/// <summary>
/// Saves a 'png' thumbnail from the input video.
/// </summary>
/// <param name="source">Source video file.</param>
/// <param name="output">Output video file</param>
/// <param name="captureTime">Seek position where the thumbnail should be taken.</param>
/// <param name="size">Thumbnail size. If width or height equal 0, the other will be computed automatically.</param>
/// <returns>Bitmap with the requested snapshot.</returns>
public Bitmap Snapshot(VideoInfo source, FileInfo output, Size?size = null, TimeSpan?captureTime = null)
{
if (captureTime == null)
{
captureTime = TimeSpan.FromSeconds(source.Duration.TotalSeconds / 3);
}
if (output.Extension.ToLower() != FileExtension.Png)
{
output = new FileInfo(output.FullName.Replace(output.Extension, FileExtension.Png));
}
if (size == null || (size.Value.Height == 0 && size.Value.Width == 0))
{
size = new Size(source.Width, source.Height);
}
if (size.Value.Width != size.Value.Height)
{
if (size.Value.Width == 0)
{
var ratio = source.Width / (double)size.Value.Width;
size = new Size((int)(source.Width * ratio), (int)(source.Height * ratio));
}
if (size.Value.Height == 0)
{
var ratio = source.Height / (double)size.Value.Height;
size = new Size((int)(source.Width * ratio), (int)(source.Height * ratio));
}
}
FFMpegHelper.ConversionExceptionCheck(source.ToFileInfo(), output);
var thumbArgs = ArgumentsStringifier.Input(source) +
ArgumentsStringifier.Video(VideoCodec.Png) +
ArgumentsStringifier.FrameOutputCount(1) +
ArgumentsStringifier.Seek(captureTime) +
ArgumentsStringifier.Size(size) +
ArgumentsStringifier.Output(output);
if (!RunProcess(thumbArgs, output))
{
throw new OperationCanceledException("Could not take snapshot!");
}
output.Refresh();
Bitmap result;
using (var bmp = (Bitmap)Image.FromFile(output.FullName))
{
using (var ms = new MemoryStream())
{
bmp.Save(ms, ImageFormat.Png);
result = new Bitmap(ms);
}
}
if (output.Exists)
{
output.Delete();
}
return(result);
}