public static void CloseItem(this BinaryWriter writer, RiffItem item)
{
var position = writer.BaseStream.Position;
var dataSize = position - item.DataStart;
if (dataSize > int.MaxValue - RiffItem.ITEM_HEADER_SIZE)
{
throw new InvalidOperationException("Item size is too big.");
}
if (item.DataSize < 0)
{
item.DataSize = (int)dataSize;
writer.BaseStream.Position = item.DataSizeStart;
writer.Write((uint)dataSize);
writer.BaseStream.Position = position;
}
else if (dataSize != item.DataSize)
{
throw new InvalidOperationException("Item size is not equal to what was previously specified.");
}
// Pad to the WORD boundary according to the RIFF spec
if (position % 2 > 0)
{
writer.SkipBytes(1);
}
}
private void WriteHeader()
{
header = fileWriter.OpenList(KnownFourCC.Lists.Header);
WriteFileHeader();
foreach (var stream in streams)
{
WriteStreamList(stream);
}
WriteOdmlHeader();
WriteJunkInsteadOfMissingSuperIndexEntries();
fileWriter.CloseItem(header);
}
private void CreateNewRiffIfNeeded(int approximateSizeOfNextChunk)
{
var estimatedSize = fileWriter.BaseStream.Position + approximateSizeOfNextChunk - currentRiff.ItemStart;
if (isFirstRiff && EmitIndex1)
{
estimatedSize += RiffItem.ITEM_HEADER_SIZE + index1Count * INDEX1_ENTRY_SIZE;
}
if (estimatedSize > riffSizeTreshold)
{
CloseCurrentRiff();
currentRiff = fileWriter.OpenList(KnownFourCC.Lists.AviExtended, KnownFourCC.ListTypes.Riff);
currentMovie = fileWriter.OpenList(KnownFourCC.Lists.Movie);
}
}
private void PrepareForWriting()
{
startedWriting = true;
foreach (var stream in streams)
{
stream.PrepareForWriting();
}
AviUtils.SplitFrameRate(FramesPerSecond, out frameRateNumerator, out frameRateDenominator);
streamsInfo = streams.Select(s => new StreamInfo(KnownFourCC.Chunks.IndexData(s.Index))).ToArray();
riffSizeTreshold = RIFF_AVI_SIZE_TRESHOLD;
currentRiff = fileWriter.OpenList(KnownFourCC.Lists.Avi, KnownFourCC.ListTypes.Riff);
WriteHeader();
currentMovie = fileWriter.OpenList(KnownFourCC.Lists.Movie);
}