Jacopo di Cione, St. Peter
Tempera and gold on wood panel
Pinacoteca Vaticana, Rome
The festive scene with bugles may suggest the Feast of St. Peter's chair on February 22. With his pointy beard and bald forehead, the one haloed figure on the left should be St. Paul. The two kneeling figures may be the donors. The others seem not to be saints. They do not have haloes, and one of them wears the conical Jewish hat. Perhaps they represent the citizenry as a whole.
Images of the enthroned St. Peter were not unfamiliar in this period. Here is one by Giotto from 1320 (also from the Pinacoteca Vaticana):
The di Cione panel in full resolution
The Giotto altarpiece in full resolution
More of St. Peter
Photographed at the Pinacoteca Vaticana by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.