mtags
Version:
Media file tag parser
287 lines (252 loc) • 7.49 kB
JavaScript
/*
* Binary Ajax 0.1.5
* Copyright (c) 2008 Jacob Seidelin, cupboy@gmail.com, http://blog.nihilogic.dk/
* MIT License [http://www.opensource.org/licenses/mit-license.php]
*
* Extended by António Afonso <antonio.afonso gmail.com>
*/
var BinaryFile = function(strData, iDataOffset, iDataLength) {
var data = strData;
var dataOffset = iDataOffset || 0;
var dataLength = 0;
this.getRawData = function() {
return data;
}
if (typeof strData == "string") {
dataLength = iDataLength || data.length;
this.getByteAt = function(iOffset) {
return data.charCodeAt(iOffset + dataOffset) & 0xFF;
}
} else if (typeof strData == "unknown") {
dataLength = iDataLength || IEBinary_getLength(data);
this.getByteAt = function(iOffset) {
return IEBinary_getByteAt(data, iOffset + dataOffset);
}
}
// @aadsm
this.getBytesAt = function(iOffset, iLength) {
var bytes = new Array(iLength);
for( var i = 0; i < iLength; i++ ) {
bytes[i] = this.getByteAt(iOffset+i);
}
return bytes;
}
this.getLength = function() {
return dataLength;
}
// @aadsm
this.isBitSetAt = function(iOffset, iBit) {
var iByte = this.getByteAt(iOffset);
return (iByte & (1 << iBit)) != 0;
}
this.getSByteAt = function(iOffset) {
var iByte = this.getByteAt(iOffset);
if (iByte > 127)
return iByte - 256;
else
return iByte;
}
this.getShortAt = function(iOffset, bBigEndian) {
var iShort = bBigEndian ?
(this.getByteAt(iOffset) << 8) + this.getByteAt(iOffset + 1)
: (this.getByteAt(iOffset + 1) << 8) + this.getByteAt(iOffset)
if (iShort < 0) iShort += 65536;
return iShort;
}
this.getSShortAt = function(iOffset, bBigEndian) {
var iUShort = this.getShortAt(iOffset, bBigEndian);
if (iUShort > 32767)
return iUShort - 65536;
else
return iUShort;
}
this.getLongAt = function(iOffset, bBigEndian) {
var iByte1 = this.getByteAt(iOffset),
iByte2 = this.getByteAt(iOffset + 1),
iByte3 = this.getByteAt(iOffset + 2),
iByte4 = this.getByteAt(iOffset + 3);
var iLong = bBigEndian ?
(((((iByte1 << 8) + iByte2) << 8) + iByte3) << 8) + iByte4
: (((((iByte4 << 8) + iByte3) << 8) + iByte2) << 8) + iByte1;
if (iLong < 0) iLong += 4294967296;
return iLong;
}
this.getSLongAt = function(iOffset, bBigEndian) {
var iULong = this.getLongAt(iOffset, bBigEndian);
if (iULong > 2147483647)
return iULong - 4294967296;
else
return iULong;
}
// @aadsm
this.getInteger24At = function(iOffset, bBigEndian) {
var iByte1 = this.getByteAt(iOffset),
iByte2 = this.getByteAt(iOffset + 1),
iByte3 = this.getByteAt(iOffset + 2);
var iInteger = bBigEndian ?
((((iByte1 << 8) + iByte2) << 8) + iByte3)
: ((((iByte3 << 8) + iByte2) << 8) + iByte1);
if (iInteger < 0) iInteger += 16777216;
return iInteger;
}
this.getStringAt = function(iOffset, iLength) {
var aStr = [];
for (var i=iOffset,j=0;i<iOffset+iLength;i++,j++) {
aStr[j] = String.fromCharCode(this.getByteAt(i));
}
return aStr.join("");
}
// @aadsm
this.getStringWithCharsetAt = function(iOffset, iLength, iCharset) {
var bytes = this.getBytesAt(iOffset, iLength);
var sString;
switch( iCharset.toLowerCase() ) {
case 'utf-16':
case 'utf-16le':
case 'utf-16be':
sString = StringUtils.readUTF16String(bytes, iCharset);
break;
case 'utf-8':
sString = StringUtils.readUTF8String(bytes);
break;
default:
sString = StringUtils.readNullTerminatedString(bytes);
break;
}
return sString;
}
this.getCharAt = function(iOffset) {
return String.fromCharCode(this.getByteAt(iOffset));
}
this.toBase64 = function() {
return window.btoa(data);
}
this.fromBase64 = function(strBase64) {
data = window.atob(strBase64);
}
}
var BinaryAjax = (function() {
function createRequest() {
var oHTTP = null;
if (window.XMLHttpRequest) {
oHTTP = new XMLHttpRequest();
} else if (window.ActiveXObject) {
oHTTP = new ActiveXObject("Microsoft.XMLHTTP");
}
return oHTTP;
}
function getHead(strURL, fncCallback, fncError) {
var oHTTP = createRequest();
if (oHTTP) {
if (fncCallback) {
if (typeof(oHTTP.onload) != "undefined") {
oHTTP.onload = function() {
if (oHTTP.status == "200") {
fncCallback(this);
} else {
if (fncError) fncError();
}
oHTTP = null;
};
} else {
oHTTP.onreadystatechange = function() {
if (oHTTP.readyState == 4) {
if (oHTTP.status == "200") {
fncCallback(this);
} else {
if (fncError) fncError();
}
oHTTP = null;
}
};
}
}
oHTTP.open("HEAD", strURL, true);
oHTTP.send(null);
} else {
if (fncError) fncError();
}
}
function sendRequest(strURL, fncCallback, fncError, aRange, bAcceptRanges, iFileSize) {
var oHTTP = createRequest();
if (oHTTP) {
var iDataOffset = 0;
if (aRange && !bAcceptRanges) {
iDataOffset = aRange[0];
}
var iDataLen = 0;
if (aRange) {
iDataLen = aRange[1]-aRange[0]+1;
}
if (fncCallback) {
if (typeof(oHTTP.onload) != "undefined") {
oHTTP.onload = function() {
if (oHTTP.status == "200" || oHTTP.status == "206") {
this.binaryResponse = new BinaryFile(this.responseText, iDataOffset, iDataLen);
this.fileSize = iFileSize || this.getResponseHeader("Content-Length");
fncCallback(this);
} else {
if (fncError) fncError();
}
oHTTP = null;
};
} else {
oHTTP.onreadystatechange = function() {
if (oHTTP.readyState == 4) {
if (oHTTP.status == "200" || oHTTP.status == "206") {
this.binaryResponse = new BinaryFile(oHTTP.responseBody, iDataOffset, iDataLen);
this.fileSize = iFileSize || this.getResponseHeader("Content-Length");
fncCallback(this);
} else {
if (fncError) fncError();
}
oHTTP = null;
}
};
}
}
oHTTP.open("GET", strURL, true);
if (oHTTP.overrideMimeType) oHTTP.overrideMimeType('text/plain; charset=x-user-defined');
if (aRange && bAcceptRanges) {
oHTTP.setRequestHeader("Range", "bytes=" + aRange[0] + "-" + aRange[1]);
}
oHTTP.setRequestHeader("If-Modified-Since", "Sat, 1 Jan 1970 00:00:00 GMT");
oHTTP.send(null);
} else {
if (fncError) fncError();
}
}
return function(strURL, fncCallback, fncError, aRange) {
if (aRange) {
getHead(
strURL,
function(oHTTP) {
var iLength = parseInt(oHTTP.getResponseHeader("Content-Length"),10) || -1;
var strAcceptRanges = oHTTP.getResponseHeader("Accept-Ranges");
var iStart, iEnd;
iStart = aRange[0];
if (aRange[0] < 0 )
iStart += iLength;
iEnd = iStart + aRange[1] - 1;
if( iStart >= 0 ) {
sendRequest(strURL, fncCallback, fncError, [iStart, iEnd], (strAcceptRanges == "bytes"), iLength);
} else {
sendRequest(strURL, fncCallback, fncError);
}
}
);
} else {
sendRequest(strURL, fncCallback, fncError);
}
}
}());
document.write(
"<script type='text/vbscript'>\r\n"
+ "Function IEBinary_getByteAt(strBinary, iOffset)\r\n"
+ " IEBinary_getByteAt = AscB(MidB(strBinary,iOffset+1,1))\r\n"
+ "End Function\r\n"
+ "Function IEBinary_getLength(strBinary)\r\n"
+ " IEBinary_getLength = LenB(strBinary)\r\n"
+ "End Function\r\n"
+ "</script>\r\n"
);