private bool IsJPEG(SectionData sectionData)
{
byte[] jpeg = { 0xFF, 0xD8, 0xFF, 0xE0, 0x00, 0x10, 0x4A, 0x46, 0x49, 0x46 };
for (int i = 0; i < jpeg.Length; i++)
{
if (sectionData.Data[i] != jpeg[i])
{
return false;
}
}
return true;
}
internal Section(LytroFile file, SectionData sectionData)
{
this.LytroFile = file;
this.sectionData = sectionData;
}
private string FindName(SectionData sectionData)
{
// Find the sha1 in the table of contents
int quotecount = 0;
int sha1Ix = this.TableOfContents.Content.IndexOf(sectionData.SHA1);
if (sha1Ix > -1)
{
// Move backwards to the corresponding name
while (quotecount < 3 && (sha1Ix-- > 0))
{
if (this.TableOfContents.Content[sha1Ix] == '"')
{
quotecount++;
}
}
// Read the name if we can
if (quotecount == 3)
{
int afterFirstQuote = sha1Ix + 1;
return this.TableOfContents.Content.Substring(
afterFirstQuote,
this.TableOfContents.Content.IndexOf('"', afterFirstQuote) - afterFirstQuote
);
}
}
return "unknown";
}
private Section IdentifySection(SectionData sectionData)
{
// Try to figure out if the data represents an image, text, raw data, etc
Section section;
if (sectionData.Data.Length == 1600)
{
// Hard coded to assume that the 20x20 LUT is 1600 bytes
section = new LookUpTableSection(this, sectionData);
this.LookUpTable = (LookUpTableSection)section;
}
else if (IsJPEG(sectionData))
{
// Check for the magic bytes to see if its a jpg
section = new JpegSection(this, sectionData);
this.JpegSections.Add((JpegSection)section);
}
else
{
string name = FindName(sectionData);
if (name == "imageRef")
{
// Assume a raw image
section = new RawImageSection(this, sectionData);
this.RawImageSections.Add((RawImageSection)section);
}
else
{
// Assume anything that isn't called imageRef is plain text
section = new TextSection(this, sectionData);
this.TextSections.Add((TextSection)section);
}
section.Name = name;
}
return section;
}
private SectionData ParseSectionData(BinaryReader br)
{
SectionData sectionData = new SectionData();
FillSectionData(br, sectionData);
return sectionData;
}
private void FillSectionData(BinaryReader br, SectionData sectionData)
{
br.ReadBytes(MAGIC_LENGTH);
// the length is stored as a big endian unsigned 32 bit int
uint ulen = br.ReadUInt32();
int len = (int)SwapInt(ulen);
// copy SHA1
sectionData.SHA1 = Encoding.ASCII.GetString(br.ReadBytes(SHA1_LENGTH));
// move past the 35 byte empty space
br.ReadBytes(BLANK_LENGTH);
// Copy the data
sectionData.Data = br.ReadBytes(len);
// There may be some null region between sections
while (br.PeekChar() == '\0') br.ReadByte();
}
private void ParseTableOfContents(BinaryReader br)
{
SectionData sectionData = new SectionData();
FillSectionData(br, sectionData);
this.TableOfContents = new TableOfContentsSection(this, sectionData);
}