MPEG Transport Streams Packetized Digital Over IP

Jon M. Beaulieu INFSY 560 Dec 07, 2015 Cricket IP

Front

Back

2 Cricket IP

• Applications: – MPEG Transport Stream (TS) monitoring and validation. – Measure performance of the Media Delivery Index (MDI) IP flow. – Measure Internet Group Management Protocol (IGMP) performance. • Specs: – Used for MPEG-2 as well as SD/HD over SPTS (single program) and MPTS (multi program). – Continuously monitors up to 10 IP unicast or multicast flows w/ deep MPEG packet inspection. – Bandwidth monitoring via 10/100 Mb Ethernet ports. – Information correlation of multiple network probes. – 80 MB buffer for video capture.

3 System Status

L3: - IP address - subnet mask - gateway IP

L4: - Upload Port # - Mgmt Port #

4 The Transport Stream Packet

TS header = 4 bytes

Sync Error Start Program Identifier Continuity Priority Flags Byte indicator Indicator (PID) Counter

8 bits 1 bit 1 bit 1 bit 13 bits 4 bits 4 bits

Data payload will be either:

Transport - Video Data payload header - Audio - Data 4 bytes 184 bytes TS packet = 188 bytes

5 PIDs and PATs/PMTs

Program Map Program Association Table (PMT) 1 Table (PAT) PID = 0 Video PID = 26 Program Map Table 1 Main Audio PID = 17 Program Map Table 2 Second Audio Program Map PID = 32 Program Map Table (PMT) 2 Table n Video PID = 12 Main Audio PID = 44 Second Audio PID = 20

6 The IP packet

Transport Header • Sync byte • Error Indicator Transport TS packet: Data payload header • Start Indicator = 188 bytes • Priority • PID 4 bytes 184 bytes • Continuity Counter

MPEG Transport Stream = 1,316 bytes

Encapsulated IP packet Ethernet IP UDP MPEG Stream CRC = 1,366 bytes header header header

46 bytes 188 bytes 4 bytes

7 Unicast vs Multicast

Unicast: Multicast:

Signal Signal Source Source

Private One-to-One Non-private One-to-Many communication communication The signal source copies A network device (router) the signal copies the signal

8 Unicast vs Multicast with Cricket

Unicast vs Multicast

Packet size

Frame Check Sequence (FCS)

Percentage of bandwidth utilized

9 Types of Video Streams • An Elementary Stream (ES) is the basic MPEG-encoded format. Not useful for IP. • A Packetized Elementary Stream (PES) is an elementary stream broken into packets. • A Program Stream (PS) has variable bit rates, several PES’s, but a single program. • A Transport Stream (TS) uses fixed-length packets, several PES’s, multiple programs.

10 Media Overview with Cricket

Network Utilization

Video Types

MPEG-4 Stream

11 Media Overview with Cricket

Active Flows

Good Flows

12 Packetizing the Transport Stream

Elementary Packetized Transport Streams Elementary Stream Streams MPEG video video packetizer signal encoder

MPEG audio Single audio packetizer Transport signal 1 encoder Program Stream Multiplexer MPEG Transport audio audio packetizer Stream signal 2 encoder (SPTS)

data Data can be: packetizer - - program info - PCR

13 TS Packet Loss

• Jitter measures the variation in the arrival time of the TS packets in the IP stream. • Delay Factor (DF) is the cumulative IP jitter (buffer fill/emptying) on an IP network. • Media Loss Rate (MLR) counts the out-of- order or lost packets per second. • Media Delivery Index (MDI) is the standard for measuring media delivery quality. • The Program Clock Reference (PCR)

14 TS Concept: Jitter

Transport Stream (ideal)

TS packets buffer Ideally, packets arrive: - the same size - at the same rate - with the same interval

Transport Stream (reality, with jitter)

TS packets buffer buffer overflow buffer underrun lost packet

15 Flow Census with Cricket

Color coded alarm indicators

16 Flow Census with Cricket

MPEG-4 video signal MDI – total # of sec with Number of Media TS Programs: TS Packet packet loss: - Total Identifiers - 15 minutes - Monitored - 24 hours - Faulted Number of PIDs in TS: MDI - MLR in MDI – total - Total Media TS Media TS - Monitored packets per packets lost: - Faulted sec - 15 minutes - 24 hours 17 Flow Census with Cricket

Amount of Streaming bit # of PIDs that buffer (in msec) rate (payload do not appear required to only) in the PAT PID handle jitter structure

Various Amount of Program Clock measures for buffer Reference RTP packet (in bytes) (in kbps) loss and required to aka: video TS sequence handle jitter bit rate errors 18 Program Status with Cricket

- # of PIDs - Bit Rate statics

PIDs for the PMT and PESs

- PIDs for the PMT and PESs

19 Flow Statistics with Cricket

Highlighting this flow Brings up this metrics window

20 Sources

• Ineoquest Technologies, Inc. (October 2009). Cricket IP User’s Guide - HUG-CTIPXX-001. [User’s guide]. • Ineoquest Technologies, Inc. (18 July 2012). . [Presentation]. Retrieved 21 Oct 2015 from http://dvac-scte.org/digital-video.pdf. • Ineoquest Technologies, Inc. (n.d.). Quality of Video-over-IP. [White paper]. Retrieved 17 Nov 2015 from http://ftp.ineoquest.com/pub/docs/ Papers/VideoOverIPStreamQuality.pdf. • RFC4445. A Proposed Media Delivery Index (MDI). J. Welch, J. Clark. April 2006. (Format: TXT=24171 bytes) (Status: INFORMATIONAL) (DOI: 10.17487/RFC4445). [Technical paper]. Retrieved 23 Oct 2015 from https://tools.ietf.org/html/rfc4445. • Simpson, W. (2008). Video Over IP. [Book] Burlington, MA. Focal Press.

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