Сложновато оказалось (давно с видео не работал)
Получилось как то так
(Пример видео - какой нашел в инете не самый короткий
<body>
<video id='video' src='https://www.nlm.nih.gov/web/documentation/TemplateDocumentation/video_files/IN_Intro-800.mp4'>
</video>
<br>
<button id=bs>Start</button>
<script>
let duration;
const start = 20;
const dplay = 3;
const dskip = 7;
const video = document.getElementById('video')
const play = (d) => {
console.log('play', video.currentTime)
const te = Math.min(video.currentTime + d, duration)
const result = !(te === duration)
return new Promise ((res) => {
const handl = () => {
if (video.currentTime > te-0.05) {
video.removeEventListener('timeupdate', handl)
res (result);
}
}
video.addEventListener('timeupdate', handl)
video.play();
})
}
const skip = (d) => {
console.log('skip', video.currentTime)
const ts = Math.min(video.currentTime + d, duration)
return new Promise ((res) => {
if (ts === duration) res (false);
const handl = () => {
video.removeEventListener('seeked', handl)
res (true);
}
video.addEventListener('seeked', handl)
video.currentTime = ts;
})
}
const work = async () => {
let result = true;
result = await skip (start)
while (result) {
result = await play(dplay)
if (result) result = await skip(dskip)
}
}
video.addEventListener('durationchange', () => {
duration = video.duration;
})
document.getElementById('bs').onclick = () => work()
</script>
</body>
