js上传视频获取截图黑屏 可以尝试先播放一下

var videoElement = $(“video”)[0];

        videoElement.play(); //播放控制

        videoElement.addEventListener(“canplay”, function (_event) {

            var canvas = document.createElement(“canvas”);

            canvas.width = videoElement.videoWidth*0.25;

            canvas.height = videoElement.videoHeight*0.25;

            console.log(videoElement.videoWidth)

            canvas.getContext(‘2d’).drawImage(videoElement, 0, 0, canvas.width, canvas.height);

            var img = document.createElement(“img”);

            img.src = canvas.toDataURL(“image/png”);

            $(“#output”).html(img);

            console.log(img.src);

        });