海康攝像頭抓圖
curl --insecure --anyauth -u admin:password -X GET http://admin:[email protected]/ISAPI/Streaming/channels/110/picture >d:/b.jpg

海康RTSP流
rtsp://admin:[email protected]:554/Streaming/Channels/201

ffmpeg壓縮海康錄影檔案 壓縮率大概 15%
ffmpeg -i Downtest_ch0001_00000003678000000.mp4 -c:v libx264 -crf 28 -preset veryfast -c:a copy -movflags +faststart output.mp4 -y

JS Video截圖上傳程式碼

// 視訊繪製canvas畫布、截圖上傳
function canvasUpload() {
    let v = $('video')[0];
    let canvas = document.createElement("canvas");
    canvas.width = v.videoWidth;
    canvas.height = v.videoHeight;
    let ctx = canvas.getContext("2d");
    ctx.drawImage(v, 0, 0, canvas.width, canvas.height);
    
 
// document.body.appendChild(canvas);
    let imgSrc = canvas.toDataURL("image/jpeg", 0.8);
    $('#img1').prop('src', imgSrc);


    //獲取裁剪完後的base64圖片url,轉換為blob
    var data = imgSrc;
    var formData = new FormData();
    formData.append("img_file", dataURLtoBlob(data));
    var httprequest = null;
    
 
if (window.XMLHttpRequest) {
        httprequest = new XMLHttpRequest();
    } else {
        httprequest = new ActiveXObject('MicroSoft.XMLHTTP');
    }
    var apiurl = "save.php?sn=" + $('#txtSn').val(); //上傳圖片的api介面，自行填寫
    httprequest.open('POST', apiurl, true);
    httprequest.send(formData);
    httprequest.onreadystatechange = function () {
        if (httprequest.readyState == 4) {
            if (httprequest.status == 200) {
                console.log('上傳成功');
            }
            else {
                console.error('獲取資料錯誤,錯誤程式碼：' + httprequest.status + '錯誤資訊：' + httprequest.statusText);
            }
        }
    };
}

//把base64位的toDataURL圖片轉換成blob
function dataURLtoBlob(dataurl) {
    var arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1],
        bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n);
    while (n--) {
        u8arr[n] = bstr.charCodeAt(n);
    }
    return new Blob([u8arr], { type: mime });
}