error recovery for packet audio and video
DESCRIPTION
Error recovery for Packet Audio and Video. Henning Schulzrinne Columbia University New York, NY. Options for reliability. retransmission redundancy interleaving forward error correction. Redundancy. packet redundant coding offset in time but: lose coding state. RTP packet header. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Error recovery for Packet Audio and Video](https://reader036.vdocuments.site/reader036/viewer/2022082405/5681305d550346895d9626c4/html5/thumbnails/1.jpg)
Error recovery for Packet Audio and Video
Henning SchulzrinneColumbia UniversityNew York, NY
![Page 2: Error recovery for Packet Audio and Video](https://reader036.vdocuments.site/reader036/viewer/2022082405/5681305d550346895d9626c4/html5/thumbnails/2.jpg)
Options for reliability
retransmissionredundancyinterleavingforward error correction
![Page 3: Error recovery for Packet Audio and Video](https://reader036.vdocuments.site/reader036/viewer/2022082405/5681305d550346895d9626c4/html5/thumbnails/3.jpg)
Redundancy
packet
redundant coding offset in timebut: lose coding state
hi-bw content
(e.g. MPEG audio) lo-bwcontent
RTP packet header
![Page 4: Error recovery for Packet Audio and Video](https://reader036.vdocuments.site/reader036/viewer/2022082405/5681305d550346895d9626c4/html5/thumbnails/4.jpg)
Retransmission
receiver requests missing packets by sequence number
scalable multicast under developmentused by RTP H.261 codecusually, delay too highuseful for passive listeners, recording
devices
![Page 5: Error recovery for Packet Audio and Video](https://reader036.vdocuments.site/reader036/viewer/2022082405/5681305d550346895d9626c4/html5/thumbnails/5.jpg)
Forward Error Correction
exclusive OR (XOR) or Reed-SolomonN > 1 redundant packets within blockXOR: parity of other packets in blockcan recover if <= N lostXOR: low complexitymedia independentgreat for multicast
![Page 6: Error recovery for Packet Audio and Video](https://reader036.vdocuments.site/reader036/viewer/2022082405/5681305d550346895d9626c4/html5/thumbnails/6.jpg)
Interleaving
typically, several frames per packet (header overhead!)
split samples or frames across packets
packet loss affects smaller amount of voice data
increases delay, header overhead