I had better results by calculating values for the interval and the time subtraction based on the frames-per-second. The interval for one frame is calculated in milliseconds (1000 / fps) and the time subtraction for one frame is calculated in seconds (1 / fps).
I also set the playbackRate
to zero when playing in reverse, since the playhead position is set manually.
var video = document.getElementById('video');
var intervalRewind;
var fps = 30;
$(video).on('play', function() {
clearInterval(intervalRewind);
video.playbackRate = 1.0;
});
$(video).on('pause', function() {
clearInterval(intervalRewind);
});
$("#speed").click(function() { // button function for 4x fast speed forward
clearInterval(intervalRewind);
video.playbackRate = 4.0;
video.play();
});
$("#negative").click(function() { // button function for rewind
video.playbackRate = 0;
clearInterval(intervalRewind);
intervalRewind = setInterval(function() {
if (video.currentTime == 0) {
clearInterval(intervalRewind);
//video.pause();
} else {
video.currentTime -= (1 / fps);
}
}, (1000 / fps));
});
video {
height: 400px;
}
button {
display: block;
font-size: 1rem;
margin-bottom: 0.5rem;
padding: 1rem;
border-radius: 6px;
cursor: pointer;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<video id="video" controls="controls">
<source src="https://www.quirksmode.org/html5/videos/big_buck_bunny.mp4" type="video/mp4">
<source src="https://www.quirksmode.org/html5/videos/big_buck_bunny.webm" type="video/webm">
<source src="https://www.quirksmode.org/html5/videos/big_buck_bunny.ogv" type="video/ogg">
</video>
<button id="speed">Fast Forward</button>
<button id="negative">Rewind</button>
Also see:
Playing HTML5 Video Backwards @ nicbell.net.
Alternatively, you might consider controlling the frames-per-second by using requestAnimationFrame
. See Controlling fps with requestAnimationFrame?
Per your request, here is a version that accommodates multiple videos on a page by using classes instead of IDs. I also used the requestAnimationFrame
method by markE described here: Controlling fps with requestAnimationFrame.
var fps = 30;
var fpsInterval = 1000 / fps;
jQuery('.video_block').each(function(i, $thisBlock) {
var thisVideo = this.querySelector('video');
jQuery('.video', $thisBlock).on('play', function() {
thisVideo.reverse_stop = true;
thisVideo.playbackRate = 1.0;
}).on('pause', function() {
thisVideo.reverse_stop = true;
});
jQuery('.btn_fast', $thisBlock).on('click', function() {
thisVideo.reverse_stop = true;
thisVideo.playbackRate = 4.0;
});
jQuery('.btn_reverse', $thisBlock).on('click', function() {
thisVideo.playbackRate = 0;
thisVideo.reverse_stop = false;
startReverse(fps, thisVideo);
});
});
function startReverse(fps, video) {
video.playbackRate = 0;
video.reverse_stop = false;
video.then = Date.now();
animateReverse(video);
}
function animateReverse(video) {
// stop playing in reverse
if (video.reverse_stop) {
return;
}
// request another frame
requestAnimationFrame(function() {
animateReverse(video);
});
// calculate elapsed time since last loop
var now = Date.now();
var elapsed = now - video.then;
// if enough time has elapsed, draw the next frame
if (elapsed > fpsInterval) {
video.then = now - (elapsed % fpsInterval);
// if we reach the beginning, stop playing in reverse.
// otherwise, move backward.
if (video.currentTime <= 0) {
video.reverse_stop = true;
} else {
video.currentTime -= (1 / fps);
}
}
}
.video {
height: 400px;
}
.btn {
display: block;
font-size: 1rem;
margin-bottom: 0.5rem;
padding: 1rem;
border-radius: 6px;
cursor: pointer;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="video_block">
<video class="video" controls="controls">
<source src="https://www.quirksmode.org/html5/videos/big_buck_bunny.mp4" type="video/mp4">
<source src="https://www.quirksmode.org/html5/videos/big_buck_bunny.webm" type="video/webm">
<source src="https://www.quirksmode.org/html5/videos/big_buck_bunny.ogv" type="video/ogg">
</video>
<button class="btn btn_fast">Fast Forward</button>
<button class="btn btn_reverse">Reverse</button>
</div>
<div class="video_block">
<video class="video" controls="controls">
<source src="https://www.quirksmode.org/html5/videos/big_buck_bunny.mp4" type="video/mp4">
<source src="https://www.quirksmode.org/html5/videos/big_buck_bunny.webm" type="video/webm">
<source src="https://www.quirksmode.org/html5/videos/big_buck_bunny.ogv" type="video/ogg">
</video>
<button class="btn btn_fast">Fast Forward</button>
<button class="btn btn_reverse">Reverse</button>
</div>