private void UpdateFrame()
{
_currentFrameIndex = Math.Max(0, Math.Min(_frameHeaders.Length - 1, _currentFrameIndex));
FrameIndexTextBlock.Text = $"{_currentFrameIndex + 1}/{_frameHeaders.Length}";
if (_frameHeaders.IsEmpty())
{
return;
}
var header = _frameHeaders[_currentFrameIndex];
IVideoFrame frame;
using (var stream = new FileStream(_dataFilePrefix + VideoFramesFileWriter.FileSuffix, FileMode.Open))
{
stream.Position = header.Position;
frame = VideoFrameRecord.Read(stream, header.Index).Frame;
}
VideoFrameImage.Source = frame.ToBitmap().ToBitmapSource();
FrameIndexTextBlock.Text = $"{_currentFrameIndex + 1}/{_frameHeaders.Length} ({frame.Width}×{frame.Height}, T:{header.Timestamp})";
}
private static VideoFrameHeader[] LoadVideoFrameHeaders(string dataFilePrefix)
{
var file = dataFilePrefix + VideoFramesFileWriter.FileSuffix;
if (!File.Exists(file))
{
return(EmptyArray <VideoFrameHeader> .Instance);
}
var videoFrameRecords = new LinkedList <VideoFrameHeader>();
uint index = 0;
using (var fileStream = new FileStream(file, FileMode.Open))
while (fileStream.Position < fileStream.Length)
{
var pos = fileStream.Position;
var timestamp = VideoFrameRecord.ReadTimestampAndSkip(fileStream);
videoFrameRecords.AddLast(new VideoFrameHeader(pos, index++, timestamp));
}
return(videoFrameRecords.OrderByTimestamp().ToArray());
}