Add the vid2twitter script

bin/vid2twitter

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+
+INPUT="$1"
+OUTPUT="${INPUT%.*}.mp4"
+
+if [ $# -ne 1 ]; then
+    echo "Usage: vid2twitter [source_video_file]" >&2
+    exit 1
+fi
+
+if [ -f "$OUTPUT" ]; then
+    echo -n "$OUTPUT: file exists, overwrite? (y|N) "
+    read -r overwrite
+    case "${overwrite,,}" in
+        "y" | "yes") ;;
+        *)
+            exit 0
+            ;;
+    esac
+fi
+
+ffmpeg -i "$INPUT" -vcodec libx264 -pix_fmt yuv420p -strict -2 -acodec aac "$OUTPUT"