public 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;
$this->fseek($info['avdataoffset']);
$offset = 0;
$BMPheader = $this->fread(14 + 40);
$thisfile_bmp_header_raw['identifier'] = substr($BMPheader, $offset, 2);
$offset += 2;
$magic = 'BM';
if ($thisfile_bmp_header_raw['identifier'] != $magic) {
$info['error'][] = 'Expecting "' . Utils::PrintHexBytes($magic) . '" at offset ' . $info['avdataoffset'] . ', found "' . Utils::PrintHexBytes($thisfile_bmp_header_raw['identifier']) . '"';
unset($info['fileformat']);
unset($info['bmp']);
return false;
}
$thisfile_bmp_header_raw['filesize'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['reserved1'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 2));
$offset += 2;
$thisfile_bmp_header_raw['reserved2'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 2));
$offset += 2;
$thisfile_bmp_header_raw['data_offset'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['header_size'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
// check if the hardcoded-to-1 "planes" is at offset 22 or 26
$planes22 = Utils::LittleEndian2Int(substr($BMPheader, 22, 2));
$planes26 = Utils::LittleEndian2Int(substr($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;
$info['video']['pixel_aspect_ratio'] = (double) 1;
if ($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 */
$thisfile_bmp_header_raw['width'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 2));
$offset += 2;
$thisfile_bmp_header_raw['height'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 2));
$offset += 2;
$thisfile_bmp_header_raw['planes'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 2));
$offset += 2;
$thisfile_bmp_header_raw['bits_per_pixel'] = Utils::LittleEndian2Int(substr($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 */
$thisfile_bmp_header_raw['compression'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['bmp_data_size'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['resolution_h'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['resolution_v'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['colors_used'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['colors_important'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['resolution_units'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 2));
$offset += 2;
$thisfile_bmp_header_raw['reserved1'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 2));
$offset += 2;
$thisfile_bmp_header_raw['recording'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 2));
$offset += 2;
$thisfile_bmp_header_raw['rendering'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 2));
$offset += 2;
$thisfile_bmp_header_raw['size1'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['size2'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['color_encoding'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['identifier'] = Utils::LittleEndian2Int(substr($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() ?
$thisfile_bmp_header_raw['width'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4), true);
$offset += 4;
$thisfile_bmp_header_raw['height'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4), true);
$offset += 4;
$thisfile_bmp_header_raw['planes'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 2));
$offset += 2;
$thisfile_bmp_header_raw['bits_per_pixel'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 2));
$offset += 2;
$thisfile_bmp_header_raw['compression'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['bmp_data_size'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['resolution_h'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4), true);
$offset += 4;
$thisfile_bmp_header_raw['resolution_v'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4), true);
$offset += 4;
$thisfile_bmp_header_raw['colors_used'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['colors_important'] = Utils::LittleEndian2Int(substr($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 .= $this->fread(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;
$thisfile_bmp_header_raw['red_mask'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['green_mask'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['blue_mask'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['alpha_mask'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['cs_type'] = Utils::LittleEndian2Int(substr($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;
$thisfile_bmp_header_raw['gamma_red'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['gamma_green'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['gamma_blue'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header['ciexyz_red'] = Utils::FixedPoint2_30(strrev($thisfile_bmp_header_raw['ciexyz_red']));
$thisfile_bmp_header['ciexyz_green'] = Utils::FixedPoint2_30(strrev($thisfile_bmp_header_raw['ciexyz_green']));
$thisfile_bmp_header['ciexyz_blue'] = Utils::FixedPoint2_30(strrev($thisfile_bmp_header_raw['ciexyz_blue']));
}
if ($thisfile_bmp['type_version'] >= 5) {
$BMPheader .= $this->fread(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;
$thisfile_bmp_header_raw['intent'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['profile_data_offset'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['profile_data_size'] = Utils::LittleEndian2Int(substr($BMPheader, $offset, 4));
$offset += 4;
$thisfile_bmp_header_raw['reserved3'] = Utils::LittleEndian2Int(substr($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 = $this->fread(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;
$blue = Utils::LittleEndian2Int(substr($BMPpalette, $paletteoffset++, 1));
$green = Utils::LittleEndian2Int(substr($BMPpalette, $paletteoffset++, 1));
$red = Utils::LittleEndian2Int(substr($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) {
$this->fseek($thisfile_bmp_header_raw['data_offset']);
$RowByteLength = ceil($thisfile_bmp_header_raw['width'] * ($thisfile_bmp_header_raw['bits_per_pixel'] / 8) / 4) * 4;
// round up to nearest DWORD boundry
$BMPpixelData = $this->fread($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 & 0x1 << $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 & 0xf << 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)) {
$firstbyte = Utils::LittleEndian2Int(substr($BMPpixelData, $pixeldataoffset++, 1));
$secondbyte = Utils::LittleEndian2Int(substr($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.
$colincrement = Utils::LittleEndian2Int(substr($BMPpixelData, $pixeldataoffset++, 1));
$rowincrement = Utils::LittleEndian2Int(substr($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++) {
$paletteindex = Utils::LittleEndian2Int(substr($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)) {
$firstbyte = Utils::LittleEndian2Int(substr($BMPpixelData, $pixeldataoffset++, 1));
$secondbyte = Utils::LittleEndian2Int(substr($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.
$colincrement = Utils::LittleEndian2Int(substr($BMPpixelData, $pixeldataoffset++, 1));
$rowincrement = Utils::LittleEndian2Int(substr($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++) {
$paletteindexbyte = Utils::LittleEndian2Int(substr($BMPpixelData, $pixeldataoffset++, 1));
$paletteindexes[] = ($paletteindexbyte & 0xf0) >> 4;
$paletteindexes[] = $paletteindexbyte & 0xf;
}
while ($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] = $secondbyte & 0xf;
for ($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 & 0x1) == 0) {
$redshift++;
}
while (($thisfile_bmp_header_raw['green_mask'] >> $greenshift & 0x1) == 0) {
$greenshift++;
}
while (($thisfile_bmp_header_raw['blue_mask'] >> $blueshift & 0x1) == 0) {
$blueshift++;
}
for ($row = $thisfile_bmp_header_raw['height'] - 1; $row >= 0; $row--) {
for ($col = 0; $col < $thisfile_bmp_header_raw['width']; $col++) {
$pixelvalue = Utils::LittleEndian2Int(substr($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;
}
