user35900: I've been using kdenlive to make videos on ubuntu for a while and the screen grab has been fine but, for some reason (probably something I did to try to get the desktop start button to work on ubuntu 20.04) my display has changed from :0 to :1
I have been able to muddle on by starting screen capture in a terminal with
ffmpeg -video_size 1306x745 -framerate 25 -f x11grab -i :1.0+60,23 ./scrgrab01.mp4

Then importing each of the clips into kdenlive. But it's a bit messy having to edit a terminal command and remember which clip is which. Also I have now set up a desktop computer with more muscle and want to use that for rendering but that too has the display :1 not :0
I tried going into configure->capture->manage encoding profiles and trying to add ffmpeg arguments like
-crf 25 -i :1.0+60,23 -vcodec libx264 -preset veryfast -threads 0

(and lots of different permutations of that) But nothing has worked so far.
Is there something really obvious that I have overlooked?

user38352: From what I can see, kdenlive is hard-coded to use DISPLAY :0, while ubuntu and gnome/gdm have switched (around ubuntu 18??) to put the user on DISPLAY :1. When I tried the lightdm manager, I found that it still has the older convention of putting the user on the :0 DISPLAY, which is compatible with kdenlive screen grab. So if you don't mind switching window manager, that could be a way to do it.
I also tried to understand if it is possible to have gdm3 put the user on DISPLAY :0 as a default at boot time through some custom configuration, but couldn't figure it out.
In the user's gdm3 session that is on :1 by default, I also tried to set DISPLAY :0 in an xterm and start kdenlive from the command line in that xterm. However, for some reason I got a Qt error doing that, and so I couldn't tell if that was a useful workaround or not.
Note that kdenlive screen grab has some wonky behaviour, which made it harder for me to understand this problem. The 21.12.3 version I was using didn't show me the error output from the ffmpeg command, and it was only by chance I tried the 22.04 version this evening (which was scheduled for release tomorrow but I guess it went out early) and it did now show that error output.
Note also KDE documentation talks about a need to obtain an ffmpeg binary compiled with --enable-x11grab (or more properly, --enable-libxcb) in order for kdenlive screen grab to work. In fact, I don't seem to need this ffmpeg option to get a screen grab. It was just the DISPLAY business that had to be fixed.

35900: <p>I've been using kdenlive to make videos on ubuntu for a while and the screen grab has been fine but, for some reason (probably something I did to try to get the desktop start button to work on ubuntu 20.04) my display has changed from <code>:0</code> to <code>:1</code></p>
<p>I have been able to muddle on by starting screen capture in a terminal with</p>
<pre class="lang-bash prettyprint-override"><code>ffmpeg -video_size 1306x745 -framerate 25 -f x11grab -i :1.0+60,23 ./scrgrab01.mp4
</code></pre>
<p>Then importing each of the clips into kdenlive. But it's a bit messy having to edit a terminal command and remember which clip is which. Also I have now set up a desktop computer with more muscle and want to use that for rendering but that too has the display <code>:1</code> not <code>:0</code></p>
<p>I tried going into <code>configure</code>-&gt;<code>capture</code>-&gt;<code>manage encoding profiles</code> and trying to add ffmpeg arguments like</p>
<pre class="lang-bash prettyprint-override"><code>-crf 25 -i :1.0+60,23 -vcodec libx264 -preset veryfast -threads 0
</code></pre>
<p>(and lots of different permutations of that) But nothing has worked so far.</p>
<p>Is there something really obvious that I have overlooked?</p>
 38352: <p>From what I can see, kdenlive is hard-coded to use DISPLAY :0, while ubuntu and gnome/gdm have switched (around ubuntu 18??) to put the user on DISPLAY :1. When I tried the lightdm manager, I found that it still has the older convention of putting the user on the :0 DISPLAY, which is compatible with kdenlive screen grab. So if you don't mind switching window manager, that could be a way to do it.</p>
<p>I also tried to understand if it is possible to have gdm3 put the user on DISPLAY :0 as a default at boot time through some custom configuration, but couldn't figure it out.</p>
<p>In the user's gdm3 session that is on :1 by default, I also tried to set DISPLAY :0 in an xterm and start kdenlive from the command line in that xterm. However, for some reason I got a Qt error doing that, and so I couldn't tell if that was a useful workaround or not.</p>
<p>Note that kdenlive screen grab has some wonky behaviour, which made it harder for me to understand this problem. The 21.12.3 version I was using didn't show me the error output from the ffmpeg command, and it was only by chance I tried the 22.04 version this evening (which was scheduled for release tomorrow but I guess it went out early) and it did now show that error output.</p>
<p>Note also KDE documentation talks about a need to obtain an ffmpeg binary compiled with --enable-x11grab (or more properly, --enable-libxcb) in order for kdenlive screen grab to work. In fact, I don't seem to need this ffmpeg option to get a screen grab. It was just the DISPLAY business that had to be fixed.</p>
