Copy video quality on ffmpeg

I want to use ffmpeg to add a watermark but I want the video will have the same quality. How do I do that ? I tried to use -vcodec copy -acodec copy but was without watermark

<?php

echo "Starting ffmpeg...".'</br>';
    echo  exec('ffmpeg -y -i treino.mp4 -vf "movie=logo.png [watermark]; [in][watermark] overlay=10:main_h-overlay_h-10 [out]"  -vcodec copy -acodec copy video2.mp4 2> out.txt').'</br>';

    echo "Done.n";


?>