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radek-k / FFMediaToolkit

FFMediaToolkit is a cross-platform video decoder/encoder library for .NET that uses FFmpeg native libraries. It supports video frames extraction, reading stream metadata and creating videos from bitmaps in any format supported by FFmpeg.
MIT License
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Performance Recomendations #9

Closed redbaty closed 3 years ago

redbaty commented 4 years ago

Are there any improvements to be made on the performance side? Currently file.Video.ReadNextFrame(); is taking on average 22,33ms to run, which on a 24fps video isn't much faster than real-time ☹️

Are there any options for making it faster?

radek-k commented 4 years ago

I know that the library performance isn't optimal, but I currently don't have many time to improve it. If you have any ideas, please open a pull request.

redbaty commented 4 years ago

Yeah, this is more of a "where to look" kind of question, the question I'm gonna ask is kinda dumb, but I don't know FFmpeg too much, can you walk me through the frame grabbing process?

Example

        //VideoStream.cs - Line 95
        private unsafe ImageData Read()
        {
            stream.Read(frame); //This does blabla bla and send packet so that this does that.
            FramePosition++; // Moves frame position.

            var targetLayout = GetTargetSize(); //Calculate targetsize.
            var bitmap = ImageData.CreatePooled(targetLayout, mediaOptions.VideoPixelFormat); // Rent memory space.
            scaler.AVFrameToBitmap(frame, bitmap); // Do a thing.
            return bitmap;
        }