public async Task Preview(string id)
{
byte[] preview = previewService.GetCached(id);
if (preview == null)
{
AVideoEntity video = await videoService.FindAsync(id);
preview = await previewService.GetAsync(video);
}
using (Stream stream = this.Response.BodyWriter.AsStream())
{
await stream.WriteAsync(preview, 0, preview.Length);
}
}