ffmpeg \
    -y \
    -t 100ms -f lavfi -i anullsrc=cl=stereo:sample_rate=44100 \
    -t 100ms -f lavfi -i anullsrc=cl=mono:sample_rate=44100 \
    -t 100ms -f lavfi -i sine=sample_rate=44100:frequency=100 \
    -t 100ms -f lavfi -i sine=sample_rate=44100:frequency=600 \
    -t 100ms -f lavfi -i anoisesrc=sample_rate=44100:seed=1 \
    -t 100ms -f lavfi -i anoisesrc=sample_rate=44100:seed=2 \
    -t 100ms -f lavfi -i sine=sample_rate=44100:frequency=600 \
    -t 100ms -f lavfi -i sine=sample_rate=44100:frequency=50 \
    -t 100ms -f lavfi -i anoisesrc=sample_rate=44100:seed=3 \
    -t 100ms -f lavfi -i sine=sample_rate=44100:frequency=20 \
    -filter_complex \
'[0:0][1:0]amerge=inputs=2[merge0];
[2:0][3:0]amerge=inputs=2[merge1];
[4:0][5:0]amerge=inputs=2[merge2];
[6:0][7:0]amerge=inputs=2[merge3];
[8:0][9:0]amerge=inputs=2[merge4];
[merge0][merge1][merge2][merge3][merge4]concat=n=5:v=0:a=1[concat0];
[concat0]asplit=outputs=6[out0][out1][out2][out3][out4][out5]' \
    -map '[out0]' -ar 44100 -ac 1 -c:a pcm_u8 -f wav mono8.wav \
    -map '[out1]' -ar 44100 -ac 1 -c:a pcm_s16le -f wav mono16.wav \
    -map '[out2]' -ar 44100 -ac 1 -c:a pcm_s24le -f wav mono24.wav \
    -map '[out3]' -ar 44100 -ac 2 -c:a pcm_u8 -f wav stereo8.wav \
    -map '[out4]' -ar 44100 -ac 2 -c:a pcm_s16le -f wav stereo16.wav \
    -map '[out5]' -ar 44100 -ac 2 -c:a pcm_s24le -f wav stereo24.wav
flac -fo mono8.flac mono8.wav
flac -fo mono16.flac mono16.wav
flac -fo mono24.flac mono24.wav
flac -fo stereo8.flac stereo8.wav
flac -fo stereo16.flac stereo16.wav
flac -fo stereo24.flac stereo24.wav
rm -f mono8.wav mono16.wav mono24.wav
rm -f stereo8.wav stereo16.wav stereo24.wav

ffmpeg -y -t 10ms -f lavfi -i sine picture_seek_gain.flac
convert -size 4x4 "xc:#000" 4x4.png
metaflac --add-replay-gain --add-seekpoint=10 --import-picture-from 4x4.png picture_seek_gain.flac
rm 4x4.png

for i in mono8 mono16 mono24 stereo8 stereo16 stereo24 picture_seek_gain ; do
    echo "/$i.flac:" > $i.fqtest
    echo "> fq -d flac $i.flac verbose" >> $i.fqtest
done