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TV Tech Basics forNon-Linear Editors
GVExpo 2006
TV Tech Basics forNon-Linear Editors
GVExpo 2006
Eric Wenocur
Lab Tech Systems
Silver Spring, MD
eric@lab-tech-systems.com
Eric Wenocur
Lab Tech Systems
Silver Spring, MD
eric@lab-tech-systems.com
2
Tutorial OverviewTutorial Overview
Elements of a Non-Linear Editing System
Monitors, Scopes and Video
Mixers and Audio
Videotape Machines
Simple Troubleshooting
Elements of a Non-Linear Editing System
Monitors, Scopes and Video
Mixers and Audio
Videotape Machines
Simple Troubleshooting
3
NLEVTR Storage
Mixer
SpeakersVideo Mon & Scopes
Typical NLE SystemTypical NLE System
4
System Engineering PerspectiveSystem Engineering Perspective
Maintain Signal Quality
Accurate Monitoring What is the signal really like?
How will it look/sound elsewhere?
Flexibility
Maintain Signal Quality
Accurate Monitoring What is the signal really like?
How will it look/sound elsewhere?
Flexibility
5
Monitors, Scopes & VideoMonitors, Scopes & Video
Top Four Mistakes or Misconceptions
6
Monitors, Scopes & VideoMonitors, Scopes & Video
Top Four Mistakes or Misconceptions
1) Adjusting the monitor to make the picture look “right”
7
Monitors, Scopes & VideoMonitors, Scopes & Video
Top Four Mistakes or Misconceptions
1) Adjusting the monitor to make the picture look “right”
2) Lack of colorbars at head of tape or sequence
8
Monitors, Scopes & VideoMonitors, Scopes & Video
Top Four Mistakes or Misconceptions
1) Adjusting the monitor to make the picture look “right”
2) Lack of colorbars at head of tape or sequence
3) Program not referenced to Bars
9
Monitors, Scopes & VideoMonitors, Scopes & Video
Top Four Mistakes or Misconceptions
1) Adjusting the monitor to make the picture look “right”
2) Lack of colorbars at head of tape or sequence
4) Incorrect levels and other errors in the picture
3) Program not referenced to Bars
10
Why Bars & Tone Matter!Why Bars & Tone Matter!
How does anyone know what
YOUR show is supposed to look like?
And furthermore…
How does anyone know what
ANYTHING is supposed to look like?
11
Why Bars & Tone Matter!Why Bars & Tone Matter!
We know what colorbars are supposed to look like(they have been defined by Standards).
Establish a known reference for Content(which includes the conditions at the time)
Use for setting up tape playback toproduce the desired result
Useful for verifying proper operation of equipment and systems
We know what colorbars are supposed to look like(they have been defined by Standards).
Establish a known reference for Content(which includes the conditions at the time)
Use for setting up tape playback toproduce the desired result
Useful for verifying proper operation of equipment and systems
12
The Monitor as a ToolThe Monitor as a Tool
Apply a known good signal
Set up the monitor
Leave it alone!
Apply a known good signal
Set up the monitor
Leave it alone!
13
Simple Monitor SetupSimple Monitor Setup
Use known correct SMPTE Bars (composite)
Set desired ambient light
Set controls back to Presets
Adjust brightness (black level) for correct Pluge
Adjust chroma and phase in “blue gun” mode
Set contrast for moderate intensity
Use known correct SMPTE Bars (composite)
Set desired ambient light
Set controls back to Presets
Adjust brightness (black level) for correct Pluge
Adjust chroma and phase in “blue gun” mode
Set contrast for moderate intensity
14
Where to get test signals?Where to get test signals?
Facility test generator
Non-linear editor
Many newer VTRs
Professional cameras
Facility test generator
Non-linear editor
Many newer VTRs
Professional cameras
15
Other Monitor ControlsOther Monitor Controls
16
So…So…
How do we know if the
TEST SIGNAL is good?
17
Waveform Monitor/VectorscopeConventional & Rasterizing
Waveform Monitor/VectorscopeConventional & Rasterizing
18
Waveform Monitor & Vectorscope
Waveform Monitor & Vectorscope
Measure luminance and chrominance levels
Find appropriate black or white levels,appropriate saturation, check hue
Display color-balance information(for color-correction)
Find flaws in video, track downsystem problems
Measure luminance and chrominance levels
Find appropriate black or white levels,appropriate saturation, check hue
Display color-balance information(for color-correction)
Find flaws in video, track downsystem problems
19
Waveform MonitorWaveform Monitor
20
VectorscopeVectorscope
21
Recommended LevelsRecommended Levels
Keep luma between 7.5 and 105 ire
Keep chroma between -20 and 100 ire
Rules are most stringent for conventionalbroadcasting and anything on satellite
Use common sense…
Keep luma between 7.5 and 105 ire
Keep chroma between -20 and 100 ire
Rules are most stringent for conventionalbroadcasting and anything on satellite
Use common sense…
Using composite scopes…
22
Typical NLE Video Signal PathTypical NLE Video Signal Path
NLEVTR
Signals could be composite, Y/Ccomponent, SDI…
23
Video Signal FormatsVideo Signal Formats“F” Cable:
RF (cable TV)“F” Cable:
RF (cable TV)
RGB Set:Component Analog
RGB Set:Component Analog
BNC Cable:Analog & Digital
Video
BNC Cable:Analog & Digital
Video
Y/C Cable:S-Video
Y/C Cable:S-Video
24
Critical Video Connection RulesCritical Video Connection Rules
Video signal lines must terminatein 75-ohms at the end of the run!
You cannot passively “split” or “combine”video signals!
You can passively “loop” signals betweendevices, but must terminate at end!
Video signal lines must terminatein 75-ohms at the end of the run!
You cannot passively “split” or “combine”video signals!
You can passively “loop” signals betweendevices, but must terminate at end!
25
Possible NLE Video Signal PathPossible NLE Video Signal Path
NLEVTR
Note: VTR signal loops through monitor
Mon
A B
Term
26
Typical Monitor Rear ViewTypical Monitor Rear View
27
Some CommonVideo System Problems
Some CommonVideo System Problems
No termination or double-termination(watch those switches and terminators)
Two signals feeding same input(improperly using passive loop-thrus)
Component cable mixup (Y, R-Y, B-Y)
Component mode error (YRB vs. RGB)
No termination or double-termination(watch those switches and terminators)
Two signals feeding same input(improperly using passive loop-thrus)
Component cable mixup (Y, R-Y, B-Y)
Component mode error (YRB vs. RGB)
28
Video UnterminatedVideo Unterminated
29
Video Double-terminatedVideo Double-terminated
30
Component Cable MixupComponent Cable Mixup
CorrectCorrect R-Y & B-Y SwappedR-Y & B-Y Swapped
31
A few words aboutReference, Genlock and Timing
A few words aboutReference, Genlock and Timing
Reference signals are used to make equipmentproduce output signals in sync with each other.
Reference is about playback, not recording;the recording device always locks to its input signal.
To “genlock” means locking a device to a reference signal.
“Timing” is about the relationship between two devices that both feed a third device (such as cameras feedinga switcher).
There is NO “timing” in a standalone NLE system!
Having devices locked to a common reference is highlyrecommended, but not critical in most cases.
Reference signals are used to make equipmentproduce output signals in sync with each other.
Reference is about playback, not recording;the recording device always locks to its input signal.
To “genlock” means locking a device to a reference signal.
“Timing” is about the relationship between two devices that both feed a third device (such as cameras feedinga switcher).
There is NO “timing” in a standalone NLE system!
Having devices locked to a common reference is highlyrecommended, but not critical in most cases.
32
Mixers & AudioMixers & Audio
Top Three Mistakes or Misconceptions
33
Mixers & AudioMixers & Audio
Top Three Mistakes or Misconceptions
1) Incorrect signal levels between equipment
34
Mixers & AudioMixers & Audio
Top Three Mistakes or Misconceptions
1) Incorrect signal levels between equipment
2) Monitoring incorrect or mixed-up signals
35
Mixers & AudioMixers & Audio
Top Three Mistakes or Misconceptions
1) Incorrect signal levels between equipment
2) Monitoring incorrect or mixed-up signals
3) Distortion and other problems in audio
36
Basic Mixer SectionsBasic Mixer Sections
Input ChannelsProcess signals entering mixer(input jacks, mic preamp, equalizer, channel fader)
Buses & OutputsCombine signals together and send out(bus assign, bus master level, output jacks)
MonitoringControls speaker volume and what is heard(mon source select, speaker select, speaker volume)
Input ChannelsProcess signals entering mixer(input jacks, mic preamp, equalizer, channel fader)
Buses & OutputsCombine signals together and send out(bus assign, bus master level, output jacks)
MonitoringControls speaker volume and what is heard(mon source select, speaker select, speaker volume)
37
Basic Mixer SectionsBasic Mixer Sections
Monitor
Section
Output Bus
Masters
Aux Bus
Masters&
Misc.
Input Channel Strips
38
Mixer Flow #1Input Channels
BusesOutputs
Mixer Flow #1Input Channels
BusesOutputs
39
Mixer Flow #2Input Channel
Aux Send with Pre/Post SelectBuses & Outputs
Mixer Flow #2Input Channel
Aux Send with Pre/Post SelectBuses & Outputs
40
Mixer Flow #3
Added MonitorSection
Mixer Flow #3
Added MonitorSection
41
Issues with Audio ConnectorsIssues with Audio Connectors
The same types of connectors are often usedfor different types of signals(eg: XLRs for both mic and line level).
Some connectors look similar but aren’t(eg: 2- and 3-conductor phone plugs).
Preponderance of unbalanced “consumer” connectors (RCA phono plug) on gear.
The same types of connectors are often usedfor different types of signals(eg: XLRs for both mic and line level).
Some connectors look similar but aren’t(eg: 2- and 3-conductor phone plugs).
Preponderance of unbalanced “consumer” connectors (RCA phono plug) on gear.
42
Common Audio ConnectorsCommon Audio Connectors
Phone plugsPhone plugs
Terminal Block
Terminal Block
XLR plugsXLR plugs
RCA plugRCA plugMini plugMini plug
43
Audio Operating LevelAudio Operating Level There are roughly three categories of audio operating level:
Mic, Line and Speaker.
“Line” has a wide range of levels in usebetween equipment.
Professional equipment line levels are typically10-20 dB higher than consumer or “prosumer”.
Pro level is often referred to as “+4”Consumer level is often known as “-10”
It is not wise to connect these devices together without proper interfacing to compensate!
There are roughly three categories of audio operating level: Mic, Line and Speaker.
“Line” has a wide range of levels in usebetween equipment.
Professional equipment line levels are typically10-20 dB higher than consumer or “prosumer”.
Pro level is often referred to as “+4”Consumer level is often known as “-10”
It is not wise to connect these devices together without proper interfacing to compensate!
44
Connectors & Signals ChartConnectors & Signals Chart
45
Typical Mixer ConnectionsTypical Mixer Connections
Aux Sends
SubBusOuts
TapeIns/Outs
MainBusOuts
CRMonOuts
Input Channels
Channel InsertLine Input
Mic Input
46
A Word about Phantom PowerA Word about Phantom Power
48 volts DC used to power condensor microphones
This voltage can damage other equipment.
Unless you are using a condensor micLEAVE IT OFF!
48 volts DC used to power condensor microphones
This voltage can damage other equipment.
Unless you are using a condensor micLEAVE IT OFF!
47
Possible NLE Audio Signal PathPossible NLE Audio Signal Path
NLEVTR
Mixer
Input Channels
Output Buses
Monitoring
48
VTR to Mixer to NLEVTR to Mixer to NLE
NLEVTR
Mixer
Input Channels
Output Buses
Monitoring
49
NLE to Mixer to VTRNLE to Mixer to VTR
NLEVTR
Mixer
Input Channels
Output Buses
Monitoring
50
Possible NLE Audio Signal PathPossible NLE Audio Signal Path
NLEVTR
Mixer
Input Channels
Output Buses
Monitoring
51
Interfacing Consumer GearInterfacing Consumer Gear
VHS
Mixer
Input Channels
Output Buses
Monitoring
Use TAPE Outsto feed VHS or DVD-R
(same signal as Main Outs but correct level)
52
Audio MeteringAudio Metering
Why does the same audio
look different
on
different meters?
Why does the same audio
look different
on
different meters?
53
Uh oh…Uh oh…
54
Audio MeteringAudio Metering
Mechanical analog or bargraph?
Where is “0”? Different for analog and digital applications.
How large is the scale range? Meters vary from 23dB to 60 or 80dB scales.
How quickly does the meter respond to changes in audio? Ballistics can be average, peak, PPM, etc.
Mechanical analog or bargraph?
Where is “0”? Different for analog and digital applications.
How large is the scale range? Meters vary from 23dB to 60 or 80dB scales.
How quickly does the meter respond to changes in audio? Ballistics can be average, peak, PPM, etc.
55
Audio Metering AnalogAudio Metering Analog
Analog audio will distort when level is too high, but the effect is usually gradual.
Analog meters were designed to show average levels around 0VU.
There is usually 10-20 dB left above 0VU before distortion.
Tone should be at 0VU.
Analog audio will distort when level is too high, but the effect is usually gradual.
Analog meters were designed to show average levels around 0VU.
There is usually 10-20 dB left above 0VU before distortion.
Tone should be at 0VU.
56
Audio Metering DigitalAudio Metering Digital
Digital audio has an absolute upper limitwhich is called Full Scale.
Digital meters read in terms of dBFS (decibels under Full Scale)
Maximum possible level is at 0 dBFS.
Tone is usually at about -20 dBFS so there is 20dB of headroom before overload.
Digital audio has an absolute upper limitwhich is called Full Scale.
Digital meters read in terms of dBFS (decibels under Full Scale)
Maximum possible level is at 0 dBFS.
Tone is usually at about -20 dBFS so there is 20dB of headroom before overload.
57
Typical Audio FlawsTypical Audio Flaws
Clipping and other distortion
Excessive noise beneath audio
Tonal imbalance
Channel phase reversal
Audio/video lip-sync errors
Clipping and other distortion
Excessive noise beneath audio
Tonal imbalance
Channel phase reversal
Audio/video lip-sync errors
58
Balanced andUnbalanced Connections
Balanced andUnbalanced Connections
This has nothing to do with “sonic balance.”
Balanced audio connections cancel out noise picked up on the cable.
Balanced typically uses two signal wires and a shield, connectors have three terminals.
Balanced is usually also “pro” (+4) level.
You can connect balanced and unbalanced together but it requires knowledge!
This has nothing to do with “sonic balance.”
Balanced audio connections cancel out noise picked up on the cable.
Balanced typically uses two signal wires and a shield, connectors have three terminals.
Balanced is usually also “pro” (+4) level.
You can connect balanced and unbalanced together but it requires knowledge!
59
Videotape MachinesVideotape Machines
Top Four Mistakes or Misconceptions
60
Videotape MachinesVideotape Machines
Top Four Mistakes or Misconceptions
1) Wrong format / wrong deck
61
Videotape MachinesVideotape Machines
Top Four Mistakes or Misconceptions
1) Wrong format / wrong deck
2) Failure to begin with controls in PRESET
62
Videotape MachinesVideotape Machines
Top Four Mistakes or Misconceptions
1) Wrong format / wrong deck
2) Failure to begin with controls in PRESET
3) Failure to set up playback to Bars
63
Videotape MachinesVideotape Machines
Top Four Mistakes or Misconceptions
1) Wrong format / wrong deck
2) Failure to begin with controls in PRESET
3) Failure to set up playback to Bars
4) Screwing with menus and switches
64
Videotape FormatsVideotape Formats
Legacy Analog:
VHS, S-VHS, Hi-8
3/4” (U-matic), 1”
Betacam, Beta SP
Legacy Analog:
VHS, S-VHS, Hi-8
3/4” (U-matic), 1”
Betacam, Beta SP
65
Videotape FormatsVideotape Formats
Legacy Digital:
D-1, D-3 (component)
D-2 (composite)
Legacy Digital:
D-1, D-3 (component)
D-2 (composite)
66
Videotape FormatsVideotape Formats
Digital Betacam Family:
Digi Beta
Betacam SX
Betacam IMX
Digital Betacam Family:
Digi Beta
Betacam SX
Betacam IMX
67
Videotape FormatsVideotape Formats
Other Current Digital:
D-5
D-9 (Digital-S)
Other Current Digital:
D-5
D-9 (Digital-S)
68
Videotape FormatsVideotape Formats
DV-based:
DV, mini-DV
DVCam
DVCPro 25/50/100
DV-based:
DV, mini-DV
DVCam
DVCPro 25/50/100
69
PVW-2800 Internal ViewPVW-2800 Internal View
Cassette ElevatorCassette Elevator
Video & AudioCircuit BoardsVideo & AudioCircuit Boards
Control & Misc.Circuit Boards
Control & Misc.Circuit Boards
Video Head DrumVideo Head Drum
Audio HeadsAudio Heads
CapstanCapstan
Threading MotorThreading Motor
70
VTR SystemsVTR Systems
Video processing
Audio processing
Capstan servo -- controls tape movement
Drum servo -- controls head drum
Video processing
Audio processing
Capstan servo -- controls tape movement
Drum servo -- controls head drum
71
VTR ServosVTR Servos
Lock to Reference input during playback
Lock to Record input during recording
Internal TBC (timebase corrector) may lock differently than servo system
Lock to Reference input during playback
Lock to Record input during recording
Internal TBC (timebase corrector) may lock differently than servo system
72
VTR Tape TracksVTR Tape Tracks
Longitudinal Audio TracksLongitudinal Audio Tracks
Longitudinal Control TrackLongitudinal Control Track
Helical Video TracksHelical Video Tracks
Longitudinal TC TrackLongitudinal TC Track
Similar for analog or digital formatsSimilar for analog or digital formats
73
VTR Recording ModesVTR Recording Modes
E/E (electronics-to-electronics) -- passes input signals through to output
Hard (crash) Record -- erases and records all tracks at once, no sync with previous recording
Assemble Record -- erases and records all tracks, but picks up in sync with previous recording
Insert Record -- only erases and records selected tracks (control track must be present!)
E/E (electronics-to-electronics) -- passes input signals through to output
Hard (crash) Record -- erases and records all tracks at once, no sync with previous recording
Assemble Record -- erases and records all tracks, but picks up in sync with previous recording
Insert Record -- only erases and records selected tracks (control track must be present!)
74
VTR Front PanelVTR Front Panel
Audio Level Controls& Meters Transport
Controls
Editing Controls
Remote Select
Timecode Display & Menus
Timecode Controls may be various places!
75
VTR Rear Panel ConnectorsVTR Rear Panel ConnectorsAnalog Audio I/O
d
dd
d
d
Analog VideoInputs
Analog VideoOuputs
Remote ControlAnd Misc.
Digital AudioI/O
Digital VideoI/O
76
Menus & Special SwitchesMenus & Special Switches
Ref Auto/Manual: Set to AUTO
Audio input 600-ohm terminations: Set to OFF
Audio input level: Set to HIGH
Ref Auto/Manual: Set to AUTO
Audio input 600-ohm terminations: Set to OFF
Audio input level: Set to HIGH
If your VTR has any of the followingswitches on the back…
If your VTR has any of the followingswitches on the back…
77
Menus & Special SwitchesMenus & Special Switches
When in doubtuse the Factory Default settings!
When in doubtuse the Factory Default settings!
78
Simple TroubleshootingSimple Troubleshooting
Use good observation techniques:
Note all conditions during problem
Note conditions leading up to problem
When was the last good operation?What changed?
Be clear about meaning of words!
Use good observation techniques:
Note all conditions during problem
Note conditions leading up to problem
When was the last good operation?What changed?
Be clear about meaning of words!
79
Troubleshooting StrategiesTroubleshooting Strategies
It pays to know how things are SUPPOSED to work.
Start with known good signals (bars and tone), good path and monitoring.
Change one thing and observe…
Swap things: cables, equipment, software
Cut problem in half
It pays to know how things are SUPPOSED to work.
Start with known good signals (bars and tone), good path and monitoring.
Change one thing and observe…
Swap things: cables, equipment, software
Cut problem in half
80
Troubleshooting StrategiesTroubleshooting Strategies
Manuals are like GOLD!Manuals are like GOLD!
81
Are you a professional?Are you a professional?
Please send me feedbackon this workshop!
And visit the SMPTE boothon the exhibit floor!
Please send me feedbackon this workshop!
And visit the SMPTE boothon the exhibit floor!
Eric Wenocur
Lab Tech Systems
Silver Spring, MD
eric@lab-tech-systems.com
Eric Wenocur
Lab Tech Systems
Silver Spring, MD
eric@lab-tech-systems.com
Copyright 2006 Eric WenocurAll photos copyright their respective owners.
Copyright 2006 Eric WenocurAll photos copyright their respective owners.
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