Bash script for creating the Mandelbrot Set zoom movie.

run.bash

#!/bin/bash
Fail()
{
    echo "FATAL($0): $1"
    exit 1
}

# Compile the source code for mandelzoom. Optimize for speed.
echo "Building C++ code..."
g++ -Wall -Werror -Ofast -o mandelzoom mandelzoom.cpp lodepng.cpp || Fail "Error building C++ code."

# Destroy the "movie" directory and its contents, if it exists.
rm -rf movie || Fail "Error deleting movie directory."

# Create a brand new, empty "movie" directory, for holding the output files.
mkdir movie || Fail "Error creating movie directory."

# Run the mandelbrot generator. This creates all the output PNG files.
./mandelzoom movie $((30*30)) -0.74498410019 -0.13523854817 1.0e8 ||
    Fail "Error running Mandelbrot Zoom program."

# Convert the PNG files to a video file zoom.mp4.
# Explanation of the ffmpeg command-line arguments:
# "-r 30" means 30 frames per second
# "-f image2" : convert a series of images to a video.
# "-s 1280x720" indicates the dimensions of the output video, in pixels.
# "-i movie/frame_%05d.png" specifies filenames of the series of png files to be used as input.
# "-vcodec libx264": the codec library to use. See: https://www.videolan.org/developers/x264.html
# "-crf 15" : Constant Rate Factor, specifies amount of lossy compression. https://trac.ffmpeg.org/wiki/Encode/H.264
# "-pix_fmt yuv420p" defines how colors are encoded in an mp4 file.  https://en.wikipedia.org/wiki/YUV
# "zoom.mp4" is the output filename.
ffmpeg -r 30 -f image2 -s 1280x720 -i movie/frame_%05d.png -vcodec libx264 -crf 15 -pix_fmt yuv420p zoom.mp4 ||
    Fail "Error in ffmpeg."

echo "Created movie zoom.mp4"
exit 0