Making screencasts in Linux

This post is just for future reference.  I figured I'd make this information available to people via Google searches.

This is my current setup for screencasting.

The best software I've found so far is simplescreenrecorder.

Here are my settings for recording slide shows. (For recording anything fast, like video, you would need to adjust them.) This will give you LOSSLESS video and audio.

Left: 0     Top: 100
Width: 854  Height: 480
Frame rate: 10
Audio input source: H5 Multichannel
Separate file per segment
Container: Matroska (MKV)
Video Codec: H.264
Constant rate factor: 0
Preset: veryslow
Allow frame skipping
Audio Codec: flac
Bit rate: 128

When you're finished recording, here's the editing magic:

Concatenate:

for f in ./*.mkv; do echo "file '$f'" >> list.txt; done
ffmpeg -f concat -safe 0 -i list.txt -c copy original.mkv 

Open original.mkv in Audacity:

SetRMS: -22
Limiter: 0 0 -3.5 10
Noise Reduction: 12, 6, 3 (First you need to select some "noise", that is some silent part of your track, and click "Get Noise Profile", the go back to Noise Reduction and "Ok".)
Noise Gate: 0 -15 -20 250


Save as: doctored_audio.flac

Convert to Youtube's preferred format:

ffmpeg -i original.mkv -i doctored_audio.flac -map 0:v -map 1:a -vcodec copy youtube_upload.mp4

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