public ByteVector Render()
{
ByteVector data = header.Render();
if (packets.IsEmpty)
{
if (file != null)
{
file.Seek(packetOffset);
data.Add(file.ReadBlock(dataSize));
}
else
{
TagLibDebugger.Debug("Ogg.Page.Render() -- this page is empty!");
}
}
else
{
foreach (ByteVector v in packets)
{
data.Add(v);
}
}
// Compute and set the checksum for the Ogg page. The checksum is taken over
// the entire page with the 4 buffer reserved for the checksum zeroed and then
// inserted in buffer 22-25 of the page header.
ByteVector checksum = ByteVector.FromUInt(data.Checksum, false);
for (int i = 0; i < 4; i++)
{
data [i + 22] = checksum [i];
}
return(data);
}
private void Read(OggFile file, long file_offset)
{
file.Seek(file_offset);
// An Ogg page header is at least 27 buffer, so we'll go ahead and read that
// much and then get the rest when we're ready for it.
ByteVector data = file.ReadBlock(27);
// Sanity check -- make sure that we were in fact able to read as much data as
// we asked for and that the page begins with "OggS".
if (data.Count != 27 || !data.StartsWith("OggS"))
{
TagLibDebugger.Debug("Ogg.PageHeader.Read() -- error reading page header");
return;
}
byte flags = data[5];
firstPacketContinued = (flags & 1) != 0;
firstPageOfStream = ((flags >> 1) & 1) != 0;
lastPageOfStream = ((flags >> 2) & 1) != 0;
absoluteGranularPosition = data.Mid(6, 8).ToLong(false);
streamSerialNumber = data.Mid(14, 4).ToUInt(false);
pageSequenceNumber = (int)data.Mid(18, 4).ToUInt(false);
// Byte number 27 is the number of page segments, which is the only variable
// length portion of the page header. After reading the number of page
// segments we'll then read in the coresponding data for this count.
int pageSegmentCount = data[26];
ByteVector page_segments = file.ReadBlock(pageSegmentCount);
// Another sanity check.
if (pageSegmentCount < 1 || page_segments.Count != pageSegmentCount)
{
return;
}
// The base size of an Ogg page 27 buffer plus the number of lacing values.
size = 27 + pageSegmentCount;
int packetSize = 0;
for (int i = 0; i < pageSegmentCount; i++)
{
dataSize += page_segments[i];
packetSize += page_segments[i];
if (page_segments[i] < 255)
{
packetSizes.Add(packetSize);
packetSize = 0;
}
}
if (packetSize > 0)
{
packetSizes.Add(packetSize);
lastPacketCompleted = false;
}
else
{
lastPacketCompleted = true;
}
isValid = true;
}
private void Read(OggFile file, long file_offset)
{
file.Seek(file_offset);
// An Ogg page header is at least 27 buffer, so we'll go ahead and read that
// much and then get the rest when we're ready for it.
ByteVector data = file.ReadBlock(27);
// Sanity check -- make sure that we were in fact able to read as much data as
// we asked for and that the page begins with "OggS".
if (data.Count != 27 || !data.StartsWith("OggS"))
{
TagLibDebugger.Debug("Ogg.PageHeader.Read() -- error reading page header");
return;
}
byte flags = data[5];
firstPacketContinued = (flags & 1) != 0;
firstPageOfStream = ((flags >> 1) & 1) != 0;
lastPageOfStream = ((flags >> 2) & 1) != 0;
absoluteGranularPosition = data.Mid(6, 8).ToLong(false);
streamSerialNumber = data.Mid(14, 4).ToUInt(false);
pageSequenceNumber = (int)data.Mid(18, 4).ToUInt(false);
// Byte number 27 is the number of page segments, which is the only variable
// length portion of the page header. After reading the number of page
// segments we'll then read in the coresponding data for this count.
int pageSegmentCount = data[26];
ByteVector page_segments = file.ReadBlock(pageSegmentCount);
// Another sanity check.
if (pageSegmentCount < 1 || page_segments.Count != pageSegmentCount)
return;
// The base size of an Ogg page 27 buffer plus the number of lacing values.
size = 27 + pageSegmentCount;
int packetSize = 0;
for (int i = 0; i < pageSegmentCount; i++)
{
dataSize += page_segments[i];
packetSize += page_segments[i];
if (page_segments[i] < 255)
{
packetSizes.Add(packetSize);
packetSize = 0;
}
}
if (packetSize > 0)
{
packetSizes.Add(packetSize);
lastPacketCompleted = false;
}
else
lastPacketCompleted = true;
isValid = true;
}
