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Error converting byte array to Image

I've read images in and saved them in a database in byte[] format. Later I want to retrieve the images and convert them into Image format. I've written the following method:
private List<Image> ConvertByteArraysToImages(List<byte[]> byteDataList)
{
List<Image> retVal = new List<Image>();
int counter = 0;
foreach (byte[] byteData in byteDataList)
{
// Something is wrong here
MemoryStream memstr = new MemoryStream(byteData);
Image img = Image.FromStream(memstr);
retVal.Add(img);
memstr.Dispose();// Just added this
// This works fine, the images appear in the folder
System.IO.File.WriteAllBytes(String.Format(#"C:\dev\test{0}.png", counter), byteData);
counter++;
}
return retVal;
}
I'm calling this method from an action which adds the images to the ViewBag to use in the view.
public ActionResult ViewTicket(Incident ticket)
{
//Read the ticket via the web API
string serialisedJSON = JsonConvert.SerializeObject(ticket.ID);
string response = TicketUtilities.JSONRequestToAPI(serialisedJSON, "GetSingleIncident");
Incident retVal = JsonConvert.DeserializeObject<Incident>(response);
//Convert byte[] to Image and add to ViewBag
List<Image> ScreenshotImagesFullsize = ConvertByteArraysToImages(retVal.Screenshots);
ViewBag.Add(ScreenshotImagesFullsize); //Error here
return View(retVal);
}
When I try to add the images to the ViewBag I get the following error in the browser:
Cannot perform runtime binding on a null reference
Writing the byte arrays to file produces the correct output but I'm not getting a list of Images in my return value. Hovering over retVal in debug mode shows the following:
I passed in two byte arrays and I see 2 objects in retVal, but I also I see the error: "Cannot evaluate expression because the code of the current method is optimized". Why does this occur?
Update: I disabled JIT optimization and now I can see the following:
I can see that the object has correctly acquired properties such as the height and width but the actual data is null.

Do not dispose the stream and do keep at least one reference to it as long as you need the image.
"You must keep the stream open for the lifetime of the Image."
https://msdn.microsoft.com/de-de/library/1kcb3wy4(v=vs.110).aspx
Note that there is no need to manually call dispose on a MemoryStream because it does not have unmanaged resources

So I solved this, the problem turned out not to be the conversion but rather adding Image objects to the view. For some reason adding Image objects to the view does not work, to overcome this I converted the image to a Base64 string
using (MemoryStream m = new MemoryStream())
{
retVal.Img.Save(m, retVal.Img.RawFormat);
byte[] imageBytes = m.ToArray();
// Convert byte[] to Base64 String
string imreBase64Data = Convert.ToBase64String(imageBytes);
retVal.ImgB64 = string.Format("data:image/png;base64,{0}", imreBase64Data);
}

creating a video from frames

In my windows universal app, I'm trying to use a WinRT component: http://blogs.msdn.com/b/eternalcoding/archive/2013/03/06/developing-a-winrt-component-to-create-a-video-file-using-media-foundation.aspx (which is basically a C++ wrapper for sinkWriter)
to create a video with frames.
I put all this code in a C++ project and I can call it from my C# code without problem.
The problem come with the constructor first:
HRESULT CVideoGenerator::InitializeSinkWriter(Windows::Storage::Streams::IRandomAccessStream^ stream)
I'm not sure of how to create the stream:
var filename = "exportedVideo.wmv";
var folder = Windows.Storage.KnownFolders.VideosLibrary;
StorageFile storageFile = await folder.CreateFileAsync(filename, CreationCollisionOption.ReplaceExisting);
IRandomAccessStream stream = await storageFile.OpenAsync(FileAccessMode.ReadWrite);
StorageFile file = await StorageFile.GetFileFromPathAsync(App.PhotoModel.Path);
CVideoGenerator videoGenerator = new CVideoGenerator(1280, 720, stream, 20);
The other thing is coming from this line:
hr = sinkWriter->SetInputMediaType(streamIndex, mediaTypeIn, NULL);
//hr 0xc00d5212 : No suitable transform was found to encode or decode the content. HRESULT
Any ideas ?

I've used this VideoGenerator sample, and got the same problem.
I'm not an expert of Media Foundation, but after some researchs, I've found that the problem was at these lines :
encodingFormat = MFVideoFormat_WMV3;
inputFormat = MFVideoFormat_RGB32;
Well, I've replaced the first format by the second one, like this :
encodingFormat = MFVideoFormat_RGB32;
inputFormat = MFVideoFormat_RGB32;
And it seems to work till the new exception in the WriteSample methods
hr = MFCopyImage(
pData, // Destination buffer.
cbWidth, // Destination stride.
(BYTE*)videoFrameBuffer, // First row in source image.
cbWidth, // Source stride.
cbWidth, // Image width in bytes.
videoHeight // Image height in pixels.
);
Apparently an Access Violation while writing in the memory.
Still trying to figure it out !
McSime

How to get the stream for a Multipart file in webapi upload?

I need to upload a file using Stream (Azure Blobstorage), and just cannot find out how to get the stream from the object itself. See code below.
I'm new to the WebAPI and have used some examples. I'm getting the files and filedata, but it's not correct type for my methods to upload it. Therefore, I need to get or convert it into a normal Stream, which seems a bit hard at the moment :)
I know I need to use ReadAsStreamAsync().Result in some way, but it crashes in the foreach loop since I'm getting two provider.Contents (first one seems right, second one does not).
[System.Web.Http.HttpPost]
public async Task<HttpResponseMessage> Upload()
{
if (!Request.Content.IsMimeMultipartContent())
{
this.Request.CreateResponse(HttpStatusCode.UnsupportedMediaType);
}
var provider = GetMultipartProvider();
var result = await Request.Content.ReadAsMultipartAsync(provider);
// On upload, files are given a generic name like "BodyPart_26d6abe1-3ae1-416a-9429-b35f15e6e5d5"
// so this is how you can get the original file name
var originalFileName = GetDeserializedFileName(result.FileData.First());
// uploadedFileInfo object will give you some additional stuff like file length,
// creation time, directory name, a few filesystem methods etc..
var uploadedFileInfo = new FileInfo(result.FileData.First().LocalFileName);
// Remove this line as well as GetFormData method if you're not
// sending any form data with your upload request
var fileUploadObj = GetFormData<UploadDataModel>(result);
Stream filestream = null;
using (Stream stream = new MemoryStream())
{
foreach (HttpContent content in provider.Contents)
{
BinaryFormatter bFormatter = new BinaryFormatter();
bFormatter.Serialize(stream, content.ReadAsStreamAsync().Result);
stream.Position = 0;
filestream = stream;
}
}
var storage = new StorageServices();
storage.UploadBlob(filestream, originalFileName);**strong text**
private MultipartFormDataStreamProvider GetMultipartProvider()
{
var uploadFolder = "~/App_Data/Tmp/FileUploads"; // you could put this to web.config
var root = HttpContext.Current.Server.MapPath(uploadFolder);
Directory.CreateDirectory(root);
return new MultipartFormDataStreamProvider(root);
}

This is identical to a dilemma I had a few months ago (capturing the upload stream before the MultipartStreamProvider took over and auto-magically saved the stream to a file). The recommendation was to inherit that class and override the methods ... but that didn't work in my case. :( (I wanted the functionality of both the MultipartFileStreamProvider and MultipartFormDataStreamProvider rolled into one MultipartStreamProvider, without the autosave part).
This might help; here's one written by one of the Web API developers, and this from the same developer.

Hi just wanted to post my answer so if anybody encounters the same issue they can find a solution here itself.
here
MultipartMemoryStreamProvider stream = await this.Request.Content.ReadAsMultipartAsync();
foreach (var st in stream.Contents)
{
var fileBytes = await st.ReadAsByteArrayAsync();
string base64 = Convert.ToBase64String(fileBytes);
var contentHeader = st.Headers;
string filename = contentHeader.ContentDisposition.FileName.Replace("\"", "");
string filetype = contentHeader.ContentType.MediaType;
}
I used MultipartMemoryStreamProvider and got all the details like filename and filetype from the header of content.
Hope this helps someone.

Unable to pass MemoryStream parameter to WCF method?

I have a method in Service1.svc.cs, below is the code
public void SaveData(int UserId, System.IO.MemoryStream File)
{
//Some code
}
I am passing values from xaml.cs
savedata.SaveDataAsync(userId, ms);
The error is
cannot convert from 'System.IO.MemoryStream' to
'SignSilverlight.ServiceReference1.MemoryStream'
How to solve ?

Memory stream is a .NET local object and it is not possible to pass it to a remote machine that might not even run .NET.
You have to pass a byte[] array instead. But be aware of size limits in endpoint's settings.
Here is how to (de)serialize a memory stream to array
// first endpoint
var streamSending = new MemoryStream();
var array = streamSending.ToArray();
// second endpoint
var streamRecieving = new MemoryStream(array);

Getting Json Output from Byte Array

I just started a new project on WCF and to be honest I'm very new at this with limited knowledge.
So what I'm trying to do is open a file that is stored in my computer (e.g. word, pdf, etc.) and display the contents in the webpage in JSon format. I converted the file in a byte array and tried to display the Stream. When I did that it asked me to open the file or save it. I don't want that - I just want the contents of the file to be displayed on my local host when i call the method.
Here's what I have:
public string GetRawFile()
{
string file = #"C:\.....\TestFile.pdf";
byte[] rawFile = File.ReadAllBytes(file);
//Stream stream = new MemoryStream(rawFile);
//DataContractJsonSerializer obj = newDataContractJsonSerializer(typeof(string));
//string result = obj.ReadObject(stream).ToString();
//Deserializing
MemoryStream stream = new MemoryStream();
BinaryFormatter binForm = new BinaryFormatter();
stream.Write(rawFile, 0, rawFile.Length);
stream.Seek(0, SeekOrigin.Begin);
Object obj = (Object) binForm.Deserialize(stream);
System.Web.Script.Serialization.JavaScriptSerializer xyz = new System.Web.Script.Serialization.JavaScriptSerializer();
string ejson = xyz.Serialize(obj);
WebOperationContext.Current.OutgoingRequest.ContentType = "text/json";
return ejson;
}
I'm trying to return a string and it's not working, but when I return just the stream it's popping up the "openwith" message.
Also should I use the GET or POST on my datacontract. I'm using REST in C#.

I'm assuming that your file actually contains json. If that is the case just do this;
string file = File.ReadAllText("C:\path\to\file.extension");
You're making the problem a lot more complicated than it needs to be. Just read the file and return it's data as a string. I think you want to use GET for the http method. Generally speaking, you all use post if you're adding new content. If for example the users request would cause the application to write some data to a file or data base then you would typically use POST for the http method. If they're just requesting data, you almost always use GET.