User manual

Automation Protocol Filename-Based Commands
Miranda Technologies Ltd Page 93
Example of parsing the information returned (using C).
sscanf(&buff[1],
“R6%01x%03x%03x%03x%03x%03x%03x%03x%02x%04x%01x%02x%01x%s”,
&Info->file_exists, &Info->xpos, &Info->ypos,
&Info->width, &Info->height, &Info->clip, &Info->gain,
&Info->trans, &Info->image_type, &Info->no_frames,
&Info->anim_mode, &Info->load_time,
&Info->associated_audio, Info->FileName);
Preload Image R7
This command is used to preload an image, animation or clock for the
specified layer. This copies the media file into an off-screen (free) area of
store memory. When a subsequent load command (R0) is issued, the
preloaded image name is checked against the image requested. If they match,
then the preloaded image is immediately selected onto that layer. This
enables on-air media to be swapped with new media without any load delay.
If a different file is requested via ‘Load’, then the preloaded image is cleared.
If no extension is specified, the Imagestore will try both .OXA and .OXT.
Note: On Imagestore 2 and earlier products, there is a single process
which handles all file loads, saves, deletes and preloads in strict
order of reception. In other words, if a load is in progress on
layer 0, load (or save, etc.) requests on another layer will be
deferred until the first load completes.
This command (as with other filename-based commands) will return an ACK
as soon as the request has been queued, rather than waiting for its
completion.
Note: For long animations, please be aware that you may not be able
to hold both a pre-loaded image and the current on-air image in
the store memory available. In this case, the preload will fail.
Larger video memory will address this problem.
Note that the progress of the preload can be monitored by checking the ‘disk
busy’ bit returned by the Enquire loaded image status ‘O’ command as part
of the key type field.
One disadvantage of using R7 is that the new media can not be previewed
prior to it being shown on-air (assuming the Program keyer remains cut up).
CMD Param_1 Param_2
R7 %1x: Layer No. Filename