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)); } } } }