public Sample(BinaryReader reader)
: this()
{
SourceStart = reader.ReadInt32BE();
SourceLength = reader.ReadUInt16BE()*2;
LoopStart = reader.ReadInt32BE();
Data = new byte[SourceLength];
}
/// <summary>
/// Reads a JPEG image's dimensions and returns a <see cref="Size"/> object. Much faster
/// than using the built in <see cref="System.Drawing.Image"/> class which loads the entire image into memory
/// Rewinds the stream after reading.
/// </summary>
/// <param name="stream"></param>
/// <exception cref="InvalidDataException">Thrown when the Stream is not a JPEG image</exception>
/// <returns></returns>
public static Size GetJpegImageSize(Stream stream)
{
if (!ImageTypeHelper.IsJpeg(stream))
throw new InvalidDataException("This is not a JPEG stream");
try {
var br = new BinaryReader(stream);
// skip the 0xFFD8 marker
br.BaseStream.Seek(2, SeekOrigin.Current);
// keep reading packets until we find one that contains Size info
while (true) {
ushort b1 = 0x00;
while (b1 != 0xFF)
b1 = br.ReadByte();
while (b1 == 0xFF)
b1 = br.ReadByte();
if (b1 >= 0xC0 && b1 <= 0xC3) {
// this is the SOF (Start Of Frame) marker. skip 3 bytes
br.BaseStream.Seek(3, SeekOrigin.Current);
var h = br.ReadUInt16BE();
var w = br.ReadUInt16BE();
return new Size(w, h);
}
else {
// this isn't the SOF marker, skip to the next marker
br.BaseStream.Seek(br.ReadUInt16BE() - 2, SeekOrigin.Current);
}
}
}
catch (EndOfStreamException ex) {
throw new Exception("Hit the end of the stream without finding the dimensions. This file may be corrupt.", ex);
}
finally {
if (stream != null && stream.CanSeek)
stream.Seek(0, SeekOrigin.Begin);
}
}
public static NetworkAddress DecodeNetworkAddress(BinaryReader reader)
{
return new NetworkAddress
(
Services: reader.ReadUInt64(),
IPv6Address: reader.ReadExactly(16).ToImmutableArray(),
Port: reader.ReadUInt16BE()
);
}
#pragma warning disable CS0219
public override string GetTitle(BinaryReader fileStream)
{
// using the official id3 tag documentation
// http://id3.org/id3v2.3.0#ID3_tag_version_2.3.0
int read_count = 10;
// read + validate header [10 bytes]
// skipped for TagID >03 bytes
byte version_major = fileStream.ReadByte(); // >01 bytes
byte version_minor = fileStream.ReadByte(); // >01 bytes
byte data_flags = fileStream.ReadByte(); // >01 bytes
byte[] tag_size = fileStream.ReadBytes(4); // >04 bytes
int tag_size_int = 0;
for (int i = 0; i < 4; i++)
tag_size_int |= tag_size[3 - i] << (i * 7);
read_count += 10;
#region ID3v2
if (version_major == 2)
{
while (read_count < tag_size_int + 10)
{
// frame header [06 bytes]
int frame_id = fileStream.ReadInt24BE(); // >03 bytes
int frame_size = fileStream.ReadInt24BE(); // >03 bytes
read_count += 6;
if (frame_id == v2_TT2)
{
string title;
byte[] textBuffer = fileStream.ReadBytes(frame_size);
if (textBuffer[0] == 0)
title = Encoding.GetEncoding(28591).GetString(textBuffer, 1, frame_size - 1);
else
throw new FormatException("The id3 tag is damaged");
return title;
}
else
{
fileStream.ReadBytes(frame_size);
read_count += frame_size;
}
}
throw new FormatException("The id3 tag contains no title");
}
#endregion
#region ID3v3/4
else if (version_major == 3 || version_major == 4)
{
while (read_count < tag_size_int + 10)
{
// frame header [10 bytes]
uint frame_id = fileStream.ReadUInt32BE(); // >04 bytes
int frame_size = fileStream.ReadInt32BE(); // >04 bytes
ushort frame_flags = fileStream.ReadUInt16BE(); // >02 bytes
read_count += 10;
// content
if (frame_id == v3_TIT2)
{
string title;
byte[] textBuffer = fileStream.ReadBytes(frame_size);
// is a string, so the first byte is a indicator byte
switch (textBuffer[0])
{
case 0:
title = Encoding.GetEncoding(28591).GetString(textBuffer, 1, frame_size - 1); break;
case 1:
title = Encoding.Unicode.GetString(textBuffer, 1, frame_size - 1); break;
case 2:
title = new UnicodeEncoding(true, false).GetString(textBuffer, 1, frame_size - 1); break;
case 3:
title = Encoding.UTF8.GetString(textBuffer, 1, frame_size - 1); break;
default:
throw new FormatException("The id3 tag is damaged");
}
return title;
}
else if (frame_id == 0)
break;
else
{
fileStream.ReadBytes(frame_size);
read_count += frame_size;
}
}
throw new FormatException("The id3 tag contains no title");
}
#endregion
return null;
}
