From 736c7a9f09af460b51d1f5c3d885f9176189b5c6 Mon Sep 17 00:00:00 2001
From: "Gary E. Deschaines" <gedeschaines@gmail.com>
Date: Mon, 18 Dec 2023 08:43:35 -0600
Subject: [PATCH] Added same NOTE as in Batch files

---
 util/png2gif.sh | 11 +++++++++--
 util/png2mp4.sh | 21 +++++++++++++++------
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/util/png2gif.sh b/util/png2gif.sh
index 7cfa9fb..afc9721 100644
--- a/util/png2gif.sh
+++ b/util/png2gif.sh
@@ -5,8 +5,15 @@
 #AUTH:  G. E. Deschaines
 #DESC:  Converts a sequence of PNG files to GIF files and merges
 #       the GIF files into an animated GIF file.
-
-#NOTE:  Requires the ImageMagick convert program.
+#
+# NOTE:
+#
+#   [1] Requires ImageMagick magick program.
+#
+#   [2] Invoke this shell script while working within the pyThreeD
+#       subdirectory containing img_####.png files (i.e., ./Ximg)
+#       as ../util/png2gif.sh since it's assumed relative path
+#       ../pyThreeD.py exists from where this shell script executes.
 
 # Get list of PNG files.
 
diff --git a/util/png2mp4.sh b/util/png2mp4.sh
index 2cf6593..346f32c 100644
--- a/util/png2mp4.sh
+++ b/util/png2mp4.sh
@@ -5,8 +5,17 @@
 #AUTH:  G. E. Deschaines
 #DESC:  Converts a sequence of PNG files to JPEG files and merges
 #       the JPEG files into a MP4 video file.
-
-#NOTE:  Requires ffmpeg and the ImageMagick convert program.
+#
+# NOTE:
+#
+#   [1] Requires ffmpeg and the ImageMagick magick program.
+#
+#   [2] Invoke this shell script while working within the pyThreeD
+#       subdirectory containing img_####.png files (i.e., ./Ximg)
+#       as ../util/png2mp4.sh since it's assumed relative path
+#       ../pyThreeD.py exists from where this shell script executes.
+
+FFMPEG_EXE=/usr/bin/ffmpeg
 
 # Get list of PNG files.
 
@@ -34,17 +43,17 @@ FPS=`grep "img_FPS = " ../pyThreeD.py | gawk '{ print gensub(";","",1,$3) }'`
 
 SYSNAM=`uname -a`
 
-if [ "${SYSNAM%% *}" == "Linux" ] && [ -e  /usr/bin/ffmpeg ]
+if [ "${SYSNAM%% *}" == "Linux" ] && [ -e ${FFMPEG_EXE} ]
 then
   echo "Creating MP4 video:  img_anim.mp4 @ 25 fps"
-  /usr/bin/ffmpeg -loglevel error -f image2 -framerate ${FPS} -i ./img_%04d.jpg -r 25 -vcodec libx264 -b:v 8000k -crf 18 -pix_fmt yuv420p ./img_anim.mp4
+  ${FFMPEG_EXE} -loglevel error -f image2 -framerate ${FPS} -i ./img_%04d.jpg -r 25 -vcodec libx264 -b:v 8000k -crf 18 -pix_fmt yuv420p ./img_anim.mp4
   exit 0
 fi
 
-if [ "${SYSNAM%%_*}" == "CYGWIN" ] && [ -e  /usr/bin/ffmpeg ]
+if [ "${SYSNAM%%_*}" == "CYGWIN" ] && [ -e ${FFMPEG_EXE} ]
 then
   echo "Creating MP4 video:  img_anim.mp4 @ 25 fps"
-  /usr/bin/ffmpeg -loglevel error -f image2 -framerate ${FPS} -i ./img_%04d.jpg -r 25 -vcodec mpeg4 -b:v 8000k -crf 18 -pix_fmt yuv420p ./img_anim.mp4
+  ${FFMPEG_EXE} -loglevel error -f image2 -framerate ${FPS} -i ./img_%04d.jpg -r 25 -vcodec mpeg4 -b:v 8000k -crf 18 -pix_fmt yuv420p ./img_anim.mp4
   exit 0
 fi