How to convert image into DIB bitmap using dotnet cross platform libraries

Question

I got a webcam that records Video and i wanna write it to a file.

While there are many libraries (mostly based on ffmpeg) that allow you to combine frames, i need a library that can be used to continously write frames to file.

I found such a library called SharpAvi but now i am stuck at converting my image to the DIB bitmap format it expects.

Heres my Code so far:

using FlashCap;
using SharpAvi.Codecs;
using SharpAvi.Output;

var path = Console.ReadLine();

var devices = new CaptureDevices();
var descriptor = devices.EnumerateDescriptors().First(x => x.Characteristics.Length > 0);

var characteristics = descriptor.Characteristics.First(x => x.Height == 720);


var writer = new AviWriter(path);

var stream = writer.AddEncodingVideoStream(new UncompressedVideoEncoder(
    characteristics.Width,
    characteristics.Height));

stream.Height = characteristics.Height;
stream.Width = characteristics.Width;


using var device = await descriptor.OpenAsync(
    characteristics,
    async bufferScope =>
    {
        
        byte[] image = bufferScope.Buffer.ExtractImage();

        var ms = new MemoryStream(image);

        byte[] buffer = new byte[bitmap.Height * bitmap.Width * (characteristics.FixedBitsPerPixel/8)];
        //how can i get the image as a DIB bitmap in my buffer?

        await stream.WriteFrameAsync(true, buffer, 0, buffer.Length);
    });

await device.StartAsync();

await Task.Delay(5000);

await device.StopAsync();

the example uses a standard System.Drawing Bitmap and then uses this code:

var bits = bitmap.LockBits(new Rectangle(0, 0, screenWidth, screenHeight), ImageLockMode.ReadOnly, PixelFormat.Format32bppRgb);
Marshal.Copy(bits.Scan0, buffer, 0, buffer.Length);

However the System.Drawing.Common nuget is not cross platform which is a key criteria. I tried using ImageSharp and IronSoftware.Drawing but didn't get it to run. The documentation theres this line.

AVI expects uncompressed data in the format of a standard Windows DIB, that is a bottom-up bitmap of the specified bit-depth. For each frame, put its data in a byte array and call IAviVideoStream.WriteFrame.

How to convert image into DIB bitmap using dotnet cross platform libraries

0 Answers0