H.263 Video Codec

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Video Transmission over Ethernet using H.263 Codec

Text of H.263 Video Codec

  • 1. Video Transmission Over Ethernet Using H.263 Codec |2013 VIDEO TRANSMISSION OVER ETHERNET USINGClick to edit Master text styles Second level H.263 CODECThird level Fourth levelFifth level Presented by:KavishaBTBTI09124 B.Tech(I.T.)-VII sem

2. Video Transmission Over Ethernet Using H.263 Codec | 2013 AIM OF THE PROJECTThe project aims at capturing a real time video frame Click to edit web camera and compressing thesequence by a Master text stylesSecond levelcaptured frames with H.263 codec and transmittingThird bitthe encodedlevel stream over Ethernet, subsequentlydecoding Fourththe receiving end for display, by theit at level Fifth levelimplementation of codec & analyzing its performance& its image quality. 3. Video Transmission Over Ethernet Using H.263 Codec | 2013TOOLS USEDPlatform:Linux (Red Hat Enterprise Linux 6)Click to edit Master text stylesLanguage : CSecond levelTools Used :level Eclipse ThirdHardwareFourth level Webcam:PC, Fifth level 4. Video Transmission Over Ethernet Using H.263 Codec |2013 WHAT IS A VIDEO?Video consists of a time ordered sequence of Click to edit Master text stylescorrelated images called frames.Second level Third levelLive streaming of video refers to the sequence ofFourth levelframes constantlylevelFifthreceived by and presented to theend user while being delivered by the stream provider. 5. Video Transmission Over Ethernet Using H.263 Codec | 2013 WHY WE NEED COMPRESSION?One movie video without compression having:Clickxto edit Master text styles 640 480 pixels per frame Second level 30 frames per secondThird level Total 90 minutesFourth level Full color Fifth levelThe total quantity of data = 167.96 GB !!How to stream this large amount of data over network?The purpose of video compression is to cram more information into less space and bandwidth. 6. Video Transmission Over Ethernet Using H.263 Codec |2013VIDEO COMPRESSIONClick to edit Master text stylesSecond level Third levelFourth level Fifth level1. Compress and in one frame.2. Compress the motion of in remaining frames. 7. Video Transmission Over Ethernet Using H.263 Codec |2013 VIDEO COMPRESSION CODEC stands for enCOder/DECoder.Click to edit Master text styles--convert video stream into a format that takes up lessSecond level space when its stored or transmitted & then decodeThird level that format into video stream again.Fourth levelFifth level A device or a program that compresses a video signalis called an encoder and a device or a program thatdecompresses the video signal is called a decoder. 8. Video Transmission Over Ethernet Using H.263 Codec |2013H.263 H.263 is a real time compression & decompressionalgorithm for video communication at low bitrates.Click to edit Master text styles Second level It gives enhanced visual quality at very low bitrates Third levelsay around 28 kbps.Fourth level Fifth level It is used for Video on Demand and streamingservices. It is based on using the Discrete Cosine Transform(DCT) and Motion Estimation and Compensation toremove temporal redundancies. 9. Video Transmission Over Ethernet Using H.263 Codec |2013VIDEO ENCODINGClick to edit Master text stylesSecond level Third levelFourth level Fifth levelDemonstration Flow Diagram 10. Video Transmission Over Ethernet Using H.263 Codec | 2013VIDEO CAPTURE Video stream is captured by means of a webcam with Click to of SDLMaster DirectMedia Layer).the help edit (Simple text styles Second level Simple DirectMedia Layer (SDL) is a free cross- Third levelplatform multi-media development API.Fourth level Fifth level The code for video capture is written using SDLlibraries and Video For Linux 2 (V4L2) specifications. The standard file for accessing webcam on linux is/dev/video0. 11. Video Transmission Over Ethernet Using H.263 Codec |2013VIDEO CAPTURE The web cam captures video in YUV format but for rendering it on screen its converted to RGB format. Click to edit Master text stylesIn the application it is converted to RGB(BITMAP) Second level format using the formulae: Third level r = y + (1.370705 * (v-128));Fourth level g = y - (0.698001 * (v-128)) - (0.337633 * (u-128));Fifth level b = y + (1.732446 * (u-128)); where, y: represents Luminance. u (Cb): is the Chroma channel, blue component. v (Cr) : is the Chroma channel, red component. 12. Video Transmission Over Ethernet Using H.263 Codec |2013 VIDEO CAPTUREClick to edit Master text stylesSecond level Third levelFourth level Fifth level 13. Video Transmission Over Ethernet Using H.263 Codec |2013 VIDEO FRAME FORMATSAll versions of H.263 support five standardized pictureformats:Click to edit Master text styles Second levelThird level Fourth levelFifth level The choice of frame resolution depends onapplication and available storage or transmissioncapacity. CIF and QCIF are popular for the videoconferencingapplications. 14. Video Transmission Over Ethernet Using H.263 Codec |2013 VIDEO ENCODING Video coding aims at providing a compact Click to edit Masterinformation in the video frames representation of the text styles by removing spatial redundancies that exist withinSecond level the frames, and also temporal redundancies that exist Third level between successive frames.Fourth level Fifth level Each picture is divided into Macroblocks (16x16)where each macroblock consists of 4 luminance blocksand 2 spatially aligned color difference blocks. Eachblock consists of 8 pixels x 8 lines of luminance orchrominance. 15. Video Transmission Over Ethernet Using H.263 Codec |2013 VIDEO FORMATClick to edit Master text stylesSecond level Third levelFourth level Fifth level 16. Video Transmission Over Ethernet Using H.263 Codec |2013 VIDEO ENCODINGClick to edit Master text stylesSecond level Third levelFourth level Fifth level 17. Video Transmission Over Ethernet Using H.263 Codec | 2013VIDEO ENCODING 16 16 MacroblocksClick to Frame n Master text styleseditSecond levelThird levelFrame n-1Y Fourth level DCT, Quantization, Fifth level Residual Zigzag, Entropy coding Cb CrMotion vector Search range 18. Video Transmission Over Ethernet Using H.263 Codec |2013ENCODING PARAMETERS Input sequence is YUV format video with frame rateClick25fps. This is the video we get directly for of to edit Master text styles webcam.Second level Bitmap format is used for rendering the image onThird level screen.Fourth level Fifth level In encoder, profile is with 8x8 transform and VLC (Variable Length Coding) Entropy coding method is used. Frame rate is initialized with 25fps. Initialization Quantization Parameter is taken as 10. 19. Video Transmission Over Ethernet Using H.263 Codec | 2013PACKETIZATION Datagram Sockets are created at both ends for sending & receiving encoded video bitstream.Clickencoded Master text styles packets of size The to edit bitstream is made intoSecond to be 1300 byteslevel transmitted over network.Third packet_struct defines the packet header. Structure level Fourth levelFifth level#define DATA_SIZE1300typedef struct packet_struct{ int seq_no; int packets; int data_len;}packet_struct; 20. Video Transmission Over Ethernet Using H.263 Codec |2013PACKETIZATION The packets are formed after attaching the packet Click toto data. header edit Master text stylesSecond level The packets are pushed into the queue to be Third level transmitted over the network.Fourth level PACKET QUEUEFifth level 21. Video Transmission Over Ethernet Using H.263 Codec | 2013 PACKETIZATION/* to count the number of packets */ Click to edit% data_size) stylesif(data_length Master text Second leveltotal_packets = data_length/data_size+1;Third levelelseFourth leveltotal_packetslevel Fifth = data_length/data_size; At the receiver side the incoming packets are pushedin the queue until the complete buffer is received. 22. Video Transmission Over Ethernet Using H.263 Codec |2013 PACKETIZATIONClick to edit Master text stylesSecond level Third levelFourth level Fifth level 23. Video Transmission Over Ethernet Using H.263 Codec |2013 PACKETIZATIONClick to edit Master text stylesSecond level Third levelFourth level Fifth level 24. Video Transmission Over Ethernet Using H.263 Codec |2013 VIDEO DECODINGClick to edit Master text stylesSecond level Third levelFourth level Fifth level 25. Video Transmission Over Ethernet Using H.263 Codec |2013 VIDEO DECODINGClick to edit Master text stylesSecond level Third levelFourth level Fifth level 26. Video Transmission Over Ethernet Using H.263 Codec | 2013OUTPUTClick to edit Master text stylesSecond level Third levelFourth level Fifth levelCaptured Image Decompressed Image 27. Video Transmission Over Ethernet Using H.263 Codec | 2013 COMPRESSION RATIO The size of a single YUV frame (176x144) is about 50KB. The captured YUV frame is converted to RGB (176x144) Click to edit rendered for display.Bitmap image Master text stylesSecond level The size of a single RGB frame is about 75 KB. Third level The sizeFourth level of compressed bitstream for a single frame is~9.6 KB. Fifth levelCR = Compressed Size / Uncompressed Size CR= 9.6 / 49.5 = 0.19 ~ 0.2 The image is thus compressed nearly by 5 times withrespect to the original one. 28. Video Transmission Over Ethernet Using H.263 Codec | 2013 Quality Measurement & PSNR Click(Peak Signal to Noise Ratio) calculation of twoPSNR to edit Master text stylesimages, one level Secondoriginal and an altered image, describeshow far two levelThird images are equal. A higherFourth levelPSNR would normally indicate that the Fifth levelreconstruction is of higher quality.. PSNR formulaMSE: Mean-Square error.x: width of image.y: height. 29. Video Transmission Over Ethernet Using H.263 Codec | 2013 Quality Measurement & PSNRThe Peak Signal to Noise Ratio (PSNR) for a QCIF FrameClick to calculated at text styles(176x144) is edit Masterdifferent frame rates say 25 fps,Second level30fps. Third level ComponentFourth levelPSNR(dB) Fifth levelPSNR_Y30.74