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R
rossIDM
Participant
December 15, 2010
Question

FLV playback speed

  • December 15, 2010
  • 2 replies
  • 4788 views

I've been trawling the internet for a few hours now trying to find the solution to what apparently seems to be quite a common problem:

How can you dynamically change the playback speed of a streaming flv?

(essentially Im trying to get a video to gradually slow down and stop)

Changing the frame rate of the swf its being streamed into wont work because the flv simply ignores this and plays at the flvs set frame rate.

The only thing I could think of would be to add cue points to the flv on each frame and create a increasing timing loop telling it when to go to each cue point - only problem is that the audio wouldn't work and the video would be HUGE!

Any suggestions anyone?

This topic has been closed for replies.

2 replies

adninjastrator
adninjastrator
Inspiring
December 18, 2010

Seems like Flash will just not do the job... so here's another option..

It sounds like you sort of want the slowdown hardwired?? that is you'll always want the video to slow down, speed up in the same places in the video?? or maybe not.. but here's one idea.

Edit the original video and include some slowmo sections..most video editing applications can do that.. adds in extra frames every so often. If course whenever you add extra frames, the audio may or may not be duplicated also... but for sure it's not the same as the original.

so now you've got a video that slows down / speeds up every so often.

Or maybe if the video was a real short one, edit the original video so the entire thing runs in slowmo, then as its playing, scrub the playhead to speed the progress, You could even take it one step farther. While playing the slowmo version of the video and scrubbing the playhead, use a screen capture program to capture the screen display, and a mic or other audio device to create audio to better match what you see on the screen. You see this done a lot in video tutorials...

Some outside the box ideas anyway..

Best wishes,

Adninjastrator

J
jackquack
Participant
July 15, 2013

Well, I still have questions about this topic (yes, resurecting oooold thread). This software 'myspeed' by Enounce are able to dynamically adjust video playback speed. So, how do they accomplish this? I would very much like to know because I find their product extremely unreliable, but I like the functionality.

So, they have demonstrated that it is possible. So does anyone have any ideas now?

A
Andrei1-bKoviI
Inspiring
July 16, 2013

They don't use Flash for video speed manipulations. Most probably they hijack video before it gets to flash and fetch back edited frames.

kglad
Community Expert
kgladCommunity Expert
Community Expert
December 15, 2010

you can't adjust the playback more frequently than a few times per second without causing problems.  but if that works for you, can use the seek() method of the flvplayback class.

R
rossIDMAuthor
Participant
December 17, 2010

Thank kglad, thanks for your help.

Iv given that a go but like you said its not reliable enough and doesn't produce a smooth enough look when changing as frequently as I need.

Apart from creating exactly the same video as a swf and then displaying it and slowing down the frame rate when i want the effect to happen I cant think of any other method that would work - and I really don't want to do that because the file size would be huge and make streaming the video pointless.

Does anybody have any other suggestions?

A
Andrei1-bKoviI
Inspiring
December 17, 2010

I am sure there is no way to change playback speed and retain smoothness. After all, smoothness you observe in videos is a result of special frame rendering when video IS CREATED. Flash can just convey each video frame image.

Theoretically, yes, it is possible to draw bitmaps out of video frames and create a functionality that manipulates BitmapData but this is an extremely advanced and tedious task. This is not to mention all-in-all application performance deterioration.

Even the very concept of changin playback speed is flwed as far as Flash capa bilities are concerned.

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