBAdjBlueAmber',
    0x20125 => {
        Name => 'WBAdjRGGBLevels',
        PrintConv => '$val =~ s/^\d+ //; $val',  # remove first integer (14: what is this for?)
        PrintConvInv => '"14 $val"',
    },
    0x20200 => { Name => 'GammaLinear', %noYes },
    0x20301 => {
        Name => 'PictureStyle',
        PrintHex => 1,
        PrintConv => {
            0x81 => 'Standard',
            0x82 => 'Portrait',
            0x83 => 'Landscape',
            0x84 => 'Neutral',
            0x85 => 'Faithful',
            0x86 => 'Monochrome',
            0x87 => 'Auto',
            0x88 => 'Fine Detail',
            0xf0 => 'Shot Settings',
            0xff => 'Custom',
        },
    },
    # 0x20302 - Gamma curve data
    0x20303 => 'ContrastAdj',
    0x20304 => 'ColorToneAdj',
    0x20305 => 'ColorSaturationAdj',
    0x20306 => {
        Name => 'MonochromeToningEffect',
        PrintConv => {
            0 => 'None',
            1 => 'Sepia',
            2 => 'Blue',
            3 => 'Purple',
            4 => 'Green',
        },
    },
    0x20307 => {
        Name => 'MonochromeFilterEffect',
        PrintConv => {
            0 => 'None',
            1 => 'Yellow',
            2 => 'Orange',
            3 => 'Red',
            4 => 'Green',
        },
    },
    0x20308 => 'UnsharpMaskStrength',
    0x20309 => 'UnsharpMaskFineness',
    0x2030a => 'UnsharpMaskThreshold',
    0x2030b => 'ShadowAdj',
    0x2030c => 'HighlightAdj',
    0x20310 => {
        Name => 'SharpnessAdj',
        PrintConv => {
            0 => 'Sharpness',
            1 => 'Unsharp Mask',
        },
    },
   '0x20310.0' => { Name => 'SharpnessAdjOn', %noYes },
    0x20311 => 'SharpnessStrength',
    0x20400 => {
        Name => 'ToneCurve',
        SubDirectory => { TagTable => 'Image::ExifTool::CanonVRD::ToneCurve' },
    },
   '0x20400.1' => { Name => 'ToneCurveOriginal', %noYes },
    # 0x20401 - fmt=33 (312 bytes)
    0x20410 => 'ToneCurveBrightness',
    0x20411 => 'ToneCurveContrast',
    0x20500 => {
        Name => 'AutoLightingOptimizer',
        PrintConv => {
            0 => 'Low',
            1 => 'Standard',
            2 => 'Strong',
        },
    },
   '0x20500.0' => {
        Name => 'AutoLightingOptimizerOn',
        Notes => 'ignored if gamma is linear',
        %noYes,
    },
    # 0x20501 - fmt=13: 0
    # 0x20502 - fmt=13: 0
    0x20600 => 'LuminanceNoiseReduction',
    0x20601 => 'ChrominanceNoiseReduction',
    # 0x20650 - fmt=9: 0 (JPG images)
    0x20670 => 'ColorMoireReduction',
   '0x20670.0' => { Name => 'ColorMoireReductionOn', %noYes },
    0x20701 => {
        Name => 'ShootingDistance',
        Notes => '100% = infinity',
        ValueConv => '$val / 10',
        ValueConvInv => '$val * 10',
        PrintConv => 'sprintf("%.0f%%", $val * 100)',
        PrintConvInv => 'ToFloat($val) / 100',
    },
    0x20702 => {
        Name => 'PeripheralIllumination',
        PrintConv => 'sprintf "%g", $val',
        PrintConvInv => '$val',
    },
   '0x20702.0' => { Name => 'PeripheralIlluminationOn', %noYes },
    0x20703 => {
        Name => 'ChromaticAberration',
        PrintConv => 'sprintf "%g", $val',
        PrintConvInv => '$val',
    },
   '0x20703.0' => { Name => 'ChromaticAberrationOn', %noYes },
    0x20704 => { Name => 'ColorBlurOn', %noYes },
    0x20705 => {
        Name => 'DistortionCorrection',
        PrintConv => 'sprintf "%g", $val',
        PrintConvInv => '$val',
    },
   '0x20705.0' => { Name => 'DistortionCorrectionOn', %noYes },
    0x20706 => 'DLOSetting',
   '0x20706.0' => { Name => 'DLOOn', %noYes },
    0x20707 => {
        Name => 'ChromaticAberrationRed',
        PrintConv => 'sprintf "%g", $val',
        PrintConvInv => '$val',
    },
    0x20708 => {
        Name => 'ChromaticAberrationBlue',
        PrintConv => 'sprintf "%g", $val',
        PrintConvInv => '$val',
    },
    0x20709 => {
        Name => 'DistortionEffect',
        PrintConv => {
            0 => 'Shot Settings',
            1 => 'Emphasize Linearity',
            2 => 'Emphasize Distance',
            3 => 'Emphasize Periphery',
            4 => 'Emphasize Center',
        },
    },
    # 0x20800 - fmt=1: 0
    # 0x20801 - fmt=1: 0
    0x2070b => { Name => 'DiffractionCorrectionOn', %noYes },
    0x20900 => 'ColorHue',
    0x20901 => 'SaturationAdj',
    0x20910 => 'RedHSL',
    0x20911 => 'OrangeHSL',
    0x20912 => 'YellowHSL',
    0x20913 => 'GreenHSL',
    0x20914 => 'AquaHSL',
    0x20915 => 'BlueHSL',
    0x20916 => 'PurpleHSL',
    0x20917 => 'MagentaHSL',
    0x20a00 => {
        Name => 'GammaInfo',
        SubDirectory => { TagTable => 'Image::ExifTool::CanonVRD::GammaInfo' },
    },
    # 0x20a01 - Auto picture style settings
    # 0x20a02 - Standard picture style settings
    # 0x20a03 - Portrait picture style settings
    # 0x20a04 - Landscape picture style settings
    # 0x20a05 - Neutral picture style settings
    # 0x20a06 - Faithful picture style settings
    # 0x20a07 - Monochrome picture style settings
    # 0x20a08 - (unknown picture style settings)
    # 0x20a09 - Custom picture style settings
    # 0x20a20 - Fine Detail picture style settings
    0x30101 => {
        Name => 'CropAspectRatio',
        PrintConv => {
            0 => 'Free',
            1 => 'Custom',
            2 => '1:1',
            3 => '3:2',
            4 => '2:3',
            5 => '4:3',
            6 => '3:4',
            7 => '5:4',
            8 => '4:5',
            9 => '16:9',
            10 => '9:16',
        },
    },
    0x30102 => 'CropAspectRatioCustom',
    # 0x30103 - fmt=33: "0 0 8"
    0xf0100 => {
        Name => 'CropInfo',
        SubDirectory => { TagTable => 'Image::ExifTool::CanonVRD::CropInfo' },
    },
    0xf0500 => {
        Name => 'CustomPictureStyleData',
        Binary => 1,
    },
    0xf0510 => {
        Name => 'StampInfo',
        SubDirectory => { TagTable => 'Image::ExifTool::CanonVRD::StampInfo' },
    },
    0xf0511 => {
        Name => 'DustInfo',
        SubDirectory => { TagTable => 'Image::ExifTool::CanonVRD::DustInfo' },
    },
    0xf0512 => 'LensFocalLength',
    # 0xf0521 - DLO data
    # 0xf0520 - DLO data
    # 0xf0530 - created when dust delete data applied (4 bytes, all zero)
    # 0xf0600 - fmt=253 (2308 bytes, JPG images)
    # 0xf0601 - fmt=253 (2308 bytes, JPG images)
    # 0x1ff52c - values: 129,130,132 (related to custom picture style somehow)
    # to do:
    # - find 8-15mm CR2 sample and decode linear distortion effect fine-tune
);

# Version 4 header information (ref PH)
%Image::ExifTool::CanonVRD::DR4Header = (
    PROCESS_PROC => \&Image::ExifTool::ProcessBinaryData,
    WRITE_PROC => \&Image::ExifTool::WriteBinaryData,
    CHECK_PROC => \&Image::ExifTool::CheckBinaryData,
    WRITABLE => 1,
    FIRST_ENTRY => 0,
    FORMAT => 'int32u',
    GROUPS => { 2 => 'Image' },
    # 0 - value: 'IIII' (presumably byte order)
    # 1 - value: 0x00040004 (currently use this for magic number)
    # 2 - value: 6
    3 => {
        Name => 'DR4CameraModel',
        Writable => 'int32u',
        PrintHex => 1,
        SeparateTable => 'Canon CanonModelID',
        PrintConv => \%Image::ExifTool::Canon::canonModelID,
    },
    # 4 - value: 3
    # 5 - value: 4
    # 6 - value: 5
    # 7 - DR4 directory entry count
);

# Version 4 RGB tone curve information (ref PH)
%Image::ExifTool::CanonVRD::ToneCurve = (
    PROCESS_PROC => \&Image::ExifTool::ProcessBinaryData,
    WRITE_PROC => \&Image::ExifTool::WriteBinaryData,
    CHECK_PROC => \&Image::ExifTool::CheckBinaryData,
    WRITABLE => 1,
    FIRST_ENTRY => 0,
    FORMAT => 'int32u',
    GROUPS => { 2 => 'Image' },
    0x00 => {
        Name => 'ToneCurveColorSpace',
        PrintConv => {
            0 => 'RGB',
            1 => 'Luminance',
        },
    },
    0x01 => {
        Name => 'ToneCurveShape',
        PrintConv => {
            0 => 'Curve',
            1 => 'Straight',
        },
    },
    0x03 => { Name => 'ToneCurveInputRange',  Format => 'int32u[2]', Notes => '255 max' },
    0x05 => { Name => 'ToneCurveOutputRange', Format => 'int32u[2]', Notes => '255 max' },
    0x07 => {
        Name => 'RGBCurvePoints',
        Format => 'int32u[21]',
        PrintConv => 'Image::ExifTool::CanonVRD::ToneCurvePrint($val)',
        PrintConvInv => 'Image::ExifTool::CanonVRD::ToneCurvePrintInv($val)',
    },
    0x0a => 'ToneCurveX',
    0x0b => 'ToneCurveY',
    0x2d => {
        Name => 'RedCurvePoints',
        Format => 'int32u[21]',
        PrintConv => 'Image::ExifTool::CanonVRD::ToneCurvePrint($val)',
        PrintConvInv => 'Image::ExifTool::CanonVRD::ToneCurvePrintInv($val)',
    },
    0x53 => {
        Name => 'GreenCurvePoints',
        Format => 'int32u[21]',
        PrintConv => 'Image::ExifTool::CanonVRD::ToneCurvePrint($val)',
        PrintConvInv => 'Image::ExifTool::CanonVRD::ToneCurvePrintInv($val)',
    },
    0x79 => {
        Name => 'BlueCurvePoints',
        Format => 'int32u[21]',
        PrintConv => 'Image::ExifTool::CanonVRD::ToneCurvePrint($val)',
        PrintConvInv => 'Image::ExifTool::CanonVRD::ToneCurvePrintInv($val)',
    },
);

# Version 4 gamma curve information (ref PH)
%Image::ExifTool::CanonVRD::GammaInfo = (
    PROCESS_PROC => \&Image::ExifTool::ProcessBinaryData,
    WRITE_PROC => \&Image::ExifTool::WriteBinaryData,
    CHECK_PROC => \&Image::ExifTool::CheckBinaryData,
    WRITABLE => 1,
    FIRST_ENTRY => 0,
    FORMAT => 'double',
    GROUPS => { 2 => 'Image' },
    0x02 => 'GammaContrast',
    0x03 => 'GammaColorTone',
    0x04 => 'GammaSaturation',
    0x05 => 'GammaUnsharpMaskStrength',
    0x06 => 'GammaUnsharpMaskFineness',
    0x07 => 'GammaUnsharpMaskThreshold',
    0x08 => 'GammaSharpnessStrength',
    0x09 => 'GammaShadow',
    0x0a => 'GammaHighlight',
    # 0x0b-0x10 are the same as first 6 doubles of tag DR4_0x20302
    # 0x0b - value: 14
    0x0c => {
        Name => 'GammaBlackPoint',
        ValueConv => q{
            return 0 if $val <= 0;
            $val = log($val / 4.6875) / log(2) + 1;
            return abs($val) > 1e-10 ? $val : 0;
        },
        ValueConvInv => '$val ? exp(($val - 1) * log(2)) * 4.6876 : 0',
        PrintConv => 'sprintf("%+.3f", $val)',
        PrintConvInv => '$val',
    },
    0x0d => {
        Name => 'GammaWhitePoint',
        ValueConv => q{
            return $val if $val <= 0;
            $val = log($val / 4.6875) / log(2) - 11.77109325169954;
            return abs($val) > 1e-10 ? $val : 0;
        },
        ValueConvInv => '$val ? exp(($val + 11.77109325169954) * log(2)) * 4.6875 : 0',
        PrintConv => 'sprintf("%+.3f", $val)',
        PrintConvInv => '$val',
    },
    0x0e => {
        Name => 'GammaMidPoint',
        ValueConv => q{
            return $val if $val <= 0;
            $val = log($val / 4.6875) / log(2) - 8;
            return abs($val) > 1e-10 ? $val : 0;
        },
        ValueConvInv => '$val ? exp(($val + 8) * log(2)) * 4.6876 : 0',
        PrintConv => 'sprintf("%+.3f", $val)',
        PrintConvInv => '$val',
    },
    0x0f => { Name => 'GammaCurveOutputRange', Format => 'double[2]', Notes => '16383 max' },
);

# Version 4 crop information (ref PH)
%Image::ExifTool::CanonVRD::CropInfo = (
    PROCESS_PROC => \&Image::ExifTool::ProcessBinaryData,
    WRITE_PROC => \&Image::ExifTool::WriteBinaryData,
    CHECK_PROC => \&Image::ExifTool::CheckBinaryData,
    WRITABLE => 1,
    FIRST_ENTRY => 0,
    FORMAT => 'int32s',
    GROUPS => { 2 => 'Image' },
    0 => { Name => 'CropActive', %noYes },
    1 => 'CropRotatedOriginalWidth',
    2 => 'CropRotatedOriginalHeight',
    3 => 'CropX',
    4 => 'CropY',
    5 => 'CropWidth',
    6 => 'CropHeight',
    8 => {
        Name => 'CropRotation',
        Format => 'double',
        PrintConv => 'sprintf("%.7g",$val)',
        PrintConvInv => '$val',
    },
    0x0a => 'CropOriginalWidth',
    0x0b => 'CropOriginalHeight',
    # 0x0c double - value: 100
);

# DR4 Stamp Tool tags (ref PH)
%Image::ExifTool::CanonVRD::StampInfo = (
    PROCESS_PROC => \&Image::ExifTool::ProcessBinaryData,
    GROUPS => { 2 => 'Image' },
    FORMAT => 'int32u',
    FIRST_ENTRY => 0,
    0x02 => 'StampToolCount',
);

# DR4 dust delete information (ref PH)
%Image::ExifTool::CanonVRD::DustInfo = (
    PROCESS_PROC => \&Image::ExifTool::ProcessBinaryData,
    GROUPS => { 2 => 'Image' },
    FORMAT => 'int32u',
    FIRST_ENTRY => 0,
    0x02 => { Name => 'DustDeleteApplied', %noYes },
);

#------------------------------------------------------------------------------
# sort DR4 tag ID's for the documentation
sub SortDR4($$)
{
    my ($a, $b) = @_;
    my ($aHex, $aDec, $bHex, $bDec);
    ($aHex, $aDec) = ($1, $2) if $a =~ /^(0x[0-9a-f]+)?\.?(\d*?)$/;
    ($bHex, $bDec) = ($1, $2) if $b =~ /^(0x[0-9a-f]+)?\.?(\d*?)$/;
    if ($aHex) {
        return 1 unless defined $bDec;  # $b is 'header';
        return hex($aHex) <=> hex($bHex) || $aDec <=> $bDec if $bHex;
        return hex($aHex) <=> $bDec || 1;
    } elsif ($bHex) {
        return -1 unless defined $aDec;
        return $aDec <=> hex($bHex) || -1;
    } else {
        return 1 unless defined $bDec;
        return -1 unless defined $aDec;
        return $aDec <=> $bDec;
    }
}

#------------------------------------------------------------------------------
# Tone curve print conversion
sub ToneCurvePrint($)
{
    my $val = shift;
    my @vals = split ' ', $val;
    return $val unless @vals == 21;
    my $n = shift @vals;
    return $val unless $n >= 2 and $n <= 10;
    $val = '';
    while ($n--) {
        $val and $val .= ' ';
        $val .= '(' . shift(@vals) . ',' . shift(@vals) . ')';
    }
    return $val;
}

#------------------------------------------------------------------------------
# Inverse print conversion for tone curve
sub ToneCurvePrintInv($)
{
    my $val = shift;
    my @vals = ($val =~ /\((\d+),(\d+)\)/g);
    return undef unless @vals >= 4 and @vals <= 20 and not @vals & 0x01;
    unshift @vals, scalar(@vals) / 2;
    while (@vals < 21) { push @vals, 0 }
    return join(' ',@vals);
}

#------------------------------------------------------------------------------
# Read/Write VRD edit data
# Inputs: 0) ExifTool object ref, 1) dirInfo ref, 2) tag table ref
# Returns: Reading: 1 on success; Writing: modified edit data, or undef if nothing changed
sub ProcessEditData($$$)
{
    my ($et, $dirInfo, $tagTablePtr) = @_;
    $et or return 1;    # allow dummy access
    my $dataPt = $$dirInfo{DataPt};
    my $pos = $$dirInfo{DirStart};
    my $dataPos = $$dirInfo{DataPos};
    my $outfile = $$dirInfo{OutFile};
    my $dirLen = $$dirInfo{DirLen};
    my $verbose = $et->Options('Verbose');
    my $out = $et->Options('TextOut');
    my $oldChanged = $$et{CHANGED};

    $et->VerboseDir('VRD Edit Data', 0, $dirLen) unless $outfile;

    if ($outfile) {
        # make a copy for editing in place
        my $buff = substr($$dataPt, $pos, $dirLen);
        $dataPt = $$dirInfo{DataPt} = \$buff;
        $dataPos += $pos;
        $pos = $$dirInfo{DirStart} = 0;
    }
    my $dirEnd = $pos + $dirLen;

    # loop through all records in the edit data
    my ($recNum, $recLen, $err);
    for ($recNum=0;; ++$recNum, $pos+=$recLen) {
        if ($pos + 4 > $dirEnd) {
            last if $pos == $dirEnd;    # all done if we arrived at end
            $recLen = 0;    # just reset record size (will exit loop on test below)
        } else {
            $recLen = Get32u($dataPt, $pos);
            # (DR4 has a null terminator)
            last if $recLen == 0 and $pos + 4 == $dirEnd;
        }
        $pos += 4;          # move to start of record
        if ($pos + $recLen > $dirEnd) {
            $et->Warn('Possibly corrupt CanonVRD Edit record');
            $err = 1;
            last;
        }
        my $saveRecLen = $recLen;
        if ($verbose > 1 and not $outfile) {
            printf $out "$$et{INDENT}CanonVRD Edit record ($recLen bytes at offset 0x%x)\n",
                   $pos + $dataPos;
            $et->VerboseDump($dataPt, Len => $recLen, Start => $pos, Addr => $pos + $dataPos) if $recNum;
        }

        # our edit information is the 0th record, so don't process the others
        next if $recNum;

        # process VRD edit information
        my $subTablePtr = $tagTablePtr;
        my $index;
        my %subdirInfo = (
            DataPt   => $dataPt,
            DataPos  => $dataPos,
            DirStart => $pos,
            DirLen   => $recLen,
            OutFile  => $outfile,
        );
        my $subStart = 0;
        # loop through various sections of the VRD edit data
        for ($index=0; ; ++$index) {
            my $tagInfo = $$subTablePtr{$index} or last;
            my $subLen;
            my $maxLen = $recLen - $subStart;
            if ($$tagInfo{Size}) {
                $subLen = $$tagInfo{Size};
            } elsif (defined $$tagInfo{Size}) {
                # get size from int32u at $subStart
                last unless $subStart + 4 <= $recLen;
                $subLen = Get32u($dataPt, $subStart + $pos);
                $subStart += 4; # skip the length word
            } else {
                $subLen = $maxLen;
            }
            $subLen > $maxLen and $subLen = $maxLen;
            if ($subLen) {
                my $subTable = GetTagTable($$tagInfo{SubDirectory}{TagTable});
                my $subName = $$tagInfo{Name};
                $subdirInfo{DirStart} = $subStart + $pos;
                $subdirInfo{DirLen} = $subLen;
                $subdirInfo{DirName} = $subName;
                if ($outfile) {
                    # rewrite this section of the VRD edit information
                    $verbose and print $out "  Rewriting Canon $subName\n";
                    my $newVal = $et->WriteDirectory(\%subdirInfo, $subTable);
                    if ($newVal) {
                        my $sizeDiff = length($newVal) - $subLen;
                        substr($$dataPt, $pos+$subStart, $subLen) = $newVal;
                        if ($sizeDiff) {
                            $subLen = length $newVal;
                            $recLen += $sizeDiff;
                            $dirEnd += $sizeDiff;
                            $dirLen += $sizeDiff;
                        }
                    }
                } else {
                    $et->VPrint(0, "$$et{INDENT}$subName (SubDirectory) -->\n");
                    $et->VerboseDump($dataPt,
                        Start => $pos + $subStart,
                        Addr  => $dataPos + $pos + $subStart,
                        Len   => $subLen,
                    );
                    # extract tags from this section of the VRD edit information
                    $et->ProcessDirectory(\%subdirInfo, $subTable);
                }
            }
            # next section starts at the end of this one
            $subStart += $subLen;
        }
        if ($outfile and $saveRecLen ne $recLen) {
            # update record length if necessary
            Set32u($recLen, $dataPt, $pos - 4)
        }
    }
    if ($outfile) {
        return undef if $oldChanged == $$et{CHANGED};
        return substr($$dataPt, $$dirInfo{DirStart}, $dirLen);
    }
    return $err ? 0 : 1;
}

#------------------------------------------------------------------------------
# Process VRD IHL data
# Inputs: 0) ExifTool object ref, 1) dirInfo ref, 2) tag table ref
# Returns: 1 on success
sub ProcessIHL($$$)
{
    my ($et, $dirInfo, $tagTablePtr) = @_;
    my $dataPt = $$dirInfo{DataPt};
    my $dataPos = $$dirInfo{DataPos};
    my $pos = $$dirInfo{DirStart};
    my $dirLen = $$dirInfo{DirLen};
    my $dirEnd = $pos + $dirLen;

    $et->VerboseDir('VRD IHL', 0, $dirLen);

    SetByteOrder('II'); # (make up your mind, Canon!)
    while ($pos + 48 <= $dirEnd) {
        my $hdr = substr($$dataPt, $pos, 48);
        unless ($hdr =~ /^IHL Created Optional Item Data\0\0/) {
            $et->Warn('Possibly corrupted VRD IHL data');
            last;
        }
        my $tag  = Get32u($dataPt, $pos + 36);
        my $size = Get32u($dataPt, $pos + 40); # size of data in IHL record
        my $next = Get32u($dataPt, $pos + 44); # size of complete IHL record
        if ($size > $next or $pos + 48 + $next > $dirEnd) {
            $et->Warn(sprintf('Bad size for VRD IHL tag 0x%.4x', $tag));
            last;
        }
        $pos += 48;
        $et->HandleTag($tagTablePtr, $tag, substr($$dataPt, $pos, $size),
            DataPt  => $dataPt,
            DataPos => $dataPos,
            Start   => $pos,
            Size    => $size
        );
        $pos += $next;
    }
    return 1;
}

#------------------------------------------------------------------------------
# Process VRD IHL EXIF data
# Inputs: 0) ExifTool object ref, 1) dirInfo ref, 2) tag table ref
# Returns: 1 on success
sub ProcessIHLExif($$$)
{
    my ($et, $dirInfo, $tagTablePtr) = @_;
    $$et{DOC_NUM} = 1;
    # the IHL-edited maker notes may look messed up, but the offsets should be OK
    my $oldFix = $et->Options(FixBase => 0);
    my $rtnVal = $et->ProcessTIFF($dirInfo, $tagTablePtr);
    $et->Options(FixBase => $oldFix);
    delete $$et{DOC_NUM};
    return $rtnVal;
}

#------------------------------------------------------------------------------
# Wrap DR4 data with the VRD header/footer and edit record
# Inputs: 0) DR4 record
# Returns: VRD[Edit[DR4]] data
sub WrapDR4($)
{
    my $val = shift;
    my $n = length $val;
    my $oldOrder = GetByteOrder();
    SetByteOrder('MM');
    $val = $blankHeader . "\xff\xff\0\xf7" . Set32u($n+8) . Set32u($n) .
                $val . "\0\0\0\0" . $blankFooter;
    # update the new VRD length in the header/footer
    Set32u($n + 16, \$val, 0x18);  # (extra 16 bytes for the edit record wrapper)
    Set32u($n + 16, \$val, length($val) - 0x2c);
    SetByteOrder($oldOrder);
    return $val;
}

#------------------------------------------------------------------------------
# Read/Write DPP version 4 edit data or DR4 file
# Inputs: 0) ExifTool object ref, 1) dirInfo ref, 2) tag table ref
# Returns:
#   Reading from memory (not RAF and not IsWriting): 1 on success
#   Editing from memory (not RAF and IsWriting): modified edit data, or undef if nothing changed
#   Reading file (RAF and not OutFile): 1 if a valid DR4 file, 0 if not
#   Writing file (RAF and OutFile): 1 if valid DR4 file, 0 if not, -1 on write error
# (serves me right for not having a consistent interface for the various modes of operation)
sub ProcessDR4($$;$)
{
    my ($et, $dirInfo, $tagTablePtr) = @_;
    $et or return 1;    # allow dummy access
    my $dataPt = $$dirInfo{DataPt};
    my $raf = $$dirInfo{RAF};
    my $outfile = $$dirInfo{OutFile};
    my $isWriting = $outfile || $$dirInfo{IsWriting};
    my $dataPos = $$dirInfo{DataPos} || 0;
    my $verbose = $et->Options('Verbose');
    my $unknown = $et->Options('Unknown');
    my ($pos, $dirLen, $numEntries, $err, $newTags);

    # write CanonDR4 as a block if specified
    if ($isWriting) {
        my $nvHash;
        my $newVal = $et->GetNewValue('CanonDR4', \$nvHash);
        if ($newVal) {
            $et->VPrint(0, "  Writing CanonDR4 as a block\n");
            $$et{DidCanonVRD} = 1;  # set flag so we don't add this twice
            ++$$et{CHANGED};
            if ($outfile) {
                Write($$dirInfo{OutFile}, $newVal) or return -1;
                return 1;
            } else {
                return $newVal;
            }
        } elsif (not $dataPt and ($nvHash or $$et{DEL_GROUP}{CanonVRD})) {
            $et->Error("Can't delete all CanonDR4 information from a DR4 file");
            return 1;
        }
    }
    if ($dataPt) {
        $pos = $$dirInfo{DirStart} || 0;
        $dirLen = $$dirInfo{DirLen} || length($$dataPt) - $pos;
    } else {
        # load DR4 file into memory
        my $buff;
        $raf->Read($buff, 8) == 8 and $buff eq "IIII\x04\0\x04\0" or return 0;
        $et->SetFileType();
        $raf->Seek(0, 2) or return $err = 1;
        $dirLen = $raf->Tell();
        $raf->Seek(0, 0) or return $err = 1;
        $raf->Read($buff, $dirLen) == $dirLen or $err = 1;
        $err and $et->Warn('Error reading DR4 file'), return 1;
        $tagTablePtr = GetTagTable('Image::ExifTool::CanonVRD::DR4');
        $dataPt = \$buff;
        $pos = 0;
    }
    my $dirEnd = $pos + $dirLen;

    if (($$et{TAGS_FROM_FILE} and
        not $$et{EXCL_TAG_LOOKUP}{canondr4}) or $$et{REQ_TAG_LOOKUP}{canondr4})
    {
        # extract CanonDR4 block if copying tags, or if requested
        $et->FoundTag('CanonDR4', substr($$dataPt, $pos, $dirLen));
    }

    # version 4 header is 32 bytes (int32u[8])
    if ($dirLen < 32) {
        $err = 1;
    } else {
        SetByteOrder(substr($$dataPt, $pos, 2)) or $err = 1;
        # process the DR4 header
        my %hdrInfo = (
            DataPt   => $dataPt,
            DirStart => $pos,
            DirLen   => 32,
            DirName  => 'DR4Header',
        );
        my $hdrTable = GetTagTable('Image::ExifTool::CanonVRD::DR4Header');
        if ($outfile) {
            my $hdr = $et->WriteDirectory(\%hdrInfo, $hdrTable);
            substr($$dataPt, $pos, 32) = $hdr if $hdr and length $hdr == 32;
        } else {
            $et->VerboseDir('DR4Header', undef, 32);
            $et->ProcessDirectory(\%hdrInfo, $hdrTable);
        }
        # number of entries in the DR4 directory
        $numEntries = Get32u($dataPt, $pos + 28);
        $err = 1 if $dirLen < 36 + 28 * $numEntries;
    }
    $err and $et->Warn('Invalid DR4 directory'), return $outfile ? undef : 0;

    if ($outfile) {
        $newTags = $et->GetNewTagInfoHash($tagTablePtr);
    } else {
        $et->VerboseDir('DR4', $numEntries, $dirLen);
    }

    my $index;
    for ($index=0; $index<$numEntries; ++$index) {
        my ($val, @flg, $i);
        my $entry = $pos + 36 + 28 * $index;
        last if $entry + 28 > $dirEnd;
        my $tag = Get32u($dataPt, $entry);
        my $fmt = Get32u($dataPt, $entry + 4);
        $flg[0] = Get32u($dataPt, $entry + 8);
        $flg[1] = Get32u($dataPt, $entry + 12);
        $flg[2] = Get32u($dataPt, $entry + 16);
        my $off = Get32u($dataPt, $entry + 20) + $pos;
        my $len = Get32u($dataPt, $entry + 24);
        next if $off + $len >= $dirEnd;
        my $format = $vrdFormat{$fmt};
        if (not $format) {
            $val = unpack 'H*', substr($$dataPt, $off, $len);
            $format = 'undef';
        } elsif ($format eq 'double' and $len == 8) {
            # avoid teeny weeny values
            $val = ReadValue($dataPt, $off, $format, undef, $len);
            $val = 0 if abs($val) < 1e-100;
        }
        if ($outfile) {
            # write (binary data) subdirectory if it exists
            my $tagInfo = $et->GetTagInfo($tagTablePtr, $tag);
            if ($tagInfo and $$tagInfo{SubDirectory}) {
                my %subdirInfo = (
                    DataPt   => $dataPt,
                    DirStart => $off,
                    DirLen   => $len,
                    DirName  => $$tagInfo{Name},
                );
                my $subTablePtr = GetTagTable($$tagInfo{SubDirectory}{TagTable});
                my $saveChanged = $$et{CHANGED};
                my $dat = $et->WriteDirectory(\%subdirInfo, $subTablePtr);
                if (defined $dat and length($dat) == $len) {
                    substr($$dataPt, $off, $len) = $dat;
                } else {
                    $$et{CHANGED} = $saveChanged;   # didn't change anything after all
                }
            } else {
                # loop through main tag and flags (don't yet consider flag 2)
                for ($i=-1; $i<2; ++$i) {
                    $tagInfo = $$newTags{$i>=0 ? sprintf('0x%x.%d',$tag,$i) : $tag};
                    next unless $tagInfo;
                    if ($i >= 0) {
                        $off = $entry + 8 + 4 * $i;
                        $format = 'int32u';
                        $len = 4;
                        undef $val;
                    }
                    $val = ReadValue($dataPt, $off, $format, undef, $len) unless defined $val;
                    my $nvHash;
                    my $newVal = $et->GetNewValue($tagInfo, \$nvHash);
                    if ($et->IsOverwriting($nvHash, $val) and defined $newVal) {
                        my $count = int($len / Image::ExifTool::FormatSize($format));
                        my $rtnVal = WriteValue($newVal, $format, $count, $dataPt, $off);
                        if (defined $rtnVal) {
                            $et->VerboseValue("- CanonVRD:$$tagInfo{Name}", $val);
                            $et->VerboseValue("+ CanonVRD:$$tagInfo{Name}", $newVal);
                            ++$$et{CHANGED};
                        }
                    }
                }
            }
            next;
        }
        $et->HandleTag($tagTablePtr, $tag, $val,
            DataPt  => $dataPt,
            DataPos => $dataPos,
            Start   => $off,
            Size    => $len,
            Index   => $index,
            Format  => $format,
            # $flg[0] is on/off flag
            # $flg[1] "is default" flag?
            # $flg[2] changed to 0 when some unsharp mask settings were changed
            Extra   => ", fmt=$fmt flags=" . join(',', @flg),
        );
        foreach $i (0..2) {
            my $flagID = sprintf('0x%x.%d', $tag, $i);
            $et->HandleTag($tagTablePtr, $flagID, $flg[$i]) if $$tagTablePtr{$flagID};
        }
    }
    return 1 unless $isWriting;
    return substr($$dataPt, $pos, $dirLen) unless $raf;
    return 1 if Write($outfile, substr($$dataPt, $pos, $dirLen));
    return -1;
}

#------------------------------------------------------------------------------
# Read/write Canon VRD file
# Inputs: 0) ExifTool object reference, 1) dirInfo reference
# Returns: 1 if this was a Canon VRD file, 0 otherwise, -1 on write error
sub ProcessVRD($$)
{
    my ($et, $dirInfo) = @_;
    my $raf = $$dirInfo{RAF};
    my $buff;
    my $num = $raf->Read($buff, 0x1c);

    # initialize write directories if necessary
    $et->InitWriteDirs(\%vrdMap, 'XMP') if $$dirInfo{OutFile};

    if (not $num and $$dirInfo{OutFile}) {
        # create new VRD file from scratch
        my $newVal = $et->GetNewValue('CanonVRD');
        if ($newVal) {
            $et->VPrint(0, "  Writing CanonVRD as a block\n");
            Write($$dirInfo{OutFile}, $newVal) or return -1;
            $$et{DidCanonVRD} = 1;
            ++$$et{CHANGED};
        } else {
            # allow VRD to be created from individual tags
            if ($$et{ADD_DIRS}{CanonVRD}) {
                my $newVal = '';
                if (ProcessCanonVRD($et, { OutFile => \$newVal }) > 0) {
                    Write($$dirInfo{OutFile}, $newVal) or return -1;
                    ++$$et{CHANGED};
                    return 1;
                }
            }
            $et->Error('No CanonVRD information to write');
        }
    } else {
        $num == 0x1c or return 0;
        $buff =~ /^CANON OPTIONAL DATA\0/ or return 0;
        $et->SetFileType();
        $$dirInfo{DirName} = 'CanonVRD';    # set directory name for verbose output
        my $result = ProcessCanonVRD($et, $dirInfo);
        return $result if $result < 0;
        $result or $et->Warn('Format error in VRD file');
    }
    return 1;
}

#------------------------------------------------------------------------------
# Write VRD data record as a block
# Inputs: 0) ExifTool object ref, 1) dirInfo ref, 2) tag table ref
# Returns: VRD data block (may be empty if no VRD data)
# Notes: Increments ExifTool CHANGED flag if changed
sub WriteCanonVRD($$;$)
{
    my ($et, $dirInfo, $tagTablePtr) = @_;
    $et or return 1;    # allow dummy access
    my $nvHash = $et->GetNewValueHash($Image::ExifTool::Extra{CanonVRD});
    my $val = $et->GetNewValue($nvHash);
    $val = '' unless defined $val;
    return undef unless $et->IsOverwriting($nvHash, $val);
    ++$$et{CHANGED};
    return $val;
}

#------------------------------------------------------------------------------
# Write DR4-type CanonVRD edit record
# Inputs: 0) ExifTool object ref, 1) dirInfo ref, 2) tag table ref
# Returns: VRD data block (may be empty if deleted, of undef on error)
sub WriteCanonDR4($$;$)
{
    my ($et, $dirInfo, $tagTablePtr) = @_;
    $et or return 1;    # allow dummy access
    my $nvHash = $et->GetNewValueHash($Image::ExifTool::Extra{CanonDR4});
    my $val = $et->GetNewValue($nvHash);
    if (defined $val) {
        return undef unless $et->IsOverwriting($nvHash, $val);
        $et->VPrint(0, "  Writing CanonDR4 as a block\n");
        ++$$et{CHANGED};
        return WrapDR4($val);
    }
    my $buff = '';
    $$dirInfo{OutFile} = \$buff;
    return $buff if ProcessCanonVRD($et, $dirInfo, $tagTablePtr) > 0;
    return undef;
}

#------------------------------------------------------------------------------
# Read/write CanonVRD information (from VRD file or VRD trailer)
# Inputs: 0) ExifTool object reference, 1) dirInfo reference
# Returns: 1 on success, 0 not valid VRD, or -1 error writing
# - updates DataPos to point to start of CanonVRD information
# - updates DirLen to existing trailer length
sub ProcessCanonVRD($$;$)
{
    my ($et, $dirInfo, $tagTablePtr) = @_;
    my $raf = $$dirInfo{RAF};
    my $offset = $$dirInfo{Offset} || 0;
    my $outfile = $$dirInfo{OutFile};
    my $dataPt = $$dirInfo{DataPt};
    my $verbose = $et->Options('Verbose');
    my $out = $et->Options('TextOut');
    my ($buff, $created, $err, $blockLen, $blockType, %didDir, $fromFile);
#
# The CanonVRD trailer has a 0x1c-byte header and a 0x40-byte footer,
# each beginning with "CANON OPTIONAL DATA\0" and containing an int32u
# giving the size of the contained data (at byte 0x18 and 0x14 respectively)
#
    if ($raf) {
        $fromFile = 1;
    } else {
        unless ($dataPt) {
            return 1 unless $outfile;
            # create blank VRD data from scratch
            my $blank = $blankHeader . $blankFooter;
            $dataPt = \$blank;
            $verbose and print $out "  Creating CanonVRD trailer\n";
            $created = 1;
        }
        $raf = new File::RandomAccess($dataPt);
    }
    # read and validate the footer
    $raf->Seek(-0x40-$offset, 2)    or return 0;
    $raf->Read($buff, 0x40) == 0x40 or return 0;
    $buff =~ /^CANON OPTIONAL DATA\0(.{4})/s or return 0;
    my $dirLen = unpack('N', $1) + 0x5c;  # size including header+footer

    # read and validate the header
    unless ($dirLen < 0x80000000 and
            $raf->Seek(-$dirLen, 1) and
            $raf->Read($buff, 0x1c) == 0x1c and
            $buff =~ /^CANON OPTIONAL DATA\0/ and
            $raf->Seek(-0x1c, 1))
    {
        $et->Warn('Bad CanonVRD trailer');
        return 0;
    }
    # set variables returned in dirInfo hash
    $$dirInfo{DataPos} = $raf->Tell();
    $$dirInfo{DirLen} = $dirLen;

    if ($outfile and ref $outfile eq 'SCALAR' and not length $$outfile) {
        # write directly to outfile to avoid duplicating data in memory
        $$outfile = $$dataPt unless $fromFile;
        # TRICKY! -- copy to outfile memory buffer and edit in place
        # (so we must disable all Write() calls for this case)
        $dataPt = $outfile;
    }
    if ($fromFile or $$dirInfo{DirStart}) {
        $dataPt = \$buff unless $dataPt;
        # read VRD data into memory if necessary
        unless ($raf->Read($$dataPt, $dirLen) == $dirLen) {
            $$dataPt = '' if $outfile and $outfile eq $dataPt;
            $et->Warn('Error reading CanonVRD data');
            return 0;
        }
    }
    # exit quickly if writing and no CanonVRD tags are being edited
    if ($outfile and not exists $$et{EDIT_DIRS}{CanonVRD}) {
        print $out "$$et{INDENT}  [nothing changed]\n" if $verbose;
        return 1 if $outfile eq $dataPt;
        return Write($outfile, $$dataPt) ? 1 : -1;
    }

    my $vrdType = 'VRD';

    if ($outfile) {
        $verbose and not $created and print $out "  Rewriting CanonVRD trailer\n";
        # delete CanonVRD information if specified
        my $doDel = $$et{DEL_GROUP}{CanonVRD};
        unless ($doDel) {
            $doDel = 1 if $$et{DEL_GROUP}{Trailer} and $$et{FILE_TYPE} ne 'VRD';
            unless ($doDel) {
                # also delete if writing as a block (will get added back again later)
                if ($$et{NEW_VALUE}{$Image::ExifTool::Extra{CanonVRD}}) {
                    # delete if this isn't version 4
                    $doDel = 1 unless $$dataPt =~ /^.{28}\xff\xff\0\xf7/s;
                }
                if ($$et{NEW_VALUE}{$Image::ExifTool::Extra{CanonDR4}} and not $doDel) {
                    # delete if this is version 4
                    $doDel = 1 if $$dataPt =~ /^.{28}\xff\xff\0\xf7/s;
                }
            }
        }
        if ($doDel) {
            if ($$et{FILE_TYPE} eq 'VRD') {
                my $newVal = $et->GetNewValue('CanonVRD');
                if ($newVal) {
                    $verbose and print $out "  Writing CanonVRD as a block\n";
                    if ($outfile eq $dataPt) {
                        $$outfile = $newVal;
                    } else {
                        Write($outfile, $newVal) or return -1;
                    }
                    $$et{DidCanonVRD} = 1;
                    ++$$et{CHANGED};
                } else {
                    $et->Error("Can't delete all CanonVRD information from a VRD file");
                }
            } else {
                $verbose and print $out "  Deleting CanonVRD trailer\n";
                $$outfile = '' if $outfile eq $dataPt;
                ++$$et{CHANGED};
            }
            return 1;
        }
        # write now and return if CanonVRD was set as a block
        my $val = $et->GetNewValue('CanonVRD');
        unless ($val) {
            $val = $et->GetNewValue('CanonDR4');
            $vrdType = 'DR4' if $val;
        }
        if ($val) {
            $verbose and print $out "  Writing Canon$vrdType as a block\n";
            # must wrap DR4 data with the VRD header/footer and edit record
            $val = WrapDR4($val) if $vrdType eq 'DR4';
            if ($outfile eq $dataPt) {
                $$outfile = $val;
            } else {
                Write($outfile, $val) or return -1;
            }
            $$et{DidCanonVRD} = 1;
            ++$$et{CHANGED};
            return 1;
        }
    } elsif ($verbose or $$et{HTML_DUMP}) {
        $et->DumpTrailer($dirInfo) if $$dirInfo{RAF};
    }

    $tagTablePtr = GetTagTable('Image::ExifTool::CanonVRD::Main');

    # validate VRD trailer and get position and length of edit record
    SetByteOrder('MM'); # VRD header/footer is big-endian
    my $pos = 0x1c;     # start at end of header

    # loop through the VRD blocks
    for (;;) {
        my $end = $dirLen - 0x40;   # end of last VRD block (and start of footer)
        if ($pos + 8 > $end) {
            last if $pos == $end;
            $blockLen = $end;       # mark as invalid
        } else {
            $blockType = Get32u($dataPt, $pos);
            $blockLen = Get32u($dataPt, $pos + 4);
        }
        $vrdType = 'DR4' if $blockType == 0xffff00f7;
        $pos += 8;  # move to start of block
        if ($pos + $blockLen > $end) {
            $et->Warn('Possibly corrupt CanonVRD block');
            last;
        }
        if ($verbose > 1 and not $outfile) {
            printf $out "  CanonVRD block 0x%.8x ($blockLen bytes at offset 0x%x)\n",
                $blockType, $pos + $$dirInfo{DataPos};
            $et->VerboseDump($dataPt, Len => $blockLen, Start => $pos, Addr => $pos + $$dirInfo{DataPos});
        }
        my $tagInfo = $$tagTablePtr{$blockType};
        unless ($tagInfo) {
            unless ($et->Options('Unknown')) {
                $pos += $blockLen;  # step to next block
                next;
            }
            my $name = sprintf('CanonVRD_0x%.8x', $blockType);
            my $desc = $name;
            $desc =~ tr/_/ /;
            $tagInfo = {
                Name        => $name,
                Description => $desc,
                Binary      => 1,
            };
            AddTagToTable($tagTablePtr, $blockType, $tagInfo);
        }
        if ($$tagInfo{SubDirectory}) {
            my $subTablePtr = GetTagTable($$tagInfo{SubDirectory}{TagTable});
            my %subdirInfo = (
                DataPt   => $dataPt,
                DataLen  => length $$dataPt,
                DataPos  => $$dirInfo{DataPos},
                DirStart => $pos,
                DirLen   => $blockLen,
                DirName  => $$tagInfo{Name},
                Parent   => 'CanonVRD',
                OutFile  => $outfile,
            );
            if ($outfile) {
                # set flag indicating we did this directory
                $didDir{$$tagInfo{Name}} = 1;
                my ($dat, $diff);
                if ($$et{NEW_VALUE}{$tagInfo}) {
                    # write as a block
                    $et->VPrint(0, "Writing $$tagInfo{Name} as a block\n");
                    $dat = $et->GetNewValue($tagInfo);
                    $dat = '' unless defined $dat;
                    ++$$et{CHANGED};
                } else {
                    $dat = $et->WriteDirectory(\%subdirInfo, $subTablePtr);
                }
                # update data with new directory
                if (defined $dat) {
                    if (length $dat or $$et{FILE_TYPE} !~ /^(CRW|VRD)$/) {
                        # replace with new block (updating the block length word)
                        substr($$dataPt, $pos-4, $blockLen+4) = Set32u(length $dat) . $dat;
                    } else {
                        # remove block totally (CRW/VRD files only)
                        substr($$dataPt, $pos-8, $blockLen+8) = '';
                    }
                    # make necessary adjustments if block changes length
                    if (($diff = length($$dataPt) - $dirLen) != 0) {
                        $pos += $diff;
                        $dirLen += $diff;
                        # update the new VRD length in the header/footer
                        Set32u($dirLen - 0x5c, $dataPt, 0x18);
                        Set32u($dirLen - 0x5c, $dataPt, $dirLen - 0x2c);
                    }
                }
            } else {
                # extract as a block if requested
                $et->ProcessDirectory(\%subdirInfo, $subTablePtr);
            }
        } else {
            $et->HandleTag($tagTablePtr, $blockType, substr($$dataPt, $pos, $blockLen));
        }
        $pos += $blockLen;  # step to next block
    }
    if ($outfile) {
        # create XMP block if necessary (CRW/VRD files only)
        if ($$et{ADD_DIRS}{CanonVRD} and not $didDir{XMP}) {
            my $subTablePtr = GetTagTable('Image::ExifTool::XMP::Main');
            my $dat = $et->WriteDirectory({ Parent => 'CanonVRD' }, $subTablePtr);
            if ($dat) {
                my $blockLen = length $dat;
                substr($$dataPt, -0x40, 0) = Set32u(0xffff00f6) . Set32u(length $dat) . $dat;
                $dirLen = length $$dataPt;
                # update the new VRD length in the header/footer
                Set32u($dirLen - 0x5c, $dataPt, 0x18);
                Set32u($dirLen - 0x5c, $dataPt, $dirLen - 0x2c);
            }
        }
        # write CanonVRD trailer unless it is empty
        if (length $$dataPt) {
            Write($outfile, $$dataPt) or $err = 1 unless $outfile eq $dataPt;
        } else {
            $verbose and print $out "  Deleting CanonVRD trailer\n";
        }
    } elsif ($vrdType eq 'VRD' and (($$et{TAGS_FROM_FILE} and
        not $$et{EXCL_TAG_LOOKUP}{canonvrd}) or $$et{REQ_TAG_LOOKUP}{canonvrd}))
    {
        # extract CanonVRD block if copying tags, or if requested (and not DR4 info)
        $et->FoundTag('CanonVRD', $buff);
    }
    undef $buff;
    return $err ? -1 : 1;
}

1;  # end

__END__