videowmark: ensure temp files get deleted when done

Signed-off-by: Stefan Westerfeld <stefan@space.twc.de>

src/TODO

@@ -2,7 +2,6 @@ possible improvements:
 - dynamic bit strength
 
 videowmark:
-temp files
 --key
 --help
 stream issue

src/videowmark

@@ -24,21 +24,41 @@ function audio_encode_options
     }'
 }
 
+function create_temp_files
+{
+  local fd
+
+  for fd in "$@"
+  do
+    local tmpfile=$(mktemp /tmp/videowmark.XXXXXX)
+    eval "exec $fd>$tmpfile"
+    rm "$tmpfile"
+  done
+}
+
 if [ "$1" == "add" ]; then
+  # create tmpfiles
+  create_temp_files 3 4
+  orig_wav=/dev/fd/3
+  wm_wav=/dev/fd/4
+
   # get audio as wav
-  ffmpeg -y -i "$2" tmp.wav
+  ffmpeg -y -i "$2" -f wav "$orig_wav"
   # watermark
-  audiowmark add tmp.wav tmp1.wav "$4"
+  audiowmark add "$orig_wav" "$wm_wav" "$4"
   # rejoin
-  ffmpeg -y -i "$2" -i tmp1.wav -c:v copy $(audio_encode_options "$2") -map 0:v:0 -map 1:a:0 "$3"
+  ffmpeg -y -i "$2" -i "$wm_wav" -c:v copy $(audio_encode_options "$2") -map 0:v:0 -map 1:a:0 "$3"
 elif [ "$1" == "get" ]; then
+  # create tmpfiles
+  create_temp_files 3
+  wav=/dev/fd/3
+
   # get audio as wav
-  ffmpeg -y -i "$2" tmp.wav
+  ffmpeg -y -i "$2" -f wav "$wav"
   # get watermark
-  audiowmark get tmp.wav
+  audiowmark get "$wav"
 elif [ "$1" == "probe" ]; then
   echo $2 $(audio_encode_options "$2")
 else
   echo "videowmark: error parsing command line arguments"
 fi
-rm -f tmp*