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Can you get a video thumbnail using MediaToolkit without reading/writing to disk?

I have a video file that's already loaded in memory (an IFormFile that's converted to a byte[]).
I've been trying to figure out how to take that video and get a thumbnail image from it, without having to read/write to disk.
I found use cases for MediaToolkit and FFmpeg here, and Movie Thumbnailer here, but from what I can find, those require the video already be saved to disk and have write access to output the thumbnail to a file.
Is there any way I can take either an IFormFile or byte[] and do something similar to what MediaToolkit is doing while being able to keep the result in memory?
I know a lot of folks are saying byte[] isn't the way to go. In that case, I'm more than happy to convert from IFormFile to a Stream, but I still need a way to do that and keep it in memory.

please try this with Windows.Media.Editing should work, not fully tested..
int frameHeight; // you can set the height
int frameWidth; // ...
TimeSpan getFrameInTime = new TimeSpan(0, 0, 1);
//Using Windows.Media.Editing get your ImageStream
var yourClip = await MediaClip.CreateFromFileAsync(someFile);
var composition = new MediaComposition();
// add the section of the video as needed
composition.Clips.Add(yourClip);
// Answer - now that your have your imageStream, get the thumbnail
var yourImageStream = await composition.GetThumbnailAsync(
getFrameInTime,
Convert.ToInt32(frameWidth),
Convert.ToInt32(frameHeight),
VideoFramePrecision.NearestFrame);
//now create your thumbnail bitmap
var yourThumbnailBitmap = new WriteableBitmap(
Convert.ToInt32(frameWidth),
Convert.ToInt32(frameHeight)
);
yourThumbnailBitmap.SetSource(yourImageStream);

Locating file path of image in android devices

sorry im very new to unity and c#.
Im trying to read an image and apply it as a texture.
The code works when i try it with an image on my computer, however, when i try it with my android devices (phone and AR glasses), i've not been able to specify the file path correctly. How do i specify the file path properly of android devices or is there a way i can get these file path?
Thank you so much for any help in advance! :)
void Start()
{
thisTexture = new Texture2D(100, 100);
//string path = "C:/Users/kenny/Desktop/5th March/im.png"; //this works
string path = "file:///storage/emulated/0/im2.png"; // this doesnt work
bytes = File.ReadAllBytes(path);
thisTexture.LoadImage(bytes);
GetComponent<Renderer>().material.mainTexture = thisTexture;
}

For mobile devices it is not as straightforward to get a file from a plain path.
One way of doing so is by using the Resources folder. In your root folder (Assets), create a new folder named Resources. Put your image there.
Then you can do something like this:
// path without file extension!
var texture = Resources.Load<Texture2D>("path/to/texture");
You can get more references for this functionality here: https://forum.unity.com/threads/how-to-load-a-image-from-the-resources-folder-to-a-texture2d.101542/
Alternatively, you could use the StreamingAssets folder, but that's another story.

Save PDF to file

I am working on a Windows Store app for Windows 8.1, and I can't find anything that addresses what I need to do. I am trying to save an image of a pdf page to my local app data storage. I have the following:
private async void GetFirstPage()
{
// Retrieve file from FutureAccessList
StorageFile file = await Windows.Storage.AccessCache.StorageApplicationPermissions.FutureAccessList.GetFileAsync(token);
// Truncate last 4 chars; ex: '.pdf'
FileName = file.Name.Substring(0, file.Name.Length - 4);
// Get access to pdf functionality from file
PdfDocument doc = await PdfDocument.LoadFromFileAsync(file);
// Get a copy of the first page
PdfPage page = doc.GetPage(0);
// Below could be used to tweak render options for optimizations later
//PdfPageRenderOptions options = new PdfPageRenderOptions();
// Render the first page to the BitmapImage
InMemoryRandomAccessStream stream = new InMemoryRandomAccessStream();
await page.RenderToStreamAsync(stream);
// Common code
Cover.SetSource(stream);
// Convert the active BitmapImage Cover to a storage file to be stored locally
// ???
}
The variable, Cover, is a BitmapImage that is bound in XAML to display the image to the user. I want to save this image to my local app data so that I don't have to re-render it through the PDF library every time my app opens! The problem is I can't save anything in a Windows Store app from a stream unless it is text to my knowledge, (no filestream or fileoutputstreams for me), and Cover's URI source is null, since it was sourced from a stream, making it difficult to get my BitmapImage, Cover, to a StorageFile for proper Windows Store saving.
Everything works for me currently, I'm just upset about re-rendering the pdf page to my bitmapimage from scratch every time my app opens. Thanks in advance for any input!

You need to save the image from the PdfPage directly rather than from the BitmapImage since you can't get the data out of the BitmapImage. The PdfPage.RenderToStreamAsync already encodes the stream as a bitmap so you don't need to do any manipulation beyond sending it to the file. This is essentially the same as what you are doing to save to the InMemoryRandomAccessStream, except to a file based stream:
//We need a StorageFile to save into.
StorageFile saveFile = await ApplicationData.Current.LocalFolder.CreateFileAsync("safedPdf.png",CreationCollisionOption.GenerateUniqueName);
using (var saveStream = await saveFile.OpenAsync(FileAccessMode.ReadWrite))
{
await page.RenderToStreamAsync(saveStream);
}

File IO in Windows 8

I have been trying to read a file, and calculate the hash of the contents to find duplicates. The problem is that in Windows 8 (or WinRT or windows store application or however it is called, I'm completely confused), System.IO has been replaced with Windows.Storage, which behaves differently, and is very confusing. The official documentation is not useful at all.
First I need to get a StorageFile object, which in my case, I get from browsing a folder from a file picker:
var picker = new Windows.Storage.Pickers.FolderPicker();
picker.SuggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.MusicLibrary;
picker.FileTypeFilter.Add("*");
var folder = await picker.PickSingleFolderAsync();
var files = await folder.GetFilesAsync(Windows.Storage.Search.CommonFileQuery.OrderByName);
Now in files I have the list of files I need to index. Next, I need to open that file:
foreach (StorageFile file in files)
{
var filestream = file.OpenAsync(Windows.Storage.FileAccessMode.Read);
Now is the most confusing part: getting the data from the file. The documentation was useless, and I couldn't find any code example. Apparently, Microsoft thought getting pictures from the camera is more important than opening a file.
The file stream has a member ReadAsync which I think reads the data. This method needs a buffer as a parameter and returns another buffer (???). So I create a buffer:
var buffer = new Windows.Storage.Streams.Buffer(1024 * 1024 * 10); // 10 mb should be enough for an mp3
var resultbuffer = await filestream.ReadAsync(buffer, 1024 * 1024 * 10, Windows.Storage.Streams.InputStreamOptions.ReadAhead);
I am wondering... what happens if the file doesn't have enough bytes? I haven't seen any info in the documentation.
Now I need to calculate the hash for this file. To do that, I need to create an algorithm object...
var alg = Windows.Security.Criptography.Core.HashAlgorithmProvider.OpenAlgorithm("md5");
var hashbuff = alg.HashData(resultbuffer);
// Cleanup
filestream.Dispose();
I also considered reading the file in chunks, but how can I calculate the hash like that? I looked everywhere in the documentation and found nothing about this. Could it be the CryptographicHash class type with it's 'append' method?
Now I have another issue. How can I get the data from that weird buffer thing to a byte array? The IBuffer class doesn't have any 'GetData' member, and the documentation, again, is useless.
So all I could do now is wonder about the mysteries of the universe...
// ???
}
So the question is... how can I do this? I am completely confused, and I wonder why did Microsoft choose to make reading a file so... so... so... impossible! Even in Assembly I could figure it out easier than.... this thing.

WinRT or Windows Runtime should not be confused with .NET as it is not .NET. WinRT has access to only a subset of the Win32 API but not to everything like the .NET is. Here is a pretty good article on what are the rules and restrictions in WinRT.
The WinRT in general does not have access to the file system. It works with capabilities and you can allow file access capability but this would restrict your app's access only to certain areas. Here is a good example of how do to file access via WinRT.

Add sound to swf file via SwfDotNet tool

I need to make swf file (slide show) from images and sounds (narrations).
I am trying to use SwfDotNet tool for it.
There is article which describes how to add images to swf http://www.codeproject.com/KB/graphics/jpeg2swf.aspx?fid=369197&df=90&mpp=10&noise=3&prof=True&sort=Position&view=Quick&fr=21#xx0xx
I can't add sound to swf.
I try to use next code, but it doesn't work.
Looks that DefineSoundTag works because file size is increased, but StartSoundTag doesn't work.
var soundId = swf.GetNewDefineId();
swf.Tags.Add(DefineSoundTag.FromFile(soundId, fileName));
var soundInfo = new SoundInfo() {
InPoint = 1,
OutPoint = 10000
};
swf.Tags.Add(new StartSoundTag(soundId, soundInfo));
Does anyone know how to add sound to swf via swfdotnet tool?