/// <summary>Initializes a new instance of the <see cref="ID3v2FrameHeader"/> class.</summary>
/// <param name="header">The header.</param>
/// <param name="reader">The reader.</param>
/// <exception cref="NotSupportedException"></exception>
public ID3v2FrameHeader(ID3v2Header header, DataFrameReader reader)
{
TagHeader = header;
switch (header.Version)
{
case 2: ParseVersion2(reader.Read(0, 6)); break;
case 3: ParseVersion3(reader.Read(0, 10)); break;
case 4: ParseVersion4(reader.Read(0, 10)); break;
default: throw new NotSupportedException(string.Format("Unsupported ID3v2 Version {0}", header.Version));
}
}
/// <summary>Initializes a new instance of the <see cref="ID3v2Frame" /> class.</summary>
/// <param name="header">The header.</param>
/// <param name="reader">The reader.</param>
/// <exception cref="ArgumentNullException">Header.</exception>
/// <exception cref="NotSupportedException"></exception>
public ID3v2Frame(ID3v2Header header, DataFrameReader reader)
{
if (reader == null)
{
throw new ArgumentNullException("Reader");
}
m_Header = new ID3v2FrameHeader(header, reader);
// prepare content (has to be decoded, decrypted, decompressed, ...
m_Content = reader.Read(m_Header.HeaderSize, m_Header.ContentSize);
switch (header.Version)
{
case 2: /*nothing to do, raw plain content data*/ break;
case 3: ParseVersion3(reader); break;
case 4: ParseVersion4(reader); break;
default: throw new NotSupportedException(string.Format("ID3v2.{0} is not supported!", header.Version));
}
// copy raw data and remove from reader
m_Data = reader.GetBuffer(m_Header.HeaderSize + m_Header.ContentSize);
}
bool ParseVersion3(DataFrameReader reader)
{
if (!reader.EnsureBuffer(4))
{
return false;
}
// calc size
byte[] sizeBytes = reader.Read(0, 4);
int size = 0;
for (int i = 0; i < 4; i++)
{
size = (size << 8) | sizeBytes[i];
}
size += 4;
// get data
if (!reader.EnsureBuffer(size))
{
return false;
}
m_Data = reader.GetBuffer(size);
// get flags
m_Flags = ID3v2ExtendedHeaderFlags.FromID3v23(m_Data);
return true;
}
/// <summary>
/// Parses the specified buffer starting at index to load all data for this frame.
/// </summary>
/// <param name="reader">FrameReader to read from.</param>
public override bool Parse(DataFrameReader reader)
{
if (reader == null)
{
throw new ArgumentNullException("Reader");
}
if (!reader.EnsureBuffer(10))
{
return(false);
}
m_Data = reader.Read(0, 10);
ParseData();
return(true);
}
bool ParseVersion4(DataFrameReader reader)
{
if (!reader.EnsureBuffer(4))
{
return false;
}
// calc size
int size = ID3v2DeUnsync.Int32(reader.Read(0, 4), 0);
// get data
if (!reader.EnsureBuffer(size))
{
return false;
}
m_Data = reader.GetBuffer(size);
// get flags
m_Flags = ID3v2ExtendedHeaderFlags.FromID3v24(m_Data);
return true;
}
/// <summary>
/// Parses the specified stream to load all fields for this instance.
/// </summary>
/// <param name="reader">FrameReader to read from.</param>
public override bool Parse(DataFrameReader reader)
{
if (reader == null)
{
throw new ArgumentNullException("Reader");
}
if (!reader.EnsureBuffer(4))
{
return(false);
}
var headerData = reader.Read(0, 4);
Header = new MP3AudioFrameHeader(headerData);
if (Header.Validation != MP3AudioFrameHeadervalidation.Valid)
{
return(false);
}
var dataLength = Header.Length;
if (dataLength == 0)
{
return(false);
}
if (!reader.EnsureBuffer(dataLength))
{
return(false);
}
m_Data = reader.Read(0, dataLength);
// check next header
if (reader.EnsureBuffer(dataLength + 4))
{
var nextHeaderBuffer = reader.Read(dataLength, 4);
var next = new MP3AudioFrameHeader(nextHeaderBuffer);
if (next.Validation != MP3AudioFrameHeadervalidation.Valid)
{
if ((nextHeaderBuffer[0] == 'I') && (nextHeaderBuffer[1] == 'D') && (nextHeaderBuffer[2] == '3'))
{
// ID3 v2 tag incoming
}
else if ((nextHeaderBuffer[0] == 'T') && (nextHeaderBuffer[1] == 'A') && (nextHeaderBuffer[2] == 'G'))
{
// ID3 v1 tag incoming
}
else
{
// next header is invalid, check if the padding bit is set incorrectly
// there is a high pobability that the padding bit is invalid if
// the framestart is not directly after our buffer but one byte late
var newStart = dataLength + (Header.Padding ? -1 : 1);
nextHeaderBuffer = reader.Read(newStart, 4);
next = new MP3AudioFrameHeader(nextHeaderBuffer);
if (next.Validation == MP3AudioFrameHeadervalidation.Valid)
{
if (!Header.Padding)
{
// frame has a padding byte but the header padding bit is not set
m_Data = reader.Read(0, newStart);
}
else
{
// frame has no padding byte but the header padding bit is set
m_Data = reader.Read(0, newStart);
}
InvalidPaddingCorrected = true;
}
}
}
}
reader.Remove(m_Data.Length);
return(true);
}
