/// <summary>
/// Create a scaled image based on mediaItemType
/// </summary>
/// <param name="request"></param>
/// <param name="mediaItemType"></param>
/// <param name="image"></param>
/// <returns></returns>
private async Task <MediaItemStorageLocationDto> CreateMediaItem(ProcessMediaItemRequestEvent request,
MediaItemType mediaItemType,
Image image)
{
using (Image scaled = ScaleImage(mediaItemType, image))
{
return(await SaveImage(request, mediaItemType, scaled));
}
}
/// <summary>
/// Save the image as a png in a public bucket.
/// </summary>
/// <param name="request"></param>
/// <param name="mediaItemType"></param>
/// <param name="image"></param>
/// <returns></returns>
private async Task <MediaItemStorageLocationDto> SaveImage(ProcessMediaItemRequestEvent request,
MediaItemType mediaItemType,
Image image)
{
Guid id = request.Id;
// Default encoding as png for everything
// except the original image.
ImageFormat format = ImageFormat.Jpeg; // ImageFormat.Png; // TODO: Use gif if original was gif.
// Try to preserve the original content type.
if (mediaItemType == MediaItemType.OriginalItem || request.PreserveImageFormat)
{
format = GetFormat(request.StorageLocation.ContentType);
}
DateTime date = DateTime.UtcNow;
string contentType = GetContentType(format);
string imageName = string.Format("{0}/{1}/{2}/{3}/{4}.{5}",
date.Year,
date.Month,
date.Day,
mediaItemType,
id,
format);
using (MemoryStream stream = new MemoryStream())
{
// Save to png...
// unless the original was gif to preserve animated gifs?
image.Save(stream, format);
stream.Position = 0;
var mediaItemStorageLocation = new MediaItemStorageLocation
{
Bucket = _imageBucket,
ContentType = contentType,
ItemType = mediaItemType.ToString(),
ContentLength = (int)stream.Length,
Filename = imageName,
};
await _fileStore.SaveAsync(mediaItemStorageLocation, stream);
return(Mapper.Map <MediaItemStorageLocationDto>(mediaItemStorageLocation));
}
}
public async Task OnRequestAsync(ProcessMediaItemRequestEvent request)
{
Logger.LogMessage("Process Media Item Request. Id: {0}", request.Id);
Stopwatch stopWatch = Stopwatch.StartNew();
try
{
List <MediaItemStorageLocationDto> storageLocations = new List <MediaItemStorageLocationDto>();
// If the content type is an image then create a scaled version for each of the
// image type options
if (IsImage(request.StorageLocation.ContentType))
{
// Load the image at the original storage location
Image image = await LoadImage(request.StorageLocation);
Logger.LogMessage("Got image. Width: {0}, Height: {1}", image.Width, image.Height);
IList <MediaItemType> mediaItemTypes = GetImageMediaItems();
foreach (var mediaItemType in mediaItemTypes)
{
var itemStorageLocation = await CreateMediaItem(request, mediaItemType, image);
storageLocations.Add(itemStorageLocation);
}
}
else
{
// TODO: For non-image media item just move them
// to the appropriate bucket/folder
Logger.LogWarn("Media item was not an image. Unable to process.");
}
await PublishMediaItemProcessedAsync(request.Id, storageLocations);
}
catch (Exception ex)
{
Logger.LogException(ex, "Failed to convert image: " + request.Id);
throw;
}
finally
{
stopWatch.Stop();
Logger.LogMessage("Image processing for {0} took {1}ms", request.Id, stopWatch.ElapsedMilliseconds);
}
}
/// <summary>
/// Publish a request to convert the media at the storage location
/// into the appropriate media items (scaled down etc)
/// </summary>
/// <param name="mediaItem"></param>
/// <param name="storageLocation"></param>
/// <returns></returns>
private async Task PublishProcessMediaItemAsync(MediaItem mediaItem, MediaItemStorageLocation storageLocation, bool preserveImageFormat)
{
ProcessMediaItemRequestEvent requestEvent = new ProcessMediaItemRequestEvent
{
Id = mediaItem.Id,
StorageLocation = new MediaItemStorageLocationDto
{
Bucket = storageLocation.Bucket,
ContentLength = storageLocation.ContentLength,
ContentType = storageLocation.ContentType,
Filename = storageLocation.Filename,
ItemType = (MediaItemType)Enum.Parse(typeof(MediaItemType), storageLocation.ItemType),
},
PreserveImageFormat = preserveImageFormat
};
await _bus.PublishAsync(requestEvent);
}
