Sony Vegas 6 Manual

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CHP. 16PREVIEWING AND ANALYZING VIDEO
CHAPTER287
Previewing and 
Analyzing Video
As you work in Vegas® software, you can preview your video by using the Video Preview window or by 
connecting to an external monitor. You can optimize previews by adjusting preview quality, prerendering 
video, or building a dynamic RAM preview. The Video Preview window also provides features such as safe 
area overlays, grid overlays, and isolated color channel displays to further enhance your productivity.
Understanding the Video Preview window
The workspace for editing video can get quite crowded, so the Video Preview window can be configured in a 
number of ways to make it more useful. The Video Preview window can be used on a separate monitor or 
Windows display (if your video hardware supports this feature), docked at the bottom of the workspace, or 
floated freely on the screen.
Docked windowFloating window
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Using the Video Preview window shortcut menu
Right-click the Video Preview window to adjust the following options:
 Choose Default Background, Black Background, or White Background to set the background color for the 
window.
Simulate Device Aspect Ratio displays the output in square pixels. This can prevent distortion of the preview 
when using sources with rectangular pixels. This does not affect the final render.
Show Toolbar toggles the toolbar at the top of the window.
Show Status Bar toggles the information display at the bottom of the window.
Preview Device Preferences displays the Preview Device tab of the Preferences dialog, allowing you to 
configure an external monitor.
ButtonDescription
Project Video 
PropertiesDisplays the project’s properties (pg. 238).
Preview on External 
MonitorSends the preview out to an external monitor. This only functions if your hardware supports this 
feature (pg. 339).
Video Output FXOpens the Video Output FX window for adding video effects plug-ins for the entire project (pg. 241).
Split-Screen ViewTurns split-screen previews on or off. Split-screen previews allow you to split the preview window so 
you can see your affected and unaffected video or your video and the contents of your clipboard at the 
same time. Available only in the full version of Vegas software.
Preview QualityChanges the preview resolution and display size. You can choose a lower resolution to drop fewer 
frames during playback. Choose an Auto option to display the preview at the current Video Preview 
window size; choose a Full option to display the preview at project size.
Note: If your project properties are set to either the Blend or Interpolate deinterlace method, you will 
not see the effects of deinterlacing in Draft and Preview quality preview modes. Deinterlacing only 
occurs in the Good and Best quality preview modes.
OverlaysOptions include safe areas, grids, and individual channels.
Copy Snapshot to 
ClipboardCopies the contents of the frame to the clipboard
Save Snapshot to FileSaves the contents of the preview window as a JPEG or PNG. The new image file is automatically 
saved to the Project Media window (pg. 227).
Preview Quality
Copy Snapshot to Clipboard Project Video Properties
Preview on External Monitor
Video Output FX
Properties status bar
Save Snapshot to File
Split-Screen ViewOverlays 
						

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Optimizing the Video Preview window
Timing and synchronization are critical aspects of any multimedia production. Because complex multimedia 
projects are challenging for any computer, a number of tools are provided to maintain real-time playback 
even though the computer may not be able to process the data quickly enough.
Reducing preview quality
You can adjust the resolution of the Video Preview window and the quality of the preview rendering in order 
to improve playback. Lower-resolution previews are less clear but allow more frames to be displayed per 
second. This may be particularly important with projects that use overlays, transitions, and effects. Click the 
Preview Quality button to choose different preview resolutions.
Note: To view the effects of the deinterlacing method you 
chose in your project properties, you will need to use the 
Good 
or 
Best quality preview mode. The Draft and Preview quality 
preview modes do not deinterlace.
Prerendering video
There are times where nothing but a full, high-quality preview will do. In these cases, Vegas software can 
take the time necessary to selectively render only the portions of your project that need extra processing. 
These sections are prerendered and short files are created to use for previews. The prerendering can take 
anywhere from a few seconds to a few minutes, depending on the length and complexity of the video. 
Once these temporary files have been created, they are used whenever those sections of the project are 
played back, increasing playback quality and performance. As long as no changes are made to the events in 
the prerendered sections, the newly created files continue to be used for previews, even if changes are made 
to other sections of the project.
1.To prerender a portion of the project, create a selection containing the portion you want to prerender.
2.From the To o l s menu, choose Selectively Prerender Video. The Prerender Video dialog appears.  
						

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3.Select the type of prerender file to create in the Prerender as drop-down list. Click Custom to configure any 
custom compression options.
Note: Youll need to choose a rendering template that inserts 
pulldown fields to create a standard DV file if your project 
properties are set to 24p or if you selected the 
Allow pulldown 
removal when opening 24p DV 
check box on the General tab 
of the Preferences dialog. Use the 
NTSC DV 24p (inserting 2-3-
3-2 pulldown)
 template if you intend to use the file on the 
Vegas timeline. This feature is available only in the full 
version of Vegas software.
Note: If you cleared the Allow pulldown removal when 
opening 24p DV
 check box before adding your media and your 
project properties are not set to 24p, your 24p video is read as 
29.97 fps interlaced video (60i), so you can choose 
whichever NTSC DV or PAL DV template suits your project 
requirements. This feature is available only in the full 
version of Vegas software.
4.To preview just a portion of the project, verify that Render loop region only is selected. To create a prerender 
of the entire project, clear this check box.
5.Select the Stretch video to fill output frame size (do not letterbox) check box when you are rendering to an 
output format with a slightly different aspect ratio than your project settings. This will prevent black bars 
from appearing on the top and bottom or the sides of the output.
6.Click OK. A progress bar displays the progress of the render. 
When prerendering is complete, bars appear at the top of the timeline indicating the sections that have been 
prerendered.
As a default, these preview files are saved when a project is closed. To delete these files when you close the 
project, from the 
Options menu, choose Preferences and, on the General tab, clear the Save active previews on 
project close 
check box. 
You can set the location of these preview files by clicking the Project Video Properties button () and 
choosing a 
Prerendered files folder in the Project Properties dialog. Ideally, this folder should be on a different 
physical drive from where Windows is installed. You can delete prerendered preview files from your hard disk 
by choosing 
Clean Up Prerendered Video from the Tools menu.
Prerendered sections 
						

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Note: Each prerendered section will consist of no more than 
10 seconds (approximately 40 megabytes). Because selective 
prerendering creates multiple files, minor editing on the 
timeline will not invalidate all of your prerendered video—
only the sections you modify will need to be rerendered.
Building dynamic RAM previews
Video frames are automatically dropped when previewing if the computer can’t keep up with processing 
demands. This means that you may not be seeing all video frames as you preview your project. If you prefer 
not to prerender your project, there is another option for improving previews of selected portions of a 
project. A portion of your RAM is dedicated to cache video frames that Vegas software cannot render in real 
time. 
A cache of 16 MB is automatically maintained for dynamic RAM previews. To change the cache amount, 
choose 
Preferences from the Options menu and change the Dynamic RAM Preview Max value on the Video tab.
Note: Although not all frames appear in previews of a 
project, all frames are included when you render a file. For 
more information, see Rendering a project on page 307.
You can make a time selection and add each frame in the selection to the cache. Once the frames are 
cached, all video frames can display in a selection. 
1.Select a region containing the frames you want to cache.
2.From the To o l s menu, choose Build Dynamic RAM Preview.
Vegas software plays through the time selection and builds the cache frame by frame.  
						

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Using split-screen previewing
This feature is available only in the full version of Vegas software.
Click the Split-Screen View button () in the Video Preview window to turn split-screen previews on or off.
Split-screen previews allow you to split the Video Preview window so you can see your affected and 
unaffected video or your video and the contents of the clipboard at the same time. Use split-screen previews 
to fine-tune video effects or to match colors for color correction.
Note: The Video Preview window temporarily enters split-
screen preview mode when you slip-trim a video event. This 
temporary split-screen mode allows you to see the events first 
and last frame as you trim. You can toggle this preview mode 
by selecting or deselecting the 
Video Event Edge Frames option 
on the View menu.
Previewing affected and unprocessed video
1.Click the down arrow next to the Split-Screen View button () and choose FX Bypassed from the menu.
2.Select the Split-Screen View button (). The cursor is displayed as a .
3.Choose a preset selection or drag in the Video Preview section to create a selection. This selection will 
display the unprocessed video. In the following example, the Add Noise plug-in was applied to the event, 
and the selection displays the original video.
Tip: Double-click in the Video Preview window to select the 
full window, or drag again to replace the existing selection. 
						

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Showing the video at the cursor position and the contents of the clipboard
1.Position the cursor on the timeline and click the Copy Snapshot button () in the Video Preview window 
to copy a frame to the clipboard.
2.Position the cursor at another point on the timeline.
3.Click the down arrow next to the Split-Screen View button () and choose Clipboard from the menu.
4.Select the Split-Screen View button (). 
5.Choose a preset selection or drag in the Video Preview section to create a selection. This selection will 
display the contents of the clipboard.
Tip: Double-click in the Video Preview window to select the 
full window, or drag again to replace the existing selection.
Changing the selection for displaying split-screen views
Click the down arrow next to the Split-Screen View button () and choose Select Right Half, Select Left Half, 
or 
Select All to indicate which portion of the Video Preview window you want to use to display unprocessed 
video or the contents of the clipboard.
When the Split-Screen View button () is selected, the cursor is displayed as a . Drag a rectangle in the 
Video Preview window to create a custom selection.
Identifying safe areas
The Video Preview window displays the entire video frame data. However, most television monitors do not 
display all of this data. Previewing the video on a television monitor is the only way to verify what frame 
information will display. You should also note that individual television monitors vary in what they display. 
While there is no substitute for previewing on a television, safe areas are a good method of estimating the 
extent of the masking.
1.Click the down arrow next to the Overlays button () 
and choose 
Safe Areas.
2.Click the Overlays button to toggle the safe areas display on 
or off. The display shows two areas:
 The safe action area is the frame area that is visible on a 
television screen.
 The safe title area is a suggested area to limit the extent of 
titles. It is always smaller than the safe action area.
Tip: To customize safe area sizes, choose Preferences on the 
Options 
menu, and on the Video tab, enter the Action safe 
area 
and Title safe area values as a percent of the frame size. 
For more information, see Video tab on page 333.Safe action Safe title 
						

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Viewing the grid
The Video Preview window can display vertical and horizontal lines over your video. You can use the grid to 
help you align objects. To view the grid, click the down arrow next to the 
Overlays button () and choose 
Grid.
Set the grid spacing using the Horizontal grid divisions and Vertical grid divisions settings on the Video tab in the 
Preferences dialog.
Isolating color channels
The Video Preview window allows you to select a specific channel to be isolated and whether the channel 
should be displayed in grayscale only. To display a channel, click the down arrow next to the 
Overlays button 
(
) and choose a color channel.
Note: Use the Alpha as Grayscale setting to isolate the Alpha 
channel mask and display it in grayscale.
Monitoring video with scopes
Video scopes are only available in the full version of Vegas software.
From the View menu, choose Video Scopes to toggle the display of the Video Scopes window.
Broadcast video uses a narrower range of color than the RGB you see on your computer. When you broadcast 
a project that contains out-of-range colors, you can introduce image problems or even noise into the audio 
stream.
Use the scopes to analyze the your video and adjust accordingly with the Brightness and Contrast, Broadcast 
Colors, Color Corrector, Color Corrector (Secondary), and Levels plug-ins before rendering.
Choose a setting from the drop-down list to choose which scope you want to display.
Choose settingDisplay video scopes settings
Update scopes
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Note: If your video hardware will add a 7.5 IRE setup, click 
the 
Settings button () and select the 7. 5  I R E  S e t u p check box 
in the Video Scopes Settings dialog. Black will be displayed as 
7.5 in the waveform monitor. If your video hardware does 
not add a 7.5 setup, clear the check box, and black will be 
displayed as 0.
Displaying chrominance using the vectorscope monitor
The vectorscope monitor in the Video Scopes window allows you to monitor the chrominance (color 
content) of your video signal. The monitor plots hue and saturation on a color wheel.
The vectorscope displays targets for broadcast-legal saturations of red (R), magenta (Mg), blue (B), cyan 
(Cy), green (G), and yellow (Yl). Individual colors in your video signal are displayed as dots in the 
vectorscope. A dots distance from the center of the scope represents its saturation, and the angle of the line 
from the dot to the center of the scope represents its hue.
For example, if an image has a blue cast, the distribution of dots in the vectorscope will be concentrated 
toward the blue portion of the color wheel. If the image includes out-of-range blue values, vectorscope 
display will extend beyond the blue target.
You can use the vectorscope to calibrate color between scenes. Without calibration, you may see noticeable 
color differences between scenes from multicamera shoots.
1.From the View menu, choose Video Scopes to toggle the display of the Video Scopes window.
2.Choose Vectorscope from the drop-down list.
3.Position the cursor in the frame you want to analyze. If the Update Scopes While Playing button () is 
selected, you can monitor your video during playback.
4.The vectorscope monitor displays the chrominance of the video signal:
FrameVectorscope display of frame 
						

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5.Hover over a portion of the monitor to display the chroma value at the pointer position:
Displaying luminance using the waveform monitor
The waveform monitor in the Video Scopes window allows you to monitor the luminance (brightness or Y 
component) of your video signal. The monitor plots luminance on the vertical axis and the width of the 
current frame on the horizontal axis.
If you want to include chroma (color or C component) information in the waveform monitor, choose 
Composite from the drop-down list at the top of the monitor window. When you choose Luminance, chroma 
information is omitted.
1.From the View menu, choose Video Scopes to toggle the display of the Video Scopes window.
2.Choose Waveform from the drop-down list.
3.Position the cursor in the frame you want to analyze. If the Update Scopes While Playing button () is 
selected, you can monitor the waveform during playback.
4.The waveform monitor displays the luminance of the video signal:
Chroma value
FrameWaveform display of frame