There is new article at CentOS 8.x cinelerra
This is very nice audio/video editing tool. With the help of this tool we can edit vidoes recorded using gtk-recordmydesktop
Removing portions of video without affecting audio
We can remove portions of video without affecting audio using cinelerra. To do this first we have to open video file using cinelerra. Then we have to select the region which we want to hide from video. Then we should right click on selected area and choose "Render Effect". (We should not use menu option Video and then render effect as that causes delay problems between audio and video. Hence we should always right click on selected region and choose render effect). Choosing effect as freeze frame would hide the video for the selected duration showing only the first frame. Then we should go to begining of video file. Then we have to choose File -> Render option to create a new video file in which the selected area appears frozen and there is no problem with audio.
Removing noise from audio from recorded videos
If we record video tutorials suing gtk-record-mydesktop we may end up having noise in audio of resulting video. Rather then re-recording the video we can use cinelerra to remove noise from such videos. To remove noise load the file into cinelerra. Then use menu Audio -> Render effect. Choose effect denoiseFFT. You can save the output in some temp file on Desktop (ex /home/saurabh/Desktop/temp.ogg) in Ogg Theora/Vorbis Format. You should choose option "Append in new tracks" so that two new audio tracks get created. You can delete or mute the older two audio tracks and check if output is satisfactory. I got good output when filter was set to value 0.5. When result is good delete the older tracks and use File -> render option. Save the output in new file using strategy like "Replace current project".
- Remember to rewind to home before doing any kind of rendering, otherwise rendering will take place from current location which is generally not useful.