Ubuntu – How to uninstall ffmpeg

How to Compile FFmpeg in Ubuntu tells you how to undo everything in the Reverting Changes Made by This Guide section:

rm -rf ~/ffmpeg_build ~/ffmpeg_sources ~/bin/{ffmpeg,ffprobe,ffserver,vsyasm,x264,yasm,ytasm}

sudo apt-get autoremove autoconf automake build-essential git libass-dev \
libgpac-dev libmp3lame-dev libopus-dev libsdl1.2-dev libtheora-dev \
libtool libva-dev libvdpau-dev libvorbis-dev libvpx-dev libx11-dev \
libxext-dev libxfixes-dev texi2html zlib1g-dev

hash -r

However, seeing your other recent ffmpeg question it appears that you did not follow the guide or did not follow it correctly so this may not work for you.

The guide does not install ffmpeg to the system. This is to avoid conflicts with packages from the repository, but I'm guessing you did install to the system with sudo make install without using checkinstall; therefore it is not integrated in the package management system. If this is the case then try:

cd ~/ffmpeg
sudo make uninstall
hash -r

The guide is supposed to make compiling easy since the ideas is that the user must only successfully copy and paste, but compiling is not for everyone and results may vary.

It is well worth running a deinterlacing video filter during your video encode and this may very well lessen some of the odd screen effects that you are seeing in your output video. A second thought, unrelated to motion artefact but well worth adding in, is the use of a de-noising filter.

1. Deinterlacing:

For FFmpeg the best and fastest choice is yadif which in the usual quirky geek fashion simply stands for 'Yet Another DeInterlacing Filter'!

yadif can be used with no options or you can specify an option for each of 3 fields:

1. mode: The basic interlacing mode to adopt
2. parity: The picture field parity assumed for the input interlaced video
3. deint: Specify which frames to deinterlace

The safe defaults can be specified on the FFmpeg command line as:

-vf yadif=0:-1:0

If you wish to alter these all of the deeper detail is contained here:

FFmpeg Filter Documentation: yadif
https://ffmpeg.org/ffmpeg-filters.html#yadif-1

A further deinterlacing filter called mcdeint (motion-compensation deinterlacing) can also be applied but you may find this painfully slow. A typical command line for use of this filter would be:

-vf yadif=1:-1:0,mcdeint=2:1:10

And again the fine detail of the mcdeint options can be seen in the FFmpeg documentation:

FFmpeg Filter Documentation: mcdeint
https://ffmpeg.org/ffmpeg-filters.html#mcdeint

2. Denoising:

A final though that may well be worth some experimentation is the use of a denoising filter, although this should not effect motion artefact it is still a well worth addition. Under FFmpeg there are a few choices but one well worth looking at is nlmeans (denoise frames using Non-Local Means algorithm). You will need the very latest FFmpeg for this one.

To use this in the easiest command line try the following:

-vf yadif=0:-1:0,nlmeans

There is a hit with nlmeans in terms of encoding time, not as severe a penalty as is seen with mcdeint but still a consideration...

If you have an older copy of FFmpeg with no access to this newest filter there is an older denoise filter that can safely be used with trust in the sane defaults:

-vf yadif=0:-1:0,hqdn3d

I note on my own system that hqdn3d is very, very much faster than the newer nlmeans. Better? Well I suspect that is a debate for another forum :)

And hopefully a combination of any of these thoughts will solve your problem...

References:

• Non-Local Means Filter for FFMPEG
• FFmpeg Filters Documentation
• What is Deinterlacing? Facts, solutions, examples.