creating a video from an image plus audio files

audiobook.sh

# assumptions: audio files in .flac, no other flac files, named alphabetically

# cut to part of a recording
ffmpeg -ss mm:ss -to mm2:ss2 -i in.flac -codec copy out.flac
# replace a segment
ffmpeg -to mm:ss -i in.flac -codec copy pre.flac; ffmpeg -ss mm2:ss2 -i in.flac -codec copy post.flac; ffmpeg -f concat -safe 0 -i <( for f in {pre,replacement,post}.flac; do echo "file '$(pwd)/$f'"; done ) -c copy out.wav; flac out.wav; rm pre.flac; rm post.flac; rm out.wav

# get chapter timestamps for youtube
for song_file in *.flac; do echo $song_file; done
duration=0; total=0; rounded=$total; hours=0; mins=0; secs=0; for song_file in *.flac; do rm -f tmp.wav; echo "$hours:$(printf "%02d\n" $mins):$(printf "%02d\n" $secs)"; flac -d -o tmp.wav $song_file > /dev/null 2>&1; duration=`soxi -D tmp.wav`; total=`echo "$total + $duration" | bc`; rounded=`printf "%.*f\n" "" "$total"`; hours=`expr $rounded / 3600`; mins=$((`expr $rounded / 60` - $hours * 60)); secs=$(($rounded - $hours * 3600 - $mins * 60)); done; rm -f tmp.wav

# concatenate audio files
ffmpeg -f concat -safe 0 -i <( for f in *.flac; do echo "file '$(pwd)/$f'"; done ) -c copy audio.flac

# restore metadata
sox audio.flac audio_.flac --show-progress

# # denoise audio
# sox audio.flac -n noiseprof noise_profile_file
# sox audio.flac audio_denoised.flac noisered noise_profile_file 0.31

# video

# svg to image
inkscape -w 2580 -h 1470 -y 1 logo.svg --export-filename logo.png
# preferably use youtube's 16:9 aspect ratio i.e. 1.777~
magick logo.png -resize 1025x577 -background white -compose Copy -gravity center -extent 1025x577 -quality 92 youtube.png

# video from image + audio
ffmpeg -stream_loop -1 -r 1 -i youtube.png -i audio_.flac -vcodec h264 -shortest -q:v 5 video.mp4