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I am recording screencasts with ffmpeg(*), and editing them with kdenlive(**)

I have a problem: My videos often look much less sharp after rendering by kdenlive. I have to choose both a video profile and a rendering profile, and I am not sure I found the adequate ones.

First: Do I really have to choose profiles and such ? Is there a way to produce the cuts just keeping the resolution of the original (maybe with another software ?) ? I work with videos with the same resolution and sound, all the time

If not: What are the best profiles for me, considering quality ?

(*) ffmpeg -f x11grab -r 25 -s 800x450 -i :0.0+26,65 -f alsa -i plughw:1,0 -vcodec libx264 -crf 0 -preset ultrafast -acodec pcm_s16le video.mkv

(**) video profile 1024:576 PAL, rendering profile 1280:720 youtube, dowloaded from kdenlive itself

josinalvo
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1 Answers1

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Parts of this answer comes from: Downsize video for use on Android phone

It is about the bitrate itself. You can change it in kdenlive by creating a new custom render profile.

Transcoding will reduce the bitrate as in your case, thus the file size, but preserving the video scale/aspect ratio/size. Anyway, reducing the bitrate may harm quality if you exceed the limits.

Once understood the last, if you increase the bitrate, preserving the video scale/aspect ratio/size, you will get better quality but also a bigger file size.

Follow the instructions in this kde wiki/manual related to Create custom render profiles in order to learn how to add a new profile to the list, after which you can include the details of your profile. Make sure you add the maxrate value in order to be able to include your desired maximum bitrate and this way get the best quality in kdenlive.

As recommended in the wiki page, I suggest you to also take a look at the Render Profile Parameters - How to read them so that you can be able to add the proper parameters to your new profile.

Anything above 10000kbps should give you a good quality video file but you may wish to go for 15000k, 25000k or so in order to get broadcast quality.

BTW: You can also change the video and audio bitrates separately if you wish in order to keep sound quality.

Good luck!

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Geppettvs D'Constanzo
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