diff --git a/genpreamble.sh b/genpreamble.sh
index 17a90a2..bf2b6e1 100755
--- a/genpreamble.sh
+++ b/genpreamble.sh
@@ -2,8 +2,8 @@
 
 ffmpeg \
   -use_wallclock_as_timestamps 1 \
-  -t 5 -r 50 -f lavfi -i color=c=black:s=1280x720 \
-  -t 5 -f lavfi -i anullsrc=r=48000:cl=stereo \
+  -t 1 -r 50 -f lavfi -i color=c=black:s=1280x720 \
+  -t 1 -f lavfi -i anullsrc=r=48000:cl=stereo \
   -pix_fmt:v yuv420p -color_range:v tv -color_primaries:v bt709 -colorspace bt709 -color_trc bt709 -profile:v high -b:v 3500000 -c:v libx264 \
   -b:a 128000 -c:a aac \
   -f mpegts -y out.ts