Initial import

NB: SVN to Git Migration corrected initial import issues by squashing
all commits relating to that into this initial commit.

1 files changed, 699 insertions, 0 deletions

diff --git a/lib/Parse/EDID.pm b/lib/Parse/EDID.pm
new file mode 100755
index 0000000..fb57416
--- /dev/null
+++ b/lib/Parse/EDID.pm
@@ -0,0 +1,699 @@
+# Copyright (C) 2005-2010 by Mandriva SA
+#                            Pascal Rigaux
+#                            Anssi Hannula
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# This program 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package Parse::EDID;
+
+use strict;
+use warnings;
+
+my @CVT_ratios = qw(5/4 4/3 3/2 16/10 15/9 16/9);
+my @known_ratios = @CVT_ratios;
+
+my @edid_info = group_by2(
+    a8 => '_header',
+    a2  => 'manufacturer_name',
+
+    v => 'product_code',
+    V => 'serial_number',
+    C => 'week',
+    C => 'year',
+    C => 'edid_version',
+    C => 'edid_revision',
+    a => 'video_input_definition',
+
+    C => 'max_size_horizontal', # in cm, 0 on projectors
+    C => 'max_size_vertical', # in cm, 0 on projectors
+    C => 'gamma',
+    a => 'feature_support',
+    a10 => '_color_characteristics',
+    a3  => 'established_timings',
+    a16 => 'standard_timings',
+    a72 => 'monitor_details',
+
+    C => 'extension_flag',
+    C => 'checksum',
+);
+
+my %subfields = (
+    manufacturer_name => [ group_by2(
+	1 => '',
+	5 => '1',
+	5 => '2',
+	5 => '3',
+    ) ],
+
+    video_input_definition => [ group_by2(
+	1 => 'digital',
+	1 => 'separate_sync',
+	1 => 'composite_sync',
+	1 => 'sync_on_green',
+	2 => '',
+	2 => 'voltage_level',
+    ) ],
+
+    feature_support => [ group_by2(
+	1 => 'DPMS_standby',
+	1 => 'DPMS_suspend',
+	1 => 'DPMS_active_off',        
+	1 => 'rgb',
+
+	1 => '',
+        1 => 'sRGB_compliance',
+	1 => 'has_preferred_timing',
+        1 => 'GTF_compliance',
+    ) ],
+
+    established_timings => [ group_by2(
+	1 => '720x400_70',
+	1 => '720x400_88',
+	1 => '640x480_60',
+	1 => '640x480_67',
+	1 => '640x480_72',
+	1 => '640x480_75',
+	1 => '800x600_56',
+	1 => '800x600_60',
+	1 => '800x600_72',
+	1 => '800x600_75',
+	1 => '832x624_75',
+	1 => '1024x768_87i',
+	1 => '1024x768_60',
+	1 => '1024x768_70',
+	1 => '1024x768_75',
+	1 => '1280x1024_75',
+    ) ],
+
+    detailed_timing => [ group_by2(
+	8 => 'horizontal_active',
+	8 => 'horizontal_blanking',
+	4 => 'horizontal_active_hi',
+	4 => 'horizontal_blanking_hi',
+	8 => 'vertical_active',
+	8 => 'vertical_blanking',
+	4 => 'vertical_active_hi',
+	4 => 'vertical_blanking_hi',
+	8 => 'horizontal_sync_offset',
+	8 => 'horizontal_sync_pulse_width',
+	4 => 'vertical_sync_offset',
+	4 => 'vertical_sync_pulse_width',
+	2 => 'horizontal_sync_offset_hi',
+	2 => 'horizontal_sync_pulse_width_hi',
+	2 => 'vertical_sync_offset_hi',
+	2 => 'vertical_sync_pulse_width_hi',
+	8 => 'horizontal_image_size', # in mm
+	8 => 'vertical_image_size', # in mm
+	4 => 'horizontal_image_size_hi',
+	4 => 'vertical_image_size_hi',
+	8 => 'horizontal_border',
+	8 => 'vertical_border',
+
+	1 => 'interlaced',
+	2 => 'stereo',      
+	2 => 'digital_composite',
+	1 => 'horizontal_sync_positive',
+	1 => 'vertical_sync_positive',
+	1 => '',
+    ) ],
+
+    standard_timing => [ group_by2(
+	8 => 'X',
+	2 => 'aspect',
+	6 => 'vfreq',
+    ) ],
+    monitor_range => [ group_by2(
+	8 => 'vertical_min',
+	8 => 'vertical_max',
+	8 => 'horizontal_min',
+	8 => 'horizontal_max',
+	8 => 'pixel_clock_max',
+    ) ],
+
+    manufacturer_specified_range_timing => [ group_by2(
+	# http://www.spwg.org/salisbury_march_19_2002.pdf
+	# for the glossary: http://www.vesa.org/Public/PSWG/PSWG15v1.pdf
+	8 => 'horizontal_sync_pulse_width_min', # HSPW (Horizontal Sync Pulse Width)
+	8 => 'horizontal_sync_pulse_width_max',
+	8 => 'horizontal_back_porch_min', # t_hbp
+	8 => 'horizontal_back_porch_max',
+	8 => 'vertical_sync_pulse_width_min', # VSPW (Vertical Sync Pulse Width)
+	8 => 'vertical_sync_pulse_width_max',
+	8 => 'vertical_back_porch_min', # t_vbp (Vertical Back Porch)
+	8 => 'vertical_back_porch_max',
+	8 => 'horizontal_blanking_min', # t_hp (Horizontal Period)
+	8 => 'horizontal_blanking_max',
+	8 => 'vertical_blanking_min', # t_vp
+	8 => 'vertical_blanking_max',
+	8 => 'module_revision',
+    ) ],
+    
+    cea_data_block_collection => [ group_by2(
+	3 => 'type',
+	5 => 'size',
+    ) ],
+
+    cea_video_data_block => [ group_by2(
+	1 => 'native',
+	7 => 'mode',
+    ) ],
+);
+
+my @cea_video_mode_to_detailed_timing = ('pixel_clock', 'horizontal_active', 'vertical_active', 'aspect',
+    'horizontal_blanking', 'horizontal_sync_offset', 'horizontal_sync_pulse_width',
+    'vertical_blanking', 'vertical_sync_offset', 'vertical_sync_pulse_width',
+    'horizontal_sync_positive', 'vertical_sync_positive', 'interlaced');
+
+my @cea_video_modes = (
+# [0] pixel clock, [1] X, [2] Y, [3] aspect, [4] Hblank, [5] Hsync_offset, [6] Hsync_pulse_width,
+# [7] Vblank, [8] Vsync_offset, [9] Vsync_pulse_width, [10] Hsync+, [11] Vsync+, [12] interlaced
+# 59.94/29.97 and similar modes also have a 60.00/30.00 counterpart by raising the pixel clock
+    [  25.175,  640,  480,  "4/3",  160,   16,  96,  45, 10,  2, 0, 0, 0 ], #  1:  640x 480@59.94
+    [  27.000,  720,  480,  "4/3",  138,   16,  62,  45,  9,  6, 0, 0, 0 ], #  2:  720x 480@59.94
+    [  27.000,  720,  480, "16/9",  138,   16,  62,  45,  9,  6, 0, 0, 0 ], #  3:  720x 480@59.94
+    [  74.250, 1280,  720, "16/9",  370,  110,  40,  30,  5,  5, 1, 1, 0 ], #  4: 1280x 720@60.00
+    [  74.250, 1920, 1080, "16/9",  280,   88,  44,  45,  4, 10, 1, 1, 1 ], #  5: 1920x1080@30.00
+    [  27.000, 1440,  480,  "4/3",  276,   38, 124,  45,  8,  6, 0, 0, 1 ], #  6: 1440x 480@29.97
+    [  27.000, 1440,  480, "16/9",  276,   38, 124,  45,  8,  6, 0, 0, 1 ], #  7: 1440x 480@29.97
+    [  27.000, 1440,  240,  "4/3",  276,   38, 124,  22,  4,  3, 0, 0, 0 ], #  8: 1440x 240@60.05
+    [  27.000, 1440,  240, "16/9",  276,   38, 124,  22,  4,  3, 0, 0, 0 ], #  9: 1440x 240@60.05
+    [  54.000, 2880,  480,  "4/3",  552,   76, 248,  45,  8,  6, 0, 0, 1 ], # 10: 2880x 480@29.97
+    [  54.000, 2880,  480, "16/9",  552,   76, 248,  45,  8,  6, 0, 0, 1 ], # 11: 2880x 480@29.97
+    [  54.000, 2880,  240,  "4/3",  552,   76, 248,  22,  4,  3, 0, 0, 0 ], # 12: 2880x 240@60.05
+    [  54.000, 2880,  240, "16/9",  552,   76, 248,  22,  4,  3, 0, 0, 0 ], # 13: 2880x 240@60.05
+    [  54.000, 1440,  480,  "4/3",  276,   32, 124,  45,  9,  6, 0, 0, 0 ], # 14: 1440x 480@59.94
+    [  54.000, 1440,  480, "16/9",  276,   32, 124,  45,  9,  6, 0, 0, 0 ], # 15: 1440x 480@59.94
+    [ 148.500, 1920, 1080, "16/9",  280,   88,  44,  45,  4,  5, 1, 1, 0 ], # 16: 1920x1080@60.00
+    [  27.000,  720,  576,  "4/3",  144,   12,  64,  49,  5,  5, 0, 0, 0 ], # 17:  720x 576@50.00
+    [  27.000,  720,  576, "16/9",  144,   12,  64,  49,  5,  5, 0, 0, 0 ], # 18:  720x 576@50.00
+    [  74.250, 1280,  720, "16/9",  700,  440,  40,  30,  5,  5, 1, 1, 0 ], # 19: 1280x 720@50.00
+    [  74.250, 1920, 1080, "16/9",  720,  528,  44,  45,  4, 10, 1, 1, 1 ], # 20: 1920x1080@25.00
+    [  27.000, 1440,  576,  "4/3",  288,   24, 126,  49,  4,  6, 0, 0, 1 ], # 21: 1440x 576@25.00
+    [  27.000, 1440,  576, "16/9",  288,   24, 126,  49,  4,  6, 0, 0, 1 ], # 22: 1440x 576@25.00
+    [  27.000, 1440,  288,  "4/3",  288,   24, 126,  24,  2,  3, 0, 0, 0 ], # 23: 1440x 288@50.08
+    [  27.000, 1440,  288, "16/9",  288,   24, 126,  24,  2,  3, 0, 0, 0 ], # 24: 1440x 288@50.08
+    [  54.000, 2880,  576,  "4/3",  576,   48, 252,  49,  4,  6, 0, 0, 1 ], # 25: 2880x 576@25.00
+    [  54.000, 2880,  576, "16/9",  576,   48, 252,  49,  4,  6, 0, 0, 1 ], # 26: 2880x 576@25.00
+    [  54.000, 2880,  288,  "4/3",  576,   48, 252,  24,  2,  3, 0, 0, 0 ], # 27: 2880x 288@50.08
+    [  54.000, 2880,  288, "16/9",  576,   48, 252,  24,  2,  3, 0, 0, 0 ], # 28: 2880x 288@50.08
+    [  54.000, 1440,  576,  "4/3",  288,   24, 128,  49,  5,  5, 0, 0, 0 ], # 29: 1440x 576@50.00
+    [  54.000, 1440,  576, "16/9",  288,   24, 128,  49,  5,  5, 0, 0, 0 ], # 30: 1440x 576@50.00
+    [ 148.500, 1920, 1080, "16/9",  720,  528,  44,  45,  4,  5, 1, 1, 0 ], # 31: 1920x1080@50.00
+    [  74.250, 1920, 1080, "16/9",  830,  638,  44,  45,  4,  5, 1, 1, 0 ], # 32: 1920x1080@24.00
+    [  74.250, 1920, 1080, "16/9",  720,  528,  44,  45,  4,  5, 1, 1, 0 ], # 33: 1920x1080@25.00
+    [  74.250, 1920, 1080, "16/9",  280,   88,  44,  45,  4,  5, 1, 1, 0 ], # 34: 1920x1080@30.00
+    [ 108.000, 2880,  480,  "4/3",  552,   64, 248,  45,  9,  6, 0, 0, 0 ], # 35: 2880x 480@59.94
+    [ 108.000, 2880,  480, "16/9",  552,   64, 248,  45,  9,  6, 0, 0, 0 ], # 36: 2880x 480@59.94
+    [ 108.000, 2880,  576,  "4/3",  576,   48, 256,  49,  5,  5, 0, 0, 0 ], # 37: 2880x 576@50.00
+    [ 108.000, 2880,  576, "16/9",  576,   48, 256,  49,  5,  5, 0, 0, 0 ], # 38: 2880x 576@50.00
+    [  72.000, 1920, 1080, "16/9",  384,   32, 168, 170, 46, 10, 1, 0, 1 ], # 39: 1920x1080@25.00
+    [ 148.500, 1920, 1080, "16/9",  720,  528,  44,  45,  4, 10, 1, 1, 1 ], # 40: 1920x1080@50.00
+    [ 148.500, 1280,  720, "16/9",  700,  440,  40,  30,  5,  5, 1, 1, 0 ], # 41: 1280x 720@100.00
+    [  54.000,  720,  576,  "4/3",  144,   12,  64,  49,  5,  5, 0, 0, 0 ], # 42:  720x 576@100.00
+    [  54.000,  720,  576, "16/9",  144,   12,  64,  49,  5,  5, 0, 0, 0 ], # 43:  720x 576@100.00
+    [  54.000, 1440,  576,  "4/3",  288,   24, 126,  49,  4,  6, 0, 0, 0 ], # 44: 1440x 576@50.00
+    [  54.000, 1440,  576, "16/9",  288,   24, 126,  49,  4,  6, 0, 0, 0 ], # 45: 1440x 576@50.00
+    [ 148.500, 1920, 1080, "16/9",  280,   88,  44,  45,  4, 10, 1, 1, 1 ], # 46: 1920x1080@60.00
+    [ 148.500, 1280,  720, "16/9",  370,  110,  40,  30,  5,  5, 1, 1, 0 ], # 47: 1280x 720@120.00
+    [  54.000,  720,  480,  "4/3",  138,   16,  62,  45,  9,  6, 0, 0, 0 ], # 48:  720x 480@119.88
+    [  54.000,  720,  480, "16/9",  138,   16,  62,  45,  9,  6, 0, 0, 0 ], # 49:  720x 480@119.88
+    [  54.000, 1440,  480,  "4/3",  276,   38, 124,  45,  8,  6, 0, 0, 1 ], # 50: 1440x 480@59.94
+    [  54.000, 1440,  480, "16/9",  276,   38, 124,  45,  8,  6, 0, 0, 1 ], # 51: 1440x 480@59.94
+    [ 108.000,  720,  576,  "4/3",  144,   12,  64,  49,  5,  5, 0, 0, 0 ], # 52:  720x 576@200.00
+    [ 108.000,  720,  576, "16/9",  144,   12,  64,  49,  5,  5, 0, 0, 0 ], # 53:  720x 576@200.00
+    [ 108.000, 1440,  576,  "4/3",  288,   24, 126,  49,  4,  6, 0, 0, 1 ], # 54: 1440x 576@100.00
+    [ 108.000, 1440,  576, "16/9",  288,   24, 126,  49,  4,  6, 0, 0, 1 ], # 55: 1440x 576@100.00
+    [ 108.000,  720,  480,  "4/3",  138,   16,  62,  45,  9,  6, 0, 0, 0 ], # 56:  720x 480@239.76
+    [ 108.000,  720,  480, "16/9",  138,   16,  62,  45,  9,  6, 0, 0, 0 ], # 57:  720x 480@239.76
+    [ 108.000, 1440,  480,  "4/3",  276,   38, 124,  45,  8,  6, 0, 0, 1 ], # 58: 1440x 480@119.88
+    [ 108.000, 1440,  480, "16/9",  276,   38, 124,  45,  8,  6, 0, 0, 1 ], # 59: 1440x 480@119.88
+    [  59.400, 1280,  720, "16/9", 2020, 1760,  40,  30,  5,  5, 1, 1, 0 ], # 60: 1280x 720@24.00
+    [  74.250, 1280,  720, "16/9", 2680, 2420,  40,  30,  5,  5, 1, 1, 0 ], # 61: 1280x 720@25.00
+    [  74.250, 1280,  720, "16/9", 2020, 1760,  40,  30,  5,  5, 1, 1, 0 ], # 62: 1280x 720@30.00
+    [ 297.000, 1920, 1080, "16/9",  280,   88,  44,  45,  4,  5, 1, 1, 0 ], # 63: 1920x1080@120.00
+    [ 297.000, 1920, 1080, "16/9",  720,  528,  44,  45,  4, 10, 1, 1, 0 ], # 64: 1920x1080@100.00
+);
+
+sub within_limit {
+    my ($value, $type, $limit) = @_;
+    $type eq 'min' ? $value >= $limit : $value <= $limit;
+}
+
+sub get_many_bits {
+    my ($s, $field_name) = @_;
+    my @bits = split('', unpack('B*', $s));
+    my %h;
+    foreach (@{$subfields{$field_name}}) {
+	my ($size, $field) = @$_;
+	my @l = ('0' x (8 - $size), splice(@bits, 0, $size));
+	$h{$field} = unpack("C", pack('B*', join('', @l))) if $field && $field !~ /^_/;
+    }
+    \%h;
+}
+
+sub check_parsed_edid {
+    my ($edid) = @_;
+
+    $edid->{edid_version} >= 1 && $edid->{edid_version} <= 2 or return 'bad edid_version';
+    $edid->{edid_revision} != 0xff or return 'bad edid_revision';
+
+    if ($edid->{monitor_range}) {
+	$edid->{monitor_range}{horizontal_min} && 
+	  $edid->{monitor_range}{horizontal_min} <= $edid->{monitor_range}{horizontal_max} 
+	    or return 'bad HorizSync';
+	$edid->{monitor_range}{vertical_min} &&
+	  $edid->{monitor_range}{vertical_min} <= $edid->{monitor_range}{vertical_max} 
+	    or return 'bad VertRefresh';
+    }
+
+    '';
+}
+
+sub build_detailed_timing {
+    my ($pixel_clock, $vv) = @_;
+
+    my $h = get_many_bits($vv, 'detailed_timing');
+    $h->{pixel_clock} = $pixel_clock / 100; # to have it in MHz
+    my %detailed_timing_field_size = map { $_->[1], $_->[0] } @{$subfields{detailed_timing}};
+    foreach my $field (keys %detailed_timing_field_size) {
+	$field =~ s/_hi$// or next;
+	my $hi = delete($h->{$field . '_hi'});
+	$h->{$field} += $hi << $detailed_timing_field_size{$field};
+    }
+    $h;
+}
+
+sub add_standard_timing_modes {
+    my ($edid, $v) = @_;
+
+    my @aspect2ratio = (
+	$edid->{edid_version} > 1 || $edid->{edid_revision} > 2 ? '16/10' : '1/1',
+	'4/3', '5/4', '16/9',
+    );
+    $v = [ map {
+	my $h = get_many_bits($_, 'standard_timing');
+	$h->{X} = ($h->{X} + 31) * 8;
+	if ($_ ne "\x20\x20" && $h->{X} > 256) { # cf VALID_TIMING in Xorg edid.h
+	    $h->{vfreq} += 60;
+	    if ($h->{ratio} = $aspect2ratio[$h->{aspect}]) {
+		delete $h->{aspect};
+		$h->{Y} = $h->{X} / eval($h->{ratio});
+	    }
+	    $h;
+	} else { () }
+    } unpack('a2' x (length($v) / 2), $v) ];
+    $v;
+}
+
+sub parse_edid {
+    my ($raw_edid, $verbose) = @_;
+
+    my %edid;
+    my ($main_edid, @eedid_blocks) = unpack("a128" x (length($raw_edid) / 128), $raw_edid);
+    my @vals = unpack(join('', map { $_->[0] } @edid_info), $main_edid);
+    my $i;
+    foreach (@edid_info) {
+	my ($field, $v) = ($_->[1], $vals[$i++]);
+
+	if ($field eq 'year') {
+	    $v += 1990;
+	} elsif ($field eq 'manufacturer_name') {
+	    my $h = get_many_bits($v, 'manufacturer_name');
+	    $v = join('', map { chr(ord('A') + $h->{$_} - 1) } 1 .. 3);
+	    $v = "" if $v eq "@@@";
+	} elsif ($field eq 'video_input_definition') {
+	    $v = get_many_bits($v, 'video_input_definition');
+	} elsif ($field eq 'feature_support') {
+	    $v = get_many_bits($v, 'feature_support');
+	} elsif ($field eq 'established_timings') {
+	    my $h = get_many_bits($v, 'established_timings');
+	    $v = [
+		sort { $a->{X} <=> $b->{X} || $a->{vfreq} <=> $b->{vfreq} }
+		map { /(\d+)x(\d+)_(\d+)(i?)/ ? { X => $1, Y => $2, vfreq => $3, $4 ? (interlace => 1) : () } : () }
+		grep { $h->{$_} } keys %$h ];
+	} elsif ($field eq 'standard_timings') {
+	    $v = add_standard_timing_modes(\%edid, $v);
+	} elsif ($field eq 'monitor_details') {
+	    while ($v) {
+		(my $pixel_clock, my $vv, $v) = unpack("v a16 a*", $v);
+
+		if ($pixel_clock) {
+		    # detailed timing
+		    my $h = build_detailed_timing($pixel_clock, $vv);
+		    push @{$edid{detailed_timings}}, $h
+		      if $h->{horizontal_active} > 1 && $h->{vertical_active} > 1;
+		} else {
+		    (my $flag, $vv) = unpack("n x a*", $vv);
+
+		    if ($flag == 0xfd) {
+			# range
+			$edid{monitor_range} = get_many_bits($vv, 'monitor_range');
+			if ($edid{monitor_range}{pixel_clock_max} == 0xff) {
+			    delete $edid{monitor_range}{pixel_clock_max};
+			} else {
+			    $edid{monitor_range}{pixel_clock_max} *= 10; #- to have it in MHz
+			}
+		    } elsif ($flag == 0xf) {
+			my $range = get_many_bits($vv, 'manufacturer_specified_range_timing');
+
+			my $e = $edid{detailed_timings}[0];
+			my $valid = 1;
+			foreach my $m ('min', 'max') {
+			    my %total;
+			    foreach my $dir ('horizontal', 'vertical') {
+				$range->{$dir . '_sync_pulse_width_' . $m} *= 2;
+				$range->{$dir . '_back_porch_' . $m} *= 2;
+				$range->{$dir . '_blanking_' . $m} *= 2;
+				if ($e && $e->{$dir . '_active'}
+				    && within_limit($e->{$dir . '_blanking'}, $m, $range->{$dir . '_blanking_' . $m})
+				    && within_limit($e->{$dir . '_sync_pulse_width'}, $m, $range->{$dir . '_sync_pulse_width_' . $m})
+				    && within_limit($e->{$dir . '_blanking'} - $e->{$dir . '_sync_offset'} - $e->{$dir . '_sync_pulse_width'},
+					    $m, $range->{$dir . '_back_porch_' . $m})) {
+				    $total{$dir} = $e->{$dir . '_active'} + $range->{$dir . '_blanking_' . $m};
+				}
+			    }
+			    if ($total{horizontal} && $total{vertical}) {
+				my $hfreq = $e->{pixel_clock} * 1000 / $total{horizontal};
+				my $vfreq = $hfreq * 1000 / $total{vertical};
+				$range->{'horizontal_' . ($m eq 'min' ? 'max' : 'min')} = round($hfreq);
+				$range->{'vertical_' . ($m eq 'min' ? 'max' : 'min')} = round($vfreq);
+			    } else {
+				$valid = 0;
+			    }
+			}
+			$edid{$valid ? 'monitor_range' : 'manufacturer_specified_range_timing'} = $range;
+
+		    } elsif ($flag == 0xfa) {
+			push @{$edid{standard_timings}}, add_standard_timing_modes(\%edid, unpack('a12', $vv));
+		    } elsif ($flag == 0xfc) {
+			my $prev = $edid{monitor_name};
+			$edid{monitor_name} = ($prev ? "$prev " : '') . unpack('A13', $vv);
+		    } elsif ($flag == 0xfe) {
+			push @{$edid{monitor_text}}, unpack('A13', $vv);
+		    } elsif ($flag == 0xff) {
+			push @{$edid{serial_number2}}, unpack('A13', $vv);
+		    } else {
+		       $verbose && $vv ne "\0" x 13 && $vv ne " " x 13 and
+			 warn "parse_edid: unknown flag $flag\n";
+		    }
+		}
+	    }
+	}
+
+	$edid{$field} = $v if $field && $field !~ /^_/;
+    }
+
+    foreach (@eedid_blocks) {
+	my ($tag, $v) = unpack("C a*", $_);
+
+	if ($tag == 0x02) { # CEA EDID
+	    my $dtd_offset;
+	    ($dtd_offset, $v) = unpack("x C x a*", $v);
+
+	    next if $dtd_offset < 4;
+	    $dtd_offset -= 4;
+
+	    while ($dtd_offset > 0) {
+		my $h = get_many_bits($v, 'cea_data_block_collection');
+		$dtd_offset -= $h->{size} + 1;
+
+		my $vv;
+		($vv, $v) = unpack("x a$h->{size} a*", $v);
+		if ($h->{type} == 0x02) { # Video Data Block
+		    my @vmodes = unpack("a" x $h->{size}, $vv);
+		    foreach my $vmode (@vmodes) {
+			$h = get_many_bits($vmode, 'cea_video_data_block');
+			my $cea_mode = $cea_video_modes[$h->{mode} - 1];
+			if (!$cea_mode) {
+			    warn "parse_edid: unhandled CEA mode $h->{mode}\n" if $verbose;
+			    next;
+			}
+			my %det_mode = (source => 'cea_vdb');
+			@det_mode{@cea_video_mode_to_detailed_timing} = @$cea_mode;
+			push @{$edid{detailed_timings}}, \%det_mode;
+		    }
+		}
+	    }
+
+	    while (length($v) >= 18) {
+		(my $pixel_clock, my $vv, $v) = unpack("v a16 a*", $v);
+		last if !$pixel_clock;
+		my $h = build_detailed_timing($pixel_clock, $vv);
+		push @{$edid{detailed_timings}}, $h
+		    if $h->{horizontal_active} > 1 && $h->{vertical_active} > 1;
+	    }
+	} else {
+	    $verbose && warn "parse_edid: unknown tag $tag\n";
+	}
+    }
+
+    $edid{max_size_precision} = 'cm';
+    $edid{EISA_ID} = $edid{manufacturer_name} . sprintf('%04x', $edid{product_code}) if $edid{product_code} && $edid{manufacturer_name};
+
+    if ($edid{monitor_range}) {
+	$edid{HorizSync} = $edid{monitor_range}{horizontal_min} . '-' . $edid{monitor_range}{horizontal_max};
+	$edid{VertRefresh} = $edid{monitor_range}{vertical_min} . '-' . $edid{monitor_range}{vertical_max};
+    }
+
+    if ($edid{max_size_vertical}) {
+	$edid{ratio} = $edid{max_size_horizontal} / $edid{max_size_vertical};
+	$edid{ratio_name} = ratio_name($edid{max_size_horizontal}, $edid{max_size_vertical}, 'cm');
+	$edid{ratio_precision} = 'cm';
+    }
+    
+    if ($edid{feature_support}{has_preferred_timing} && $edid{detailed_timings}[0]) {
+	$edid{detailed_timings}[0]{preferred} = 1;
+    }
+
+    foreach my $h (@{$edid{detailed_timings}}) {
+
+	# EDID standard is ambiguous on how interlaced modes should be
+	# specified; workaround clearly broken modes:
+	if ($h->{interlaced}) {
+	    foreach ("720x480", "1440x480", "2880x480", "720x576", "1440x576", "2880x576", "1920x1080") {
+		if ($_ eq $h->{horizontal_active} . 'x' . $h->{vertical_active} * 2) {
+		    $h->{vertical_active} *= 2;
+		    $h->{vertical_blanking} *= 2;
+		    $h->{vertical_sync_offset} *= 2;
+		    $h->{vertical_sync_pulse_width} *= 2;
+		    $h->{vertical_blanking} |= 1;
+		}
+	    }
+	}
+
+	# if the mm size given in the detailed_timing is not far from the cm size
+	# put it as a more precise cm size
+	my %in_cm = map { $_ => $h->{$_ . '_image_size'} / 10 } ('horizontal', 'vertical');
+	my ($error) = sort { $b <=> $a } map { abs($edid{'max_size_' . $_} - $in_cm{$_}) } keys %in_cm;
+	if ($error <= 0.5) {
+	    $edid{'max_size_' . $_} = $in_cm{$_} foreach keys %in_cm;
+	    $edid{max_size_precision} = 'mm';
+	}
+	if ($error < 1 && $in_cm{vertical}) {
+	    # using it for the ratio
+	    $edid{ratio} = $in_cm{horizontal} / $in_cm{vertical};
+	    $edid{ratio_name} = ratio_name($in_cm{horizontal}, $in_cm{vertical}, 'mm');
+	    $edid{ratio_precision} = 'mm';
+	}
+
+	$h->{bad_ratio} = 1 if abs($edid{ratio} - $h->{horizontal_active} / $h->{vertical_active}) > ($edid{ratio_precision} eq 'mm' ? 0.02 : 0.2);
+
+	if ($edid{max_size_vertical}) {
+	    $h->{vertical_dpi} = $h->{vertical_active} / $edid{max_size_vertical} * 2.54;
+	}
+	if ($edid{max_size_horizontal}) {
+	    $h->{horizontal_dpi} = $h->{horizontal_active} / $edid{max_size_horizontal} * 2.54;
+	}
+	my $dpi_string = '';
+	if ($h->{vertical_dpi} && $h->{horizontal_dpi}) {
+	    $dpi_string = 
+	      abs($h->{vertical_dpi} / $h->{horizontal_dpi} - 1) < 0.05 ? 
+		sprintf("%d dpi", $h->{horizontal_dpi}) :
+		sprintf("%dx%d dpi", $h->{horizontal_dpi}, $h->{vertical_dpi});
+	}
+
+	my $horizontal_total = $h->{horizontal_active} + $h->{horizontal_blanking};
+	my $vertical_total = $h->{vertical_active} + $h->{vertical_blanking};
+
+	$h->{ModeLine_comment} = sprintf qq(# Monitor %s%s modeline (%.1f Hz vsync, %.1f kHz hsync, %sratio %s%s)),
+	  $h->{preferred} ? "preferred" : "supported",
+	  $h->{source} eq 'cea_vdb' ? " CEA" : '',
+	  $h->{pixel_clock} / $horizontal_total / $vertical_total * 1000 * 1000 * ($h->{interlaced} ? 2 : 1),
+	  $h->{pixel_clock} / $horizontal_total * 1000,
+	  $h->{interlaced} ? "interlaced, " : '',
+	  nearest_ratio($h->{horizontal_active} / $h->{vertical_active}, 0.01) || sprintf("%.2f", $h->{horizontal_active} / $h->{vertical_active}),
+	  $dpi_string ? ", $dpi_string" : '';
+	  
+	$h->{ModeLine} = sprintf qq("%dx%d" $h->{pixel_clock} %d %d %d %d %d %d %d %d %shsync %svsync%s),
+	  $h->{horizontal_active}, $h->{vertical_active},
+
+	  $h->{horizontal_active},
+	  $h->{horizontal_active} + $h->{horizontal_sync_offset}, 
+	  $h->{horizontal_active} + $h->{horizontal_sync_offset} + $h->{horizontal_sync_pulse_width},
+	  $horizontal_total,
+
+	  $h->{vertical_active},
+	  $h->{vertical_active} + $h->{vertical_sync_offset}, 
+	  $h->{vertical_active} + $h->{vertical_sync_offset} + $h->{vertical_sync_pulse_width},
+	  $vertical_total,
+
+	  $h->{horizontal_sync_positive} ? '+' : '-',
+	  $h->{vertical_sync_positive} ? '+' : '-',
+	  $h->{interlaced} ? ' Interlace' : '';
+    }
+
+    $edid{diagonal_size} = sqrt(sqr($edid{max_size_horizontal}) + 
+				sqr($edid{max_size_vertical})) / 2.54;
+
+    \%edid;
+}
+
+sub nearest_ratio {
+    my ($ratio, $max_error) = @_;
+    my @sorted = 
+      sort { $a->[1] <=> $b->[1] }
+	map { 
+	    my $error = abs($ratio - eval($_));
+	    $error > $max_error ? () : [ $_, $error ];
+	} @known_ratios;
+    $sorted[0][0];
+}
+
+sub ratio_name {
+    my ($horizontal, $vertical, $precision) = @_;
+    
+    if ($precision eq 'mm') {
+	nearest_ratio($horizontal / $vertical, 0.1);
+    } else {
+	my $error = 0.5;
+	my $ratio1 = nearest_ratio(($horizontal + $error) / ($vertical - $error), 0.2);
+	my $ratio2 = nearest_ratio(($horizontal - $error) / ($vertical + $error), 0.2);
+	$ratio1 && $ratio2 or return;
+	if ($ratio1 eq $ratio2) {
+	    $ratio1;
+	} else {
+	    my $ratio = nearest_ratio($horizontal / $vertical, 0.2);
+	    join(' or ', $ratio, $ratio eq $ratio1 ? $ratio2 : $ratio1);
+	}
+    }
+}
+
+sub to_MonitorsDB {
+    my ($edid) = @_;
+
+    if (!$edid->{monitor_range}) {
+	print STDERR "No monitor range data in EDID.\n";
+	return;
+    }
+    if (!$edid->{EISA_ID}) {
+	print STDERR "No monitor EISA_ID in EDID.\n";
+	return;
+    }
+
+    my $detailed_timings = $edid->{detailed_timings} || [];
+    my @preferred_resolutions = map { 
+	join('x', $_->{horizontal_active}, $_->{vertical_active});
+    } grep { !$_->{bad_ratio} } @$detailed_timings;
+
+    (my $monitor_name = $edid->{monitor_name}) =~ s/;/,/g;
+    my ($raw_vendor, $raw_model) = $edid->{EISA_ID} =~ /(...)(.*)/;
+    my ($VendorName, $only_Model) =
+      $monitor_name =~ /(\S+)\s(.*)/ ? 
+	($1, $2) :
+	($raw_vendor, $monitor_name || $raw_model);
+
+    join('; ', 
+	 $VendorName, "$VendorName $only_Model", $edid->{EISA_ID},
+	 sprintf("%u-%u", $edid->{monitor_range}{horizontal_min}, $edid->{monitor_range}{horizontal_max}),
+	 sprintf("%u-%u", $edid->{monitor_range}{vertical_min}, $edid->{monitor_range}{vertical_max}),
+	 @$detailed_timings == 1 ? @preferred_resolutions : (),
+     );
+}
+
+sub print_edid {
+    my ($edid, $verbose) = @_;
+
+    print "Name: $edid->{monitor_name}\n" if $edid->{monitor_name};
+    print "EISA ID: $edid->{EISA_ID}\n" if $edid->{EISA_ID};
+    print "EDID version: $edid->{edid_version}.$edid->{edid_revision}\n";
+    # this is a number, despite the official name containing "flag":
+    print "EDID extension blocks: $edid->{extension_flag}\n";
+    printf "Screen size: %.1f cm x %.1f cm (%3.2f inches%s)\n",
+      $edid->{max_size_horizontal},
+      $edid->{max_size_vertical},
+      $edid->{diagonal_size},
+      $edid->{ratio_name} ? sprintf(", aspect ratio %s = %.2f", $edid->{ratio_name}, $edid->{ratio}) :
+	$edid->{ratio} ? sprintf(", aspect ratio %.2f", $edid->{ratio}) : '';
+    
+    print "Gamma: ", $edid->{gamma} / 100 + 1, "\n";
+    printf "%s signal\n", $edid->{video_input_definition}{digital} ? 'Digital' : 'Analog';
+
+    if ($verbose) {
+	foreach (@{$edid->{established_timings} || []}) {
+	    print "Standard resolution: $_->{X}x$_->{Y} @ $_->{vfreq} Hz (established timing)\n" if !$_->{interlace};
+	}
+	foreach (@{$edid->{standard_timings} || []}) {
+	    print "Standard resolution: $_->{X}x$_->{Y} @ $_->{vfreq} Hz, ratio $_->{ratio}",
+	      $edid->{ratio_name} && index($edid->{ratio_name}, $_->{ratio}) == -1 ? ' (!)' : '',
+	      "\n";
+	}
+    }
+
+    if ($edid->{monitor_range}) {
+	printf "Max video bandwidth: %u MHz\n", $edid->{monitor_range}{pixel_clock_max} if $edid->{monitor_range}{pixel_clock_max};
+	print "\n";
+	printf "\tHorizSync %u-%u\n", $edid->{monitor_range}{horizontal_min}, $edid->{monitor_range}{horizontal_max};
+	printf "\tVertRefresh %u-%u\n", $edid->{monitor_range}{vertical_min}, $edid->{monitor_range}{vertical_max};
+    }
+
+    foreach my $h (@{$edid->{detailed_timings}}) {
+	print "\n";
+	print "\t", $h->{ModeLine_comment}, $h->{bad_ratio} ? ' (bad ratio)' : '', "\n";
+	print "\tModeLine ", $h->{ModeLine}, "\n";	
+    }
+}
+
+sub edid_from_lines {
+    my (@l) = @_;
+    my $edid_str = join('', map { /\s+([0-9a-f]{32})$/ && $1 } @l);
+    if (length($edid_str) % (2 * 128) != 0 || length($edid_str) == 0) {
+	return ();
+    }
+    pack("C*", map { hex($_) } $edid_str =~ /(..)/g);
+}
+
+sub find_edid_in_string {
+    my ($input) = @_;
+
+    my @edids;
+    while ($input =~ /(?:EDID_DATA|: EDID \(in hex\)):\n((.*\n){8})/g) {
+	push @edids, edid_from_lines(split '\n', $1);
+    }
+    if (!@edids) {
+	@edids = edid_from_lines(split '\n', $input);
+    }
+    @edids;
+}
+
+sub sqr { $_[0] * $_[0] }
+sub round { int($_[0] + 0.5) }
+sub group_by2 {
+    my @l;
+    for (my $i = 0; $i < @_; $i += 2) {
+	push @l, [ $_[$i], $_[$i+1] ];
+    }
+    @l;
+}
+
+1;