Make ppmtolss16 fully compliant with the PNM spec.

diff --git a/NEWS b/NEWS
index cc01ca0..dc19521 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -8,9 +8,10 @@ Changes in 2.06:
        * ISOLINUX: Fix problem that would occationally cause a
          boot failure, depending on the length of directories.
        * SYSLINUX: Win32 installer now flushes buffers.
-       * ppmtolss16: Try to be compliant with the PPM spec;
+       * ppmtolss16: Be fully compliant with the PPM spec;
          actually process comments in the header and odd
-         alignments of the various parameters.
+         alignments of the various parameters, as well as
+         "plain" (not raw) files and PBM and PGM files.
 
 Changes in 2.05:
        * PXELINUX: Add a default query based on the hardware address

diff --git a/ppmtolss16 b/ppmtolss16
index 1f4e1a9..b3925b7 100755 (executable)
--- a/ppmtolss16
+++ b/ppmtolss16
@@ -2,7 +2,7 @@
 ## $Id$
 ## -----------------------------------------------------------------------
 ##   
-##   Copyright 2001 H. Peter Anvin - All Rights Reserved
+##   Copyright 2001-2003 H. Peter Anvin - All Rights Reserved
 ##
 ##   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
@@ -15,7 +15,7 @@
 ##
 ## ppmtolss16
 ##
-## Convert a "raw" PPM file with max 16 colors to a simple RLE-based format:
+## Convert a PNM file with max 16 colors to a simple RLE-based format:
 ##
 ## uint32 0x1413f33d    ; magic (littleendian)
 ## uint16 xsize                ; littleendian
@@ -35,11 +35,9 @@
 ##
 ## At the start of row, the "previous pixel" is assumed to be zero.
 ##
-## BUG: This program does not handle "plain" ppm format.
-##
 ## Usage:
 ##
-##     ppmtorle16 [#rrggbb=i ...] < input.ppm > output.rle
+##     ppmtolss16 [#rrggbb=i ...] < input.ppm > output.rle
 ##
 ## Command line options of the form #rrggbb=i indicate that
 ## the color #rrggbb (hex) should be assigned index i (decimal)
@@ -88,11 +86,86 @@ sub get_token() {
     return $token;
 }
 
-sub rgbconvert($$) {
-    my($rgb,$maxmult) = @_;
-    my($r,$g,$b);
+# Get a token, and make sure it is numeric (and exists)
+sub get_numeric_token() {
+    my($token) = get_token();
+
+    if ( $token !~ /^[0-9]+$/ ) {
+       print STDERR "Format error on input\n";
+       exit 1;
+    }
+
+    return $token + 0;
+}
+
+# Must be called before each pixel row is read
+sub start_new_row() {
+    $getrgb_leftover_bit_cnt = 0;
+    $getrgb_leftover_bit_val = 0;
+}
+
+# Get a single RGB token depending on the PNM type
+sub getrgb($) {
+    my($form) = @_;
+    my($rgb,$r,$g,$b);
+
+    if ( $form eq 'P6' ) {
+       # Raw PPM, most common
+       return undef unless ( read(STDIN,$rgb,3) == 3 );
+       return unpack("CCC", $rgb);
+    } elsif ( $form eq 'P3' ) {
+       # Plain PPM
+       $r = get_numeric_token();
+       $g = get_numeric_token();
+       $b = get_numeric_token();
+       return ($r,$g,$b);
+    } elsif  ( $form eq 'P5' ) {
+       # Raw PGM
+       return undef unless ( read(STDIN,$rgb,1) == 1 );
+       $r = unpack("C", $rgb);
+       return ($r,$r,$r);
+    } elsif ( $form eq 'P2' ) {
+       # Plain PGM
+       $r = get_numeric_token();
+       return ($r,$r,$r);
+    } elsif ( $form eq 'P4' ) {
+       # Raw PBM
+       if ( !$getrgb_leftover_bit_cnt ) {
+           return undef unless ( read(STDIN,$rgb,1) == 1 );
+           $getrgb_leftover_bit_val = unpack("C", $rgb);
+           $getrgb_leftover_bit_cnt = 8;
+       }
+       $r = ( $getrgb_leftover_bit_val & 0x80 ) ? 0x00 : 0xff;
+       $getrgb_leftover_bit_val <<= 1;
+       $getrgb_leftover_bit_cnt--;
+       
+       return ($r,$r,$r);
+    } elsif ( $form eq 'P1' ) {
+       # Plain PBM
+       my($ch);
+       
+       do {
+           $ch = getc(STDIN);
+           return undef if ( !defined($ch) );
+           return (255,255,255) if ( $ch eq '0' ); # White
+           return (0,0,0) if ( $ch eq '1'); # Black
+           if ( $ch eq '#' ) {
+               do {
+                   $ch = getc(STDIN);
+                   return undef if ( !defined($ch) );
+               } while ( $ch ne "\n" );
+           }
+       } while ( $ch =~ /^[ \t\n\v\f\r]$/ );
+       return undef;
+    } else {
+       die "Internal error: unknown format: $form\n";
+    }
+}
+
+sub rgbconvert($$$$) {
+    my($r,$g,$b,$maxmult) = @_;
+    my($rgb);
 
-    ($r, $g, $b) = unpack("CCC", $rgb);
     $r = int($r*$maxmult);
     $g = int($g*$maxmult);
     $b = int($b*$maxmult);
@@ -131,7 +204,7 @@ foreach $arg ( @ARGV ) {
        next;
     }
 
-    $rgb = rgbconvert(pack("CCC", $r, $g, $b), 64/256);
+    $rgb = rgbconvert($r, $g, $b, 64/256);
 
     if ( defined($index_forced{$i}) ) {
        print STDERR "$0: More than one color index $i\n";
@@ -142,31 +215,26 @@ foreach $arg ( @ARGV ) {
 }
 
 $form = get_token();
-die "$0: stdin is not a raw PPM file" if ( $form ne 'P6' );
-
-$xsize = get_token();
-$ysize = get_token();
-if ( $xsize !~ /^([0-9]+)$/ || $ysize !~ /^([0-9]+)$/ ) {
-    die "$0: Input format error 1\n";
-}
-$xsize += 0; $ysize += 0;      # Convert to number
-
-$maxcol = get_token();
-chomp $maxcol;
-if ( $maxcol !~ /^([0-9]+)$/ ) {
-    die "$0: Input format error 2\n";
+die "$0: stdin is not a PNM file" if ( $form !~ /^P[1-6]$/ );
+
+$xsize = get_numeric_token();
+$ysize = get_numeric_token();
+if ( $form =~ /^P[2356]$/ ) {
+    $maxcol = get_numeric_token();
+} else {
+    $maxcol = 255;             # Internal convention
 }
-$maxcol += 0;
 $maxmult = 64/($maxcol+1);     # Equal buckets conversion
 
 @data = ();
 
 for ( $y = 0 ; $y < $ysize ; $y++ ) {
+    start_new_row();
     for ( $x = 0 ; $x < $xsize ; $x++ ) {
        die "$0: Premature EOF at ($x,$y) of ($xsize,$ysize)\n"
-           if ( read(STDIN, $rgb, 3) != 3 );
+           if ( !defined(@pnmrgb = getrgb($form)) );
        # Convert to 6-bit representation
-       $rgb = rgbconvert($rgb, $maxmult);
+       $rgb = rgbconvert($pnmrgb[0], $pnmrgb[1], $pnmrgb[2], $maxmult);
        $color_count{$rgb}++;
        push(@data, $rgb);
     }