Efficiently converting an array of bitmaps to video

Using the Jcodec library, I had success producing and storing a video file on the Android file system from an array of Bitmap objects.

However, the encoding time takes way too long. I thought about scaling down each of the bitmaps to speed this up but this did not seem to work. Despite researching extensively, I struggled to find a helpful answer.

The below code is currently how I'm creating a bitmap, Where canvasView.getWidth() and canvasView.getHeight() correspond to 1920 x 1280 respectively.

public Bitmap loadBitmapFromView(View v) {
    Bitmap b = Bitmap.createBitmap(canvasView.getWidth(), canvasView.getHeight(), Bitmap.Config.RGB_565);
    Log.i("Downloading", "OWidth: " + b.getWidth() + " --- " + "OHeight: " +  b.getHeight());

    Canvas c = new Canvas(b);
    c.drawColor(Color.WHITE);   // Essential

    v.draw(c);
    v.invalidate();
    v.requestLayout();

    return b;
}

I noticed when you change these two parameters to something smaller, IE:

Bitmap.createBitmap(256, 256, Bitmap.Config.RGB_565);

The encoding speeds up dramatically.

The size of the entire view is 1920 x 1280, so the createBitmap method shown above would only capture a small portion of the window (256 x 256), which is not what I require.

I need help finding a way to more efficiently encode an array of bitmaps to video or use the same method I am using but scaling down each bitmap while maintaining the entire image's visibility and speeding up the encoding process.

You can use FFmpeg to speed up your process of making video from images or bitmap

ffmpeg command:-

        File dir = your directory where image stores;
        String filePrefix = "picture"; //imagename prefix
        String fileExtn = ".jpg";//image extention
        filePath = dir.getAbsolutePath();
        File src = new File(dir, filePrefix + "%03d" + fileExtn);// image name should ne picture001, picture002,picture003 soon  ffmpeg takes as input valid



complexCommand = new String[]{"-i", src + "", "-c:v", "libx264", "-c:a", "aac", "-vf", "setpts=2*PTS", "-pix_fmt", "yuv420p", "-crf", "10", "-r", "15", "-shortest", "-y", "/storage/emulated/0/" + app_name + "/Video/" + app_name + "_Video" + number + ".mp4"};

here src = directory path which contains multiple images

you ca use writingminds library fro easily integrate ffmpeg in your project

https://github.com/WritingMinds/ffmpeg-android-java

but ffmpeg increase apk size approx 18-20 mb