Allow non-sequential frames (empty frames)

[fgen.git] / fgen.sh

diff --git a/fgen.sh b/fgen.sh
index 86e9b55..7cf6abb 100755 (executable)
--- a/fgen.sh
+++ b/fgen.sh
@@ -20,7 +20,11 @@ trames=1
 dry_run=0
 
 SED=sed
-FFMPEG_OPTS="-hide_banner -loglevel error -y"
+
+# When reading a file line by line, if a command inside the loop
+# also reads stdin, it can exhaust the input file.
+# -nostdin: disable ffmpeg interaction on standard input:
+FFMPEG_OPTS="-hide_banner -loglevel error -y -nostdin"
 
 # -limit memory 5000mb -limit disk 5gb
 IM_OPS=""
@@ -107,14 +111,35 @@ function get_dup_to()
     echo "${token}"
 }
 
+# Arg1: start frame
+# Arg1: end frame
+function insert_empty_frames()
+{
+    local w
+    local start
+    local end
+
+    start=${1}
+    end=${2}
+
+    for w in $(seq ${start} ${end}); do
+        log_dbg "New frame ID: ${w} (empty)"
+        cp ${dest}/background.png ${dest}/${group}-f${w}.png
+    done
+}
+
 function generate_video()
 {
     if which ffmpeg 1> /dev/null 2>&1; then
         if [ -f ${dest}/${group}-f1.png ]; then
-            if [ ${dry_run} -eq 0 ]; then
-                # Conversion vidéo:
+            log_dbg "generate_video start"
+            if [ ${dry_run} -eq 1 ]; then
+                touch ${dest}/${group}.mp4
+            else
                 ffmpeg ${FFMPEG_OPTS} -r ${fps} -start_number 1 -i ${dest}/${group}-f%d.png ${dest}/${group}.mp4
             fi
+
+            log_dbg "generate_video: end"
         fi
     fi
 }
@@ -275,11 +300,10 @@ if [ ${trames} -eq 1 ]; then
                 expected_nf=$((${oldnf} + 1))
 
                 if [ ${expected_nf} -ne ${nf} ]; then
-                    echo "Error: invalid frame sequence: ${nf}"
+                    echo "Warning: non-sequential frame sequence: ${nf}"
                     echo "  previous: ${oldnf}"
                     echo "  expected: ${expected_nf}"
-                    files=""
-                    continue
+                    insert_empty_frames ${expected_nf} $((${nf} -1))
                 fi
             fi