/// <exception cref="System.IO.IOException"></exception>
/// <exception cref="Mp3net.InvalidDataException"></exception>
private void ScanFile(RandomAccessFile file)
{
byte[] bytes = new byte[bufferLength];
int fileOffset = PreScanFile(file);
file.Seek(fileOffset);
bool lastBlock = false;
int lastOffset = fileOffset;
while (!lastBlock)
{
int bytesRead = file.Read(bytes, 0, bufferLength);
if (bytesRead < bufferLength)
{
lastBlock = true;
}
if (bytesRead >= MINIMUM_BUFFER_LENGTH)
{
while (true)
{
try
{
int offset = 0;
if (startOffset < 0)
{
offset = ScanBlockForStart(bytes, bytesRead, fileOffset, offset);
if (startOffset >= 0 && !scanFile)
{
return;
}
lastOffset = startOffset;
}
offset = ScanBlock(bytes, bytesRead, fileOffset, offset);
fileOffset += offset;
file.Seek(fileOffset);
break;
}
catch (InvalidDataException e)
{
if (frameCount < 2)
{
startOffset = -1;
xingOffset = -1;
frameCount = 0;
bitrates.Clear();
lastBlock = false;
fileOffset = lastOffset + 1;
if (fileOffset == 0)
{
throw new InvalidDataException("Valid start of mpeg frames not found", e);
}
file.Seek(fileOffset);
break;
}
return;
}
}
}
}
}
/// <exception cref="System.IO.IOException"></exception>
private void SaveMpegFrames(RandomAccessFile saveFile)
{
int filePos = xingOffset;
if (filePos < 0)
{
filePos = startOffset;
}
if (filePos < 0)
{
return;
}
if (endOffset < filePos)
{
return;
}
RandomAccessFile file = new RandomAccessFile(filename, "r");
byte[] bytes = new byte[bufferLength];
try
{
file.Seek(filePos);
while (true)
{
int bytesRead = file.Read(bytes, 0, bufferLength);
if (filePos + bytesRead <= endOffset)
{
saveFile.Write(bytes, 0, bytesRead);
filePos += bytesRead;
}
else
{
saveFile.Write(bytes, 0, endOffset - filePos + 1);
break;
}
}
}
finally
{
file.Close();
}
}
/// <exception cref="System.IO.IOException"></exception>
/// <exception cref="Mp3net.UnsupportedTagException"></exception>
/// <exception cref="Mp3net.InvalidDataException"></exception>
private void InitId3v2Tag(RandomAccessFile file)
{
if (xingOffset == 0 || startOffset == 0)
{
id3v2Tag = null;
}
else
{
int bufferLength;
if (HasXingFrame())
{
bufferLength = xingOffset;
}
else
{
bufferLength = startOffset;
}
byte[] bytes = new byte[bufferLength];
file.Seek(0);
int bytesRead = file.Read(bytes, 0, bufferLength);
if (bytesRead < bufferLength)
{
throw new IOException("Not enough bytes read");
}
try
{
id3v2Tag = ID3v2TagFactory.CreateTag(bytes);
}
catch (NoSuchTagException)
{
id3v2Tag = null;
}
}
}
/// <exception cref="System.IO.IOException"></exception>
private void InitId3v1Tag(RandomAccessFile file)
{
byte[] bytes = new byte[ID3v1Tag.TAG_LENGTH];
file.Seek(GetLength() - ID3v1Tag.TAG_LENGTH);
int bytesRead = file.Read(bytes, 0, ID3v1Tag.TAG_LENGTH);
if (bytesRead < ID3v1Tag.TAG_LENGTH)
{
throw new IOException("Not enough bytes read");
}
try
{
id3v1Tag = new ID3v1Tag(bytes);
}
catch (NoSuchTagException)
{
id3v1Tag = null;
}
}
/// <exception cref="System.IO.IOException"></exception>
private void InitCustomTag(RandomAccessFile file)
{
int bufferLength = (int)(GetLength() - (endOffset + 1));
if (HasId3v1Tag())
{
bufferLength -= ID3v1Tag.TAG_LENGTH;
}
if (bufferLength <= 0)
{
customTag = null;
}
else
{
customTag = new byte[bufferLength];
file.Seek(endOffset + 1);
int bytesRead = file.Read(customTag, 0, bufferLength);
if (bytesRead < bufferLength)
{
throw new IOException("Not enough bytes read");
}
}
}
internal virtual int PreScanFile(RandomAccessFile file)
{
byte[] bytes = new byte[AbstractID3v2Tag.HEADER_LENGTH];
try
{
file.Seek(0);
int bytesRead = file.Read(bytes, 0, AbstractID3v2Tag.HEADER_LENGTH);
if (bytesRead == AbstractID3v2Tag.HEADER_LENGTH)
{
try
{
ID3v2TagFactory.SanityCheckTag(bytes);
return AbstractID3v2Tag.HEADER_LENGTH + BufferTools.UnpackSynchsafeInteger(bytes[
AbstractID3v2Tag.DATA_LENGTH_OFFSET], bytes[AbstractID3v2Tag.DATA_LENGTH_OFFSET
+ 1], bytes[AbstractID3v2Tag.DATA_LENGTH_OFFSET + 2], bytes[AbstractID3v2Tag.DATA_LENGTH_OFFSET
+ 3]);
}
catch (NoSuchTagException)
{
}
catch (UnsupportedTagException)
{
}
}
}
catch (IOException)
{
}
// do nothing
// do nothing
// do nothing
return 0;
}