1.
GamingAnywhere: An Open
Cloud Gaming System
Chun-Ying Huang, Cheng-Hsin Hsu, Yu-Chun
Chang, and Kuan-Ta Chen
ACM MMSys’13, Oslo, Norway
1
http://gaminganywhere.org/

2.
Tough Life of Gamers
• Games are becoming way too complex
• The overhead of setting up a game is significant
• Often locked on a specific computer
• Games may not be software or hardware compatible with
some computers
• Computer hardware constantly
demands upgrading
2

3.
Cloud Gaming
Real-time game playing via thin clients
Game servers
Internet
Streaming
Streaming
Streaming
PC
Laptop
Mobile
3

4.
Selling Points of Cloud Gaming
• Gamers’ perspectives:
• Frees gamers from indefinitely upgrading their computers
• Eliminates setup overhead and compatibility issues for trying
out a game, as everything needed will be settled in data
centers by game operators
• Enables gamers to play games anywhere, anytime
• Game manufacturers’ perspectives:
• Allows developers to support more platforms
• Reduces the production cost
• Prevents pirating
4

5.
Cloud Gaming is Hot
• Cloud gaming is expected to lead the future growth of
computer games: 9 times in 6 years [CGR]
[CGR] http://www.cgconfusa.com/report/documents/Content-5minCloudGamingReportHighlights.pdf
T5-Labs
5

6.
Limitations of Existing Services
• OnLive demands for 5 Mbps for reasonable quality
• OnLive dictates a backbone latency of 22 ms, and partially
copes with it by setting up 5 data centers (CA, VA, TX, IL, GA)
• Only people who live in 1000 mile radius from a data center can play
the game
• and more…
• We, researchers, have tons of ideas to
improve cloud gaming services, but all
cloud gaming systems are proprietary
and closed
6

7.
• Solutions: GamingAnywhere is the first cloud gaming
platform for researchers, service providers, and users
7

8.
Design Objective
• Extensibility
• Components can be implemented as modules
• Features can be easily expanded
• Portability
• Cross-platform ready
• Configurability
• Exposes as many configurations as possible
• Openness
• It will be released to the public soon
8

9.
Cloud Gaming Scenario
Portal Servers Clients/Users
Game Selection
Game
Interaction
Game
Conguration
Game Servers
9

10.
System Architecture
• The client and the server, with many modules
• Implemented by leveraging open-source packages
Game console
Data Flow
Control Flow
Running the selected game
Agent
Process/Thread
Game Server Game Client
Internet
Audio / Video
Encoder
RTSP / RTP / RTCP
Audio / Video
Capturer
Replay User Inputs
(Keyboard, Mouse, ...)
Decode Input Events
(Customized Protocol)
RTSP / RTP / RTCP
Audio / Video
Decoder
Encode Input Events
(Customized Protocol)
Audio / Video
Player
User Inputs
(Keyboard, Mouse, ...)
10

11.
Implementation Overview
• GamingAnaywhere core is majorly implemented as a library
• With several modules and executables
• Server modules
• Video source (platform dependent)
• Audio source (platform dependent)
• Encoders (various encoders via ffmpeg)
• Replayer (platform dependent)
• RTSP/RTP server (using ffmpeg)
• Client modules
• RTSP/RTP client (using live555)
• Decoders (via ffmpeg)
• Controller (using SDL)
• Renderer (using SDL)
11

12.
Server Components
12
Audio
source
Desktop/Game
Video
source
Video
encoder
Audio
encoder
Audio
buffer
Video
buffer
(1a)
audio
capture
(1v)
video
capture
Threads
Shared buffers
(2a)
write audio
frames
(2v)
write a
video
frame
(3a)
wake up
encoder
(3v)
wake up
encoder
(4a)
read
audio
frames
(4v)
read a video
frame
(5a)
encode and
send
(5v)
encode and
send
Object owner
RTSP
server
thread
Data Flow Connections (RTSP/RTP/RTCP)
(1n)
handle
clients
Input
replayer
Control Flow Connections
(2i)
replay
input
events
(1i)
receive
input
events

13.
Processing Video Frames
• Process a video frame
1. Capturer: Capture game frames (Tcapture)
2. Converter: Convert from RGB format to YUV format (Tconvert)
3. Encoder: Encoding and packetization (Tencode)
14
Video Source Converter Encoder(Frame Pools) (Frame Pools)
Job Free Job Free

14.
Improving Game Frame Throughput
• Overall frame throughput
• 1/(Tcapture + Tconvert + Tencode) frames per second
• If (Tcapture + Tconvert + Tencode) is 40 ms, the maximum frame throughput is 25 fps
• A pipelined design for parallelism
• Improved frame throughput: 1/max(Tcapture, Tconvert, Tencode)
• If max(Tcapture, Tconvert, Tencode) is 20 ms, the frame throughput can achieve 50
fps
15
F1 F2
F1
F1
F2
F2
F3
F3
F3
Video source
(frame capture)
t
Video encoder
F4
Color space converter
(RGB to YUV)
t+D t t+2D t t+3D t

15.
Client Overview
17
Game Interaction
Main
thread
Control Flow Connections
(1i)
receive
input
events
(2i)
send
input
events
SDL Rendering Input Events
Data Flow Connections
RTSP
clientthread
Video
buffer
Audio
buffer
Threads
Buffers
Object owner
(1r)
receive
encoded
A/V
frames
(2rv)
buffer
an
encoded
audio
frames
(2ra)
buffer
encoded
audio frames
(3rv)
decode and render
video frames
(3ra)
decode and render
audio frames
(callback)

16.
Video Playout Buffering
• The 1-frame buffering strategy
• An H.264 frame can be split into different numbers of packets
• The marker bit (with a value of 1) indicates the last packet of a
frame
• Assuming 30 KB frames transmitted in a 50 Mbps network 
buffering time = 30 KB * 8 bits / 50 Mbps =~ 5 ms
18
M M M M M
RTP Packets
Frame #1 Frame #2 Frame #3 Frame #4 Frame #5
time

17.
GamingAnywhere Screenshots
19
Server
Client #1
Client #2
Client #3

18.
LIVE DEMO
20

19.
21
A demonstration of GamingAnywhere system. There are four devices in the
photo. One game server (left-hand side laptop) and three game clients (an
MacBook, an Android phone, and an iPad2).

20.
Performance Evaluation
• Compare against OnLive and StreamMyGame
• Environment setup
FreeBSD with
Dummynet
LAN
OnLive
Server
Internet
LAN
GamingAnyware
and
StreamMyGame
Server
Client
Router
22

21.
Performance Evaluation (Cont’d)
• Audio: The LAME encoder
• Video: The x264 encoder
• One of the VideoLan projects
• With the below default parameters
• $r is the bitrate variable, default 3Mbps
--profile main --preset faster --tune zerolatency
--bitrate $r --ref 1 --me dia --merange 16
--intra-refresh --keyint 48 --sliced-threads
--slices 4 --threads 4 --input-res 1280x720
23

22.
t0 (Key event sent) t1 (Key event
received)
t2 (Frame sent)t3 (Frame received)
ServerClient
Menu frame
Menu screen shown
t4 (Frame displayed)
• Network delay (ND) : network RTT
• Processing delay (PD) : t2 – t1  t3 – t0 – ND
• Playout delay (OD) : t4 – t3
25

23.
GA Has Lower Response Delay
26
Low response delay

24.
Delay Decomposition of GA
• Processing delay
• Memory lock + copy
• RGB to YUV
• x264 encoder
• Packetization (RTP packets)
• Playout delay
• 1-frame buffering
• S/W decoder
• SDL rendering
27

25.
GA Incurs Low to Moderate Network Loads
• Configured to capture at 50 fps with a bitrate of 3 Mbps
28

26.
GA Provides Superior Video Quality
29

27.
30
http://gaminganywhere.org/

28.
Conclusion
• GamingAnywhere is the first open cloud gaming system
• GamingAnywhere outperforms OnLive and
StreamMyGame
• 66% – 90% of processing delay reduction
• 3 – 19 dB video quality improvement
• We hope it will stimulate more studies and
applications on cloud gaming
• Server resource scheduling
• QoS/QoE measurements and provisioning
• Mobile cloud gaming
• … and much more!
31

29.
QUESTIONS?
Thanks for your attention!
32
http://gaminganywhere.org/