private void ReadTag_FLAC(Stream stream, InternalInfo info)
{
info.FileType = FileType.Flac;
// Skip "fLaC" marker
stream.Seek(4, SeekOrigin.Current);
bool isLastMetaDataBlock;
List <FlacMetaDataBlock> metaDataBlockList = new List <FlacMetaDataBlock>();
do
{
int c = stream.ReadByte();
isLastMetaDataBlock = (((c >> 7) & 0x01) == 1);
int blocksize = stream.ReadInt24();
FlacMetaDataBlockType blockType = (FlacMetaDataBlockType)(c & 0x07);
if (blockType == FlacMetaDataBlockType.VorbisComment) // Vorbis comment
{
info.OrigVorbisCommentSize = blocksize;
long mvcoffset = stream.Position - 4;
ReadTag_VorbisComment(stream);
stream.Seek(mvcoffset + 4, SeekOrigin.Begin);
}
FlacMetaDataBlock metaDataBlock = new FlacMetaDataBlock(blockType);
metaDataBlock.SetBlockData(stream, blocksize);
metaDataBlockList.Add(metaDataBlock);
} while (isLastMetaDataBlock == false);
info.MetaDataBlockList = metaDataBlockList;
_metaDataBlockList = metaDataBlockList;
}
private void WriteTagFlac(string path, InternalInfo targetFile)
{
// This will store the metadata blocks we're actually going to write
List <FlacMetaDataBlock> myMetaDataBlocks = new List <FlacMetaDataBlock>();
// Get byte array of new vorbis comment block
byte[] newTagArray;
using (MemoryStream newTag = new MemoryStream())
{
// Write vendor
byte[] vendorBytes = Encoding.UTF8.GetBytes(_vendor);
newTag.WriteInt32LittleEndian(vendorBytes.Length);
newTag.Write(vendorBytes);
// Remove dead items and replace commonly misnamed items
foreach (NameValueItem item in new List <NameValueItem>(_items))
{
if (string.IsNullOrEmpty(item.Value))
{
_items.Remove(item);
}
else if (string.Compare(item.Name, "YEAR", true) == 0)
{
if (string.IsNullOrEmpty(_items.GetValue("DATE")))
{
_items.SetValue("DATE", item.Value);
}
_items.Remove(item);
}
}
// Write item count
newTag.WriteInt32LittleEndian(_items.Count);
// Write items
foreach (NameValueItem item in _items)
{
if (string.IsNullOrEmpty(item.Value))
{
continue;
}
byte[] keyBytes = Encoding.ASCII.GetBytes(item.Name);
byte[] valueBytes = Encoding.UTF8.GetBytes(item.Value);
newTag.WriteInt32LittleEndian(keyBytes.Length + 1 + valueBytes.Length);
newTag.Write(keyBytes);
newTag.WriteByte((byte)'=');
newTag.Write(valueBytes);
}
newTagArray = newTag.ToArray();
}
// 1. Get old size of metadata blocks.
// 2. Find StreamInfo, SeekTable, and Padding blocks.
// These blocks should occur only once. If not, an exception is thrown. The padding
// block we don't really care about so no exception is thrown if it's duplicated.
FlacMetaDataBlock paddingBlock = null;
FlacMetaDataBlock streamInfoBlock = null;
FlacMetaDataBlock seekTableBlock = null;
long origMetaDataSize = 0;
foreach (FlacMetaDataBlock metaDataBlock in targetFile.MetaDataBlockList)
{
origMetaDataSize += 4; // Identifier + Size
origMetaDataSize += metaDataBlock.Size;
if (metaDataBlock.BlockType == FlacMetaDataBlockType.Padding)
{
paddingBlock = metaDataBlock;
}
else if (metaDataBlock.BlockType == FlacMetaDataBlockType.StreamInfo)
{
if (streamInfoBlock != null)
{
throw new InvalidDataException("Multiple stream info blocks");
}
streamInfoBlock = metaDataBlock;
}
else if (metaDataBlock.BlockType == FlacMetaDataBlockType.SeekTable)
{
if (seekTableBlock != null)
{
throw new InvalidDataException("Multiple seek tables");
}
seekTableBlock = metaDataBlock;
}
}
// No Padding block found, create one
if (paddingBlock == null)
{
paddingBlock = new FlacMetaDataBlock(FlacMetaDataBlockType.Padding);
paddingBlock.SetBlockDataZeroed(2000);
}
// Padding block found, adjust size
else
{
// TODO: This is not entirely accurate, since we may be reading from one file
// and writing to another. The other blocks need to be accounted for, however for
// same file read/write this works. Not high priority.
int adjustPadding = targetFile.OrigVorbisCommentSize - newTagArray.Length;
int newSize = paddingBlock.Size + adjustPadding;
if (newSize < 10)
{
paddingBlock.SetBlockDataZeroed(2000);
}
else
{
paddingBlock.SetBlockDataZeroed(newSize);
}
}
// Set Vorbis-Comment block data
FlacMetaDataBlock vorbisCommentBlock = new FlacMetaDataBlock(FlacMetaDataBlockType.VorbisComment);
vorbisCommentBlock.SetBlockData(newTagArray);
// Create list of blocks to write
myMetaDataBlocks.Add(streamInfoBlock); // StreamInfo MUST be first
if (seekTableBlock != null)
{
myMetaDataBlocks.Add(seekTableBlock);
}
// Add other blocks we read from the original file.
foreach (FlacMetaDataBlock metaDataBlock in _metaDataBlockList)
{
if (metaDataBlock.BlockType == FlacMetaDataBlockType.Application ||
metaDataBlock.BlockType == FlacMetaDataBlockType.CueSheet ||
metaDataBlock.BlockType == FlacMetaDataBlockType.Picture)
{
myMetaDataBlocks.Add(metaDataBlock);
}
}
// Add our new vorbis comment and padding blocks
myMetaDataBlocks.Add(vorbisCommentBlock);
myMetaDataBlocks.Add(paddingBlock);
// Get new size of metadata blocks
long newMetaDataSize = 0;
foreach (FlacMetaDataBlock metaDataBlock in myMetaDataBlocks)
{
newMetaDataSize += 4; // Identifier + Size
newMetaDataSize += metaDataBlock.Size;
}
// If the new metadata size is less than the original, increase the padding
if (newMetaDataSize != origMetaDataSize)
{
int newPaddingSize = paddingBlock.Size + (int)(origMetaDataSize - newMetaDataSize);
if (newPaddingSize > 0)
{
paddingBlock.SetBlockDataZeroed(newPaddingSize);
// Get new size of metadata blocks
newMetaDataSize = 0;
foreach (FlacMetaDataBlock metaDataBlock in myMetaDataBlocks)
{
newMetaDataSize += 4; // Identifier + Size
newMetaDataSize += metaDataBlock.Size;
}
}
}
string tempFilename = null;
// no rewrite necessary
if (newMetaDataSize == origMetaDataSize)
{
//
}
// rewrite necessary - grab a snickers.
else if (newMetaDataSize > origMetaDataSize)
{
// rename
tempFilename = PathUtils.GetTemporaryFileNameBasedOnFileName(path);
File.Move(path, tempFilename);
// open for read, open for write
using (FileStream fsRead = File.Open(tempFilename, FileMode.Open, FileAccess.Read, FileShare.None))
using (FileStream fsWrite = File.Open(path, FileMode.CreateNew, FileAccess.Write, FileShare.None))
{
// copy ID3v2 tag.. technically there shouldn't be one, but we don't want to destroy data
int tmpID3v2TagSize = ID3v2.ID3v2Tag.GetTagSize(fsRead);
if (tmpID3v2TagSize != 0)
{
byte[] id3v2 = fsRead.Read(tmpID3v2TagSize);
fsWrite.Write(id3v2);
}
fsWrite.Write(FLAC_MARKER);
// create blankspace
byte[] blankSpace = new Byte[newMetaDataSize];
fsWrite.Write(blankSpace);
fsRead.Seek(4 + origMetaDataSize, SeekOrigin.Current);
byte[] buf = new byte[32768];
int bytesRead = fsRead.Read(buf, 0, 32768);
while (bytesRead != 0)
{
fsWrite.Write(buf, 0, bytesRead);
bytesRead = fsRead.Read(buf, 0, 32768);
}
}
}
// newMetaDataSize < origMetaDataSize is an error
else
{
throw new Exception(String.Format("Internal Error: newMetaDataSize ({0}) < origMetaDataSize ({1})", newMetaDataSize, origMetaDataSize));
}
using (FileStream fs = File.Open(path, FileMode.Open, FileAccess.ReadWrite, FileShare.None))
{
// skip fLaC marker and ID3v2 tag size
int tmpID3v2TagSize = ID3v2.ID3v2Tag.GetTagSize(fs);
fs.Position = tmpID3v2TagSize + 4;
byte blockType;
foreach (FlacMetaDataBlock metaDataBlock in myMetaDataBlocks)
{
// always write padding last
if (metaDataBlock == paddingBlock)
{
continue;
}
blockType = (byte)metaDataBlock.BlockType;
fs.WriteByte(blockType);
fs.WriteInt24(metaDataBlock.Size);
fs.Write(metaDataBlock.BlockData);
}
// write padding, add stop bit to block type
blockType = (byte)(paddingBlock.BlockType + 0x80);
fs.WriteByte(blockType);
fs.WriteInt24(paddingBlock.Size);
fs.Write(paddingBlock.BlockData);
}
if (!string.IsNullOrEmpty(tempFilename))
{
File.Delete(tempFilename);
}
}