diff --git a/README.md b/README.md
index 637f911..a81f110 100644
--- a/README.md
+++ b/README.md
@@ -126,15 +126,17 @@ Type=simple
 
 Environment="HOME=/root"
 Environment=PEERTUBE_LIVE="rtmp://peertube.virtonline.eu:1935/live/LIVE-STREAM-KEY"
+Environment=VIDEO_DEVICE="/dev/video0"
 
 ExecStartPre=-/usr/bin/env sh -c 'killall ffmpeg 2>/dev/null || true'
-ExecStartPre=-/usr/bin/env sh -c 'v4l2-ctl -d /dev/video0 -c video_bitrate=3500000'
+# H.264, 1920x1080, 30fps, 3,5Mbit/s
+ExecStartPre=-/usr/bin/env sh -c 'v4l2-ctl -d ${VIDEO_DEVICE} -c video_bitrate=3500000'
 
 ExecStart=/bin/bash -c 'ffmpeg -loglevel error \
 				-f v4l2 -input_format h264 \
 				-video_size 1920x1080 \
 				-framerate 30 \
-				-i /dev/video0 \
+				-i ${VIDEO_DEVICE} \
 				-c copy -f flv \
 				-tune zerolatency \
 				${PEERTUBE_LIVE}'