Save current AE composition as Jpg and process via Terminal Script

I've no idea whether this will work, but here goes!

In your Render or SmartRender function write the input buffer out to disk using a JPEG or PNG library. Then use AEGP_ExecuteScript (part of AEGP_UtilitySuite) to run a simple ExtendScript that can use the system.callSystem() method to run your external process. The script itself is just a pointer to an A_char array you can build at render time from your params.

For example, you'd want the script to look something like this:

{

   system.callSystem("GraphicsProcessor -o123 -x456 -y789 path/to/my/temp/render.jpg");

}

The script will call the command line with your GraphicsProcessor command, and wait for it to finish. It will then pass the return string from GraphicsProcessor (if there is one) back to AEGP_ExecuteScript as an AEGP_MemHandle, which you can lock to read the result in your plugin. AFAIK there's no way to directly call the command line from a plugin (but I'm probably wrong!).

Then I guess it's just a matter of reading the processed jpg back from disk, decoding it and writing it to the output buffer.

This is risky of course because the command line function might not finish and your script, and plugin will be waiting forever for it to complete.

Good luck!

Just out of interest, why can't you process your buffer directly in the plugin? Are you using third party software that can only be run from the command-line?