module.graphic.bmp.php

/getid3/module.graphic.bmp.php

https://bitbucket.org/holyfield/getid3
PHP | 685 lines | 477 code | 80 blank | 128 comment | 101 complexity | 61d013baaf4016f97108da9b2f873b7a MD5 | raw file
Possible License(s): GPL-2.0

<?php
/////////////////////////////////////////////////////////////////
/// getID3() by James Heinrich <info@getid3.org>               //
//  available at http://getid3.sourceforge.net                 //
//            or http://www.getid3.org                         //
/////////////////////////////////////////////////////////////////
// See readme.txt for more details                             //
/////////////////////////////////////////////////////////////////
//                                                             //
// module.graphic.bmp.php                                      //
// module for analyzing BMP Image files                        //
// dependencies: NONE                                          //
//                                                            ///
/////////////////////////////////////////////////////////////////


class getid3_bmp extends getid3_handler {
	var $ExtractPalette = false;
	var $ExtractData = false;
	
	function Analyze() {
		$info = &$this->getid3->info;
		
		// shortcuts
		$info ['bmp'] ['header'] ['raw'] = array ();
		$thisfile_bmp = &$info ['bmp'];
		$thisfile_bmp_header = &$thisfile_bmp ['header'];
		$thisfile_bmp_header_raw = &$thisfile_bmp_header ['raw'];
		
		// BITMAPFILEHEADER [14 bytes] - http://msdn.microsoft.com/library/en-us/gdi/bitmaps_62uq.asp
		// all versions
		// WORD    bfType;
		// DWORD   bfSize;
		// WORD    bfReserved1;
		// WORD    bfReserved2;
		// DWORD   bfOffBits;
		

		fseek ( $this->getid3->fp, $info ['avdataoffset'], SEEK_SET );
		$offset = 0;
		$BMPheader = fread ( $this->getid3->fp, 14 + 40 );
		
		$thisfile_bmp_header_raw ['identifier'] = substr ( $BMPheader, $offset, 2 );
		$offset += 2;
		
		$magic = 'BM';
		if ($thisfile_bmp_header_raw ['identifier'] != $magic) {
			$info ['error'] [] = 'Expecting "' . getid3_lib::PrintHexBytes ( $magic ) . '" at offset ' . $info ['avdataoffset'] . ', found "' . getid3_lib::PrintHexBytes ( $thisfile_bmp_header_raw ['identifier'] ) . '"';
			unset ( $info ['fileformat'] );
			unset ( $info ['bmp'] );
			return false;
		}
		
		$thisfile_bmp_header_raw ['filesize'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
		$offset += 4;
		$thisfile_bmp_header_raw ['reserved1'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 2 ) );
		$offset += 2;
		$thisfile_bmp_header_raw ['reserved2'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 2 ) );
		$offset += 2;
		$thisfile_bmp_header_raw ['data_offset'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
		$offset += 4;
		$thisfile_bmp_header_raw ['header_size'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
		$offset += 4;
		
		// check if the hardcoded-to-1 "planes" is at offset 22 or 26
		$planes22 = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, 22, 2 ) );
		$planes26 = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, 26, 2 ) );
		if (($planes22 == 1) && ($planes26 != 1)) {
			$thisfile_bmp ['type_os'] = 'OS/2';
			$thisfile_bmp ['type_version'] = 1;
		} elseif (($planes26 == 1) && ($planes22 != 1)) {
			$thisfile_bmp ['type_os'] = 'Windows';
			$thisfile_bmp ['type_version'] = 1;
		} elseif ($thisfile_bmp_header_raw ['header_size'] == 12) {
			$thisfile_bmp ['type_os'] = 'OS/2';
			$thisfile_bmp ['type_version'] = 1;
		} elseif ($thisfile_bmp_header_raw ['header_size'] == 40) {
			$thisfile_bmp ['type_os'] = 'Windows';
			$thisfile_bmp ['type_version'] = 1;
		} elseif ($thisfile_bmp_header_raw ['header_size'] == 84) {
			$thisfile_bmp ['type_os'] = 'Windows';
			$thisfile_bmp ['type_version'] = 4;
		} elseif ($thisfile_bmp_header_raw ['header_size'] == 100) {
			$thisfile_bmp ['type_os'] = 'Windows';
			$thisfile_bmp ['type_version'] = 5;
		} else {
			$info ['error'] [] = 'Unknown BMP subtype (or not a BMP file)';
			unset ( $info ['fileformat'] );
			unset ( $info ['bmp'] );
			return false;
		}
		
		$info ['fileformat'] = 'bmp';
		$info ['video'] ['dataformat'] = 'bmp';
		$info ['video'] ['lossless'] = true;
		$info ['video'] ['pixel_aspect_ratio'] = ( float ) 1;
		
		if ($thisfile_bmp ['type_os'] == 'OS/2') {
			
			// OS/2-format BMP
			// http://netghost.narod.ru/gff/graphics/summary/os2bmp.htm
			

			// DWORD  Size;             /* Size of this structure in bytes */
			// DWORD  Width;            /* Bitmap width in pixels */
			// DWORD  Height;           /* Bitmap height in pixel */
			// WORD   NumPlanes;        /* Number of bit planes (color depth) */
			// WORD   BitsPerPixel;     /* Number of bits per pixel per plane */
			

			$thisfile_bmp_header_raw ['width'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 2 ) );
			$offset += 2;
			$thisfile_bmp_header_raw ['height'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 2 ) );
			$offset += 2;
			$thisfile_bmp_header_raw ['planes'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 2 ) );
			$offset += 2;
			$thisfile_bmp_header_raw ['bits_per_pixel'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 2 ) );
			$offset += 2;
			
			$info ['video'] ['resolution_x'] = $thisfile_bmp_header_raw ['width'];
			$info ['video'] ['resolution_y'] = $thisfile_bmp_header_raw ['height'];
			$info ['video'] ['codec'] = 'BI_RGB ' . $thisfile_bmp_header_raw ['bits_per_pixel'] . '-bit';
			$info ['video'] ['bits_per_sample'] = $thisfile_bmp_header_raw ['bits_per_pixel'];
			
			if ($thisfile_bmp ['type_version'] >= 2) {
				// DWORD  Compression;      /* Bitmap compression scheme */
				// DWORD  ImageDataSize;    /* Size of bitmap data in bytes */
				// DWORD  XResolution;      /* X resolution of display device */
				// DWORD  YResolution;      /* Y resolution of display device */
				// DWORD  ColorsUsed;       /* Number of color table indices used */
				// DWORD  ColorsImportant;  /* Number of important color indices */
				// WORD   Units;            /* Type of units used to measure resolution */
				// WORD   Reserved;         /* Pad structure to 4-byte boundary */
				// WORD   Recording;        /* Recording algorithm */
				// WORD   Rendering;        /* Halftoning algorithm used */
				// DWORD  Size1;            /* Reserved for halftoning algorithm use */
				// DWORD  Size2;            /* Reserved for halftoning algorithm use */
				// DWORD  ColorEncoding;    /* Color model used in bitmap */
				// DWORD  Identifier;       /* Reserved for application use */
				

				$thisfile_bmp_header_raw ['compression'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['bmp_data_size'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['resolution_h'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['resolution_v'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['colors_used'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['colors_important'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['resolution_units'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 2 ) );
				$offset += 2;
				$thisfile_bmp_header_raw ['reserved1'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 2 ) );
				$offset += 2;
				$thisfile_bmp_header_raw ['recording'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 2 ) );
				$offset += 2;
				$thisfile_bmp_header_raw ['rendering'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 2 ) );
				$offset += 2;
				$thisfile_bmp_header_raw ['size1'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['size2'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['color_encoding'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['identifier'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				
				$thisfile_bmp_header ['compression'] = $this->BMPcompressionOS2Lookup ( $thisfile_bmp_header_raw ['compression'] );
				
				$info ['video'] ['codec'] = $thisfile_bmp_header ['compression'] . ' ' . $thisfile_bmp_header_raw ['bits_per_pixel'] . '-bit';
			}
		
		} elseif ($thisfile_bmp ['type_os'] == 'Windows') {
			
			// Windows-format BMP
			

			// BITMAPINFOHEADER - [40 bytes] http://msdn.microsoft.com/library/en-us/gdi/bitmaps_1rw2.asp
			// all versions
			// DWORD  biSize;
			// LONG   biWidth;
			// LONG   biHeight;
			// WORD   biPlanes;
			// WORD   biBitCount;
			// DWORD  biCompression;
			// DWORD  biSizeImage;
			// LONG   biXPelsPerMeter;
			// LONG   biYPelsPerMeter;
			// DWORD  biClrUsed;
			// DWORD  biClrImportant;
			

			// possibly integrate this section and module.audio-video.riff.php::ParseBITMAPINFOHEADER() ?
			

			$thisfile_bmp_header_raw ['width'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ), true );
			$offset += 4;
			$thisfile_bmp_header_raw ['height'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ), true );
			$offset += 4;
			$thisfile_bmp_header_raw ['planes'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 2 ) );
			$offset += 2;
			$thisfile_bmp_header_raw ['bits_per_pixel'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 2 ) );
			$offset += 2;
			$thisfile_bmp_header_raw ['compression'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
			$offset += 4;
			$thisfile_bmp_header_raw ['bmp_data_size'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
			$offset += 4;
			$thisfile_bmp_header_raw ['resolution_h'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ), true );
			$offset += 4;
			$thisfile_bmp_header_raw ['resolution_v'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ), true );
			$offset += 4;
			$thisfile_bmp_header_raw ['colors_used'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
			$offset += 4;
			$thisfile_bmp_header_raw ['colors_important'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
			$offset += 4;
			
			$thisfile_bmp_header ['compression'] = $this->BMPcompressionWindowsLookup ( $thisfile_bmp_header_raw ['compression'] );
			$info ['video'] ['resolution_x'] = $thisfile_bmp_header_raw ['width'];
			$info ['video'] ['resolution_y'] = $thisfile_bmp_header_raw ['height'];
			$info ['video'] ['codec'] = $thisfile_bmp_header ['compression'] . ' ' . $thisfile_bmp_header_raw ['bits_per_pixel'] . '-bit';
			$info ['video'] ['bits_per_sample'] = $thisfile_bmp_header_raw ['bits_per_pixel'];
			
			if (($thisfile_bmp ['type_version'] >= 4) || ($thisfile_bmp_header_raw ['compression'] == 3)) {
				// should only be v4+, but BMPs with type_version==1 and BI_BITFIELDS compression have been seen
				$BMPheader .= fread ( $this->getid3->fp, 44 );
				
				// BITMAPV4HEADER - [44 bytes] - http://msdn.microsoft.com/library/en-us/gdi/bitmaps_2k1e.asp
				// Win95+, WinNT4.0+
				// DWORD        bV4RedMask;
				// DWORD        bV4GreenMask;
				// DWORD        bV4BlueMask;
				// DWORD        bV4AlphaMask;
				// DWORD        bV4CSType;
				// CIEXYZTRIPLE bV4Endpoints;
				// DWORD        bV4GammaRed;
				// DWORD        bV4GammaGreen;
				// DWORD        bV4GammaBlue;
				$thisfile_bmp_header_raw ['red_mask'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['green_mask'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['blue_mask'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['alpha_mask'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['cs_type'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['ciexyz_red'] = substr ( $BMPheader, $offset, 4 );
				$offset += 4;
				$thisfile_bmp_header_raw ['ciexyz_green'] = substr ( $BMPheader, $offset, 4 );
				$offset += 4;
				$thisfile_bmp_header_raw ['ciexyz_blue'] = substr ( $BMPheader, $offset, 4 );
				$offset += 4;
				$thisfile_bmp_header_raw ['gamma_red'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['gamma_green'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['gamma_blue'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				
				$thisfile_bmp_header ['ciexyz_red'] = getid3_lib::FixedPoint2_30 ( strrev ( $thisfile_bmp_header_raw ['ciexyz_red'] ) );
				$thisfile_bmp_header ['ciexyz_green'] = getid3_lib::FixedPoint2_30 ( strrev ( $thisfile_bmp_header_raw ['ciexyz_green'] ) );
				$thisfile_bmp_header ['ciexyz_blue'] = getid3_lib::FixedPoint2_30 ( strrev ( $thisfile_bmp_header_raw ['ciexyz_blue'] ) );
			}
			
			if ($thisfile_bmp ['type_version'] >= 5) {
				$BMPheader .= fread ( $this->getid3->fp, 16 );
				
				// BITMAPV5HEADER - [16 bytes] - http://msdn.microsoft.com/library/en-us/gdi/bitmaps_7c36.asp
				// Win98+, Win2000+
				// DWORD        bV5Intent;
				// DWORD        bV5ProfileData;
				// DWORD        bV5ProfileSize;
				// DWORD        bV5Reserved;
				$thisfile_bmp_header_raw ['intent'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['profile_data_offset'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['profile_data_size'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
				$thisfile_bmp_header_raw ['reserved3'] = getid3_lib::LittleEndian2Int ( substr ( $BMPheader, $offset, 4 ) );
				$offset += 4;
			}
		
		} else {
			
			$info ['error'] [] = 'Unknown BMP format in header.';
			return false;
		
		}
		
		if ($this->ExtractPalette || $this->ExtractData) {
			$PaletteEntries = 0;
			if ($thisfile_bmp_header_raw ['bits_per_pixel'] < 16) {
				$PaletteEntries = pow ( 2, $thisfile_bmp_header_raw ['bits_per_pixel'] );
			} elseif (isset ( $thisfile_bmp_header_raw ['colors_used'] ) && ($thisfile_bmp_header_raw ['colors_used'] > 0) && ($thisfile_bmp_header_raw ['colors_used'] <= 256)) {
				$PaletteEntries = $thisfile_bmp_header_raw ['colors_used'];
			}
			if ($PaletteEntries > 0) {
				$BMPpalette = fread ( $this->getid3->fp, 4 * $PaletteEntries );
				$paletteoffset = 0;
				for($i = 0; $i < $PaletteEntries; $i ++) {
					// RGBQUAD          - http://msdn.microsoft.com/library/en-us/gdi/bitmaps_5f8y.asp
					// BYTE    rgbBlue;
					// BYTE    rgbGreen;
					// BYTE    rgbRed;
					// BYTE    rgbReserved;
					$blue = getid3_lib::LittleEndian2Int ( substr ( $BMPpalette, $paletteoffset ++, 1 ) );
					$green = getid3_lib::LittleEndian2Int ( substr ( $BMPpalette, $paletteoffset ++, 1 ) );
					$red = getid3_lib::LittleEndian2Int ( substr ( $BMPpalette, $paletteoffset ++, 1 ) );
					if (($thisfile_bmp ['type_os'] == 'OS/2') && ($thisfile_bmp ['type_version'] == 1)) {
						// no padding byte
					} else {
						$paletteoffset ++; // padding byte
					}
					$thisfile_bmp ['palette'] [$i] = (($red << 16) | ($green << 8) | $blue);
				}
			}
		}
		
		if ($this->ExtractData) {
			fseek ( $this->getid3->fp, $thisfile_bmp_header_raw ['data_offset'], SEEK_SET );
			$RowByteLength = ceil ( ($thisfile_bmp_header_raw ['width'] * ($thisfile_bmp_header_raw ['bits_per_pixel'] / 8)) / 4 ) * 4; // round up to nearest DWORD boundry
			$BMPpixelData = fread ( $this->getid3->fp, $thisfile_bmp_header_raw ['height'] * $RowByteLength );
			$pixeldataoffset = 0;
			$thisfile_bmp_header_raw ['compression'] = (isset ( $thisfile_bmp_header_raw ['compression'] ) ? $thisfile_bmp_header_raw ['compression'] : '');
			switch ($thisfile_bmp_header_raw ['compression']) {
				
				case 0 : // BI_RGB
					switch ($thisfile_bmp_header_raw ['bits_per_pixel']) {
						case 1 :
							for($row = ($thisfile_bmp_header_raw ['height'] - 1); $row >= 0; $row --) {
								for($col = 0; $col < $thisfile_bmp_header_raw ['width']; $col = $col) {
									$paletteindexbyte = ord ( $BMPpixelData {$pixeldataoffset ++} );
									for($i = 7; $i >= 0; $i --) {
										$paletteindex = ($paletteindexbyte & (0x01 << $i)) >> $i;
										$thisfile_bmp ['data'] [$row] [$col] = $thisfile_bmp ['palette'] [$paletteindex];
										$col ++;
									}
								}
								while ( ($pixeldataoffset % 4) != 0 ) {
									// lines are padded to nearest DWORD
									$pixeldataoffset ++;
								}
							}
							break;
						
						case 4 :
							for($row = ($thisfile_bmp_header_raw ['height'] - 1); $row >= 0; $row --) {
								for($col = 0; $col < $thisfile_bmp_header_raw ['width']; $col = $col) {
									$paletteindexbyte = ord ( $BMPpixelData {$pixeldataoffset ++} );
									for($i = 1; $i >= 0; $i --) {
										$paletteindex = ($paletteindexbyte & (0x0F << (4 * $i))) >> (4 * $i);
										$thisfile_bmp ['data'] [$row] [$col] = $thisfile_bmp ['palette'] [$paletteindex];
										$col ++;
									}
								}
								while ( ($pixeldataoffset % 4) != 0 ) {
									// lines are padded to nearest DWORD
									$pixeldataoffset ++;
								}
							}
							break;
						
						case 8 :
							for($row = ($thisfile_bmp_header_raw ['height'] - 1); $row >= 0; $row --) {
								for($col = 0; $col < $thisfile_bmp_header_raw ['width']; $col ++) {
									$paletteindex = ord ( $BMPpixelData {$pixeldataoffset ++} );
									$thisfile_bmp ['data'] [$row] [$col] = $thisfile_bmp ['palette'] [$paletteindex];
								}
								while ( ($pixeldataoffset % 4) != 0 ) {
									// lines are padded to nearest DWORD
									$pixeldataoffset ++;
								}
							}
							break;
						
						case 24 :
							for($row = ($thisfile_bmp_header_raw ['height'] - 1); $row >= 0; $row --) {
								for($col = 0; $col < $thisfile_bmp_header_raw ['width']; $col ++) {
									$thisfile_bmp ['data'] [$row] [$col] = (ord ( $BMPpixelData {$pixeldataoffset + 2} ) << 16) | (ord ( $BMPpixelData {$pixeldataoffset + 1} ) << 8) | ord ( $BMPpixelData {$pixeldataoffset} );
									$pixeldataoffset += 3;
								}
								while ( ($pixeldataoffset % 4) != 0 ) {
									// lines are padded to nearest DWORD
									$pixeldataoffset ++;
								}
							}
							break;
						
						case 32 :
							for($row = ($thisfile_bmp_header_raw ['height'] - 1); $row >= 0; $row --) {
								for($col = 0; $col < $thisfile_bmp_header_raw ['width']; $col ++) {
									$thisfile_bmp ['data'] [$row] [$col] = (ord ( $BMPpixelData {$pixeldataoffset + 3} ) << 24) | (ord ( $BMPpixelData {$pixeldataoffset + 2} ) << 16) | (ord ( $BMPpixelData {$pixeldataoffset + 1} ) << 8) | ord ( $BMPpixelData {$pixeldataoffset} );
									$pixeldataoffset += 4;
								}
								while ( ($pixeldataoffset % 4) != 0 ) {
									// lines are padded to nearest DWORD
									$pixeldataoffset ++;
								}
							}
							break;
						
						case 16 :
							// ?
							break;
						
						default :
							$info ['error'] [] = 'Unknown bits-per-pixel value (' . $thisfile_bmp_header_raw ['bits_per_pixel'] . ') - cannot read pixel data';
							break;
					}
					break;
				
				case 1 : // BI_RLE8 - http://msdn.microsoft.com/library/en-us/gdi/bitmaps_6x0u.asp
					switch ($thisfile_bmp_header_raw ['bits_per_pixel']) {
						case 8 :
							$pixelcounter = 0;
							while ( $pixeldataoffset < strlen ( $BMPpixelData ) ) {
								$firstbyte = getid3_lib::LittleEndian2Int ( substr ( $BMPpixelData, $pixeldataoffset ++, 1 ) );
								$secondbyte = getid3_lib::LittleEndian2Int ( substr ( $BMPpixelData, $pixeldataoffset ++, 1 ) );
								if ($firstbyte == 0) {
									
									// escaped/absolute mode - the first byte of the pair can be set to zero to
									// indicate an escape character that denotes the end of a line, the end of
									// a bitmap, or a delta, depending on the value of the second byte.
									switch ($secondbyte) {
										case 0 :
											// end of line
											// no need for special processing, just ignore
											break;
										
										case 1 :
											// end of bitmap
											$pixeldataoffset = strlen ( $BMPpixelData ); // force to exit loop just in case
											break;
										
										case 2 :
											// delta - The 2 bytes following the escape contain unsigned values
											// indicating the horizontal and vertical offsets of the next pixel
											// from the current position.
											$colincrement = getid3_lib::LittleEndian2Int ( substr ( $BMPpixelData, $pixeldataoffset ++, 1 ) );
											$rowincrement = getid3_lib::LittleEndian2Int ( substr ( $BMPpixelData, $pixeldataoffset ++, 1 ) );
											$col = ($pixelcounter % $thisfile_bmp_header_raw ['width']) + $colincrement;
											$row = ($thisfile_bmp_header_raw ['height'] - 1 - (($pixelcounter - $col) / $thisfile_bmp_header_raw ['width'])) - $rowincrement;
											$pixelcounter = ($row * $thisfile_bmp_header_raw ['width']) + $col;
											break;
										
										default :
											// In absolute mode, the first byte is zero and the second byte is a
											// value in the range 03H through FFH. The second byte represents the
											// number of bytes that follow, each of which contains the color index
											// of a single pixel. Each run must be aligned on a word boundary.
											for($i = 0; $i < $secondbyte; $i ++) {
												$paletteindex = getid3_lib::LittleEndian2Int ( substr ( $BMPpixelData, $pixeldataoffset ++, 1 ) );
												$col = $pixelcounter % $thisfile_bmp_header_raw ['width'];
												$row = $thisfile_bmp_header_raw ['height'] - 1 - (($pixelcounter - $col) / $thisfile_bmp_header_raw ['width']);
												$thisfile_bmp ['data'] [$row] [$col] = $thisfile_bmp ['palette'] [$paletteindex];
												$pixelcounter ++;
											}
											while ( ($pixeldataoffset % 2) != 0 ) {
												// Each run must be aligned on a word boundary.
												$pixeldataoffset ++;
											}
											break;
									}
								
								} else {
									
									// encoded mode - the first byte specifies the number of consecutive pixels
									// to be drawn using the color index contained in the second byte.
									for($i = 0; $i < $firstbyte; $i ++) {
										$col = $pixelcounter % $thisfile_bmp_header_raw ['width'];
										$row = $thisfile_bmp_header_raw ['height'] - 1 - (($pixelcounter - $col) / $thisfile_bmp_header_raw ['width']);
										$thisfile_bmp ['data'] [$row] [$col] = $thisfile_bmp ['palette'] [$secondbyte];
										$pixelcounter ++;
									}
								
								}
							}
							break;
						
						default :
							$info ['error'] [] = 'Unknown bits-per-pixel value (' . $thisfile_bmp_header_raw ['bits_per_pixel'] . ') - cannot read pixel data';
							break;
					}
					break;
				
				case 2 : // BI_RLE4 - http://msdn.microsoft.com/library/en-us/gdi/bitmaps_6x0u.asp
					switch ($thisfile_bmp_header_raw ['bits_per_pixel']) {
						case 4 :
							$pixelcounter = 0;
							while ( $pixeldataoffset < strlen ( $BMPpixelData ) ) {
								$firstbyte = getid3_lib::LittleEndian2Int ( substr ( $BMPpixelData, $pixeldataoffset ++, 1 ) );
								$secondbyte = getid3_lib::LittleEndian2Int ( substr ( $BMPpixelData, $pixeldataoffset ++, 1 ) );
								if ($firstbyte == 0) {
									
									// escaped/absolute mode - the first byte of the pair can be set to zero to
									// indicate an escape character that denotes the end of a line, the end of
									// a bitmap, or a delta, depending on the value of the second byte.
									switch ($secondbyte) {
										case 0 :
											// end of line
											// no need for special processing, just ignore
											break;
										
										case 1 :
											// end of bitmap
											$pixeldataoffset = strlen ( $BMPpixelData ); // force to exit loop just in case
											break;
										
										case 2 :
											// delta - The 2 bytes following the escape contain unsigned values
											// indicating the horizontal and vertical offsets of the next pixel
											// from the current position.
											$colincrement = getid3_lib::LittleEndian2Int ( substr ( $BMPpixelData, $pixeldataoffset ++, 1 ) );
											$rowincrement = getid3_lib::LittleEndian2Int ( substr ( $BMPpixelData, $pixeldataoffset ++, 1 ) );
											$col = ($pixelcounter % $thisfile_bmp_header_raw ['width']) + $colincrement;
											$row = ($thisfile_bmp_header_raw ['height'] - 1 - (($pixelcounter - $col) / $thisfile_bmp_header_raw ['width'])) - $rowincrement;
											$pixelcounter = ($row * $thisfile_bmp_header_raw ['width']) + $col;
											break;
										
										default :
											// In absolute mode, the first byte is zero. The second byte contains the number
											// of color indexes that follow. Subsequent bytes contain color indexes in their
											// high- and low-order 4 bits, one color index for each pixel. In absolute mode,
											// each run must be aligned on a word boundary.
											unset ( $paletteindexes );
											for($i = 0; $i < ceil ( $secondbyte / 2 ); $i ++) {
												$paletteindexbyte = getid3_lib::LittleEndian2Int ( substr ( $BMPpixelData, $pixeldataoffset ++, 1 ) );
												$paletteindexes [] = ($paletteindexbyte & 0xF0) >> 4;
												$paletteindexes [] = ($paletteindexbyte & 0x0F);
											}
											while ( ($pixeldataoffset % 2) != 0 ) {
												// Each run must be aligned on a word boundary.
												$pixeldataoffset ++;
											}
											
											foreach ( $paletteindexes as $paletteindex ) {
												$col = $pixelcounter % $thisfile_bmp_header_raw ['width'];
												$row = $thisfile_bmp_header_raw ['height'] - 1 - (($pixelcounter - $col) / $thisfile_bmp_header_raw ['width']);
												$thisfile_bmp ['data'] [$row] [$col] = $thisfile_bmp ['palette'] [$paletteindex];
												$pixelcounter ++;
											}
											break;
									}
								
								} else {
									
									// encoded mode - the first byte of the pair contains the number of pixels to be
									// drawn using the color indexes in the second byte. The second byte contains two
									// color indexes, one in its high-order 4 bits and one in its low-order 4 bits.
									// The first of the pixels is drawn using the color specified by the high-order
									// 4 bits, the second is drawn using the color in the low-order 4 bits, the third
									// is drawn using the color in the high-order 4 bits, and so on, until all the
									// pixels specified by the first byte have been drawn.
									$paletteindexes [0] = ($secondbyte & 0xF0) >> 4;
									$paletteindexes [1] = ($secondbyte & 0x0F);
									for($i = 0; $i < $firstbyte; $i ++) {
										$col = $pixelcounter % $thisfile_bmp_header_raw ['width'];
										$row = $thisfile_bmp_header_raw ['height'] - 1 - (($pixelcounter - $col) / $thisfile_bmp_header_raw ['width']);
										$thisfile_bmp ['data'] [$row] [$col] = $thisfile_bmp ['palette'] [$paletteindexes [($i % 2)]];
										$pixelcounter ++;
									}
								
								}
							}
							break;
						
						default :
							$info ['error'] [] = 'Unknown bits-per-pixel value (' . $thisfile_bmp_header_raw ['bits_per_pixel'] . ') - cannot read pixel data';
							break;
					}
					break;
				
				case 3 : // BI_BITFIELDS
					switch ($thisfile_bmp_header_raw ['bits_per_pixel']) {
						case 16 :
						case 32 :
							$redshift = 0;
							$greenshift = 0;
							$blueshift = 0;
							while ( (($thisfile_bmp_header_raw ['red_mask'] >> $redshift) & 0x01) == 0 ) {
								$redshift ++;
							}
							while ( (($thisfile_bmp_header_raw ['green_mask'] >> $greenshift) & 0x01) == 0 ) {
								$greenshift ++;
							}
							while ( (($thisfile_bmp_header_raw ['blue_mask'] >> $blueshift) & 0x01) == 0 ) {
								$blueshift ++;
							}
							for($row = ($thisfile_bmp_header_raw ['height'] - 1); $row >= 0; $row --) {
								for($col = 0; $col < $thisfile_bmp_header_raw ['width']; $col ++) {
									$pixelvalue = getid3_lib::LittleEndian2Int ( substr ( $BMPpixelData, $pixeldataoffset, $thisfile_bmp_header_raw ['bits_per_pixel'] / 8 ) );
									$pixeldataoffset += $thisfile_bmp_header_raw ['bits_per_pixel'] / 8;
									
									$red = intval ( round ( ((($pixelvalue & $thisfile_bmp_header_raw ['red_mask']) >> $redshift) / ($thisfile_bmp_header_raw ['red_mask'] >> $redshift)) * 255 ) );
									$green = intval ( round ( ((($pixelvalue & $thisfile_bmp_header_raw ['green_mask']) >> $greenshift) / ($thisfile_bmp_header_raw ['green_mask'] >> $greenshift)) * 255 ) );
									$blue = intval ( round ( ((($pixelvalue & $thisfile_bmp_header_raw ['blue_mask']) >> $blueshift) / ($thisfile_bmp_header_raw ['blue_mask'] >> $blueshift)) * 255 ) );
									$thisfile_bmp ['data'] [$row] [$col] = (($red << 16) | ($green << 8) | ($blue));
								}
								while ( ($pixeldataoffset % 4) != 0 ) {
									// lines are padded to nearest DWORD
									$pixeldataoffset ++;
								}
							}
							break;
						
						default :
							$info ['error'] [] = 'Unknown bits-per-pixel value (' . $thisfile_bmp_header_raw ['bits_per_pixel'] . ') - cannot read pixel data';
							break;
					}
					break;
				
				default : // unhandled compression type
					$info ['error'] [] = 'Unknown/unhandled compression type value (' . $thisfile_bmp_header_raw ['compression'] . ') - cannot decompress pixel data';
					break;
			}
		}
		
		return true;
	}
	
	function PlotBMP(&$BMPinfo) {
		$starttime = time ();
		if (! isset ( $BMPinfo ['bmp'] ['data'] ) || ! is_array ( $BMPinfo ['bmp'] ['data'] )) {
			echo 'ERROR: no pixel data<BR>';
			return false;
		}
		set_time_limit ( intval ( round ( $BMPinfo ['resolution_x'] * $BMPinfo ['resolution_y'] / 10000 ) ) );
		if (($im = ImageCreateTrueColor ( $BMPinfo ['resolution_x'], $BMPinfo ['resolution_y'] )) != false) {
			for($row = 0; $row < $BMPinfo ['resolution_y']; $row ++) {
				for($col = 0; $col < $BMPinfo ['resolution_x']; $col ++) {
					if (isset ( $BMPinfo ['bmp'] ['data'] [$row] [$col] )) {
						$red = ($BMPinfo ['bmp'] ['data'] [$row] [$col] & 0x00FF0000) >> 16;
						$green = ($BMPinfo ['bmp'] ['data'] [$row] [$col] & 0x0000FF00) >> 8;
						$blue = ($BMPinfo ['bmp'] ['data'] [$row] [$col] & 0x000000FF);
						$pixelcolor = ImageColorAllocate ( $im, $red, $green, $blue );
						ImageSetPixel ( $im, $col, $row, $pixelcolor );
					} else {
						//echo 'ERROR: no data for pixel '.$row.' x '.$col.'<BR>';
						//return false;
					}
				}
			}
			if (headers_sent ()) {
				echo 'plotted ' . ($BMPinfo ['resolution_x'] * $BMPinfo ['resolution_y']) . ' pixels in ' . (time () - $starttime) . ' seconds<BR>';
				ImageDestroy ( $im );
				exit ();
			} else {
				header ( 'Content-type: image/png' );
				ImagePNG ( $im );
				ImageDestroy ( $im );
				return true;
			}
		}
		return false;
	}
	
	function BMPcompressionWindowsLookup($compressionid) {
		static $BMPcompressionWindowsLookup = array (
													0 => 'BI_RGB', 
													1 => 'BI_RLE8', 
													2 => 'BI_RLE4', 
													3 => 'BI_BITFIELDS', 
													4 => 'BI_JPEG', 
													5 => 'BI_PNG' );
		return (isset ( $BMPcompressionWindowsLookup [$compressionid] ) ? $BMPcompressionWindowsLookup [$compressionid] : 'invalid');
	}
	
	function BMPcompressionOS2Lookup($compressionid) {
		static $BMPcompressionOS2Lookup = array (
												0 => 'BI_RGB', 
												1 => 'BI_RLE8', 
												2 => 'BI_RLE4', 
												3 => 'Huffman 1D', 
												4 => 'BI_RLE24' );
		return (isset ( $BMPcompressionOS2Lookup [$compressionid] ) ? $BMPcompressionOS2Lookup [$compressionid] : 'invalid');
	}

}