Upload video with Jquey Ajax

Hi with the APi, how to send the video to the question, I have the response : “The uploaded file is incorrect format ..” 

this the test , i have mal all test with ReadAsDataUrl for example or othe rmais si not working 

thanks for you help 

function uploadVideo(questionId)
{
    $.ajax({
        url: rootURL+'urlforpresign',
        method: 'post',
        data: {
            'questionid': questionId
        },
        success: function(json) {
            if (json.code == 0) {

            } else {
                var presignedUrl = json.presignedUrl;
                var file = $('#file_'+questionId)[0].files[0];
                var fileName = file.name;
                var reader = new FileReader();
                reader.onload = function (event) {
                   $.ajax({
                    url: presignedUrl,
                    method: 'PUT',
                    data: {
                        file: fileName,
                        file_data: event.target.result,
                        file_type: 'video/mp4'
                    },
                    timeout: 0,
                    beforeSend: function(request) {
                        request.setRequestHeader("Content-Type", "video/webm;codecs=vp8,opus");
                    },
                    headers: {
                        "Content-Type": "video/webm;codecs=vp8,opus"
                    },
                    ContentType: "video/webm;codecs=vp8,opus",
                    success: function(data) {
                        console.log('success', data)
                    },
                    done: function (response) {
                        console.log(response)
                    },
                    error: function(xhr, ajaxOptions, thrownError) {
                        if (xhr.status == 0 && thrownError == '') {
                            return;
                        }
                        console.log(thrownError);
                        //notifyError("{/literal}{t}Erreur pendant l'enregistrement{/t}{literal}");
                    }
                })
                }
                reader.readAsBinaryString(file);
            }
        }
    });
}