Screenshot script for Android

adb-screenshot.sh

#!/bin/bash
#
# adb-screenshot - simple script to take screenshots of android devices
#
# Requires: 'ffmpeg' and 'adb' to be somewhere in the PATH
#
# Author: Kevin C. Krinke <[email protected]>
# License: Public Domain

# globals / constants
NAME=$(basename $0)
TGT=~/Desktop/${NAME}.png
SRC=/sdcard/${NAME}.png
TMP=/tmp/${NAME}.$$
RAW=/tmp/${NAME}.raw
FFMPEG=$(which ffmpeg)
ADB=$(which adb)
DD=$(which dd)
USB_DEVICE=""

# remove transitory files if exist
function cleanup () {
    [ -f "${RAW}" ] && rm -f "${RAW}"
    [ -f "${TMP}" ] && rm -f "${TMP}"
    [ -z "$1" ] && die "aborting process now."
    exit 0
}

# exit with an error
function die () {
    echo "Critical Error: $@"
    exit 1
}

# catch all signals and cleanup / dump
trap cleanup \
    SIGHUP SIGINT SIGQUIT SIGILL SIGTRAP SIGABRT SIGEMT SIGFPE \
    SIGKILL SIGBUS SIGSEGV SIGSYS SIGPIPE SIGALRM SIGTERM SIGURG \
    SIGSTOP SIGTSTP SIGCONT SIGCHLD SIGTTIN SIGTTOU SIGIO SIGXCPU \
    SIGXFSZ SIGVTALRM SIGPROF SIGWINCH SIGINFO SIGUSR1 SIGUSR2

# adb is absolutely required
[ -x "${ADB}" ] || die "ADB is missing!"

# cheap getopt
while [ $# -gt 0 ]
do
    case "$1" in
        "-h"|"--help")
            echo "usage: $(basename $0) [-h|--help] [-s SERIAL] [/path/to/output.png]"
            exit 1
            ;;
        "-s")
            [ -z "$2" ] && die "Missing argument for option \"-s\", try \"${NAME} --help\""
            HAS_DEVICE=$(${ADB} devices | grep "$2" )
            [ -z "${HAS_DEVICE}" ] && die "No device found with serial $2"
            USB_DEVICE="$2"
            ;;
        *)
            [ -n "$1" -a -d "$(dirname $1)" ] && TGT="$1"
            ;;
    esac
    shift
done

# prep target with fire
[ -f "${TGT}" ] && rm -f "${TGT}"

# tweak ADB command line
if [ -n "${USB_DEVICE}" ]
then
    ADB="$(which adb) -s ${USB_DEVICE}"
fi

# calculate resolution
DISPLAY_RAW=$(${ADB} shell dumpsys window)
HRES=$(echo "${DISPLAY_RAW}" | grep SurfaceWidth  | head -1 | perl -pe 's/^.*\bSurfaceWidth\:\s*(\d+)px\b.*$/$1/')
VRES=$(echo "${DISPLAY_RAW}" | grep SurfaceHeight | head -1 | perl -pe 's/^.*\bSurfaceHeight\:\s*(\d+)px\b.*$/$1/')
RES=${HRES}x${VRES}

# check for screencap binary
HAS_SCREENCAP=$(${ADB} shell "[ -x /system/bin/screencap ] && echo 1 || echo 0" | perl -pe 's/\D+//g')
if [ "$HAS_SCREENCAP" == "1" ]
then # use screencap to get the image easy-peasy
    echo -n "Getting ${RES} screencap... "
    ( ${ADB} shell /system/bin/screencap ${SRC} 2>&1 ) > /dev/null
    [ "$?" != "0" ] && die "Failed to execute screencap"
    ( ${ADB} pull ${SRC} ${TMP} 2>&1 ) > /dev/null
    [ "$?" != "0" ] && die "Failed to pull png image"
    ( ${ADB} shell rm ${SRC} 2>&1 ) > /dev/null
    [ "$?" != "0" ] && die "Failed to remove png image"
    mv ${TMP} ${TGT}
    echo "wrote: ${TGT}"
else # fetch a framebuffer snapshot
    # ffmpeg is only needed if device is pre-ICS
    [ -x "${FFMPEG}" ] || die "FFMPEG is missing!"
    [ -x "${DD}" ] || die "DD is missing!"
    echo -n "Getting ${RES} framebuffer... "
    ( ${ADB} pull /dev/graphics/fb0 ${RAW} 2>&1 ) > /dev/null
    [ "$?" != "0" ] && die "Failed to pull raw image data"
    # calculate dd parameters
    COUNT=$((HRES*4))
    BLOCKSIZE=$((VRES))
    ( ${DD} bs=${BLOCKSIZE} count=${COUNT} if=${RAW} of=${TMP} 2>&1 ) > /dev/null
    [ "$?" != "0" ] && die "Failed to realign raw image data"
    ( ${FFMPEG} -vframes 1 -vcodec rawvideo -f rawvideo -pix_fmt rgb32 -s ${RES} -i ${TMP} -f image2 -vcodec png ${TGT} 2>&1 ) > /dev/null
    [ "$?" != "0" ] && die "Failed to encode PNG image"
    echo "wrote: ${TGT}"
fi

# exit app normal
cleanup 1