Tag: OpenCV

macOS (M1/M1 Pro) – ffmpeg with mp3 support and OpenCV

djangokatyaLeave a comment

This is not funny – I spent a few evening fixing and fixing and fixing. Now ./configure then make and sudo make, but where is binary? Why is it not is /usr/bin/ OR /usr/local/bin/? Oh you do brew install opencv – but it does not work in terminal? Amazing. I was THIS close to wiping mac os and installing Linux on my macbook guys, THIS CLOSE.

Anyhow it is simple if you do the right thing.

ffmpeg with mp3 support

brew uninstall lame —force
brew uninstall homebrew-ffmpeg/ffmpeg/ffmpeg
brew install homebrew-ffmpeg/ffmpeg/ffmpeg —with-fdk-aac

In your virtualenv

pip uninstall ffmpeg
pip uninstall ffmpeg-python
pip install ffmpeg-python

And then install OpenCV (it is now working with pip):

pip install opencv-python

How to add GIF to a static background (PIL + imageio) V.2 – The Better One

djangokatyaLeave a comment

My previous version has flaws. It works well for opaque GIFs, but OpenCV is famous for not being good with transparent images. So instead of OpenCV I use imageio for GIF iteration and PIL for adding GIF frames to the static background.

Why do more?

The original algorithm left these artifacts, look at the cyan block on the intersection of GIF frame and a darker abstract part:

The artefact in question
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ffmpeg: Non-monotonous DTS in output stream 0:0 – Video Generation Series (Part 2) [ERROR]

djangokatyaLeave a comment

This error occured when I used ffmpeg to concatenate different videos that I generated:

ffmpeg -f concat -safe 0 -i list.txt -c copy final_video.avi -y
BTW, if you want to run ffmpeg or any other command inside a python script (a very reasonable idea), use subprocess:

command = "ffmpeg -f concat -safe 0 -i list.txt -c copy final_video.avi -y"
subprocess.Popen(command.split(), stdout=subprocess.PIPE)

As a result – the videos got smashed together – some frames even never appeared.

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