Compression History Reconstruction
Every re-encode leaves forensic traces. ClipForensics reconstructs the full encoding chain to reveal a video's journey.
Why It Matters
Re-compression reveals manipulation
When someone edits a video and re-exports it, the compression chain grows. Authentic camera footage typically has a single encoding pass.
A video recorded on an iPhone and uploaded directly to YouTube has a predictable compression signature. But a video that was downloaded, edited in After Effects, re-encoded, uploaded to TikTok, screen-recorded, and re-uploaded has a very different compression profile.
ClipForensics's Compression History module detects these re-encoding artifacts and reconstructs the likely encoding chain, giving investigators visibility into how many times a video has been processed.
Reconstruction Pipeline
How we rebuild the encoding chain
Container analysis
Extract codec, profile, level, bitrate mode, and GOP structure from the container headers.
Quantization fingerprinting
Analyze DCT coefficient distributions to detect quantization table signatures from known encoders.
Re-compression detection
Look for double-compression artifacts — periodic patterns in block boundaries that indicate the video was encoded at least twice.
Encoder identification
Match encoding parameters against known profiles from x264, x265, VP9, AV1, NVENC, QuickSync, and common mobile encoders.
Chain reconstruction
Build a probabilistic model of the encoding history: original capture → edits → exports → uploads → downloads → re-uploads.
Forensic Value
What compression history tells you
Editing detection
Multiple encoding passes often indicate that the video was opened in an editor and re-exported — even if the visual edits are invisible.
Platform tracing
Different platforms (YouTube, TikTok, WhatsApp) use different compression profiles. Encoding signatures can reveal which platforms a video passed through.
Authenticity confidence
A single-pass encoding chain from a known camera encoder significantly increases confidence in authenticity. Complex chains reduce it.