DSWiki - C

C


Contents

Caches
Closed Captioning
Color Corrector
Color Space
Containers
Constructing Credit Rolls without artifacts
Constructing a fool proof credit crawl
Cull Back Faces in the 3D DVE



CACHES


CACHES SUDDENLY APPEAR YELLOW OR RED ON TIMELINE
DS is confused. Save your sequence and reopen it by doubleclicking on it in the project window and your caches will usually come back into view normally.

DISAPPEARING CACHES
To prevent processed caches from disappearing, perform a “Save As” regularly as you work.

RECOVERING LOST CACHES
Make a new sequence and drop your faulty sequence as a reference clip (hold the ALT key while dragging to the timeline). Unless something is really screwed with your machine, you should have your caches. Its convenient only if you want to output, unfortunately because next time you will open the faulty sequence DS still won't see the caches.


Closed Captioning

(Added per list request 10-24-2007)

On HD masters, you can insert audio but no video on closed Captioned masters without losing your captioning.

The Nitris BoB and the AJA will not pass high-definition captioning so you will have to re-caption anything you have ingested into DS and any video you play back to tape from DS. The Adrenaline BoB (which may not work for HD) can preserve closed captioning but one cannot, of course, use that with DS.

If you have an Adrenaline system, here is what you do:

  1. select TOOLS > VIDEO OUTPUT TOOL
  2. Click the VBI menu and select preserve.


(thanks to Rhys Llewellyn, Bogdan Grigoresco and Troy Thompson)

On SD, pull in the SD master with CC info in the header and then crop the top of the new video to leave the CC info from the original poking out from behind.

If you are using your Sony HDcamSR deck to playback a digibeta to make a dub to a digibeta machine but the closed captioning does not seem to be coming across. The setting on the SR machine to make that happen is menu item 778, "Blank Lines Select", set "all lines" to "through" in the sub menu. This works for a dub via SDI. For some reason the Sony 5500 deck comes default set to blank those lines on dBeta playback.

Zoe Creative Services in Nashville offers HD Closed Captioning.



COLOR CORRECTOR


Define BALANCE--highlights, mids, blacks on color wheel. RANGE CURVES manipulates how those color points affect what levels of pixels are affected by those colors, and how much.

Hue: Affects pixels that have Saturation only.

Gain: Works by Multiplying Values.

Brightness: Offsets values and effects brightness by adding to every value of every pixel.

Sub-region: Opens a window in the viewer to use for comparison.

Tip: Adding Gain and Removing Offset will add Contrast.

RGB CURVES—color checkboxes select the VIEW, not the color channels affected.
Hold A key to add keyframes. H.U.B. works (see ANIMATION EDITOR section).

To find a specific color/luminance range to affect, marquee select a group of keyframes with a notch or a bulge, and slide it up and down the curve.

SHIFT key helps with little sliders, but constrains increments to units of 5.

6 will toggle color picker.

To do a really quick white balance, go to curves, set the layout to combined, and drop the eyedropper on what should be white in a shot, and the use the white patch beside the hue offset, select natural match, and click on match color... done



COMPARATIVE COLOR CORRECTION
In viewer, R-click and Turn on COMPARISON BUFFER. R-click again, and use GRAB to grab current frame. These keys can be mapped to the keyboard as well under Command Mapping > Viewer

Shift and Drag the viewer next to itself and use X to pan the viewer. This allows for a side by side comparison.
Or
Use DUAL VIEWER to watch switch between both pictures on SDI monitor/wfm View individual RGB channels on each picture—visually match brightness/contrast for each channel—will result in matched color image.

Adding a bogus no RT effect like Channel Switcher will enable the output to be seen in the external monitor/scope. Good for a split screen

TIP: Using Color Correction Curves
Using the ranges curves under the curves tab of the color corrector. Horizontal (x) scale can be looked at as a grayscale. 0 is black and 100 is
white. There is a lot of overlap of the default shadow/midtone/highlight curves which is not always what you want.

For example, if you adjust the shadow curve to absolutely end at 20, when you adjust the shadows under the balance tab of the color corrector you will know that you are precisely adjusting only the color for the bottom 20% of the grayscale. If you want your midtone range to extend only from 25% to 75% of the grayscale adjust the midtone curve to those values. It is usually best if you have at least a small amount of overlap between the curves or you might get hard borders between pixels that have been modified and those that haven't.

Color Correction Example:
In the effect tree, add three channel switchers and route the input clip into all three. In each channel switcher set all channels to be fed from Red, Green and Blue respectively.

Tip: ALT click to rename an effects node in the effects tree.

Route the output of each channel switcher into its own Color Corrector and use the curves for RGB in each to effect each channel individually. Route the output of each Color Corrector to the Output node.

When Color Correcting a clip with alpha use Spill Replace / Matte, Invert Matte to isolate the clip from its alpha. Also use Mask / Alpha.

TIP: A Legalizing Technique
Slap a Color Corrector across the entire timeline and set Gain to 99 on the Basic tab, with "Clamp to Video Levels" checked.

TIP: White Balance using "Match Colour" in Hue Offset (DSlist_al - 12.19.06)

A simple way of balancing the hue in hue offset. On the
right hand side of the screen, you have the "Match Colour" function. As long as
you make sure that the colour in the right hand box is "without colour"
(ie: white, grey or black) you can use the colour picker on the left box
and match it to the box on the right and it will automatically set
white, grey or black. The luminance values are not taken into
consideration when doing match colour in the hue offset tab.


Source Side Color Correction Disconnect


Symphony has the ability to do source color correction based on a variety of source relationships just like DS. DS only has Tape and master and subclips.

Let's say you are color correcting interview (A) based on source tape and the majority of the tape is interview (A). Then the camera person decides to shoot another interview (B) on the same tape, but the skin tone is different. You would want to unlink (or disconnect) that color setting for the source tape and apply a new color for interview (B) without out removing the entire source color from interview (A).

DS has always had the 'neatness' of SSEs being effectively hidden by being on the Master Clip and not as effects on the Timeline. Unfortunately, this can also be its drawback in this regard.

I think that what everyone (including Jeff) is missing here is the power of the new "Select All Effects of Same Type" button. Whilst certainly not a replacement for SSEs it can 'do what Symphony does' if you want it to. Here's a "jover" that can get you close to the Symphony-style workflow:

  1. Apply a null CC to every clip on the Timeline
  2. Edit the CC to suit on one of the clips from Tape 1
  3. Save this CC, using the Save button on the PPG - the DS Presets folder for the project is probably a good place.
  4. Go to another of the clips from Tape 1 and Ctrl+Shift Select the SAEOST button with "From same underlying source" selected and load your saved preset.
  5. You now have your saved preset applied to every clip from that tape. If you decide later to change that effect then you can simply follow the same workflow to change it on all the same clips.

(Thanks to Jeff Krebs and Tony Jover)



When Color Correctors Go Bad

color wheels in the CC layout go nuts


This happens occasionally and is caused by the Wacom Tablet.

Go to: Start / All Programs / Wacom / Tablet Preference File Utility and clicked 'Remove All Preference Files'. This fixes the problem!

(Thanks to David Tarr, Jason Russell, Igor Ridanovic and Kristian Whitlock)


COLOR SPACE


• There are two main Color Spaces used in video - RGB and YUV (or more
correctly Y, R -Y, B-Y, but YUV is more convenient to use)

• YUV Color Space is a "bigger" color space than RGB - that is, it can contain
levels that RGB cannot contain.

• Digibeta stores its signal in YUV

• DS works natively in YUV.

• Most DS effects work in YUV

• Some DS effects (up to and inc. V6) work in RGB.

• Graphics is one of the effects that works in RGB.

• If your image contains "illegal" RGB levels (levels that cannot be contained
within the RGB Color Space) then those levels will be clipped when you apply an
RGB effect. This is what you were experiencing.

• The way to avoid seeing the clipping is to either use a ColorSpace effect to force
the levels to RGB or to apply a Color Corrector and correct the levels manually.

CONTAINERS


BACKGROUND CONTAINERS
Act as a "holder" for several clips, horizontally in the timeline . If you've cut a
sequence of shots that you'll be using (perhaps as a background) over and over
again you can just copy the container, slide it around etc, rather than having to
copy a load of individual clips. You can move this group around as if it were one
clip. You can dissolve into the background container although there may be many
clips inside covered by the dissolve.

Apply clip effects or timewarps to entire background containers.

COMPOSITE CONTAINERS
Used to place clips above each-other on layers, Multiple clips on layers grouped
may be grouped together (vertically). The entire contents of the Composite
Container will be treated as one single clip.

CREATE-CTL-CLICK two clips in timeline—Hit Composite Container.

Use the composer-like step-in/step-out buttons in timeline to move up or down levels.

• Control U goes to the parent timeline (steps out of a container)
• Control Shift U goes to the top timeline (steps out of multiple containers)

CONTAINER VIEW—R-click properties—show container time or timeline time.

Use CONTAINER PROPERTIES to rename your container.

MAKING COPIES OF COMPOSITE CONTAINERS in a timeline, so that if you
change the original, all the others automatically change:

Drag a new clip to the ribbon to create a new track in the container and add a
compositing layer.

Right-Drag a new clip to the ribbon to create a new track, with no new layer.

Container elements are where compositing elements come from. Drag a timeline track
(left side button (used to be the track jewel) into compositing window to add a layer to
the composite. Container elements may also be dragged into tree area for use in trees.

EFFECTS COMPOSITING FLOW (For each layer)
(Note: Flow chart missing -DT)
SLICE
EFFECTS
Key
GFX
DVE
CC
Opacity
%
Slider
Track
(w/clip
effects
or track
Alpha Composite Effects Tree effects)

SLICE EFFECTS occur in order shown. Change the order… R-click-drag to new order.

ALPHA CHANNELS

R-click-drag layer to ribbon—makes it a layer for alpha manipulation. Drag a
timeline’s layer’s jewel/button to layer alpha window to control alpha for that layer.
Additional Alpha manipulators can be added… R-click alpha window for Boolean
operator.

Example: Make black lines of a black and white graphic (without alpha) key over a
color. Drag the layer up to the alpha thumbnail within a composite container, click on the
top thumbnail to export the alpha up through the container. Make sure you're using the
RGB for the alpha, not the existing alpha channel (which is fully opaque.)

REPLACE SOURCE- drag new sequence track jewel to RGB window on a layer. All
effects will remain as is.

GREEN TRACK JEWEL in LAYER indicates an effects tree is present.
Mute Background: Ignores the alpha

RESULT WINDOW AT TOP—R-click to
• Mute background
• Insert a layer
• Export alpha

GLOBAL DVE- Accessed by R-click from the top of the composite area. Affects all
DVE’s below.

Tip: A shadow can be a value other than a color such as desaturation or color correction.

Viewing top timeline (final result) while working in a container: Add a bogus clip effect
to container in timeline (i.e. a blur, with zero blurriness). R-Click effect, “Open Viewer”.
A floating viewer will appear. “Pin the viewer to keep it around.

USE REFERENCE SEQUENCES
When finished creating a composite container, right click on the container (in top
timeline) and choose: Save as Reference Sequence. Now you can alt-drag this saved
container (showing as a sequence) to the timeline to create as many instances as you like.
Updating the reference sequence will update all instances.


Credit Rolls without headaches

Or how to construct a credit roll without artifacts and without using Build Roll:

  1. Create a black (bg) clip that's way longer than you need. You will cut it later.
  2. Apply a GFX effect, and create the text body for the roll.
  3. At the intended beginning of the roll, place the text body in its start position (usually barely bottom-offscreen).
  4. Set a keyframe in the Transformations property editor.
  5. Move the play cursor forward by 1 second.
  6. Enter the Y displacement value for the text body in the Translation value according to the frame rate of your sequence (see Note)
  7. Set a second keyframe.
  8. Open the animation editor
  9. Select the curve for Transformation Offset Y
  10. In the Animation Editor's Curves menu, choose Relative Cycle.

The animation for the Y value will now be extrapolated backwards and forwards to infinity.

At this point, you can see where your roll ends, and cut it off there.

If the roll needs to have a specific duration, you can extend or compress it by fiddling with the text body (Leading, font size, and/or paragraph spacing) without changing the roll speed.


If you apply the method above, you get a credit roll that makes good-looking individual frames (good for printing to film), but that look ugly when rolling.

To get around this problem, you need to create a half-speed roll (e.g., 48 lines per second intended for 96), and then apply a Interlace effect to it.

Individual frames will now look "interlaced", but the text will appear correctly when rolling.


Note


This article is a lift from Avid's website.




How to construct a foolproof credit crawl


There's a quick 'n dirty way to make a crawler (the same methodology also holds true for rollers). Crawls tend to be used more in Europe these days than they are in the US or Canada.

  1. Make your first credit as its own Graphics object and align the text suitably
  2. Copy/paste that object, drag it to the right of the 1st one and edit the text for your next credit. You may want to use the Transformations tab to ensure that it's spaced by a fixed amount from the previous text so that you can repeat the spacing for all the objects.
  3. Repeat step 2 for as many times as necessary. Bear in mind that you can "select all" any time you need to.
  4. When all the text objects are edited, select them all and use the "Relative Align Vertical Centre" button (or press Ctrl + Alt + Num9). This aligns them all vertically (you've already aligned them horizontally in Steps 2).
  5. Select Graphics Properties main PPG and click the "Crawl" button.

Now if you have to edit any of the captions you just scroll along the Timeline until the relevant one is on screen, then enter Graphics and edit it.

If you need to close the gap between any 2 objects you can select everything to the right of it and move it right or left, then re-select all and
re-create the crawl.

(Thanks to Tony Jover)


Cull Back Faces

(Added 10.31.2007 MH)

In the 3D DVE:

Back Face Culling happens on a Object by Object Basis. So you will have to turn the option on for each piece of geometry you have.
(IE: Back Face Culling is not a Global option)

  1. Select Geometry ("DVE")
  2. Select the "Render" tab for that geometry (The property page 3rd from the bottom that has an Icon that looks like a eye inside a red box with corner points)
  3. Select "Cull Back Faces"

To test how this works fly your camera inside and object like sphere and select /de-select the "Cull Back Faces" option.
When the 3D DVE culls the inside surface of the object vanishes as it is no longer being processed. With the option off the inside of the sphere is visible again.



















Revised: Jan 24, 2014 6:20 pm