ffmpeg \
    -y \
    -i "${SRCS[$i]}" \
    -map 0:v \
    -map 0:a:0 \
    -vf "scale=(iw*sar)*min(1920/(iw*sar)\,1080/ih):ih*min(1920/(iw*sar)\,1080/ih), pad=1920:1080:(1920-iw*min(1920/iw\,1080/ih))/2:(1080-ih*min(1920/iw\,1080/ih))/2" \
    -c:v libx264 \
    -pix_fmt yuv420p \
    -preset slow \
    -fflags +igndts \
    -fflags +genpts \
    -async 1 \
    -vsync 1 \
    -b:v 6000k \
    -maxrate 6000k \
    -x264-params keyint=60 \
    -c:a aac \
    -strict -2 \
    -ar 44100 \
    -b:a 160k \
    -ac 2 \
    -bufsize 7000k \
    -f flv "${DSTS[$i]}"