diff --git a/capture_video.sh b/capture_video.sh
index d5dbba4..7932589 100755
--- a/capture_video.sh
+++ b/capture_video.sh
@@ -1,13 +1,14 @@
 #!/bin/bash
 
 if [[ "$1" == *help ]]; then
-  echo "Usage: ${0} [-duration 10] [-sound plughw:1,0]"
-  echo "default duration (in seconds) is infinite"
-  echo "default sound is anullsrc i.e. silent sound"
+  echo "Example usage: ${0} [-duration 10] [-sound plughw:1,0]"
+  echo "optional -duration is in seconds"
+  echo "optional -sound values: [none, anullsrc, plughw:1,0]"
+  echo "default -sound is none i.e. no sound"
   exit 1
 fi
-# available options
 
+# available options
 # 640x480/60
 # 1296x972/43
 # 1920x1080/30
@@ -25,7 +26,7 @@ VIDEO_RES_WIDTH="640"
 VIDEO_FRAMERATE="10"
 VIDEO_FILE="camera_$(date +%Y-%m-%d_%H-%M-%S).mp4"
 VIDEO_DURATION="1000000000"
-SOUND_SOURCE="anullsrc"
+SOUND_SOURCE="none"
 
 while [[ $# -gt 0 ]]; do
   case $1 in
@@ -72,7 +73,17 @@ rpicam-vid --inline \
 		-b ${VIDEO_BITRATE} \
 		-o - | \
 
-if [ "${SOUND_SOURCE}" = "anullsrc" ]; then
+if [ "${SOUND_SOURCE}" = "none" ]; then
+    # ffmpeg params without audio
+    ffmpeg -hide_banner \
+                -thread_queue_size 1024 \
+                -use_wallclock_as_timestamps 1 \
+                -i pipe:0 \
+                -c:v copy \
+                -f mp4 \
+                -t ${VIDEO_DURATION} \
+                ${VIDEO_FILE} &
+elif [ "${SOUND_SOURCE}" = "anullsrc" ]; then
     # ffmpeg params with silent audio
     ffmpeg -hide_banner \
                 -f lavfi \