Html5 video: fast fast forward and slow slow motion?

Question

I wonder what limitations are meant for variable speed playback using html5 video.

It seems that min and max game with this demo: http://www.w3.org/2010/05/video/mediaevents.html

I have a quick look at the specification , but I see nothing there.

Answer 1

I tested this on different cpu powers computers and found that there is no upper limit. However, the fastest speed will depend on the processor power. I got a maximum speed of 15x on Corei7 -4770k @ 3.5Ghz and got about 10x on the less powerful haswell corei5 @ 2.5Ghz.

These are the chrome extensions used to change speed: chrome extension for chrome

another chrome extension with modifiable hotkeys (but you need to add it to chrome by downloading the unpacked extension)

Update

Here is something related to Internet Explorer:

The playbackRate property is a multiplier of the internal or normal video playback speed, with the default setting of 1. If you set the property to 2, it doubles the playback speed, and .5 will play at half speed. If the playbackRate parameter is set to a negative value, in Windows Internet Explorer 9 it rounds it to zero, which significantly stops playback. In Internet Explorer 10, negative values ​​for playbackRate result in reverse video playback. The W3C specification does not recommend an upper limit , but Internet Explorer limits playbackRate to 8 times.

Source: Using JavaScript to control HTML5 video player

Answer 2

Accelerating the GPU helps you achieve even more.

Besides the chrome extension for playback speed, I use enusing myspeed . This helps to achieve more revolutions when you enable the enounce myspeed function to a maximum value of 5x and increase the playback speed of the hrome extension html5 movie.

I got a maximum speed of 30-40x (only 5x from myspeed) from 6x to 8x from the chrome extension) for Full HD video on Corei7 -3770k @ 3.5Ghz with Nvidia GTX 1080 Ti. Pascal GPUs support h264 or h265 or even VP9 codecs (which are used in youtube videos).

Video that was tested: https://www.youtube.com/watch?v=PSZw8egM2Is

The GPU video module in most cases was used by more than 90%, and downloading buffering from the Internet was insufficient with my bandwidth of 100 Mbps, so still sometimes youtube sometimes stops a little at these speeds, and something more than this speed stops for buffering, becomes more frequent due to depleted buffering or sometimes even with buffering available, but possibly due to the use of more than 90% of the video monitor.

TDP was 35% of the GPU.

When I switched the resolution to 480p, it gave me 75x, although the buffering is good and the video motor is 50%, but I couldn’t increase the speed anymore due to the frequent stops with turning the buffering icons)

In my Surface pro3, which has no GPU acceleration other than the Haswell integrated GPU: I had 20x maximum smooth playback combined with myspeed for 480p.

Answer 3

I searched for it myself, and it happened on your question. You will probably want to do this using the canvas, while maintaining the frame queue. Unfortunately, this solution only works for video, not for audio. Here you can see an example:

http://techslides.com/demos/slow-motion.html

I'm still looking for information on how to slow down the sound.

EDIT:

There it is easier to find a solution - a playback property .

Answer 4

Playback speed is divided into the following. You can hack the speed to 0.1 slower, and 2.0 is the fastest, I think;

• 1.0 is normal speed.
• 0.5 - half speed (slower)
• 2.0 - double speed (faster)
• -1.0 back, normal speed
• -0.5 - back, half speed

Here is the daemon on the w3schools website . Additional information can be found when reproducing the value vid.playbackRate = 0.5; .

Full text here .