From e7451a58b4d41875b4f2a8ee585f283e8ef646ab Mon Sep 17 00:00:00 2001
From: Flinner Yuu <flinner@nand.sh>
Date: Fri, 9 Sep 2022 15:15:08 +0300
Subject: [PATCH] demusicify videos

---
 bin/bin/demusicify.sh | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100755 bin/bin/demusicify.sh

diff --git a/bin/bin/demusicify.sh b/bin/bin/demusicify.sh
new file mode 100755
index 0000000..f9439f2
--- /dev/null
+++ b/bin/bin/demusicify.sh
@@ -0,0 +1,36 @@
+#!/bin/bash
+
+[ -z "$2" ] && echo "usage: input.mp4 output.mp4" 
+[ -z "$2" ] && exit
+
+VIDEO="$1"
+VIDEO_OUTPUT="$2"
+
+TMP_RAW_AUDIO=$(mktemp --suffix ".mp3")
+TMP_VOCALS_DIR=$(mktemp --directory)
+TMP_VOCALS=$(mktemp --suffix ".mp3")
+
+# Extract Audio from Video
+ffmpeg -i "$VIDEO" -vn "$TMP_RAW_AUDIO" -y
+
+# move to a tmp file, becuase demucs creates a lot of garbage
+pushd "$TMP_VOCALS_DIR" || exit
+
+demucs --two-stems=vocals --segment 10 "$TMP_RAW_AUDIO" 
+
+cp ./separated/*/*/vocals.wav "$TMP_VOCALS"
+
+# return back to working directory for no reason
+popd || exit
+
+# https://json2video.com/how-to/ffmpeg-course/ffmpeg-add-audio-to-video.html
+ffmpeg \
+    -i "$VIDEO" -i "$TMP_VOCALS"  \
+    -c:v copy \
+    -map 0 -map 1:a \
+    -y "$VIDEO_OUTPUT"
+
+
+rm "$TMP_RAW_AUDIO"
+rm "$TMP_VOCALS"
+rm -rf "$TMP_VOCALS_DIR"