How do you account for temporal and spatial alignment between clips in the PQA500?

How do you account for temporal and spatial alignment between clips in the PQA500?

The PQA500 supports both manual and automatic alignment of reference and test clips by adjusting the following items:

1)     Temporal Sync:

• Start and end frame or time for reference clip
• Start and end frame or time for test clip
• Temporal offset (shift) between reference and test clips
• Test clip frame rate

2)     Spatial Alignment:

• Horizontal and/or vertical shift between reference and test clips
• Horizontal and/or vertical scaling or stretching between reference and test clips
• Horizontal and/or vertical cropping between reference and test clips (letterboxing, zoom etc...)
• Overall luminance gain and/or DC offset between reference and test clips

The user is given a choice of either manually adjusting each of these parameters while they watch a live-running PSNR until they achieve temporal and spatial alignment between the clips or if they wish they can run an automatic alignment which will scan a portion of the video clips looking for similarities and automatically determine the best temporal and spatial alignment.