Hi folks,

I'm using Kdenlive 15.04.2 (on Ubuntu 15.04 64) and upon rendering of a multi-track (4 video/5 audio) 720p30 video, around half time (4 minutes) the audio and video go out of sync of ~1.5 seconds.

Not sure what to do next?

Thanks in advance for your help,
E

Bump?

Oh, sorry for not responding within 24 hours - we did not know you have bought Gold Support for kdenlive.

You are in a hurry, so I'll be short: Which repo? What profile? Which audio input format? What did you already try?

If you want friendly support, do not push.

capslock wrote:Oh, sorry for not responding within 24 hours - we did not know you have bought Gold Support for kdenlive.

You are in a hurry, so I'll be short: Which repo? What profile? Which audio input format? What did you already try?

If you want friendly support, do not push.

I'm sorry if I appeared pushy. Far from being so. I was just afraid this was buried, again not my intention to sound like a d**k.
I thought this is the basics you would expect from a (great if I may say so) video compositing program so was surprise nobody showed interest. My apologies.

Let me give you the details:

• repo ppa:sunab/kdenlive-release
• profile Tried both H.264/AAC High Profile and H.264/AAC (CBR), video is 720p30
• Audio input Different formats, from MP3 44K to WAVE PCM 16 bit 22K (please note the same audio effects are rendered just fine in the first half of the video)
• What did I already try? I originally used kdelive form the same repo in Ubuntu 14.04 (version 0.9.10) and given I had this issue, I installed Ubuntu 15.04 in a virtual machine and downloaded latest kdenlive 15.04.2 form the same repo. Again, the video in the preview is synced just fine.

Please let me know if you need anything else.

Thanks in advance

Search the Google for 'mlt sync audio video'. Lots of hits. Many factors could be at play. There are some 'brute force' methods to resolve. MLT is the underlying framework therefore answers that pertain to other applications may apply.

The different sample rates might be what's causing it - your video clips' audio is probably recorded at 48kHz, and the 44.1 and 22kHz audio will gradually drift out of sync with it over longer clips.

Open all the tracks in a 48kHz Audacity project, stretch/shrink the clips as much as you need until they are perfectly synced, and then export (either the mix or separate tracks) as 48KHz WAV or FLAC. Then import them into Kdenlive.

Next time, record your audio in 48Khz WAV or FLAC if possible.

It's also worthwhile to search the forum to find help, this kind of issue has come up many times in the past. Check out the 'audio' section.

Do all tracks shift?
If the timecode where drift occurs is precise, then probably it is easy to identify the source clip causing problem.

Audio encoded with VBR (be it pure audio like MP3 or video with audio) have already caused several problems, transcoding audio to WAV usually solved issue.

Cheers,

Vincent

I get the feeling this question is a FAQ.

I have just added an answer to this question at the FAQ section in the manual

https://userbase.kde.org/Kdenlive/Manua ... mation/FAQ

I have based my answer on Vpinion' info from this thread.

Feel free to expand on the answer in the manual.

P.S. - Vincent - I did ask the forum admins to give me permissions to create "sticky posts" on the forum. But I never heard back. This sort of question would be a good "sticky". But in the mean time - such things can go in the FAQ.