The ACG lab has two ways of placing computer generated images QuickTime movies, picts, etc.. onto video tape. One allows single frame editing of the source, the other is real time recording using a hardware compression that allows our Macs to output 640 X 480 pixel at 30 frames per second. All America video is shown at 30 frames per second other countries use different frame rates. Mac Vac allows for single frame editing or real time recording (without software or hardware compression) while the Miro card uses hardware compression.
This document will aid you in using Mac Vac software, a video compositing program, that allows the user to put QuickTime movies, Pics, or Picts onto a 3/4" video tape. This maybe done one frame at a time allowing compositing of complex images from multiple graphic softwares.
To use the 3/4" tape you have purchased, it must be formatted. This is the process of putting SMTP time code and a solid black color (lack of any images) on to the tape.
Turning on the Rack Equip. | RGB/NTSC | Controls on the BVU | Recording in MacVac | Formatting 3/4" tape | Compositing images using an Alpha channel
1. Turn on the Mac, you must use the NuVista Extension set in the Extension manager, and turn on both the NuVista+ driven Electrahome Monitor and the Mac monitor2. Turn on the power strip next to the small Sony Monitor (laying in the rack.)
3. Turn on the large Monitor on the top of the rack and select EXT 1 to allow you to see the output of the Video recorder
3. Turn on the Panasonic VHS - VTR at the bottom of the rack.
4. Check that the selecting from the push buttons on the Sony monitor is the VTR option.
5. Check that your 3/4 video tape cassette has a red button if not installed nothing can be recorded on the video tape. It is a right protect option similar to the tab on a standard audio cassette. Insert the Video tape.
1. Note the color of the pilot light on the Electrahome monitor. This helps to determine if NuVista card is in the Interlace or Non-interlace mode.if red = Interlaced required for Video recording = NTSC
if green = Non Interlaced required for Computer signal = RGBAn alternate method to determine the setting of the NuVista Card is to drag a window or dialog box to the NuVista screen. If image is solid and clear it is in the RGB computer mode, if the image is jumpy the card is in the NTSC or TV mode on the Large screen and the small Sony monitor in the rack.
The command to change between Modes is CMD -=. This is a toggle which switches between the modes. You must use the = key on the number pad not the on above the letters on the keyboard.
Open the hard drive > video> MacVac folder, and activate the MacVac3.2 application.
This is a screen capture from MacVac which shows most of the controls you have on the BVU-950 tape deck in the rack.
There is a Key selection switch not shown which allows you to control the tape deck from the computer rather than form the knobs on the tape deck itself. If flipped to "local" the buttons on the hardware in the rack work if flipped to "remote" the control in MacVac on the computer control the hardware. Look for this switch on the tape deck.
The colored transport buttons are like most tape recorders you have used and the labels make there use obvious.
The large Knob on the deck has two modes of operation. To switch between them put the knob in and release, it will switch between jog and shuttle mode. Note the lights next to the knob tell which mode your in. In the shuttle mode turn the knob to right or left advances or rewinds the tape. The further you turn it the fast it advances or rewinds. Much like using a car accelerator. The jog mode allows for slow advance and rewind, you must continue turning the knob around and around (clockwise or counter clockwise) until you reach the desired location.
We always use the auto edit button when working with our tapes, which
requires setting and in point (where the recording will begin on the tape)
and never the normal red record button. Using the normal record button erases
the time code placed on the tape during the formatting process. (This is
not a good thing) When working with MacVac (remote mode) this is taken care
of automatically for us.
Audio or video maybe place on top each other (recorded at separate times)
without danger of erasing the first recording if the Audio or Video channels
are correctly selected and auto edit is used.
If you have not opened MacVac do so now by opening the hard drive > video> MacVac folder, and activate the MacVac3.2 application.
Formatting - use MacVac for ease of operation.
If the tape is new select format. This will place a video black image over the entire length of the tape and also record a time code track require to single frame recording.Time Code only is Not Available on our machine but shows in the dialogue box. (If the tape has images you do not want to be removed select the time code option. This would place a control track on the tape for single frame editing.)
The results of this action is that the tape can now be accessed by time code numbers which are record in this syntax: Hours(23):Minutes(59):seconds(59):Frames(30) - 00:00:30:00= 30 seconds.
If you have not opened MacVac do so now by opening the hard drive > video> MacVac folder, and activate the MacVac3.2 application.
Recording images is the same basic process for all file formats that MacVac accepts.
The different file type have allow for slight variation of the above
proceedure.
Bars, Blanks, Slates | QuickTime movies | Single Pictues
| Numbered Picts | Pics all may be used in MacVac.
Note on the left that a 5 sec. preroll and 1 sec. postroll are required for this particular tape deck other brands or models will have their unique requirements. The communication between the CPU and the recorder is shown in the lower right corner of the dialogue box.
To verify the communications link between the computer and the tape deck select from the menu bar option Windows and drag to VTR control. Click on play if the tape deck responds you have been successful in configuring the linkage. If not see Glen for help, something is not correct. (remember the Remote/Local switch on the tape deck should be flipped to remote). Close the window.
The next step is to setup the Video tape for recording. This involves establishing a start location on the tape beyond or after what has already been recorded on the tape. If this is not done the original images will be record over by the new images. MacVac gives a warning window of the required image size being 648x488 pixel - this maybe ignored. Click OK an move on.
IF YOU WISH TO HAVE IMAGES FIT THE ASPECT RATIO OF THE SCREEN THEY MUST BE SIZED TO 640 WIDE BY 480 HIGH. THIS IS THE SCREEN RESOLUTION STATED IN PIXELS.
Change the offset value before importing your images. In this way the pictures
will be imported for the proper placement on the tape and will not require
much adjustment. If this is your first recording on a new tape set
the recording offset to be 00:00:30:00 or 30 seconds into the tape (if
you have all ready recorded on the tape set the offset to the last recorded
frame number of your images). This will allow the beginning images to start
at 30 seconds into the tape or at the end of previously recorded images.
Also decide how many frames you wish each image to be used.
When using a QuickTime movie, each frame maybe a different image or you may
hold a image for two or three frames, making a movie's running time two to
three times a long as the original. (remember it takes 30 images for one
second of tape).
The reason for shooting on twos is not to make the movie longer but to cut the rendering time to create the QuickTime moive in half. This must be planned out in advance. Only a video guy can see the difference between shooting on 1, 2, or 3 after three, we all will start to see the difference. go to setup
Loading the computer with the files
The file formats that MacVac can use to composite your work is Pics, PICT
or QuickTime movies it will not read any other format. Copy all the images
and files you are planning to record into a new folder under your name. Copy
only the images you are planning to record not
every file on your disk.
When you have been successful in recording do not forget to drag your folder
into the Trash and Empty the trash before closing down the machines.
When you open the MacVac3.2 application in the MacVac folder. Three windows are opened, the edit, the layering, and the message windows. Using these windows we make and order a list of the pictures we want to put onto the video tape.
The Edit window allows us to import the images from a folder into MacVac.
The offset and image rate will be displayed in this
window.
Each image, movie, or pics is added to the edit window
by click on the add image. This allows for developing the proper sequence
of images. You may double click on any file in the edit list window and change
the duration, or start time of that image. The above shows a Layering of
images with Alpha channels ontop of the star background.
The Layer window shows a graphical relationship of compositing and time duration of an image
Note that the top image is Star Background and is drawn first by the program. Channel 2 is drawn on top of channel 1 and so forth until the x29 is drawn on top of channel 1,2,3,&4. Here we see three static pict files extended to be background for the animation in channel 4 and 5 which have 120 images each. The layer window and edit window work together and reflect changes made in either. The pointer at the top of this window is used to select a moment in time to preview, 00:01:17:20. The preview button is in the Edit window.
When you have the proper order of images and they preview correctly CHECK the REMOTE/LOCAL on the BVU-950 and flip it to remote. Move to the edit window and press the record. The first image is placed on the NuVisit monitor which is displayed on the large TV monitor and the litttle Sony monitor, and the tape deck backs up 5 seconds before the video off set and records the first image. This process is continued until the end of the edit list is reached. This process will take time. go to setup , to the top
Adding bars, black or slates is easy as adding a single picture.
Add a Color bars to by clicking on Tools on the Menu Bar and select one of the three color bar Icons. This will be the first image to be recorded. Note the frame/image rate set above is not reflected when you add bars or black from Icons at bottom of window. Turn off recalculate to allow up dating of the duration. The default is one second. The rate may be up dated by double clicking on the name of the item in the edit window. This will provide you with a new dialogue box to adjust the frame/image rate. Normally you will want 30 seconds of bars 15 frames of black 5 seconds of slate (Your name, date, project name, and number of frames) and another 15 frames of black before your first image in placed on the tape.
If you wish to add black before any image click on the image to highlight it in the edit window and click on the black Icon from the Menu Bar Titles. Note that the insertion location for the black frame is before the highlighted image. Also note that the time code number are not correct when you insert black. To Correct this click the recal button only if the offset is correct. Watch the time code number carefully.
Recording your images one after another these may be
static images from PhotoShop or other applications which you want to show
as a slide show.
Click the edit window at the bottom of the screen to make it active.
Click the add button to add one PICT at a time from your folder or click
add all to insert all the Pics/Pict(xxx)files in the folder. Adding images
in this way reflects the frame rate set in the Video Setup window. double
check your offset before importing all your images.
When you have developed the list of images to be recorded and time coding is correct, click the record button. The machine will read in each image in the order listed and record it to tape.
If you wish to save this listing for future reference or editing, select from the Menu Bar select File and drag to Save. Select the disk and folder desired, name the image and click save. The folder name an location must be the same if you are going to duplicate the the recording sections at a latter time.
Throw your folder in the trash when you are finished to keep maximum space on the hard drive for others.