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rendering issues with proxy files

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Sun, 02/17/2013 - 12:23
#1
tomg327
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Joined: 02/16/2013
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rendering issues with proxy files

Hello all,

Kdenlive is great. But I am feeling a bit like a granny driving a ferrari to church here, trying to edit some 1080 HD webcam footage for my website.

After Yellows excellent help I was able to get proxys going, but I have hit a new glitch that has me stumped. I have looked through the forums and the manual, but no luck.

I am using kdenlive from repositories on 12.04. My video clips are from an HD webcam (logitech) at 1600x896 .avi (I assume the webcam decided to use this format due to lower light?)

I have 3 clips (proxied) clip1, clip2, clip3.

I have edited 20 min of raw footage down to a mix of 2 min of cinematic brilliance (he says with toungue firmly planted in cheek).

The clips have segements edited out for placement into the timeline (lets say 30 sec of the middle of clip1 is on time line video 1)

When I go to render it into a webfriendly format 1280x720.mp4 I get problems.

When I "unproxy" the clips (either through manually unclicking inside main editing screen, or let render to it automatically), they will only play from the begining of the raw clip. IE In proxy I see that it is the middle 30sec I want, unproxied it just goes ahead and plays (in project monitor) or renders the first 30 sec of clip1. Same for other clips, it only plays the firsr x number of seconds, not the part I want.

Is this due to my nonstanderd format?
Any wisdom from the forum?

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Sun, 02/17/2013 - 14:17
#2
j-b-m
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Joined: 05/19/2009
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Re: rendering issues with proxy files

From your description, it seems like your libAV / FFmpeg version has problems seeking into your .avi files. Could you mail me (jb at kdenlive org) or upload somewhere a small sample clip so that I can make some tests?

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Sun, 02/17/2013 - 18:11
#3
j-b-m
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Joined: 05/19/2009
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Re: rendering issues with proxy files

That was definitely a problem with the file format (MJPEG) that is not correctly decoded in Ubuntu 12.04 and 12.10 versions. Solution is to use one of the build script version of Kdenlive to get the latest FFmpeg which decodes it correctly.

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Fri, 04/19/2013 - 14:03
#4
kn
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Joined: 04/19/2013
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Re: rendering issues with proxy files

Hallo people,
I like to add another question about problems with rendering from project using Proxy clips.

Iḿ using Linux Mint 13Maya. Kdenlive 0.9.4. I was making video footage from photocamera Panas.GH2 - format AVCHD - 1280x720 50p. So set up my Kdenlive project as HD 720 50p. I made a proxy clips and editing, now i want to make final export. I tried to render it as Mpeg-2 in different possible variation of quality settings(keeping unchecked the option "render using proxy clips"), but all results in artifacts:
video fade in: there occurs some grayish colour instead of fade in from black only
title: i use wite colour title text, but at the end of it it jumps for short to black colour text
cuts: there are artifacts occuring in every cut position

Iḿ not very good in dealing config or programming. As for codec pac i have i can say i was installing this one:
sudo apt-get install ffmpeg libavcodec-extra-53

You can see example of those artifacts on one render example here:
https://vimeo.com/64383960

Thanks a lot for your activity and help..Klara

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Fri, 04/19/2013 - 20:47
#5
yellow
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Joined: 09/09/2009
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Re: rendering issues with proxy files

Stepping through the 1280x720 download off Vimeo it's clear to see the problems. :-(

I'd suggest that they all relate to ffmpeg / libav support for AVCHD and at 50P which has been and may well still be flaky. Not sure why 50P was necessary for the subject matter really but that's an aside although keeping it simple with regard to format and framerate to suit the subject matter can help maintain compatibility. 25P would have done?

Others here with GH2's will be more help but other than trying a recent build from sunabs PPA or build script.

Otherwise maybe a remux of the AVCHD to another container like mkv or using a tool not based on ffmpeg / libav to transcode to some other suitable codec I don't know.

Do you have a short 50P sample to test?

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