nortel confidential information 1 video sample production summary leigh thorpe nortel paris, 7-11...

1 Nortel Confidential Information

Video Sample Production Summary

Leigh ThorpeNortelParis, 7-11 May 2007


Video Clip Production Lab Setup

Real Mobile Producer (Envivio)-used to produce the sample clips encoded at the required formatfrom source YUV files

Real Helix Mobile Server-plays out the clips when requested from the client

Ineoquest Singulus-used to generate dropped packets

Baystack Switch-Ethernet switch to connecteverything together

Client PC with SQQTClient capture -receives the clips over ethernetwith dropped packets, and convertsback to uncompressed YUV

NAS Drives-containing the SRC and PVS

network

Encoding PC

47.135.125.1047.135.125.11

Server PC Client PC

Step 1 – upload SRC to Encoding PCStep 2 – Encode SRC and upload to Server PCStep 3 – Stream encoded file through Singulus for packet loss to Client PC and capture resulting PVSStep 4 – upload PVS to NAS drive


Video Clip Production Procedure

source YUV filefrom VQEG poolCIF and QCIF(16-bit or 12-bit)

file encoded to.3gpusing Real Mobile Producer

video clip is sent over a network with droppedIP packet impairmentsgenerated byIneoquest Singulus

video clipis storedin Real Helix Mobile serverfor streaming(hint tracks used)

video clipreceived withimpairments

video clipconvertedto YUV formatusingSwissQual tool(appears to be 24-bit)


Notes on the Common Files Processing

Create scenarios reflecting typical current mobile video operating conditions

• Settings based on reviews of services in Europe and North America

• QCIF• MPEG-4 part 2 SP encoding, 3gppv5 format, 500 bytes / packet setting• 10 fps• 128 kbps• 1% packet loss

• CIF• H.264 encoding, 3gppv6 format, 1000 bytes / packet setting• 20 fps• 256 kbps• 1% packet loss


Sample Impairment Stills


Comments Based on Preliminary Work

Comments:• User experience impacts of packet loss are highly dependent on the player’s

response to packet loss• stability in face of packet loss• loss concealment mechanisms• OS and platform and other handset implementation specific details

• Packet loss also dependant on bytes / packet settings used in hint tracks when encoding the files for streaming

• particularly for low bit rate streams • we selected settings that resulted in a number of RTP packets streamed that aligns with what is being used in networks we’ve studied

• Packet loss effects will be dependent on encoder and levels / profiles used• Some effects of packet loss are masked by motion or encoding impairments

particularly at QCIF resolutions and low bit rates• Some packet loss results in frame loss and no other obvious impairments

(like slice / block errors) on other frames and at low frame rates (10 fps) the lost frames may not be obvious


Issues and Questions based on Preliminary Work

SQQTClient Capture tool• Some quirks in capture tool operation (need to close the file explicitly or exit

the program between captures as per the Readme)• Not sure how the frame timestamps are derived - we see indication of

delayed (and likely lost) frames during our IP packet drops but also see variability in timestamps when streaming encoded files without drops (but playback indicates consistent frame rate)

• see CIF Timecompare tab in uploaded spreadsheet• QCIF seems OK• Could be on Real Helix server side

• Seem to be getting a few frames dropped from the end of the files when streaming in some cases – not a problem since we’ll drop 2 seconds anyway

•Ex. On QCIF time compare tab in spreadsheet - .3gp file is 12.0 s but streamed and captured .avi is 11.23 s (Quicktime properties view) and .log files shows 117 frames and would have expected 120 frames (10 fps * 12s)


Nortel / CRC CIF Production Matrix

Resolution Encoded Format

Packet Drops

Clip Description

Frame Rate

Bit Rate

Clip Length

Delivery Protocol

Total

CIF(352 x 288)

H.264 0% a 15 128 k 12 sec UDP

0.5% b 20 256 k

1% c 30 512 k

2% d 768 k

4% e

10% f

g

h

1 1 6 8 3 4 1 1 576

Note: Only 136 of the 576 combinations are produced


Nortel / CRC QCIF Production Matrix

Resolution Encoded Format

Packet Drops

Clip Description

Frame Rate

Bit Rate

Clip Length

Delivery Protocol

Total

QCIF(176 x 144)

MPEG4P2 SP

0% a 7.5 64 k 12 sec UDP

0.5% b 10 128 k

1% c 15 256 k

2% d 20

4% e

10% f

g

h

1 1 6 8 4 3 1 1 576

Note: Only 136 of the 576 combinations are produced


Notes on the Production Matrix

Not all combinations are produced• 136 will be produced at each resolution• (see the detailed spreadsheet for detailed combinations)

Typically the higher the frame rates, the higher the bit rates• Therefore the low frame rate/high bit rate and high frame rate/low

bit rate are not sensible combinations in the real world• This is because if more bandwidth is available, both frame rate and

bit rate are increased in order to achieve higher quality video

In addition, there will be 16 sequences produced as follows:• 8 x QCIF, MPEG-4 Part 2 SP, 128 kb/s, 10 fps, 500-byte packets,

1% burst loss• 8 x CIF, H.264, 256 kb/s, 20 fps, 1000-byte packets, 1% burst loss


Backup Slides


Notes on the Swiss Qual tool

-open URL under “file”-press “play” under “movie”-under “movie”, click “stop” and “rewind” twice-press “record” followed by “play” and the video should download once and be converted to an AVI-be sure to “close AVI” when done-if the procedure needs to be repeated, change the file name or delete the previous AVI and log files, or else the next result will show up in another directory-check “UDP” under options


Helix Producer

-set to 3GPPv6 singlerate for both MPEG4SP and H.264

-make sure the source and destination file names are correct (so that the encoded file can be found again)

-keep a record of the encoding details for each output file name


Helix Producer

-select the bit rate, encoding format, and frame rate-uncheck audio to make sure the bit rate is all video


Helix Producer

-uncheck “resize” and/or make sure the resolution is correct


Helix Producer

-check “Progressive Download Profile” so that MPEG4 metadata arrives at beginning of stream

-check “Streaming-server profile” to generate hint tracks

-set maximum packet size to 500 or 1000 to improve error granularity


Typical File Sizes and Dropped Packets

average packet size:

500 % drop

target bit rate(kb/s)

approx. file size for 12 seconds (kB)

total packets 0.5 1 2 4 8

packets dropped:

64 96 197 1 2 4 8 16

128 192 394 2 4 8 16 31

256 384 787 4 8 16 31 63

384 576 1181 6 12 24 47 94

768 1152 2362 12 24 47 94 189

note: these figures should be independent of CIF or QCIF

nortel confidential information 1 video sample production summary leigh thorpe nortel paris, 7-11...

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