Implementation of an Android Phone
Based Video Streamer
2010 IEEE/ACM International Conference on Green Computing and Communications
2010 IEEE/ACM International Conference on Cyber, Physical and Social Computing
N Vun, Y H Ooi
School of Computer Engineering Nanyang Technological University
Digital Object Identifier : 10.1109/GreenCom-CPSCom.2010.76
Date of Conference: 18-20 Dec. 2010
Page(s):912 - 915
Adviser : Yih-Ran Sheu
Student : Chun-Chang Tu
SN : MA120110
Motivation
OUTLINE
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ABSTRACT
INTRODUCTION
ANDROID ARCHITECTURE OVERVIEW
DEVELOPMENT TOOLS AND ENVIRONMENT SETUP
VIDEO CAMERA STREAMING SYSTEM
IMPLEMENTATION RESULTS AND DISCUSSION
CONCLUDING REMARKS
Abstract
• This paper presents the implemented of the
camera on the mobile phone to capture real
time video which is then streamed over the
WiFi network. Then the video can be viewed
on other station connected to the same
network using the standard VLC media player.
Introduction 1/3
• Android technology become popular in the
consumer electronics market.
• They provide very convenient hardware
platforms for the developers to implement
and test their ideas with much lower cost.
Introduction 2/3
• The main objective of this paper is implement
a video streamer on an Android based mobile
phone.
• The implementation is done completely using
open source software tools, software modules
and technologies without the need of any
special or propriety development tool.
Introduction 3/3
• Figure 1 illustrates the use of an Android
phone as the embedded platform, connecting
to an IP network using its WiFi interface.
• The video can be viewed on LAN PCs using the
open-source VLC media player.
Android Architecture Overview
Android Architecture Overview
Android Architecture Overview
JVM
dx
SDK
Development Tools and
Environment Setup (1/3)
• Development of Android Apps can be
conveniently performed using the Eclipse IDE.
• For Android App development, extension tools
are needed. These extension tools are
packaged in the Android Development Tools.
• Android SDK starter package contains various
development tool chains and libraries are
needed by the Eclipse to compile and package
the application into the Android Package file.
Development Tools and
Environment Setup (2/3)
Development Tools and
Environment Setup (3/3)
• The emulator cannot support emulation of
specific hardware features like camera.
• Application that involves networking will also
need proper setup of the virtual router.
• As such, sometimes it is more convenient, or
inevitable, that testing has to be done with
the actual phone when the App makes use of
the hardware feature.
VIDEO CAMERA STREAMING
SYSTEM (1/11)
• The application in the Android phone is made
up of two modules: a video recorder module
and a cross-compiled LIVE555 streamer
module.
VIDEO CAMERA STREAMING
SYSTEM (2/11)
• Implementation of the video recorder module
makes use of the Media Libraries provided in
the Android SDK.
• It involves extending the SurfaceView class,
creating a SurfaceHolder class and a
MediaRecorder class, and implementing a
SurfaceHolder.Callback function.
VIDEO CAMERA STREAMING
SYSTEM (3/11)
VIDEO CAMERA STREAMING
SYSTEM (4/11)
• LIVE555 is used as the engine for streaming
the video file in this implementation.
VIDEO CAMERA STREAMING
SYSTEM (5/11)
• As the source code of the Live 555 is created
in C/C++, it cannot be compiled to run as a
native Android App.
• There are two ways to integrate the package
into this system: cross compiled the code and
run it as a standalone C program, or modify it
and compiled as a shared library package.
VIDEO CAMERA STREAMING
SYSTEM (6/11)
• LIVE555 uses the glibc for its library, which is
not included in the standard Android libraries.
• To overcome this, Live 555 has to be linked
statically during compilation, i.e. all the library
functions needed are included in the
executable code.
VIDEO CAMERA STREAMING
SYSTEM (7/11)
• The compiled LIVE555 program is then
transferred to the appropriate file directory in
the phone.
VIDEO CAMERA STREAMING
SYSTEM (8/11)
• Another complication is standard Android
phone is set to restrict user with limited
access to its lower level functions and features.
• To start the LIVE555 server through a shell
command, the user needs to have root access
in the operating environment.
• Hence a further step is needed here, the
‘rooting’ of the Android phone.
VIDEO CAMERA STREAMING
SYSTEM (9/11)
• Another alternative is integrate the LIVE555
code together with the Video recorder code
and package them as an .apk file.
• This will involve the modification of the
LIVE555 code to make it as a library function,
and combination of the C/C++ and Java
languages in an application.
VIDEO CAMERA STREAMING
SYSTEM (10/11)
• This can be achieved by Android’s recent
release toolkit, viz. the Android Native
Development Kit .
• This toolkit allows the programmers to embed
native C/C++ code into Android application.
• Java Native Interface method is used to bridge
the communication between the Java
application and the native C/C++ code.
VIDEO CAMERA STREAMING
SYSTEM (11/11)
IMPLEMENTATION RESULTS AND
DISCUSSION (1/5)
IMPLEMENTATION RESULTS AND
DISCUSSION (2/5)
• The video of the clock running on the first PC
monitor is captured by the Android phone,
then streamed through the phone WiFi link to
a LAN router, which is then playback in real
time by a VLC player running on the second PC.
• There is no observable throughput delay in
the streaming process under normal network
condition.
IMPLEMENTATION RESULTS AND
DISCUSSION (3/5)
• However, though not clearly noticeable in the
photo, there is playback frame delay between
the source and the playback image.
• The delay will depend on the instance the VLC
media player is started. This is due to the use
of the file as a buffer between the two
software modules running on the Android
phone.
IMPLEMENTATION RESULTS AND
DISCUSSION (4/5)
• While the video recorder module will start
recording the video into the file upon
launching by the user, the LIVE555 will only
start streaming the video upon receiving the
request from the VLC player.
• As the LIVE555 streamer starts the video from
the beginning of the file, it streams the image
that was recorded earlier.
IMPLEMENTATION RESULTS AND
DISCUSSION (5/5)
• Another consequence of using the file buffer
is that the system will stop operation once the
file size exceeds the maximum limit that the
Android platform can support.
• To overcome these limitations, the two
software modules have to be further modified
such that data can be passed directly between
them in real time
CONCLUDING REMARKS
• This paper describes the successful
implementation of a video streamer system
using an Android phone as the video capturing
device.
• As the system was setup as a preliminary
investigation and evaluation of using the
Android platform for embedded applications,
certain limitations remain in the implemented
system.
REFERENCES
[1] http://www.npd.com/press/releases/press_100804.html
[2] http://developer.android.com/guide/basics/what-is-android.html
[3] http://developer.android.com/sdk/eclipse-adt.html
[4] LIVE555 Media Server, http://www.live555.com/mediaServer/
[5] VLC Media Player, http://www.videolan.org/vlc/
[6] N. Vun and M Ansary, “Implementation of an Embedded H.264 Live
Video Streaming System”, IEEE ISCE 2010
[7] http://en.wikipedia.org/wiki/Rooting_(Android_OS)