H.264 (AVC)
Definition
The dominant video codec in Indian DVR/NVR fleets in 2026. Compresses using I-frames (full picture), P-frames (forward predictions) and B-frames (bidirectional). Frame-level forensic extraction usually targets the I-frames.
- Codec type
- Video compression standard
- Prevalence
- Dominant codec in Indian DVR/NVR fleets in 2026
- Frame types
- I-frames (full), P-frames (forward), B-frames (bidirectional)
- Forensic target
- I-frames, for frame-level extraction
Common questions
Why do forensic examiners target I-frames rather than P or B frames?+
An I-frame is encoded as a complete standalone image, while P-frames and B-frames only store the difference from neighbouring frames, so an I-frame yields a clean, self-contained still without needing to reconstruct it from surrounding frame data, making it more reliable for extraction and enhancement.
What forensic problem arises from H.264's reliance on predicted frames?+
Because P-frames and B-frames only encode changes relative to other frames, extracting a usable still from a non-I-frame requires decoding a chain of dependent frames correctly, and any corruption or loss in that chain can degrade or distort the reconstructed image.
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