Inter-Frame Residual
Definition
The pixel-level difference between a predicted frame and the actual frame after decoding. In unmodified video, residuals at scene cuts are elevated but follow a characteristic pattern. At a deletion or insertion point, residuals are elevated in a spatially incoherent way that differs from a natural scene cut.
- Domain
- Video codec analysis
- Definition basis
- Difference between predicted and actual decoded frame
- Natural scene cut
- Elevated residual, characteristic pattern
- Tampering signature
- Spatially incoherent residual elevation
Common questions
Why does frame deletion or insertion produce a different residual pattern than a normal scene cut?+
A genuine scene cut changes global content in a way the encoder's prediction models anticipate, producing a broadly elevated but coherent residual. Splicing in or removing frames disrupts the temporal prediction chain unevenly across the frame, so the residual spikes are scattered rather than following the coherent pattern of natural content change.
Can inter-frame residual analysis alone prove a video was edited?+
It is one indicator among several. Re-encoding, transcoding, or platform compression can also disturb residual patterns without malicious editing, so examiners corroborate residual anomalies with container metadata, GOP structure, and other artefacts before concluding tampering occurred.
Related terms
- Group of Pictures (GOP)
- The periodic structure of I-frames, P-frames, and B-frames in a compressed video stream. Each encoding generation imposes its own GOP structure. When...
- I-Frame (Intra-Coded Frame)
- A video frame that is encoded entirely from its own pixel data, without reference to any other frame. I-frames mark the start...
- Motion Vector Consistency
- In unmodified video, motion vectors across consecutive frames track the same objects and follow smooth trajectories. A deleted or inserted frame breaks...
- P-Frame (Predictive Frame)
- A frame encoded as a set of changes relative to a preceding reference frame. P-frames are smaller than I-frames because they only...
- Presentation Timestamp (PTS)
- A value stored in the container for each packet indicating when that frame should be displayed. In an unmodified recording, PTS values...