/// <summary>
/// Will write the data describing this metadata block to the given stream.
/// </summary>
/// <param name="targetStream">Stream to write the data to.</param>
public override void WriteBlockData(Stream targetStream)
{
uint totalLength = 0;
long headerPosition = targetStream.Position;
this.Header.WriteHeaderData(targetStream);
// Write the vendor string (first write the length as a 32-bit uint and then the actual bytes
byte[] vendorData = System.Text.Encoding.UTF8.GetBytes(this.vendor);
byte[] number = BinaryDataHelper.GetBytesUInt32((uint)vendorData.Length);
targetStream.Write(BinaryDataHelper.SwitchEndianness(number, 0, 4), 0, 4);
targetStream.Write(vendorData, 0, vendorData.Length);
totalLength += 4 + (uint)vendorData.Length;
// Length of list of user comments (first a 32-bit uint, then the actual comments)
number = BinaryDataHelper.GetBytesUInt32((uint)this.comments.Count);
targetStream.Write(BinaryDataHelper.SwitchEndianness(number, 0, 4), 0, 4);
totalLength += 4;
foreach (var comment in this.comments)
{
foreach (var value in comment.Value)
{
string commentText = string.Format("{0}={1}", comment.Key, value);
byte[] commentData = System.Text.Encoding.UTF8.GetBytes(commentText);
number = BinaryDataHelper.GetBytesUInt32((uint)commentData.Length);
targetStream.Write(BinaryDataHelper.SwitchEndianness(number, 0, 4), 0, 4);
targetStream.Write(commentData, 0, commentData.Length);
totalLength += 4 + (uint)commentData.Length;
}
}
long endPosition = targetStream.Position;
targetStream.Seek(headerPosition, SeekOrigin.Begin);
this.Header.MetaDataBlockLength = totalLength;
this.Header.WriteHeaderData(targetStream);
targetStream.Seek(endPosition, SeekOrigin.Begin);
// Note: FLAC does NOT have the framing bit for vorbis so we don't have to write this.
}
/// <summary>
/// Loads the Vorbis from a block of data.
/// </summary>
/// <param name="data"></param>
public override void LoadBlockData(byte[] data)
{
UInt32 vendorLength = BinaryDataHelper.GetUInt32(BinaryDataHelper.SwitchEndianness(data, 0, 4), 0);
this.vendor = Encoding.UTF8.GetString(BinaryDataHelper.GetDataSubset(data, 4, (int)vendorLength));
int startOfComments = 4 + (int)vendorLength;
UInt32 userCommentListLength = BinaryDataHelper.GetUInt32(BinaryDataHelper.SwitchEndianness(data, startOfComments, 4), 0);
// Start of comments actually four bytes further (first piece is the count of items in the list)
startOfComments += 4;
for (UInt32 i = 0; i < userCommentListLength; i++)
{
UInt32 commentLength = BinaryDataHelper.GetUInt32(BinaryDataHelper.SwitchEndianness(data, startOfComments, 4), 0);
string comment = Encoding.UTF8.GetString(BinaryDataHelper.GetDataSubset(data, startOfComments + 4, (int)commentLength));
// We're moving on in the array ...
startOfComments += 4 + (int)commentLength;
AddComment(comment);
}
// All done, note that FLAC doesn't have the "fraiming bit" for vorbis ...
}
