scripts/rec: use hardware acceleration

scripts/rec

@@ -1,19 +1,17 @@
-#!/usr/bin/env fish
+#!/bin/sh
 
-function record
+record() {
   sleep 2
   withcap sys_admin -- ffmpeg -f alsa -i recorder \
     -vaapi_device /dev/dri/renderD128 -f kmsgrab -i - -r 60 \
     -vf 'hwmap=derive_device=vaapi,scale_vaapi=w=1920:h=1080:format=nv12' \
     -c:v hevc_vaapi -qp 21 \
     -c:a libopus -b:a 96k -ac 2 -ar 48000 \
-    -y recording.mkv >/dev/null 2>&1 &
-end
+    -y recording.mkv >/dev/null 2>&1
+}
 
-if test ! -f recording.mkv
-  set -xU AUDIO_OUT record
-  record
+if test ! -f recording.mkv; then
+  record &
 else
-  set -xU AUDIO_OUT
   pkill ffmpeg
-end
+fi