#!/bin/bash                                                                                                                                                                                                                                                                                                                                                                                 

# Small script to combine some photos, cut a mp3 file into two pieces,                                                                                                                                                                                                                                                                                                                      
# fade in and out and merge everything. Rather specific so needs to be                                                                                                                                                                                                                                                                                                                      
# adapted. ;)                                                                                                                                                                                                                                                                                                                                                                               

# CC0 - Konrad Förstner                                                                                                                                                                                                                                                                                                                                                                     

main(){
    TMP_FOLDER=/tmp/tmp_images
    image_folder_to_video "input/photo_set_2/" output/Der_mutige_Hase.mp4
    add_audio
}

image_folder_to_video(){
    image_folder=$1
    output_video_path=$2

    mkdir -p ${TMP_FOLDER}
    mkdir -p output

    counter=1
    for image_file_path in ${image_folder}/*
    do
        tmp_image_file_path=${TMP_FOLDER}/$(printf "pic_%04d.jpg" "$counter")
        echo "$image_file_path" to "$tmp_image_file_path"
        cp "$image_file_path" "$tmp_image_file_path"
        let counter=counter+1
    done

    ffmpeg \
        -framerate 5 \
        -i ${TMP_FOLDER}/pic_%04d.jpg \
        -vcodec libx264 \
        -pix_fmt yuv420p \
        -y \
        ${output_video_path}
}

add_audio(){
    # Cut part 1                                                                                                                                                                                                                                                                                                                                                                            
    ffmpeg \
        -i input/Mission_Impossible_2_Theme_Instrumental.mp3 \
        -ss 00:01:17.0 \
        -to 00:01:34.0 \
        -y \
        -codec copy \
        tmp_1.mp3

    # fade in part 1                                                                                                                                                                                                                                                                                                                                                                        
    ffmpeg -y -i tmp_1.mp3 -af afade=t=in:d=4 tmp_2.mp3
    # fade out part 1                                                                                                                                                                                                                                                                                                                                                                       
    ffmpeg -y -i tmp_2.mp3 -af afade=t=out:st=16:d=1 tmp_3.mp3


    # Cut part 2                                                                                                                                                                                                                                                                                                                                                                            
    ffmpeg \
        -i input/Mission_Impossible_2_Theme_Instrumental.mp3 \
        -ss 00:00:29.0 \
        -to 00:00:42.0 \
        -y \
        -codec copy \
        tmp_4.mp3

    # fade in part 2                                                                                                                                                                                                                                                                                                                                                                        
    ffmpeg -y -i tmp_4.mp3 -af afade=t=in:d=4 tmp_5.mp3
    # fade out part 2                                                                                                                                                                                                                                                                                                                                                                       
    ffmpeg -y -i tmp_5.mp3 -af afade=t=out:st=5:d=3 tmp_6.mp3

    printf "file tmp_3.mp3\nfile tmp_6.mp3\n" > tmp.txt

    # Concat audio files                                                                                                                                                                                                                                                                                                                                                                    
    ffmpeg \
        -f concat \
        -safe 0 \
        -i tmp.txt \
        -c copy \
        -y \
        tmp_concated.mp3

    # Merge audio audio and Video                                                                                                                                                                                                                                                                                                                                                           
    ffmpeg \
        -i output/Der_mutige_Hase.mp4 \
        -i tmp_concated.mp3 \
        -codec copy \
        -shortest \
        -y \
        output/Der_mutige_Hase_mit_Audio.mp4
    rm -f tmp*
}

main