html-basic

2024年02月06日

柏拉文

越努力，越幸运

一、认识

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1.1 视频水平翻转

只需要将 video 的样式设置为 transform: scaleX(-1) 即可。

video.style.transform = "scaleX(-1)";

二、实现

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<div class="operation">
    <button id="start-record">录制</button>
    <button id="stop-record">停止</button>
</div>
<div class="video-container">
    <video id="video" autoplay></video>
</div>


<script>
    let mediaRecorder = null;
    const recordedBlobs = [];
    const video = document.getElementById('video');
    const startRecordEl = document.getElementById('start-record');
    const stopRecordEl = document.getElementById('stop-record');

    function startRecord() {
        const timeSlice = 5000;
        mediaRecorder.start(timeSlice);
    }

    async function stopRecord() {
        const stream = video.srcObject;
        const tracks = stream.getTracks();

        tracks.forEach(track => {
            track.stop();
        });

        video.srcObject = null;
        mediaRecorder.stop();
    }

    async function prepareRecord() {
        const stream = await navigator.mediaDevices.getUserMedia({
            video: true,
            audio: true
        });

        video.srcObject = stream;
        video.play();

        mediaRecorder = new MediaRecorder(stream, {
            mimeType: 'video/webm'
        });

        mediaRecorder.ondataavailable = event => {
            if (event.data && event.data.size > 0) {
            recordedBlobs.push(event.data);
            }
        };
    }

    async function checkPermissions(name) {
        try {
            return await navigator.permissions.query({ name: name });
        } catch (error) {
            return {
                state: "denied"
            };
        }
    }

    async function run() {
        const camera = await checkPermissions('camera');
        const microphone = await checkPermissions('microphone');
        if (camera.state === 'granted' && microphone.state === 'granted') {
            prepareRecord();
            startRecordEl.addEventListener('click', startRecord);
            stopRecordEl.addEventListener('click', stopRecord);
        } else {
            alert('请允许使用摄像头和麦克风');
        }
    }

    run();
</script>