package mcmall.core.codec { import flash.display.BitmapData; import flash.errors.IOError; import flash.utils.ByteArray; import flash.utils.Endian; public class BMPDecoder { //___________________________________________________________ const private const BITMAP_HEADER_TYPE:String = "BM"; private const BITMAP_FILE_HEADER_SIZE:int = 14; private const BITMAP_CORE_HEADER_SIZE:int = 12; private const BITMAP_INFO_HEADER_SIZE:int = 40; private const COMP_RGB :int = 0; private const COMP_RLE8 :int = 1; private const COMP_RLE4 :int = 2; private const COMP_BITFIELDS:int = 3; private const BIT1 :int = 1; private const BIT4 :int = 4; private const BIT8 :int = 8; private const BIT16:int = 16; private const BIT24:int = 24; private const BIT32:int = 32; //___________________________________________________________ vars private var bytes:ByteArray; private var palette:Array; private var bd:BitmapData; private var nFileSize:uint; private var nReserved1:uint; private var nReserved2:uint; private var nOffbits:uint; private var nInfoSize:uint; private var nWidth:int; private var nHeight:int; private var nPlains:uint; private var nBitsPerPixel:uint; private var nCompression:uint; private var nSizeImage:uint; private var nXPixPerMeter:int; private var nYPixPerMeter:int; private var nColorUsed:uint; private var nColorImportant:uint; private var nRMask:uint; private var nGMask:uint; private var nBMask:uint; private var nRPos:uint; private var nGPos:uint; private var nBPos:uint; private var nRMax:uint; private var nGMax:uint; private var nBMax:uint; /** * Constructor */ public function BMPDecoder() { nRPos = 0; nGPos = 0; nBPos = 0; } /** * decoder * * @param BMP file ByteArray */ public function decode( data:ByteArray ):BitmapData { bytes = data; bytes.endian = Endian.LITTLE_ENDIAN; bytes.position = 0; readFileHeader(); nInfoSize = bytes.readUnsignedInt(); switch ( nInfoSize ) { case BITMAP_CORE_HEADER_SIZE: readCoreHeader(); break; case BITMAP_INFO_HEADER_SIZE: readInfoHeader(); break; default: readExtendedInfoHeader(); break; } bd = new BitmapData( nWidth, nHeight ); switch ( nBitsPerPixel ){ case BIT1: readColorPalette(); decode1BitBMP(); break; case BIT4: readColorPalette(); if ( nCompression == COMP_RLE4 ){ decode4bitRLE(); } else { decode4BitBMP(); } break; case BIT8: readColorPalette(); if ( nCompression == COMP_RLE8 ){ decode8BitRLE(); } else { decode8BitBMP(); } break; case BIT16: readBitFields(); checkColorMask(); decode16BitBMP(); break; case BIT24: decode24BitBMP(); break; case BIT32: readBitFields(); checkColorMask(); decode32BitBMP(); break; default: throw new VerifyError("invalid bits per pixel : " + nBitsPerPixel ); } return bd; } /** * read BITMAP FILE HEADER */ private function readFileHeader():void { var fileHeader:ByteArray = new ByteArray(); fileHeader.endian = Endian.LITTLE_ENDIAN; try { bytes.readBytes( fileHeader, 0, BITMAP_FILE_HEADER_SIZE ); if ( fileHeader.readUTFBytes( 2 ) != BITMAP_HEADER_TYPE ){ throw new VerifyError("invalid bitmap header type"); } nFileSize = fileHeader.readUnsignedInt(); nReserved1 = fileHeader.readUnsignedShort(); nReserved2 = fileHeader.readUnsignedShort(); nOffbits = fileHeader.readUnsignedInt(); } catch ( e:IOError ) { throw new VerifyError("invalid file header"); } } /** * read BITMAP CORE HEADER */ private function readCoreHeader():void { var coreHeader:ByteArray = new ByteArray(); coreHeader.endian = Endian.LITTLE_ENDIAN; try { bytes.readBytes( coreHeader, 0, BITMAP_CORE_HEADER_SIZE - 4 ); nWidth = coreHeader.readShort(); nHeight = coreHeader.readShort(); nPlains = coreHeader.readUnsignedShort(); nBitsPerPixel = coreHeader.readUnsignedShort(); } catch ( e:IOError ) { throw new VerifyError("invalid core header"); } } /** * read BITMAP INFO HEADER */ private function readInfoHeader():void { var infoHeader:ByteArray = new ByteArray(); infoHeader.endian = Endian.LITTLE_ENDIAN; try { bytes.readBytes( infoHeader, 0, BITMAP_INFO_HEADER_SIZE - 4 ); nWidth = infoHeader.readInt(); nHeight = infoHeader.readInt(); nPlains = infoHeader.readUnsignedShort(); nBitsPerPixel = infoHeader.readUnsignedShort(); nCompression = infoHeader.readUnsignedInt(); nSizeImage = infoHeader.readUnsignedInt(); nXPixPerMeter = infoHeader.readInt(); nYPixPerMeter = infoHeader.readInt(); nColorUsed = infoHeader.readUnsignedInt(); nColorImportant = infoHeader.readUnsignedInt(); } catch ( e:IOError ) { throw new VerifyError("invalid info header"); } } /** * read the extend info of BITMAP INFO HEADER */ private function readExtendedInfoHeader():void { var infoHeader:ByteArray = new ByteArray(); infoHeader.endian = Endian.LITTLE_ENDIAN; try { bytes.readBytes( infoHeader, 0, nInfoSize - 4 ); nWidth = infoHeader.readInt(); nHeight = infoHeader.readInt(); nPlains = infoHeader.readUnsignedShort(); nBitsPerPixel = infoHeader.readUnsignedShort(); nCompression = infoHeader.readUnsignedInt(); nSizeImage = infoHeader.readUnsignedInt(); nXPixPerMeter = infoHeader.readInt(); nYPixPerMeter = infoHeader.readInt(); nColorUsed = infoHeader.readUnsignedInt(); nColorImportant = infoHeader.readUnsignedInt(); if ( infoHeader.bytesAvailable >= 4 ) nRMask = infoHeader.readUnsignedInt(); if ( infoHeader.bytesAvailable >= 4 ) nGMask = infoHeader.readUnsignedInt(); if ( infoHeader.bytesAvailable >= 4 ) nBMask = infoHeader.readUnsignedInt(); } catch ( e:IOError ) { throw new VerifyError("invalid info header"); } } /** * read bitfields */ private function readBitFields():void { if ( nCompression == COMP_RGB ){ if ( nBitsPerPixel == BIT16 ){ // RGB555 nRMask = 0x00007c00; nGMask = 0x000003e0; nBMask = 0x0000001f; } else { //RGB888; nRMask = 0x00ff0000; nGMask = 0x0000ff00; nBMask = 0x000000ff; } } else if ( ( nCompression == COMP_BITFIELDS ) && ( nInfoSize < 52 ) ){ try { nRMask = bytes.readUnsignedInt(); nGMask = bytes.readUnsignedInt(); nBMask = bytes.readUnsignedInt(); } catch ( e:IOError ) { throw new VerifyError("invalid bit fields"); } } } /** * read color palette */ private function readColorPalette():void { var i:int; var len:int = ( nColorUsed > 0 ) ? nColorUsed : Math.pow( 2, nBitsPerPixel ); palette = new Array( len ); for ( i = 0; i < len; ++i ){ palette[ i ] = bytes.readUnsignedInt(); } } /** * decode 1 bit BMP */ private function decode1BitBMP():void { var x:int; var y:int; var i:int; var col:int; var buf:ByteArray = new ByteArray(); var line:int = nWidth / 8; if ( line % 4 > 0 ){ line = ( ( line / 4 | 0 ) + 1 ) * 4; } try { for ( y = nHeight - 1; y >= 0; --y ){ buf.length = 0; bytes.readBytes( buf, 0, line ); for ( x = 0; x < nWidth; x += 8 ){ col = buf.readUnsignedByte(); for ( i = 0; i < 8; ++i ){ bd.setPixel( x + i, y, palette[ col >> ( 7 - i ) & 0x01 ] ); } } } } catch ( e:IOError ) { throw new VerifyError("invalid image data"); } } /** * decode 4bit RLE */ private function decode4bitRLE():void { var x:int; var y:int; var i:int; var n:int; var col:int; var data:uint; var buf:ByteArray = new ByteArray(); try { for ( y = nHeight - 1; y >= 0; --y ){ buf.length = 0; while ( bytes.bytesAvailable > 0 ){ n = bytes.readUnsignedByte(); if ( n > 0 ){ // encode data data = bytes.readUnsignedByte(); for ( i = 0; i < n/2; ++i ){ buf.writeByte( data ); } } else { n = bytes.readUnsignedByte(); if ( n > 0 ){ // abs mode bytes.readBytes( buf, buf.length, n/2 ); buf.position += n/2; if ( n/2 + 1 >> 1 << 1 != n/2 ){ bytes.readUnsignedByte(); } } else { // EOL break; } } } buf.position = 0; for ( x = 0; x < nWidth; x += 2 ){ col = buf.readUnsignedByte(); bd.setPixel( x, y, palette[ col >> 4 ] ); bd.setPixel( x + 1, y, palette[ col & 0x0f ] ); } } } catch ( e:IOError ) { throw new VerifyError("invalid image data"); } } /** * decode 4bit (no Compression) */ private function decode4BitBMP():void { var x:int; var y:int; var i:int; var col:int; var buf:ByteArray = new ByteArray(); var line:int = nWidth / 2; if ( line % 4 > 0 ){ line = ( ( line / 4 | 0 ) + 1 ) * 4; } try { for ( y = nHeight - 1; y >= 0; --y ){ buf.length = 0; bytes.readBytes( buf, 0, line ); for ( x = 0; x < nWidth; x += 2 ){ col = buf.readUnsignedByte(); bd.setPixel( x, y, palette[ col >> 4 ] ); bd.setPixel( x + 1, y, palette[ col & 0x0f ] ); } } } catch ( e:IOError ) { throw new VerifyError("invalid image data"); } } /** * decode 8bit( RLE Compression ) */ private function decode8BitRLE():void { var x:int; var y:int; var i:int; var n:int; var col:int; var data:uint; var buf:ByteArray = new ByteArray(); try { for ( y = nHeight - 1; y >= 0; --y ){ buf.length = 0; while ( bytes.bytesAvailable > 0 ){ n = bytes.readUnsignedByte(); if ( n > 0 ){ // encode data data = bytes.readUnsignedByte(); for ( i = 0; i < n; ++i ){ buf.writeByte( data ); } } else { n = bytes.readUnsignedByte(); if ( n > 0 ){ // abs mode data bytes.readBytes( buf, buf.length, n ); buf.position += n; if ( n + 1 >> 1 << 1 != n ){ bytes.readUnsignedByte(); } } else { // EOL break; } } } buf.position = 0; for ( x = 0; x < nWidth; ++x ){ bd.setPixel( x, y, palette[ buf.readUnsignedByte() ] ); } } } catch ( e:IOError ) { throw new VerifyError("invalid image data"); } } /** * decode 8bit(no Compression) */ private function decode8BitBMP():void { var x:int; var y:int; var i:int; var col:int; var buf:ByteArray = new ByteArray(); var line:int = nWidth; if ( line % 4 > 0 ){ line = ( ( line / 4 | 0 ) + 1 ) * 4; } try { for ( y = nHeight - 1; y >= 0; --y ){ buf.length = 0; bytes.readBytes( buf, 0, line ); for ( x = 0; x < nWidth; ++x ){ bd.setPixel( x, y, palette[ buf.readUnsignedByte() ] ); } } } catch ( e:IOError ) { throw new VerifyError("invalid image data"); } } /** * decode 16bit */ private function decode16BitBMP():void { var x:int; var y:int; var col:int; try { for ( y = nHeight - 1; y >= 0; --y ){ for ( x = 0; x < nWidth; ++x ){ col = bytes.readUnsignedShort(); bd.setPixel( x, y, ( ( ( col & nRMask ) >> nRPos )*0xff/nRMax << 16 ) + ( ( ( col & nGMask ) >> nGPos )*0xff/nGMax << 8 ) + ( ( ( col & nBMask ) >> nBPos )*0xff/nBMax << 0 ) ); } } } catch ( e:IOError ) { throw new VerifyError("invalid image data"); } } /** * decode 24bit BMP */ private function decode24BitBMP():void { var x:int; var y:int; var col:int; var buf:ByteArray = new ByteArray(); var line:int = nWidth * 3; if ( line % 4 > 0 ){ line = ( ( line / 4 | 0 ) + 1 ) * 4; } try { for ( y = nHeight - 1; y >= 0; --y ){ buf.length = 0; bytes.readBytes( buf, 0, line ); for ( x = 0; x < nWidth; ++x ){ bd.setPixel( x, y, buf.readUnsignedByte() + ( buf.readUnsignedByte() << 8 ) + ( buf.readUnsignedByte() << 16 ) ); } } } catch ( e:IOError ) { throw new VerifyError("invalid image data"); } } /** * decode 32bit BMP */ private function decode32BitBMP():void { var x:int; var y:int; var col:int; try { for ( y = nHeight - 1; y >= 0; --y ){ for ( x = 0; x < nWidth; ++x ){ col = bytes.readUnsignedInt(); bd.setPixel( x, y, ( ( ( col & nRMask ) >> nRPos )*0xff/nRMax << 16 ) + ( ( ( col & nGMask ) >> nGPos )*0xff/nGMax << 8 ) + ( ( ( col & nBMask ) >> nBPos )*0xff/nBMax << 0 ) ); } } } catch ( e:IOError ) { throw new VerifyError("invalid image data"); } } /** * check color mask */ private function checkColorMask():void { if ( ( nRMask & nGMask ) | ( nGMask & nBMask ) | ( nBMask & nRMask ) ){ throw new VerifyError("invalid bit fields"); } while ( ( ( nRMask >> nRPos ) & 0x00000001 ) == 0 ){ nRPos++; } while ( ( ( nGMask >> nGPos ) & 0x00000001 ) == 0 ){ nGPos++; } while ( ( ( nBMask >> nBPos ) & 0x00000001 ) == 0 ){ nBPos++; } nRMax = nRMask >> nRPos; nGMax = nGMask >> nGPos; nBMax = nBMask >> nBPos; } /** * print information */ public function traceInfo():void { trace("---- FILE HEADER ----"); trace("nFileSize: " + nFileSize ); trace("nReserved1: " + nReserved1 ); trace("nReserved2: " + nReserved2 ); trace("nOffbits: " + nOffbits ); trace("---- INFO HEADER ----"); trace("nWidth: " + nWidth ); trace("nHeight: " + nHeight ); trace("nPlains: " + nPlains ); trace("nBitsPerPixel: " + nBitsPerPixel ); if ( nInfoSize >= 40 ){ trace("nCompression: " + nCompression ); trace("nSizeImage: " + nSizeImage ); trace("nXPixPerMeter: " + nXPixPerMeter ); trace("nYPixPerMeter: " + nYPixPerMeter ); trace("nColorUsed: " + nColorUsed ); trace("nColorUsed: " + nColorImportant ); } if ( nInfoSize >= 52 ){ trace("nRMask: " + nRMask.toString( 2 ) ); trace("nGMask: " + nGMask.toString( 2 ) ); trace("nBMask: " + nBMask.toString( 2 ) ); } } } }