Post on 19-Dec-2015
MPEG-2 MusicVideos :-)
Alan Crosswellalan@columbia.edu
May, 2001 Columbia University Academic Information Systems
2
Outline
• The Content• Network Issues• Production Issues• Show and Tell• CODEC Issues and Requirements
May, 2001 Columbia University Academic Information Systems
3
Outline
• The Content• Network Issues• Production Issues• Show and Tell• CODEC Issues and Requirements
May, 2001 Columbia University Academic Information Systems
4
The Content
• Violin Master Class – December 8, 2000• Student: Wu Jie, at CANARIE in Ottawa.• Teachers: Pinchas Zukerman and Patinka
Copec (of MSM) in New York (at Columbia).• Manhattan School of Music, CANARIE,
National Research Centre, Natl Arts Centre.• Pt-to-Pt Litton CV2 MPEG2 & mcast MPEG1.
May, 2001 Columbia University Academic Information Systems
5
The Content
• Dance Rehearsal/Conference – Jan 6, 01• Peter Sparling Dance Company in Ann
Arbor.• Association for Performing Arts
Presenters conference in New York.• Demonstration/discussion of an in-
progress commissioned work involving dances, costumes, set designs.
May, 2001 Columbia University Academic Information Systems
6
The Content
• Cello Master Class – May 10, 2001• David Geber of MSM in New York (at
CU).• Erin Dunn at University of Oklahoma• YAML (Yet Another Music Lesson:-)
May, 2001 Columbia University Academic Information Systems
7
Outline
• The Content• Network Issues• Production Issues• Show and Tell• CODEC Issues and Requirements
May, 2001 Columbia University Academic Information Systems
8
• Campus network• 1% packet loss is not good enough
w/CV2.• CV2 at 15.4 Mbps sends 16K PDUs via
UDP:• 11 IP fragment Ethernet packets.• 352 ATM cells.
• Drop one cell and the whole PDU's lost.• ATM issues - cell loss, policing, bursts.
Network Issues
May, 2001 Columbia University Academic Information Systems
9
Network Issues
• Abilene/CANARIE ATM issues• Getting clobbered by QoS (shaping,
policing). • ATM cell loss on NYCM OC-12 intf
• Several sub-rate VCs.• OC-12 was not oversubscribed.• One 24 Mbps VC was heavily congested (JANET).• Caused head of line problems for other VCs.
• Brent made it go away.
May, 2001 Columbia University Academic Information Systems
10
Network Issues
• Some things to look for on campus:• 100-full duplex negotiated correctly? • Router ATM interface CRC errors?
• ATM cell loss (policing, default burst length)?
• Cisco PA-A3 (OC3 ATM) SAR HW 1.0?
• Analog video causing Codec resets that convince you there’s a network problem.
May, 2001 Columbia University Academic Information Systems
11
Outline
• The Content• Network Issues• Production Issues• Show and Tell• CODEC Issues and Requirements
May, 2001 Columbia University Academic Information Systems
12
Production Issues
• Demos Harder than the “real thing.”• A large audience for a one-on-one
event.• Added sound amplification adds echo.• Complicates echo cancellation.• Video monitors/projection screens.• Lighting for two-way video at the same
time as projecting is goofy.
May, 2001 Columbia University Academic Information Systems
13
Production Issues
• Audio• Emphasize audio over video quality.• Pops, squeals, screeches, drop-outs,
echoes.• Audience will accept a few video
artifacts.• Room-filling "rich" audio compensated
for poor video in one event.
May, 2001 Columbia University Academic Information Systems
14
Production Issues
• Audio engineers dealt with:• Room acoustics at both ends.
• Drapes and foam where hung.• Gobos used to isolate codec fan noise.
• Some echo is a good thing: room was too dead, so...
• Remote echo was used to liven the room.
May, 2001 Columbia University Academic Information Systems
15
Production Issues
• Audio echo avoidance• Can't use a voice-grade echo canceller
for music.• Off-axis speaker/mic placement.• Gobos isolating mics from speakers.• Masking the backs of mics to control
echo.• Muting ruins spontaneity.
May, 2001 Columbia University Academic Information Systems
16
Production Issues
• Audio for world-class musicians• Doing audio for people who can hear
the difference.• Frustrating not being able to directly
monitor the remote room.• Maintaining a natural listening level.• Shaping of the audio by codec, etc.
May, 2001 Columbia University Academic Information Systems
17
Production Issues
• Video (bush league)• Switching sources *must* have a time
base corrector (e.g. video mixer).• A simple video switch causes a ~5
second CV2 encoder reset.• Which also kills the audio.• Bad video (loose connector) causes
encoder resets which manifest as audio dropout.
May, 2001 Columbia University Academic Information Systems
18
Production Issues
• Video• A prosumer mixer boasts 500 effects.• Don’t <BLINK>have</BLINK> to use them.• Prosumer mixer quality is just that.• PIP may show annoying artifacts.• Good lighting, camera quality and operator
skill (get a pro video crew if it is important).• Plug a $200 camera into a $20,000
codec….
May, 2001 Columbia University Academic Information Systems
19
Production Issues
• “How do you get to Carnegie Hall?”• “Practice, Practice, Practice”
• In a new campus location, begin testing one month beforehand to have plenty of time to deal issues that will come up.
• When dealing with a new partner, there will be new routes and performance issues.
• Both ends need to rehearse from the actual location of the event.
May, 2001 Columbia University Academic Information Systems
20
Outline
• The Content• Network Issues• Production Issues• Show and Tell• CODEC Issues and Requirements
May, 2001 Columbia University Academic Information Systems
22
The Road Show
• SKB portable rack• Flat panel drawer
May, 2001 Columbia University Academic Information Systems
23
The Road Show
• SKB portable rack• Flat panel drawer• Keyboard/mouse
drawer
May, 2001 Columbia University Academic Information Systems
24
The Road Show
• SKB portable rack• Flat panel drawer• Keyboard/mouse
drawer• Video proc amp
May, 2001 Columbia University Academic Information Systems
25
The Road Show
• SKB portable rack• Flat panel drawer• Keyboard/mouse
drawer• Video proc amp• Stereo mic/line mixer
May, 2001 Columbia University Academic Information Systems
26
The Road Show
• SKB portable rack• Flat panel drawer• Keyboard/mouse
drawer• Video proc amp• Stereo mic/line mixer• Stereo VU meter
May, 2001 Columbia University Academic Information Systems
27
The Road Show
• SKB portable rack• Flat panel drawer• Keyboard/mouse
drawer• Video proc amp• Stereo mic/line mixer• Stereo VU meter• Litton CV2 MPEG-2
codec
May, 2001 Columbia University Academic Information Systems
28
The Road Show
• SKB portable rack• Flat panel drawer• Keyboard/mouse
drawer• Video proc amp• Stereo mic/line mixer• Stereo VU meter• Litton CV2 MPEG-2
codec• PC w/Z360 H.323 codec
May, 2001 Columbia University Academic Information Systems
29
The Road Show
• SKB portable rack• Flat panel drawer• Keyboard/mouse drawer• Video proc amp• Stereo mic/line mixer• Stereo VU meter• Litton CV2 MPEG-2 codec• PC w/Z360 H.323 codec• PC w/IPTV MPEG-1/2
May, 2001 Columbia University Academic Information Systems
30
The Road Show
• Belkin PC switcher (remoted to kbd drawer)
• Video & Audio DAs
May, 2001 Columbia University Academic Information Systems
31
The Road Show
• Belkin PC switcher (remoted to kbd drawer)
• Video & Audio Das• Audio/Video patch bay
May, 2001 Columbia University Academic Information Systems
32
The Road Show
• Belkin PC switcher (remoted to kbd drawer)
• Video & Audio Das• Audio/Video patch bay• Biamp echo canceller
May, 2001 Columbia University Academic Information Systems
33
The Road Show
• Belkin PC switcher (remoted to kbd drawer)
• Video & Audio Das• Audio/Video patch bay• Biamp echo canceller• UPS
May, 2001 Columbia University Academic Information Systems
34
The Road Show
• Belkin PC switcher (remoted to kbd drawer)
• Video & Audio Das• Audio/Video patch bay• Biamp echo canceller• UPS• Still missing/unfinished:
• Headphone monitor• DV capture• Echo canceller + bypass
May, 2001 Columbia University Academic Information Systems
35
The Road Show
• Videonics MXPro DV :-(
• Canon GL1 camera.• Tripod.• Powerbook w/PPT for
title slides (use S-video out).
• 2 SM57 mics.• 2 Samsung VGA/Video
15" TFT monitors.
• 2 DELVCAM 5.6" TFT monitors.
• test generators (SMPTE bars, tone).
• miniDV recorder.• 2 S-Video to S+Comp
DA. • lots and lots of cables. • adapters.• gaffers tape.
May, 2001 Columbia University Academic Information Systems
36
The Road Show
• Interfacing with the pros(umers)• Balanced vs. unbalanced audio (the audio
engineers will get over it:-)• mic/line mixer with balanced XLR, TRS,
mic and line jacks makes it easy.• Composite vs. S-video vs. component vs.
firewire. • Chose S-video throughout the rack.• DV->analog conversion in the Videonics.
May, 2001 Columbia University Academic Information Systems
39
Outline
• The Content• Network Issues• Production Issues• Show and Tell• CODEC Issues and Requirements
May, 2001 Columbia University Academic Information Systems
40
CODEC issues/reqs
• Why are we using analog audio/video?• Audio requires better than CD quality:
• 6 or more channels (e.g. Dolby 5.1, 7.1).• 96 kHz sampling.
• "Perfect" audio/video synchronization.• Better than MP@ML (SDTV)• HD 1280p would be nice.• Firewire capture instead of analog?
May, 2001 Columbia University Academic Information Systems
41
CODEC issues/reqs
• CODECs have to work with IP networks.
• QoS-enabled.• RTP.• Dynamically adjust based on
changing conditions.• Oh, and, by the way, deliver
extremely low latency:-)
May, 2001 Columbia University Academic Information Systems
42
DV capture -> MPEG with Linux on a VAIO
http://www.schirmacher.de/arne/dvgrab/http://linux1394.sourceforge.net/# modprobe ieee1394# modprobe ohci1394# modprobe raw1394# modprobe sbp2_1394# rescan-scsi-bus.sh# mount /dev/sda1 /mnt/disk# cd /mnt/disk# dvgrab --autosplit --format dv2 file
May, 2001 Columbia University Academic Information Systems
43
DV capture -> MPEG with Linux on a VAIO
$ lav2yuv -I 1 file*.avi | mpeg2enc –o video.mpg$ lav2wav file*.avi | mp2enc -s -b 384 -r 48000 -o
audio.mp3$ mplex -o final.mpg video.mpg audio.mp3$ gtv final.mpg
May, 2001 Columbia University Academic Information Systems
44
May, 2001 Columbia University Academic Information Systems
45
Thanks….
• Lou Brown & Christianne Orto, Manhattan School of Music
• Brent Sweeny, Grover Browning, Matt Davies & co., Abilene
• Marc Boulerice, Jane Hermanson, Thomas Tam, CANARIE
• Brian Shepard, Oklahoma University• Bill Owens, NYSERnet