Computer Concepts Eagle M2, Руководство пользователя

Страница: 30 / 66

4. Viewing and grabbing images
3 Display the
Grab choices
dialogue box either using
Grab
choices
on the TakeTwo menu or by clicking on the live
display window.
4 Set the file format to
Replay.
5 Set up the file save path – see
Grab choices dialogue box
for
more information.
6 If necessary, set-up the
Format
and
Rate
options.
7 If necessary, set-up the mixer controls in AudioCtrl. See the
Audio options
section of this manual for more details.
8 When the live display window shows the required image; click
on the
Record
button. This starts recording the movie.
9 Click on the
Stop
button to stop recording. (Recording also
stops if the disc becomes full.)
10 The title page of the movie is displayed. Click on
Play
to
play the movie or
Stop
to return to the live display.
How Replay movies are processed and stored
Grabbing movies makes heavy demands on the computer. A movie
image represents a large amount of data to process in real-time.
You can also quickly fill a disc with the movie data, especially if it is
stored uncompressed.
The Replay format has two speeds, 12.5 or 25fps. 25fps gives the best
results but only very fast computers can process the data. At 12.5fps,
data is read in and processed in two second "chunks". At 25fps, the
chunks are one second long. Chunks are initially stored in RAM (
memory) as they are received. When a chunk is complete, it is
processed and then stored on disc. If you have the Eidos
software and have selected
ESCaPE,
the chunk is also compressed
before storing.
The RAM requirements to hold the chunks depend on the save
format. For grey-scale format (the smallest), 1Mbyte is needed, for
RGB format (the largest), 2Mbyte.
For information on compressing a movie using the Acorn com-
pression routines, refer to 7.
RCompress.
23