An example of a hint that directly identifies existing references is a label or identifier for a current frame or an individual region of the frame. For example, “game world map top-view” is a direct hint. Another example of a direct hint is coordinates of regions that make up a frame. For example, a frame can be divided into four quadrants, and each quadrant can be associated with a respective identifier. In an example, the region-based reference manager 520 can also include a block 522 that performs region-based reference decisions. The region-based reference decisions block 522 uses frame and region descriptions, such as the example direct hints described above, to decide which frame or region of a frame to use when encoding a current frame. The region-based reference manager 520 can choose a more optimal reference with higher confidence using such explicit labels or identifiers.

An example of a hint that indirectly guides the region-based reference manager 520 to identify an optimal reference candidate includes an OS notification of a window appearing in a certain region of a screen. This OS notification can be associated with the current frame. In an example, the frame and hint pre-analysis for region detection and matching block 521 can use techniques to infer optimal reference candidates based on indirect hints. For example, when the region-based reference manager 520 detects a second OS notification with the same window information, the frame and hint pre-analysis for region detection and matching block 521 can find the previous frame that was associated with the same OS notification. Because the previous frame is associated with the same OS notification, it has a higher potential of being a higher-correlated reference for the current frame.