video

MPEG-2 MusicVideos :-): 

MPEG-2 Music Videos :-) Alan Crosswell alan@columbia.edu

Outline: 

Outline The Content Network Issues Production Issues Show and Tell CODEC Issues and Requirements

Outline: 

Outline The Content Network Issues Production Issues Show and Tell CODEC Issues and Requirements

The Content: 

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.

The Content: 

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.

The Content: 

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:-)

Outline: 

Outline The Content Network Issues Production Issues Show and Tell CODEC Issues and Requirements

Network Issues: 

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

Network Issues: 

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.

Network Issues: 

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.

Outline: 

Outline The Content Network Issues Production Issues Show and Tell CODEC Issues and Requirements

Production Issues: 

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.

Production Issues: 

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.

Production Issues: 

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.

Production Issues: 

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.

Production Issues: 

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.

Production Issues: 

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.

Production Issues: 

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….

Production Issues: 

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.

Outline: 

Outline The Content Network Issues Production Issues Show and Tell CODEC Issues and Requirements

The Road Show : 

The Road Show SKB portable rack

The Road Show : 

The Road Show SKB portable rack Flat panel drawer

The Road Show : 

The Road Show SKB portable rack Flat panel drawer Keyboard/mouse drawer

The Road Show : 

The Road Show SKB portable rack Flat panel drawer Keyboard/mouse drawer Video proc amp

The Road Show : 

The Road Show SKB portable rack Flat panel drawer Keyboard/mouse drawer Video proc amp Stereo mic/line mixer

The Road Show : 

The Road Show SKB portable rack Flat panel drawer Keyboard/mouse drawer Video proc amp Stereo mic/line mixer Stereo VU meter

The Road Show : 

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

The Road Show : 

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

The Road Show : 

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

The Road Show : 

The Road Show Belkin PC switcher (remoted to kbd drawer) Video & Audio DAs

The Road Show : 

The Road Show Belkin PC switcher (remoted to kbd drawer) Video & Audio Das Audio/Video patch bay

The Road Show : 

The Road Show Belkin PC switcher (remoted to kbd drawer) Video & Audio Das Audio/Video patch bay Biamp echo canceller

The Road Show : 

The Road Show Belkin PC switcher (remoted to kbd drawer) Video & Audio Das Audio/Video patch bay Biamp echo canceller UPS

The Road Show : 

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

The Road Show : 

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.

The Road Show : 

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.

Outline: 

Outline The Content Network Issues Production Issues Show and Tell CODEC Issues and Requirements

CODEC issues/reqs: 

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?

CODEC issues/reqs: 

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:-)

DV capture -> MPEG with Linux on a VAIO: 

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

DV capture -> MPEG with Linux on a VAIO: 

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

Thanks….: 

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

Performance Copyright (p) 2000 Pinchas Zukerman, Manhattan School of Music, National Arts Centre of Canadawww.columbia.edu/acis/networks/advancedalan@columbia.edu: 

Performance Copyright (p) 2000 Pinchas Zukerman, Manhattan School of Music, National Arts Centre of Canada www.columbia.edu/acis/networks/advanced alan@columbia.edu