如何从.mp4，webm，3gp格式的视频生成缩略图

Question

I want to generate thumbnail from video with .mp4,webm,3gp format . here is my code using jcodec but i did not get video thumbnai i am getting nullpointer exception on framegrab.getnativeline.

Answer 1

Using the latest version of jcodec, a simple helper method like this one below works as expected.

public void generate(File file) {
    try {
        double startSec = 51.632;
        int frameCount = 10;

        FrameGrab grab = FrameGrab.createFrameGrab(NIOUtils.readableChannel(file));
        grab.seekToSecondPrecise(startSec);

        for (int i = 0; i < frameCount; i++) {
            Picture picture = grab.getNativeFrame();
            System.out.println(picture.getWidth() + "x" + picture.getHeight() + " " + picture.getColor());

            BufferedImage bufferedImage = AWTUtil.toBufferedImage(picture);
            ImageIO.write(bufferedImage, "png", new File(file.getAbsolutePath() + "-frame" + i + ".png"));
        }
    } catch (Exception e) {
        log.error(e.getMessage());
    }
}