Presentation Transcript

1. Video Streamingpresented by:Amin ShahvalizadehSupervisor: Prof. Dr. Dogu Arifler First of April, 2014.
2. Outline Introduction Of Multimedia Network Samples Of Multimedia Applications Compressing Audio And Video Packet Jitter Removing Jitter at The Receiver For Audio
3. Samples Of Multimedia Applications Playing Stored Audio and Video files Alive Play Of Audio and Video Non Stop Interaction Of Audio and Video
4. Playing Stored Audio and Video files Stored Media Enable to stop the play Rewind Fast Forward Streaming Avoiding from long Delay in Receiving and Playing file
5. Alive Play Of Audio and Video This Type of Application is Similar to Programs of Public Media. These Applications are Often Called IPTV.
6. IPTV Improve The Quality of pictures and Video Viewer Can Control The Tv Programs Users can Use Another Digital Data Beside Of It Reducing Costs Of playing the programs and can Support More Tv Chanels than normal Tv
7. Non Stop Interaction Of Audio and Video This Type of Application which is based on internet is called Internet Telephone. This Type Of Application has Advantages Like Defining the absence or Presence Of Other Person, Public And Group communication and etc.
8. Compressing Audio And Video Before Transfering Audio and Video data Through a Computer Network, First of all,These Data Should be Converted to Digital Codes and then they should be compressed.if not,the data will occupy the most part of the bandwich.so the compression of these file is so important.
9. Compressing Audio File on the internet One analogue audio signal is converted to a digital signal by the following way:   First of all ,from audio analogue signal ,we get a sample with rate of 8000 p/s. then ,The value is sample approaching to a more near value. The quantified values are usually squared. Values such as 8,16,256.
10. Compressing Audio File on the internet And each sample can be defined through one byte. we need 8 * 64000 . So the rate of speed will be 64000 bps. Then this signal in location of receiver will be encrypted and will convert to a analogue signal.
11. Compressing Audio File on the internet The Basic Principle Which mentioned above , is called Pulse Code Modulation( PCM ). The most Famous Methods For compression the conversation are : GSM with the rate of 13 kbps G72q with the rate of 8 kbps MPEG1 (Mp3) with the rate of 128 or 160
12. Compressing Video File on the internet A video File is an string of images that is shown in a fixed rate of speed.for instance 24 or 30 images per second. There are Two types of addition in video images,from which of them , we can use for compression. Spatial addition like white pixels on a image , is a part of spatialaddition which can be easily compressed. The second addition is when two images are like each other.
13. Compressing Video File on the internet The most famous compression methods for images are: MPEG1: for images with the quality shown in cd 1.5mbs MPEG2: for images with the quality shown in DVD 3-6 mbs
14. Packet Jitter Random Delays which is the result of forming queu in routers,is one of the vital component of end to end delay.because of existence of these varying delays in the network,time interval between creation of one packet in the source until the receiving from destination is diffrent from each other.we call this random varieties “jitter”
15. Removing Jitter at The Receiver In one audio application such as internet telephone ,the application should provide necessary facilities for playout audio packets in presence of network jitter.
16. Removing Jitter at The Receiver Responding to these needs is conducted by following mechanism: Numbering Each packet with sequence number Define Each Packet with time stamps Delay in PlayOut
17. Fixed Playout Delay The receiver tries to reply each group of packet in q milisecond after production.the receiver reply the packet in time of t+q.the packets will received for reply after the specefic time will called loss packet.
18. Summary
19. Thanks