I-Frame (Intra-Coded Frame)
Definition
A video frame that is encoded entirely from its own pixel data, without reference to any other frame. I-frames mark the start of a new compression group-of-pictures (GOP) and are the reset points for inter-frame prediction.
Related terms
- 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...
- Bitrate Anomaly
- A departure from the expected relationship between scene complexity and compressed file size. Sudden drops, plateaux, or spikes in the per-second bitrate...
- Double Compression
- The condition in which a video has been encoded at least twice through a lossy codec. The term is also used loosely...
- 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...
- Hash Verification
- The process of computing a cryptographic hash (SHA-256 or equivalent) of the exhibit file and comparing it against a previously recorded value...
- Inter-Frame Residual
- The pixel-level difference between a predicted frame and the actual frame after decoding. In unmodified video, residuals at scene cuts are elevated...
- 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...
- 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...
- Re-Recording Artefact
- A visual or statistical signature introduced by pointing a camera at a screen playing back footage. Includes moiré patterns, screen reflections, temporal...
Explained in these topics
- Video Authentication and Integrity VerificationA video frame that is encoded entirely from its own pixel data, without reference to any other frame. I-frames mark the start of a new compression group-of-pic...
- Detecting Frame Deletion and Insertion in VideoA self-contained frame that stores a complete image, independent of other frames. It is used as a reference for the P-frames and B-frames that follow it within...