/// <summary>
/// This function parses the next frame from the stream and returns it.
/// </summary>
/// <param name="stream">The stream to parse the Frame from.</param>
/// <param name="version">The ID3 v2 Major version of the ID3 tag that the stream is reading.</param>
/// <param name="parserFactory">A FrameParserFactory to use to create FrameParsers based on Frame IDs.</param>
/// <param name="frameID">Output: outputs the frameID of the frame just parsed.</param>
/// <returns>The parsed Frame object.</returns>
/// <exception cref="Achamenes.ID3.NoFrameParserProvidedException">
/// Thrown if the FrameParserFactory object passed did not recognize the Frame ID for the given version.
/// </exception>
public static Frame Parse(System.IO.Stream stream, ID3v2MajorVersion version, FrameParserFactory parserFactory, out string frameID)
{
FrameHeaderParser headerParser=FrameHeaderParser.CreateFrameHeaderParser(version);
FrameHeader header=headerParser.Parse(stream);
frameID="";
if(header==null) // have reached the padding, no more frames.
{
return null;
}
frameID=header.FrameID;
if(header.Length > 128*128*128*128)
{
throw new FatalException("Invalid frame length for frame with frame ID '"+frameID+"'.");
}
byte[] frameData=new byte[header.Length];
stream.Read(frameData, 0, frameData.Length);
FrameParser parser=parserFactory.CreateFrameParser(version,header.FrameID);
if(parser==null)
{
throw new NoFrameParserProvidedException(frameID,version, "No frame parser object is provided to parse this type of frame in this implementation.");
}
return parser.ParseFrame(frameData);
}
private void TestTextFrame(TextFrame frame, EncodingScheme encoding, ID3v2MajorVersion version)
{
string frameId;
FrameParserFactory factory=new FrameParserFactory();
FrameWriter writer=frame.CreateWriter(version, encoding);
if(writer==null)
{
return;
}
MemoryStream stream=new MemoryStream();
writer.WriteToStream(stream);
stream.Seek(0, SeekOrigin.Begin);
Frame writtenFrame=FrameParser.Parse(stream, version, factory, out frameId);
Assert.IsInstanceOfType(writtenFrame.GetType(), frame);
TextFrame textFrame=(TextFrame)writtenFrame;
Assert.AreEqual(textFrame.Text, frame.Text);
}
/// <summary>
/// This function parses the next frame from the stream and returns it.
/// </summary>
/// <param name="stream">The stream to parse the Frame from.</param>
/// <param name="version">The ID3 v2 Major version of the ID3 tag that the stream is reading.</param>
/// <param name="parserFactory">A FrameParserFactory to use to create FrameParsers based on Frame IDs.</param>
/// <param name="frameID">Output: outputs the frameID of the frame just parsed.</param>
/// <returns>The parsed Frame object.</returns>
/// <exception cref="Achamenes.ID3.NoFrameParserProvidedException">
/// Thrown if the FrameParserFactory object passed did not recognize the Frame ID for the given version.
/// </exception>
public static Frame Parse(System.IO.Stream stream, ID3v2MajorVersion version, FrameParserFactory parserFactory, out string frameID)
{
FrameHeaderParser headerParser = FrameHeaderParser.CreateFrameHeaderParser(version);
FrameHeader header = headerParser.Parse(stream);
frameID = "";
if (header == null) // have reached the padding, no more frames.
{
return(null);
}
frameID = header.FrameID;
if (header.Length > 128 * 128 * 128 * 128)
{
throw new FatalException("Invalid frame length for frame with frame ID '" + frameID + "'.");
}
byte[] frameData = new byte[header.Length];
stream.Read(frameData, 0, frameData.Length);
FrameParser parser = parserFactory.CreateFrameParser(version, header.FrameID);
if (parser == null)
{
throw new NoFrameParserProvidedException(frameID, version, "No frame parser object is provided to parse this type of frame in this implementation.");
}
return(parser.ParseFrame(frameData));
}
private ID3v2MajorVersion Read(Stream stream, FrameParserFactory frameParserFactory)
{
TagHeader header=TagHeader.FromStream(stream);
if(header==null)
{
throw new FatalException("No ID3 v2 tag is attached to this file.");
}
if(!Enum.IsDefined(typeof(ID3v2MajorVersion),header.MajorVersion) )
{
throw new FatalException("Reading this major version of ID3 v2 is not supported.");
}
if(header.Flags!=TagHeaderFlags.None)
{
throw new FatalException("Reading tags with with any set flags are not supported in this version.");
}
long startingPosition=stream.Position;
while(stream.Position-startingPosition <header.TagSize)
{
long beginPosition=stream.Position;
Frame frame=null;
string frameID="";
try
{
frame=FrameParser.Parse(stream, (ID3v2MajorVersion)header.MajorVersion, frameParserFactory, out frameID);
if(frame==null)
{
break;
}
}
catch(NonFatalException ex)
{
RaiseReadingWarning(ex,frameID);
}
if(beginPosition==stream.Position) // Probably stuck in an infinite loop because of corrupt data in file. Exit the loop.
{
break;
}
if(frame!=null)
{
this.Frames.Add(frame);
}
}
return (ID3v2MajorVersion)header.MajorVersion;
}
public virtual ID3v2MajorVersion ReadFromFile(string fileName, FrameParserFactory frameParserFactory)
{
FileStream stream=File.Open(fileName, FileMode.Open, FileAccess.Read, FileShare.Read);
try
{
return Read(stream,frameParserFactory);
}
finally
{
if(stream!=null)
{
stream.Close();
}
}
}
