System.NullReferenceException: CrossMedia.Current.PickPhotoAsync. (HEIC/IPhoneX)

[christophedelanghe]

I get a null reference exception in the CrossMedia.Current.PickPhotoAsync when selecting a picture from the library. It only happens with some pictures.

I can't pinpoint which files go wrong but I think it might have something to do with the new HEIC format. It's also possible that it goes wrong with pictures taken on an iPhoneX.

Version Number of Plugin: 3.1.3
Device Tested On: iPhoneX

await CrossMedia.Current.Initialize();
if (CrossMedia.Current.IsPickPhotoSupported)
{
    var file = await CrossMedia.Current.PickPhotoAsync(new Plugin.Media.Abstractions.PickMediaOptions());

    if (file != null)
    {
        profilePicture.Source = ImageSource.FromStream(() =>
        {
            var stream = file.GetStream();
            return stream;
        });
    }
}

Unhandled Exception:
System.NullReferenceException: Object reference not set to an instance of an object
at Plugin.Media.MediaPickerDelegate+d__25.MoveNext () [0x00380] in :0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.6.1.3/src/mono/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:152
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00037] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.6.1.3/src/mono/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x00028] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.6.1.3/src/mono/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.6.1.3/src/mono/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.TaskAwaiter`1[TResult].GetResult () [0x00000] in :0
at Plugin.Media.MediaPickerDelegate+d__9.MoveNext () [0x000d4] in :0

[christophedelanghe]

WEIRD ... when I pass CompressionQuality=99 to the Plugin.Media.Abstractions.PickMediaOptions it does not crash anymore ...

[jamesmontemagno]

Can you pull down the source code and run through the test apps and try to reproduce. I don't have an iphone x

[christophedelanghe]

The exception is in the MediaPickerDelegate line 370 ...

image.AsJPEG(quality).Save(path, true);

the image is not null, quality=1 and the path is also correct ...

if passing 0.9 as quality there is no exception

When I split up the code in two lines I can see that image.AsJPEG(quality); returns null

if (!savedImage)
{
    var jpg = image.AsJPEG(quality);
   jpg.Save(path, true);
}

jpg = null

[jamesmontemagno]

Interesting, what if you do .99?

[christophedelanghe]

.99 is working also ...

[jamesmontemagno]

Do you happen to know what the file extension is on it? Curious if i can put some sort of hack in there. I don't have any devices that take these photos.

[christophedelanghe]

It's just jpg ...

Maybe you can do something with the data from the CGImage?

BitmapInfo: NoneSkipLast
BitsPerComponent: 8
BytesPerRow: 16128
Height: 3024
Width: 4032

I found this post. It might have something to do with the image size, which is too big to use as JPG, according to this post:
https://stackoverflow.com/questions/15120589/uiimage-aspng-and-asjpeg-fails

The AsJPEG returned null because the image size was too big (it was taken with an iPhone 5). After I Scaled it down by 2, it generates the data properly.

This fixed it (but I don't know if it's good performance wise)

private bool SaveImageWithMetadata(UIImage image, float quality, NSDictionary meta, string path)
{
        try
        {
             var imageData = image.AsJPEG(quality);
             while (imageData == null && quality > 0)
             {
                 quality-=0.01f;
                 imageData= image.AsJPEG(quality);
             }

...

[jamesmontemagno]

Awesome! Good one!

Very tricky. I am pushing out: 3.1.3.222-beta

Can you test this out. The AsJPEG code is in 3 different places.