Not sure where you are going to run the script. But if you are trying it out in script editor, do the following for accessing project output format param.
app=app1
app.getProjectParam('outputFormat').set('HD_720')
Not sure where you are going to run the script. But if you are trying it out in script editor, do the following for accessing project output format param.
app=app1
app.getProjectParam('outputFormat').set('HD_720')