Adding new weights

Author: alexarje

code/mghistory.sh

@@ -1,27 +1,29 @@
 #!/bin/bash
 # ------------------------------------------------------------------
 # Description:
-#     Will add all tiff files in folder into one combined image
+#     Create motion history (aka "blurring") from a video file.
+#     Number of frames to include in the history can be specified.
 #
 # Usage:
 #     Place in folder with video files
 #     Make executable: chmod u+x [scriptname]
 #     Run script: sh [scriptname]
 #
 # Dependency:
-#      Uses ImageMagick
+#      Uses FFmpeg
 #
 # Author:
 #     Alexander Refsum Jensenius
 #     University of Oslo
 #
 # Version:
+#     0.2 - 2022-01-09
 #     0.1 - 2020-03-01
 # ------------------------------------------------------------------
 
 
 if [ -z "$1" ]; then
-    echo "usage: ./mghistory.sh VIDEO [FRAMES=30]"
+    echo "usage: ./mghistory.sh VIDEO [FRAMES=10]"
     exit
 fi
 
@@ -30,4 +32,12 @@ NAMESTRING=`echo $FILENAME | cut -d'.' -f1`;
 
 FRAMES=$2
 
-ffmpeg -i $FILENAME -filter:v tmix=frames=30:weights="10 1 1" ${NAMESTRING}_history.mp4
+if [ -z "$FRAMES" ]; then
+    FRAMES=10
+fi
+
+# Creating weight sequence so that the first frames (the last in the sequence)
+# get heigher weights and are more visible
+WEIGHTS=`seq $FRAMES`
+
+ffmpeg -i $FILENAME -filter:v tmix=frames=${FRAMES}:weights="${WEIGHTS}" ${NAMESTRING}_history.mp4