snaprecovery.sh

#!/bin/sh
#
# by Siddharth Dushantha
#

# Colored log indicators
GOOD="\033[92;1m[✔]\033[0m"
BAD="\033[91;1m[✘]\033[0m"
INFO="\033[94;1m[I]\033[0m"
RUNNING="\033[37;1m[~]\033[0m"
NOTICE="\033[93;1m[!]\033[0m"

usage(){
cat <<EOF
usage: snaprecovery [-n, --no-merge] [SERIAL]

The serial number of the device can be found by running 'adb devices'.
It is not necessary if only one device is connected in adb devices.

Options:
    -n, --no-merge    don't merge videos with their respective overlays
EOF
    exit 1
}


# Determines whether or not to merge videos with overlays. Must be unset or null/empty to disable.
MERGE=yes

while [ "$1" ] ; do
    case $1 in
        -h|--help) usage ;;
        -n|--no-merge) unset MERGE ;;
        *) SERIAL="$1" ;;
    esac
    shift
done


for DEPENDENCY in adb awk ${MERGE:+ffmpeg stat touch}; do
    if ! command -v "$DEPENDENCY" >/dev/null 2>&1; then
        printf "%b Could not find '%s', is it installed?\n" "$BAD" "$DEPENDENCY"
        exit 1
    fi
done

# Number of devices connected to computer through USB
DEVICESCOUNT="$(adb devices | awk 'NF && NR>1' | wc -l)"

# If only one device is connected, use its serial, otherwise the user is required to specify a serial.
if [ "$DEVICESCOUNT" -eq 1 ]; then
    SERIAL="$(adb devices | awk 'NF && FNR==2{print $1}')"
else
    [ $# -eq 0 ] || [ "$1" = "" ] && usage
fi

SNAPS_DIRECTORY="snaps_$SERIAL"

# Check if the device is authorized
DEVICESTATUS="$(adb devices | grep "$SERIAL" | cut -f2)"
if [ "$DEVICESTATUS" = 'unauthorized' ]; then
  printf "%b Device '%s' is not authorized.\n" "$BAD" "$SERIAL"
  printf "%b Check for a confirmation dialog on your device.\n" "$NOTICE" 
  exit 1
fi

# Get the product model (e.g. SM-AF10F). If a product model is not found, then
# that means the given serial is invalid.
if ! PRODUCT_MODEL=$(adb -s "$SERIAL" shell getprop ro.product.model 2> /dev/null);then
    printf "%b Looks like '%s' is an invalid device\n" "$BAD" "$SERIAL"
    exit 1
fi

printf "%b Target device: %s (%s)\n" "$INFO" "$SERIAL" "$PRODUCT_MODEL"

# Restart adb as root. Root access is needed in order to access the files
adb -s "$SERIAL" root > /dev/null 2>&1

if ! adb -s "$SERIAL" pull -a /data/user/0/com.snapchat.android/files/file_manager/chat_snap/ .snaprecovery-tmp > /dev/null 2>&1; then
    printf "%b %b\n" "$BAD" "This device is not rooted!"
    exit 1
fi

mkdir -p "$SNAPS_DIRECTORY"
TOTAL_FILES=$(find .snaprecovery-tmp -mindepth 1 | wc -l)
COUNT=1

# If MERGE is unset, rename all files without merging
if [ -z "${MERGE:+x}" ]; then
    for SNAP in .snaprecovery-tmp/*.chat_snap.[012]; do
        EXTENSION=$(file --mime-type -b "$SNAP" | sed 's/.*\///g')
        NEW_FILENAME="${SNAP%chat_snap.[012]}$EXTENSION"

        # \r            Move cursor to the start of the current line
        # \e[2K         Clear whole line
        printf "\r\033[2K%b Recovering [%d/%d]: %s" "$RUNNING" "$COUNT" "$TOTAL_FILES" "$NEW_FILENAME"
        mv "$SNAP" "$NEW_FILENAME"
        COUNT=$((COUNT + 1))
    done
    rm -f .snaprecovery-tmp/*.json
else
    # If MERGE is set, rename singletons and merge overlays
    # For files without overlays, rename with the correct extension
    for SNAP in .snaprecovery-tmp/*.chat_snap.0; do
        EXTENSION=$(file --mime-type -b "$SNAP" | sed 's/.*\///g')
        NEW_FILENAME="${SNAP%chat_snap.0}$EXTENSION"

        # \r            Move cursor to the start of the current line
        # \e[2K         Clear whole line
        printf "\r\033[2K%b Recovering [%d/%d]: %s" "$RUNNING" "$COUNT" "$TOTAL_FILES" "$NEW_FILENAME"
        mv "$SNAP" "$NEW_FILENAME"
        COUNT=$((COUNT + 1))
    done

    # For files with overlays, use ffmpeg to merge the overlay
    for SNAP in .snaprecovery-tmp/*.chat_snap.1; do
        BASE="$SNAP"
        OVERLAY="${SNAP%1}2"
        NEW_FILENAME="${SNAP%.chat_snap.1}.merged.mkv"

        # if <name>.chat_snap.2 doesn't exist, don't attempt to merge anything
        [ -f "$OVERLAY" ] || continue

        # \r            Move cursor to the start of the current line
        # \e[2K         Clear whole line
        printf "\r\033[2K%b Recovering [%d/%d]: %s" "$RUNNING" "$COUNT" "$TOTAL_FILES" "$NEW_FILENAME"
        
        # merge overlay onto video
        ffmpeg -loglevel quiet -i "$BASE" -i "$OVERLAY" -filter_complex '[1:v][0:v]scale2ref[overlay][base]; [base][overlay]overlay' -c:a copy "$NEW_FILENAME"

        # adjust timestamp of new merged video to match base video
        TIMESTAMP="$(stat --format=%Y "$BASE")"
        touch -d "@$TIMESTAMP" "$NEW_FILENAME"

        # remove base, overlay, and unused JSON
        rm -f "$BASE" "$OVERLAY" "${SNAP%chat_snap.1}json"

        COUNT=$((COUNT + 1))
    done
fi

printf "\r\033[2K%b Recovered %d snaps\n" "$GOOD" "$TOTAL_FILES"
printf "%b The recovered snaps can be found in '%s'\n" "$NOTICE" "$SNAPS_DIRECTORY"

mv .snaprecovery-tmp/* "$SNAPS_DIRECTORY"
rm -rf .snaprecovery-tmp/