From f78ed50a7c5f1ccb025c8752c07b9fb52dc90b81 Mon Sep 17 00:00:00 2001
From: Arkadiusz Wieczorek <kontakt@arkadiusz-wieczorek.pl>
Date: Wed, 13 Jul 2022 08:43:35 +0200
Subject: [PATCH] Add scripts

---
 change-length-audio.sh         | 75 ++++++++++++++++++++++++++++++++++
 change-length-video-HWACCEL.sh | 75 ++++++++++++++++++++++++++++++++++
 2 files changed, 150 insertions(+)
 create mode 100755 change-length-audio.sh
 create mode 100755 change-length-video-HWACCEL.sh

diff --git a/change-length-audio.sh b/change-length-audio.sh
new file mode 100755
index 0000000..14fd956
--- /dev/null
+++ b/change-length-audio.sh
@@ -0,0 +1,75 @@
+#!/bin/bash
+
+# usage: change-length.sh 1.007 input.mp4 output.mp4 [--fast]
+#       ^output.mp4 will be be 7% longer
+#       --fast is faster, but slightly more risky
+       
+set -euo pipefail
+
+RATIO=$1;
+IN_FILE=$2;
+OUT_FILE=$3;
+MODE=${4-"--slow"};
+# BITRATE=$(ffmpeg -i "$IN_FILE" 2>&1 | grep bitrate | awk -F", " '{print $3}' | sed 's/bitrate: //' | sed 's/ //' | sed 's/b\/s//' || echo "");
+
+echo ratio set to "$RATIO"
+
+INV_RATIO=$(python -c "print(1/$RATIO)");
+
+FILTER="";
+OPTS=();
+
+AUDIO_FILTER="[0:a]atempo=$(echo "$INV_RATIO")[a]";
+
+HAS_AUDIO=$(ffprobe "$IN_FILE" 2>&1 | grep Stream | grep --count Audio || echo "0");
+HAS_VIDEO=$(ffprobe "$IN_FILE" 2>&1 | grep Stream | grep --count Video || echo "0");
+
+slow () {
+  echo " ";
+  echo " ";
+  echo " ";
+  echo " ";
+  echo "USING SLOW MODE. If you want only video, use --fast";
+  echo " ";
+  echo " ";
+  echo " ";
+  echo " ";
+  echo " ";
+  echo " ";
+  echo " ";
+  echo "Checking streams within the file...";
+
+  if [ "$HAS_AUDIO" -ge 0 ]; then
+    FILTER=$AUDIO_FILTER;
+    OPTS+=(-map "[a]");
+  fi;
+
+  if [ "$HAS_VIDEO" -ge 0 ]; then 
+    FILTER="$FILTER;[0:v]setpts=$RATIO*PTS[v]";
+    OPTS+=(-map "[v]");
+  fi;
+
+  echo "running with filter $FILTER";
+
+  # ffmpeg -i "$IN_FILE" -b:v $BITRATE -filter_complex "$FILTER" "${OPTS[@]}" "$OUT_FILE";
+  ffmpeg -i "$IN_FILE" -filter_complex "$FILTER" "${OPTS[@]}" "$OUT_FILE";
+}
+
+fast (){
+  if [ "$HAS_AUDIO" -ge 0 ]; then
+    TEMP_VIDEO="$(dirname $IN_FILE)/.temp.$(random).video.$(basename "$IN_FILE")";
+    ffmpeg -itsscale "$RATIO" -i "$IN_FILE" -c copy -an "$TEMP_VIDEO";
+    TEMP_AUDIO="$(dirname $IN_FILE)/.temp.$(random).audio.$(basename "$IN_FILE")";
+    ffmpeg -i "$IN_FILE" -filter_complex "$AUDIO_FILTER" -vn -map "[a]" "$TEMP_AUDIO";
+    ffmpeg -i "$TEMP_VIDEO" -i "$TEMP_AUDIO" -c:v copy -c:a copy "$OUT_FILE";
+    rm -f "$TEMP_AUDIO" "$TEMP_VIDEO";
+  else
+    ffmpeg -itsscale "$RATIO" -i "$IN_FILE" -c copy -an "$OUT_FILE";
+  fi;
+}
+
+if [ "$MODE" = "--fast" ]; then
+  fast;
+else
+  slow
+fi;
diff --git a/change-length-video-HWACCEL.sh b/change-length-video-HWACCEL.sh
new file mode 100755
index 0000000..66a9e0c
--- /dev/null
+++ b/change-length-video-HWACCEL.sh
@@ -0,0 +1,75 @@
+#!/bin/bash -x
+
+# usage: change-length.sh 1.007 input.mp4 output.mp4 [--fast]
+#       ^output.mp4 will be be 7% longer
+#       --fast is faster, but slightly more risky
+       
+set -euo pipefail
+
+RATIO=$1;
+IN_FILE=$2;
+OUT_FILE=$3;
+MODE=${4-"--slow"};
+BITRATE=$(ffmpeg -i "$IN_FILE" 2>&1 | grep bitrate | awk -F", " '{print $3}' | sed 's/bitrate: //' | sed 's/ //' | sed 's/b\/s//' || echo "");
+
+echo ratio set to "$RATIO"
+
+INV_RATIO=$(python -c "print(1/$RATIO)");
+
+FILTER="";
+OPTS=();
+
+AUDIO_FILTER="[0:a]atempo=$(echo "$INV_RATIO")[a]";
+
+HAS_AUDIO=$(ffprobe "$IN_FILE" 2>&1 | grep Stream | grep --count Audio || echo "0");
+HAS_VIDEO=$(ffprobe "$IN_FILE" 2>&1 | grep Stream | grep --count Video || echo "0");
+
+slow () {
+  echo " ";
+  echo " ";
+  echo " ";
+  echo " ";
+  echo "USING SLOW MODE. If you want only video, use --fast";
+  echo " ";
+  echo " ";
+  echo " ";
+  echo " ";
+  echo " ";
+  echo " ";
+  echo " ";
+  echo "Checking streams within the file...";
+
+  if [ "$HAS_AUDIO" -ge 0 ]; then
+    FILTER=$AUDIO_FILTER;
+    OPTS+=(-map "[a]");
+  fi;
+
+  if [ "$HAS_VIDEO" -ge 0 ]; then 
+    FILTER="$FILTER;[0:v]setpts=$RATIO*PTS,hwupload[v]";
+    OPTS+=(-map "[v]");
+  fi;
+
+  echo "running with filter $FILTER";
+
+  ffmpeg -hwaccel vaapi -hwaccel_output_format vaapi -vaapi_device /dev/dri/renderD128 -i "$IN_FILE" -b:v $BITRATE -filter_complex "$FILTER" "${OPTS[@]}" -c:v h264_vaapi "$OUT_FILE";
+#   ffmpeg -i "$IN_FILE" -filter_complex "$FILTER" "${OPTS[@]}" "$OUT_FILE";
+}
+
+fast (){
+  if [ "$HAS_AUDIO" -ge 0 ]; then
+    TEMP_VIDEO="$(dirname $IN_FILE)/.temp.$(random).video.$(basename "$IN_FILE")";
+    ffmpeg -itsscale "$RATIO" -i "$IN_FILE" -c copy -an "$TEMP_VIDEO";
+    TEMP_AUDIO="$(dirname $IN_FILE)/.temp.$(random).audio.$(basename "$IN_FILE")";
+    ffmpeg -i "$IN_FILE" -filter_complex "$AUDIO_FILTER" -vn -map "[a]" "$TEMP_AUDIO";
+    ffmpeg -i "$TEMP_VIDEO" -i "$TEMP_AUDIO" -c:v copy -c:a copy "$OUT_FILE";
+    rm -f "$TEMP_AUDIO" "$TEMP_VIDEO";
+  else
+    ffmpeg -itsscale "$RATIO" -i "$IN_FILE" -c copy -an "$OUT_FILE";
+  fi;
+}
+
+if [ "$MODE" = "--fast" ]; then
+  fast;
+else
+  slow
+fi;