public Task <string> CreateThumbnailAsync(string videoPath)
{
return(Task.Run(() =>
{
var url = NSUrl.FromFilename(videoPath);
var asset = AVAsset.FromUrl(url);
var assetImageGenerator = AVAssetImageGenerator.FromAsset(asset);
assetImageGenerator.AppliesPreferredTrackTransform = true;
var time = CMTime.FromSeconds(1, 1);
using (var img = assetImageGenerator.CopyCGImageAtTime(time, out CMTime _, out NSError __))
{
if (img == null)
{
Debug.WriteLine($"Could not find file at url: {videoPath}");
return string.Empty;
}
var outputPath = Path.ChangeExtension(videoPath, ".png");
var fileUrl = NSUrl.FromFilename(outputPath);
using (var imageDestination = CGImageDestination.Create(fileUrl, UTType.PNG, 1))
{
imageDestination.AddImage(img);
imageDestination.Close();
}
return outputPath;
}
}));
}
internal static async Task <StorageItemThumbnail> CreateVideoThumbnailAsync(StorageFile file)
{
AVAsset asset = AVUrlAsset.FromUrl(NSUrl.FromFilename(file.Path));
AVAssetImageGenerator generator = AVAssetImageGenerator.FromAsset(asset);
generator.AppliesPreferredTrackTransform = true;
NSError error;
CMTime actualTime;
CMTime time = CMTime.FromSeconds(asset.Duration.Seconds / 2, asset.Duration.TimeScale);
CGImage image = generator.CopyCGImageAtTime(time, out actualTime, out error);
#if __MAC__
NSMutableData buffer = new NSMutableData();
CGImageDestination dest = CGImageDestination.Create(buffer, UTType.JPEG, 1, null);
dest.AddImage(image);
return(new StorageItemThumbnail(buffer.AsStream()));
#else
UIImage image2 = UIImage.FromImage(image);
image.Dispose();
UIImage image3 = image2.Scale(new CGSize(240, 240));
image2.Dispose();
return(new StorageItemThumbnail(image3.AsJPEG().AsStream()));
#endif
}
ImageSource IVideoUtils.GetVideoThumbnail(string url)
{
NSUrl videoUrl = NSUrl.CreateFileUrl(url, null);
var asset = AVAsset.FromUrl(videoUrl);
var imageGenerator = AVAssetImageGenerator.FromAsset(asset);
imageGenerator.AppliesPreferredTrackTransform = true;
var seconds = asset.Duration.Seconds;
CoreMedia.CMTime actualTime;
CoreMedia.CMTime cmTime = asset.Duration;
var timeScale = asset.Duration.TimeScale;
cmTime.Value = (seconds > 5) ? timeScale * 5 : timeScale * 1;
NSError error;
var imageRef = imageGenerator.CopyCGImageAtTime(cmTime, out actualTime, out error);
if (imageRef == null)
{
return(null);
}
var uiImage = UIImage.FromImage(imageRef);
var img = Xamarin.Forms.ImageSource.FromStream(() => ((uiImage.AsPNG().AsStream())));
return(img);
}
void UpdateUI()
{
var formsControl = Element as VideoImagePreview;
if (formsControl == null)
{
return;
}
if (!string.IsNullOrWhiteSpace(formsControl.VideoUrl))
{
var outputTime = new CMTime();
var error = new NSError();
using (var asset = AVAsset.FromUrl(new NSUrl(formsControl.VideoUrl)))
using (var assetGenerator = AVAssetImageGenerator.FromAsset(asset))
{
var image = assetGenerator.CopyCGImageAtTime(new CMTime(0, 1), out outputTime, out error);
if (image != null)
{
Control?.InvokeOnMainThread(() => ((UIImageView)Control).Image = new UIImage(image));
}
}
}
else
{
formsControl.Source = "camera.png";
}
}
public MemoryStream GenerateThumbImage(string url, long usecond)
{
var asset = AVAsset.FromUrl(NSUrl.FromFilename(url));
var imageGenerator = AVAssetImageGenerator.FromAsset(asset);
imageGenerator.AppliesPreferredTrackTransform = true;
var actualTime = asset.Duration;
CoreMedia.CMTime cmTime = new CoreMedia.CMTime(usecond, 2000000);
NSError error;
var cgImage = imageGenerator.CopyCGImageAtTime(cmTime, out actualTime, out error);
//AVAssetImageGenerator imageGenerator = new AVAssetImageGenerator(AVAsset.FromUrl((new Foundation.NSUrl(url))));
//imageGenerator.AppliesPreferredTrackTransform = true;
//var actualTime = asset.Duration;
//CoreMedia.CMTime cmTime = new CoreMedia.CMTime(usecond, 1000000);
//NSError error;
//var cgImage = imageGenerator.CopyCGImageAtTime(cmTime, out actualTime, out error);
//CMTime actualTime;
//NSError error;
//CGImage cgImage = imageGenerator.CopyCGImageAtTime(new CMTime(usecond, 1000000), out actualTime, out error);
var zz = new UIImage(cgImage).AsJPEG().AsStream();
var a = new MemoryStream();
zz.CopyTo(a);
return(a);
//return ImageSource.FromStream(() => new UIImage(cgImage).AsJPEG().AsStream()); //mageSource.FromStream(() => new UIImage(cgImage).AsPNG().AsStream());
}
UIImage ImageFor(AVAsset avAsset, double time)
{
AVAssetImageGenerator imageGenerator = AVAssetImageGenerator.FromAsset(avAsset);
imageGenerator.AppliesPreferredTrackTransform = true;
CMTime actualTime;
NSError error = null;
var requestedTime = new CMTime((long)time, 100);
using (CGImage posterImage = imageGenerator.CopyCGImageAtTime(requestedTime, out actualTime, out error))
return(UIImage.FromImage(posterImage));
}
// Video thumbnail code:
// https://forums.xamarin.com/discussion/61903/code-snippet-how-to-generate-video-thumbnail
public void UpdateContent(string filePath)
{
this.filePath = filePath;
string cache = Common.LocalData.Storage.GetCacheFolder();
string extension = Path.GetExtension(filePath);
ImageView.BackgroundColor = UIColor.White;
ImageView.ContentMode = UIViewContentMode.ScaleAspectFill;
if (extension == ".mov")
{
// Get thumbnail
AVAsset asset = AVAsset.FromUrl(NSUrl.FromFilename(Path.Combine(cache, filePath)));
CMTime time = new CMTime(1, 1);
using (AVAssetImageGenerator imageGenerator = AVAssetImageGenerator.FromAsset(asset))
{
imageGenerator.AppliesPreferredTrackTransform = true;
using (CGImage imageRef = imageGenerator.CopyCGImageAtTime(time, out CMTime actualTime, out NSError err))
{
if (err != null || imageRef == null)
{
Console.WriteLine("Error loading thumbnail: " + err?.LocalizedDescription);
return;
}
var thumbnail = UIImage.FromImage(imageRef);
ImageView.Image = thumbnail;
}
}
}
else if ((new List <string> {
".m4a", ".mp3", ".wav"
}).Contains(extension))
{
ImageView.Image = UIImage.FromBundle("AudioIcon");
ImageView.BackgroundColor = UIColor.FromRGB(76, 175, 80);
ImageView.ContentMode = UIViewContentMode.Center;
}
else
{
ImageService.Instance.LoadFile(Path.Combine(cache, filePath)).Into(ImageView);
}
}
public static UIImage GetThumbnailFromVideoURL(NSUrl videoURL)
{
UIImage theImage = null;
var asset = AVAsset.FromUrl(videoURL);
var generator = AVAssetImageGenerator.FromAsset(asset);
generator.AppliesPreferredTrackTransform = true;
NSError error = null;
var time = new CMTime(1, 60);
CMTime actTime;
var img = generator.CopyCGImageAtTime(time, out actTime, out error);
if (error != null)
{
Console.WriteLine(error.ToString());
return(UIImage.FromBundle("videoimage.png"));
}
Console.WriteLine(img.ToString());
theImage = new UIImage(img);
var path = videoURL.RelativePath;
var imgData = SuperimposeImage(theImage, UIImage.FromBundle("btn_play.png")).AsJPEG(0.5f);
NSError err = null;
var jpgFilename = path.Replace(Path.GetExtension(path), "-thumb.jpg");
if (imgData.Save(jpgFilename, false, out err))
{
if (err == null)
{
Console.WriteLine("Thumbnail saved");
}
else
{
Console.WriteLine("error in saving " + err);
}
}
else
{
Console.WriteLine("Thumbnail not saved");
}
return(theImage);
}
private void SetVideoCell(AlbumViewCell cell, MediaItem item, int row)
{
DispatchQueue.DefaultGlobalQueue.DispatchAsync(() =>
{
using (var asset = AVAsset.FromUrl(new NSUrl(item.Path)))
using (var generator = AVAssetImageGenerator.FromAsset(asset))
{
generator.AppliesPreferredTrackTransform = true;
var duration = asset.Duration.Seconds;
var scaledImage = GetVideoThumbnail(generator, duration, _cellSize);
DispatchQueue.MainQueue.DispatchAsync(() =>
{
if (cell.Tag != row)
{
return;
}
cell.Duration = duration;
cell.Image = scaledImage;
});
}
});
}