Record, merge, and accelerate Android screen capture

adb-record.sh

#!/usr/bin/env bash

# Repeatedly records Android screen capture to files 180 seconds in length
# until Ctrl+C, then pulls those files to the desktop, merges them into
# one video, generates an additional 8x speed version (*-8x.mp4) and cleans
# up the intermediary files.

# Depends on: ffmpeg, adb
# Usage: $ adb-record <name> # => ./name.mp4

trap ctrl_c INT

function ctrl_c() {
  let MAX=COUNT+1
  let COUNT=0
  while [  $COUNT -lt $MAX ]; do
    echo "Pulling /sdcard/$NAME-$COUNT.mp4 -> ./"
    adb pull /sdcard/$NAME-$COUNT.mp4 ./

    echo "Adding ./$NAME-$COUNT.mp4 to ./$NAME.txt"
    echo "file './$NAME-$COUNT.mp4'" >> ./$NAME.txt

    echo "Removing /sdcard/$NAME-$COUNT.mp4"
    adb shell rm /sdcard/$NAME-$COUNT.mp4

    let COUNT=COUNT+1 
    export COUNT
  done

  echo "Concatenating files to ./$NAME.mp4"
  ffmpeg -f concat -i ./$NAME.txt -c copy ./$NAME.mp4

  echo "Cleaning up"
  rm -v ./$NAME-*.mp4
  rm -v ./$NAME.txt

  echo "Copying at 8x speed (by dropping frames) to ./$NAME.mp4-8x.mp4"
  ffmpeg -r:v "240/1" -i ./$NAME.mp4 -an -r:v "12/1" ./$NAME-8x.mp4

  break
}

COUNT=0
export NAME=$1
echo "Press CTRL+C to finish, pull and cat video"
for (( ; ; ))
do
  echo "Recording to /sdcard/$NAME-$COUNT.mp4"
  adb shell screenrecord --time-limit 180 --rotate /sdcard/$NAME-$COUNT.mp4
  let COUNT=COUNT+1
  export COUNT
done