W4995 VoIP

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W4995 VoIP SecurityInstructor Prof. Henning
Schulzrinne COLUMBIA VIDEO TOOL
(COVIT)Project TeamArchana Rao Supreeth
SubramanyaElectrical Engineering, Columbia
University
Date Dec 6, 2006
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STRUCTURE OF THE TALK

• Definition and Scope
• Requirements Analysis
• System Architecture
• System Components
• Testing
• Project Takeaways
• Milestones

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DEFINITION SCOPE

• Development of a generic and scalable media
  streaming client that renders video in a platform
  independent way
• Targeted at Video IP Phones
• Requirements
• Video capture/display
• Video encode/decode
• Video streaming

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SYSTEM SURVEY

• VLC Media Player
• Cross-platform media player and streaming server
• Supports virtually all formats, containers and
  streaming protocols.
• VIC
• Real-time, multimedia application for video
  conferencing from UC Berkeley
• Strongly coupled with the H.261 codec
• FFmpeg
• Complete solution to record, convert and stream
  audio and video
• Consists of
• ffmpeg tool to convert one video file format to
  another
• ffserver HTTP based multimedia streaming server
• ffplay a media player

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COVIT ARCHITECTURE
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SYSTEM COMPONENTS
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MEDIA TRANSPORT

• RTP Interface
• COVIT_RTP_SessionInit
• COVIT_RTP_SessionTerminate
• COVIT_RTP_Send
• COVIT_RTP_Receive
• Library used
• ccRTP from GNU Telephony
• Provides RTP stack with full RTCP support
• Supports both unicast and multicast

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VIDEO CODEC

• Video Interface
• COVIT_Codec_Alloc
• COVIT_Codec_Init
• COVIT_Codec_GetNextFrame
• COVIT_Codec_PutNextFrame
• COVIT_Codec_Free
• Libraries used
• libavcodec, libavformat
• Supports H26x, MPEGx, MJPEG, RealMedia
• Supports containers - avi, asf, mov, mpg etc

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MEMORY MANAGEMENT

• Memory Manager Interface
• COVIT_MemoryManager_Init
• COVIT_Memorymanager_Free
• COVIT_MemoryManager_Push
• COVIT_MemoryManager_Pop

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CONTROLLER

• Session Interface
• COVIT_Session_Init
• COVIT_Session_Free
• COVIT_Session_CreateClientSession
• COVIT_Session_CreateServerSession
• COVIT_Session_TerminateClientSession
• COVIT_Session_TerminateServerSession

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CONTROL / DATA FLOW
COVIT Decoder
COVIT Encoder
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TESTING

• Unit Testing
• To uncover bugs in the functionality
• Test suites with known input/output
• Integration Testing
• To uncover bugs in the interfaces
• Run COVIT as a client/server/both (in tandem with
  VLC)
• System Testing
• To uncover bugs at the system level
• Plugging into sipc and/or pjsip

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PROJECT TAKEAWAYS

• Challenges
• A systems project
• Theres too much to do
• Identification of a target application reduces
  some complexity
• System testing is never complete
• New formats, new utilities keep coming
• Key learning
• Hands on with two of the largest multimedia code
  bases
• Trade-off between a cleaner design and performance

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PROJECT MILESTONES
Completion Tasks

• Requirements gathering existing system survey
  AR, SS
• System interface design AR, SS
• RTP library (ccrtp) testing integration AR
• Video library (libavcode/libavformat) integration
  SS
• Memory management AR
• Linux display (SDL based) AR
• Linux capture (webcam/screen-capture) SS
• Simultaneous capture/display AR, SS
• Project package, documentation and report
  generation AR, SS

Tasks to be done
Tasks completed
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REFERENCES

• http//ffmpeg.mplayerhq.hu/
• http//www-nrg.ee.lbl.gov/vic/
• http//www.videolan.org/vlc/
• http//www.gnu.org/software/ccrtp/
• http//www.gnu.org/software/ccrtp/doc/refman/html/
  examples.html