<?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.audio-video.swf.php                                  //
// module for analyzing Shockwave Flash files                  //
// dependencies: NONE                                          //
//                                                            ///
/////////////////////////////////////////////////////////////////


class getid3_swf
{

    function getid3_swf(&$fd, &$ThisFileInfo, $ReturnAllTagData=false) {
        $ThisFileInfo['fileformat']          = 'swf';
        $ThisFileInfo['video']['dataformat'] = 'swf';

        // http://www.openswf.org/spec/SWFfileformat.html

        fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET);

//echo 'reading '.($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']).' bytes<br>';
        $SWFfileData = fread($fd, $ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']); // 8 + 2 + 2 + max(9) bytes NOT including Frame_Size RECT data

        $ThisFileInfo['swf']['header']['signature']  = substr($SWFfileData, 0, 3);
        switch ($ThisFileInfo['swf']['header']['signature']) {
            case 'FWS':
                $ThisFileInfo['swf']['header']['compressed'] = false;
                break;

            case 'CWS':
                $ThisFileInfo['swf']['header']['compressed'] = true;
                break;

            default:
                $ThisFileInfo['error'][] = 'Expecting "FWS" or "CWS" at offset '.$ThisFileInfo['avdataoffset'].', found "'.$ThisFileInfo['swf']['header']['signature'].'"';
                unset($ThisFileInfo['swf']);
                unset($ThisFileInfo['fileformat']);
                return false;
                break;
        }
        $ThisFileInfo['swf']['header']['version'] = getid3_lib::LittleEndian2Int(substr($SWFfileData, 3, 1));
        $ThisFileInfo['swf']['header']['length']  = getid3_lib::LittleEndian2Int(substr($SWFfileData, 4, 4));

//echo '1<br>';
        if ($ThisFileInfo['swf']['header']['compressed']) {

//echo '2<br>';
//            $foo = substr($SWFfileData, 8, 4096);
//            echo '['.strlen($foo).']<br>';
//            $fee = gzuncompress($foo);
//            echo '('.strlen($fee).')<br>';
//return false;
//echo '<br>time: '.time().'<br>';
//return false;
            if ($UncompressedFileData = gzuncompress(substr($SWFfileData, 8))) {

//echo '3<br>';
                $SWFfileData = substr($SWFfileData, 0, 8).$UncompressedFileData;

            } else {

//echo '4<br>';
                $ThisFileInfo['error'][] = 'Error decompressing compressed SWF data';
                return false;

            }

        }

        $FrameSizeBitsPerValue = (ord(substr($SWFfileData, 8, 1)) & 0xF8) >> 3;
        $FrameSizeDataLength   = ceil((5 + (4 * $FrameSizeBitsPerValue)) / 8);
        $FrameSizeDataString   = str_pad(decbin(ord(substr($SWFfileData, 8, 1)) & 0x07), 3, '0', STR_PAD_LEFT);
        for ($i = 1; $i < $FrameSizeDataLength; $i++) {
            $FrameSizeDataString .= str_pad(decbin(ord(substr($SWFfileData, 8 + $i, 1))), 8, '0', STR_PAD_LEFT);
        }
        list($X1, $X2, $Y1, $Y2) = explode("\n", wordwrap($FrameSizeDataString, $FrameSizeBitsPerValue, "\n", 1));
        $ThisFileInfo['swf']['header']['frame_width']  = getid3_lib::Bin2Dec($X2);
        $ThisFileInfo['swf']['header']['frame_height'] = getid3_lib::Bin2Dec($Y2);

        // http://www-lehre.informatik.uni-osnabrueck.de/~fbstark/diplom/docs/swf/Flash_Uncovered.htm
        // Next in the header is the frame rate, which is kind of weird.
        // It is supposed to be stored as a 16bit integer, but the first byte
        // (or last depending on how you look at it) is completely ignored.
        // Example: 0x000C  ->  0x0C  ->  12     So the frame rate is 12 fps.

        // Byte at (8 + $FrameSizeDataLength) is always zero and ignored
        $ThisFileInfo['swf']['header']['frame_rate']  = getid3_lib::LittleEndian2Int(substr($SWFfileData,  9 + $FrameSizeDataLength, 1));
        $ThisFileInfo['swf']['header']['frame_count'] = getid3_lib::LittleEndian2Int(substr($SWFfileData, 10 + $FrameSizeDataLength, 2));

        $ThisFileInfo['video']['frame_rate']         = $ThisFileInfo['swf']['header']['frame_rate'];
        $ThisFileInfo['video']['resolution_x']       = intval(round($ThisFileInfo['swf']['header']['frame_width']  / 20));
        $ThisFileInfo['video']['resolution_y']       = intval(round($ThisFileInfo['swf']['header']['frame_height'] / 20));
        $ThisFileInfo['video']['pixel_aspect_ratio'] = (float) 1;

        if (($ThisFileInfo['swf']['header']['frame_count'] > 0) && ($ThisFileInfo['swf']['header']['frame_rate'] > 0)) {
            $ThisFileInfo['playtime_seconds'] = $ThisFileInfo['swf']['header']['frame_count'] / $ThisFileInfo['swf']['header']['frame_rate'];
        }


        // SWF tags

        $CurrentOffset = 12 + $FrameSizeDataLength;
        $SWFdataLength = strlen($SWFfileData);

        while ($CurrentOffset < $SWFdataLength) {

            $TagIDTagLength = getid3_lib::LittleEndian2Int(substr($SWFfileData, $CurrentOffset, 2));
            $TagID     = ($TagIDTagLength & 0xFFFC) >> 6;
            $TagLength = ($TagIDTagLength & 0x003F);
            $CurrentOffset += 2;
            if ($TagLength == 0x3F) {
                $TagLength = getid3_lib::LittleEndian2Int(substr($SWFfileData, $CurrentOffset, 4));
                $CurrentOffset += 4;
            }

            unset($TagData);
            $TagData['offset'] = $CurrentOffset;
            $TagData['size']   = $TagLength;
            $TagData['id']     = $TagID;
            $TagData['data']   = substr($SWFfileData, $CurrentOffset, $TagLength);
            switch ($TagID) {
                case 0: // end of movie
                    break 2;

                case 9: // Set background color
                    //$ThisFileInfo['swf']['tags'][] = $TagData;
                    $ThisFileInfo['swf']['bgcolor'] = strtoupper(str_pad(dechex(getid3_lib::BigEndian2Int($TagData['data'])), 6, '0', STR_PAD_LEFT));
                    break;

                default:
                    if ($ReturnAllTagData) {
                        $ThisFileInfo['swf']['tags'][] = $TagData;
                    }
                    break;
            }

            $CurrentOffset += $TagLength;
        }

        return true;
    }

}


?>