private static IEnumerable<Face> ParseFaces(byte[] bytes, int firstRecordOffset, int posOffset, int recordLength)
{
if (bytes == null)
yield break;
var reader = new ByteArrayReader(bytes) { IsMotorolaByteOrder = false };
int faceCount = reader.GetUInt16(0);
if (faceCount == 0 || bytes.Length < firstRecordOffset + faceCount*recordLength)
yield break;
posOffset += firstRecordOffset;
for (int i = 0, recordOffset = firstRecordOffset; i < faceCount; i++, recordOffset += recordLength, posOffset += recordLength)
{
yield return new Face(
x: reader.GetUInt16(posOffset),
y: reader.GetUInt16(posOffset + 2),
width: reader.GetUInt16(posOffset + 4),
height: reader.GetUInt16(posOffset + 6),
name: recordLength == 44 ? reader.GetString(recordOffset, 20, Encoding.ASCII).Trim(' ', '\0') : null,
age: recordLength == 44 ? Age.FromPanasonicString(reader.GetString(recordOffset + 28, 20, Encoding.ASCII).Trim(' ', '\0')) : null);
}
}
public void ProcessChunk(string fourCc, byte[] payload)
{
switch (fourCc)
{
case "EXIF":
{
_directories.AddRange(new ExifReader().Extract(new ByteArrayReader(payload)));
break;
}
case "ICCP":
{
_directories.Add(new IccReader().Extract(new ByteArrayReader(payload)));
break;
}
case "XMP ":
{
_directories.Add(new XmpReader().Extract(payload));
break;
}
case "VP8X":
{
if (payload.Length != 10)
break;
IndexedReader reader = new ByteArrayReader(payload);
reader.IsMotorolaByteOrder = false;
try
{
// Flags
// var hasFragments = reader.getBit(0);
var isAnimation = reader.GetBit(1);
// var hasXmp = reader.getBit(2);
// var hasExif = reader.getBit(3);
var hasAlpha = reader.GetBit(4);
// var hasIcc = reader.getBit(5);
// Image size
var widthMinusOne = reader.GetInt24(4);
var heightMinusOne = reader.GetInt24(7);
var directory = new WebPDirectory();
directory.Set(WebPDirectory.TagImageWidth, widthMinusOne + 1);
directory.Set(WebPDirectory.TagImageHeight, heightMinusOne + 1);
directory.Set(WebPDirectory.TagHasAlpha, hasAlpha);
directory.Set(WebPDirectory.TagIsAnimation, isAnimation);
_directories.Add(directory);
}
catch (IOException e)
{
Debug.WriteLine(e);
}
break;
}
case "VP8L":
{
if (payload.Length < 5)
break;
IndexedReader reader = new ByteArrayReader(payload);
reader.IsMotorolaByteOrder = false;
try
{
// https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification#2_riff_header
// Expect the signature byte
if (reader.GetByte(0) != 0x2F)
break;
var b1 = reader.GetByte(1);
var b2 = reader.GetByte(2);
var b3 = reader.GetByte(3);
var b4 = reader.GetByte(4);
// 14 bits for width
var widthMinusOne = (b2 & 0x3F) << 8 | b1;
// 14 bits for height
var heightMinusOne = (b4 & 0x0F) << 10 | b3 << 2 | (b2 & 0xC0) >> 6;
var directory = new WebPDirectory();
directory.Set(WebPDirectory.TagImageWidth, widthMinusOne + 1);
directory.Set(WebPDirectory.TagImageHeight, heightMinusOne + 1);
_directories.Add(directory);
}
catch (IOException e)
{
Debug.WriteLine(e);
}
break;
}
case "VP8 ":
{
if (payload.Length < 10)
break;
IndexedReader reader = new ByteArrayReader(payload);
reader.IsMotorolaByteOrder = false;
try
{
// https://tools.ietf.org/html/rfc6386#section-9.1
// https://github.com/webmproject/libwebp/blob/master/src/enc/syntax.c#L115
// Expect the signature bytes
if (reader.GetByte(3) != 0x9D ||
reader.GetByte(4) != 0x01 ||
reader.GetByte(5) != 0x2A)
break;
var width = reader.GetUInt16(6);
var height = reader.GetUInt16(8);
var directory = new WebPDirectory();
directory.Set(WebPDirectory.TagImageWidth, width);
directory.Set(WebPDirectory.TagImageHeight, height);
_directories.Add(directory);
}
catch (IOException e)
{
Debug.WriteLine(e);
}
break;
}
}
}