Reply to topic

Video drift away from audio

sbelkin
Registered Member
Posts
3
Karma
0

Video drift away from audio

Mon Nov 11, 2013 4:03 am
Hi,

I was using kdenlive almost the entire year making screen captures (video + audio) with no big issue, and suddenly every time that it does a screen grab the results are bad.

In the middle of the clip the video goes faster than audio, and I have to make dirty hacks to fix it, for example, cut the video and make slower, but it's a pain.

The version of kdenlive I use is kdenlive-0.9.6-2.fc19.x86_64. The really strange thing is that kdenlive was not updated since the problem it arised.

you may take a look of all packages that were updated since the las time that I used with no problem at http://pastebin.com/CmYq6wrh

I tried the earlier kernel release and failed too.

Please any ideas?

Thanks in advance!
sbelkin
Registered Member
Posts
3
Karma
0

Re: Video drift away from audio

Wed Nov 13, 2013 3:35 pm
Well I reply myself :D

It seems that is a ffmpeg issue, because the same problem happens at command line. I've mitigate the problem with this encoding profile of screen grab:

Code: Select all
-f alsa  -i pulse -async 1 -acodec libvorbis -ab 256k -vcodec libx264 -preset fast  -threads 0 -r 30


I've tried several times and only one time I suffer video-audio drifting.... surely this is not a kdenlive bug, but if you have any idea/opinions, please share it :)
User avatar Ubu the Tech Guru
Registered Member
Posts
22
Karma
0

Re: Video drift away from audio

Mon Nov 25, 2013 4:32 am
try simplescreenrecorder, he has a great audio/video sync'ing code within his app, my audio and video is always in sync.


Check out my YouTube Channel http://www.youtube.com/ubuntuaddicted
Follow me on Twitter http://www.twitter.com/ubuntuaddicted
Check out my Google+ Profile https://plus.google.com/+UbutheTechGuru
User avatar hvdwolf
Registered Member
Posts
60
Karma
1
OS

Re: Video drift away from audio

Mon Nov 25, 2013 9:16 am
Did you check whether your video has dropped frames. If you record at 25 fps (for example) and you miss at certain moments half of your video frames, you video seems to go ahead of your audio.
Check whether your video has a fixed framerate or a variable framerate.

 
Reply to topic

Bookmarks



Who is online

Registered users: AGB, Alexa [Bot], anditosan, Baidu [Spider], Bing [Bot], Blingy, bshah, Charblaze, Exabot [Bot], franku, garthecho, Google [Bot], google01103, jgrulich, joshaughnessy, ken300, koriun, La Ninje, lazyit, Majestic-12 [Bot], mtvee, ooker, renatoatilio, rulet111, scummos, Sentynel, Steve Guilford, verbalshadow, vylaern, Wiz, Yahoo [Bot]