public Maybe<VideoFrame> TryParseVideoFrame(Stream rawStream)
{
using (var rewindGuard = new RewindGuard(rawStream))
{
var frameHeaderParser = new FrameHeaderParser(_header);
Maybe<Header> frameHeaderMaybe = frameHeaderParser.TryParseHeader(rawStream); // We don't do anything with the frame, so who cares?
if (frameHeaderMaybe.IsNothing())
{
// We have to at least succeed
return Maybe<VideoFrame>.Nothing;
}
Maybe<VideoFrame> videoFrame = from lumaPlane in TryReadLumaPlane(rawStream)
from blueDiff in TryReadChromaPlane(rawStream)
from redDiff in TryReadChromaPlane(rawStream)
from frameHeader in frameHeaderMaybe
from colorSpace in frameHeader.ColorSpace
from colorMatrix in ColorConverters.TryConvertFrameToRGB(
colorSpace,
lumaPlane,
blueDiff,
redDiff,
_header.Width,
_header.Height
)
select new VideoFrame(frameHeader, colorMatrix);
videoFrame.Apply(_ =>
{
rewindGuard.DoNotRewind();
});
return videoFrame;
}
}
public Maybe<Header> TryParseHeader(Stream rawStream)
{
using (var rewindGuard = new RewindGuard(rawStream))
{
if (TryReadHeaderMagicTag(rawStream, HeaderMagicTag) == false)
{
return Maybe<Header>.Nothing;
}
Maybe<Header> candidateHeader = TryReadHeaderParameters(rawStream);
candidateHeader.Apply(header =>
{
rewindGuard.DoNotRewind();
});
return candidateHeader;
}
}