Service · Video decoding
Video decoding to play and recover footage that won’t open
Video decoding is the forensic recovery of video from proprietary, damaged or unplayable files. We decode DVR and NVR exports, separate multi-channel recordings, recover embedded timestamps and repair corrupted files, without altering the original evidence.
Expert Witness Code of Conduct
Reports prepared in line with court rules on expert evidence
SWGDE best practice
Recognised methods for digital and multimedia evidence
Repeatable methods
Documented workflow that another examiner can reproduce
Hash-verified custody
SHA-256 recorded on receipt and at every hand-off
Strictly confidential
Encrypted transfer and secure storage of evidence
Overview
What is video decoding?
Video decoding turns an unplayable or proprietary recording into video that can be viewed and examined, while keeping every frame and its timing exactly as recorded. It is often the first step before any analysis, enhancement or authentication can begin.
Many CCTV systems save footage in their own formats, which only play in the manufacturer’s software. Others store several cameras in one file, or write timestamps in a way ordinary players ignore. Files can also be damaged when a recorder loses power, a drive fails or an export is interrupted. Converting these files with general-purpose software often drops frames, changes the frame rate or loses the timestamps, which can undermine the evidence. A forensic decode works from a hash-verified copy, reads the file structure directly, and extracts the original video stream without re-encoding it wherever possible. Every step is logged, so another examiner can check that nothing was added, removed or changed.
What we can recover
Problems video decoding solves
Each file is examined at the level of its structure, so we can explain what was recovered, how, and whether anything is missing.
Proprietary formats
Decoding of DVR and NVR exports that only play in the manufacturer’s software.
Missing player software
Playback of exports that arrived without their player, or with one that will not run.
Corrupted and partial files
Recovery of video from damaged, fragmented or interrupted exports and drives.
Multi-channel separation
Splitting recordings that hold several cameras into one file per camera.
Timestamp recovery
Extraction of the date and time embedded in the stream for each frame.
Frame-accurate extraction
The original stream extracted without re-encoding, with a verified frame count.
Court-ready copies
Working copies that play on standard software, documented against the original.
Processing log
Every tool, setting and output recorded, with hash values for each file.
Common problems
Common decoding problems, and what to keep
The right decode depends on how the file was made and what happened to it. Keeping the file exactly as received gives us the best chance of recovering everything.
The export will not play
The file opens with an error, plays as a black screen or is not recognised at all.
Keep: the export exactly as received, with any player or extra files that came with it.
Player software missing
The footage was exported without its player, or the player will not run on modern computers.
Keep: the recorder make and model, so we can identify the format and its player.
Corrupted or partial file
The file stops early, freezes, shows blocks of colour or will not open after an interruption.
Keep: the damaged file as it is. Repeated attempts to repair or convert it can make recovery harder.
Several cameras in one file
A single export holds many camera channels, which ordinary players show one at a time or not at all.
Keep: the full export. We can separate every channel without losing the others.
Garbled image or wrong colours
The video plays, but with distorted colours, smearing or a squashed picture.
Keep: the original file, not a screen recording of it, so the correct decode can be applied.
Only a converted copy
The file was converted, compressed or re-saved before it reached you.
Keep: the converted copy, and ask the system owner whether the native export still exists.
Related forensic services
Services often used after decoding
Once footage can be played, it can be examined. Each of these services has its own page.
Video Authentication
Testing decoded footage for editing, deleted frames, splicing and re-encoding.
Video authentication →
CCTV Footage Analysis
Event reconstruction and multi-camera timelines built from the decoded channels.
CCTV footage analysis →
Forensic Video Enhancement
Clarification of recovered footage, with every step logged and kept representative.
Forensic video enhancement →
Common questions
What lawyers and insurers ask us about decoding
Short, direct answers to the questions we are asked most often when footage will not play.
Can you play files my computer can’t open?
Yes. Decoding proprietary DVR and NVR formats is a core service. We identify the format from the file structure, extract the original video stream, and produce working copies that play on standard software, documented against the original.
Most unplayable CCTV files are not damaged. They are simply stored in a format that ordinary players do not recognise. The example below shows the stages of a typical decode. In a report, each stage is recorded with the tools used and the hash values of every file, so the process can be checked.
Which video formats can you decode?
Almost any format used by CCTV, dashcams, body-worn cameras and phones, including proprietary exports. Where a format is unfamiliar, we analyse its structure directly to locate the video stream and its timestamps.
| Type of file | What we decode |
|---|---|
| Proprietary DVR and NVR exports | Manufacturer formats such as .dav, .264 and self-playing .exe exports, decoded from their file structure. |
| H.264 and H.265 streams | The most common CCTV codecs, often stored in unusual containers or without the information players need. |
| MJPEG and older formats | Sequences of still images and legacy codecs from older recorders and analogue systems. |
| Video management system exports | Database or signed exports from enterprise systems, with their audit information kept. |
| Dashcam, body-worn and phone video | Files with embedded GPS, sensor data or variable frame rates that need careful handling. |
Will decoding change the evidence?
No. We never work on the original. We record a hash value on receipt, decode a verified copy, and extract the original stream without re-encoding wherever possible, so frames, timing and quality are preserved.
Where conversion is unavoidable, for example to produce a copy the court can play, we keep the conversion separate from the decoded original and document exactly what was changed. A frame count and timing check confirm that no frames were lost, duplicated or added. More on video authentication.
Can you recover video from a corrupted file?
Often, yes. Even when a file will not open, most of its video data usually survives. We locate the intact frames, rebuild the stream around damaged sections, and report exactly which frames were recovered and which were lost.
Partial recovery is common after a power cut, a drive fault or an interrupted export. Recovered footage is marked clearly, and any concealed or missing frames are listed in the report, so nobody mistakes a gap for continuous recording. More on CCTV footage analysis.
Instructing us
What to send us, and what you receive
The more of the original export you can send, the more we can recover. Please contact us before sending files so we can arrange a secure transfer.
What to send us
- The file exactly as exported or received, without converting it
- Every file and folder that came with the export, including any player software
- The make and model of the recorder or camera, if known
- How the file was exported and by whom
- Any error messages you see when trying to play it
- Which cameras, dates and times you need
- The specific questions you need answered
Do not try to repair, convert or re-save the file first. Every attempt risks losing data that a forensic decode could recover.
What you receive
An independent expert report, prepared in line with the Expert Witness Code of Conduct, that sets out:
- InstructionsThe questions we were asked to address
- Materials examinedEvery file, with its hash value
- Format identificationThe container, codec and structure found
- Decoding methodEach stage, tool and setting used
- ResultsFiles produced, frame counts and timestamps
- LimitationsDamaged sections, lost frames and their effect
- ExhibitsDecoded files, stills and the processing log
Our process
How a decoding examination works
We tell you whether the file can be decoded before you commit. You receive a written scope and quote before any work begins.
Initial check
We look at the file and tell you whether it can be decoded, and how.
Secure evidence transfer
Encrypted transfer or original media by courier. SHA-256 hash recorded on receipt.
Format and structure analysis
The container, codec, channels and timestamps identified from the file itself.
Decode and verify
Stream extracted, frame count and timing checked, then peer reviewed.
Files, log and report
Decoded files, a processing log and a report, with testimony if required.
Most proprietary exports can be decoded within days. Corrupted or fragmented files take longer, and urgent court deadlines can be accommodated.
See the full process7–30
days to overwrite
Don’t convert the file, and don’t wait
Converting, compressing or screen-recording an export can lose frames and timestamps for good. Keep the file as exported with its player files, and secure CCTV recorders before they overwrite within 7 to 30 days.
Frequently asked questions
Video decoding FAQs
Answers to the questions we are asked most often about files that will not play.
See all FAQsKeep the original export and any files that came with it, and send everything exactly as exported. Do not convert it or try other players that might re-save it. We can usually identify the format and decode it, even without the original player.
Most proprietary exports can be decoded within days. Corrupted, fragmented or very large files take longer. We confirm a timeframe in writing before work starts, and urgent court deadlines can be accommodated.
Usually. Many CCTV formats store a date and time for each frame inside the stream, separate from the on-screen display. We extract these and map them to each frame. They still reflect the recorder’s clock, so its accuracy should be checked as part of any analysis.
We do not recommend it. General-purpose converters often drop frames, change the frame rate, re-compress the image and discard timestamps. Send us the original export, and we will produce documented copies that play on standard software.
Yes. Many recorders export several cameras in one file. We separate every channel into its own file, without re-encoding, so each camera can be viewed and examined on its own.
Fees depend on the format, the number of files and channels, the condition of the files and whether a report or court attendance is needed. We offer fixed-fee and hourly engagements, and you receive a written quote before any work begins.
Related services
Other video and image forensic services
Decoded footage often goes on to further examination. These services are provided by the same team.
Video Forensics
Analysis of CCTV, dashcam, body-worn and phone video.
All video forensic services →
Speed, Height and Distance
Measurements from decoded footage, using verified frame timing.
Speed, height and distance →
Digital Image Forensics
Authentication and analysis of stills extracted from video.
Digital image forensics →
Expert Witness
Independent expert reports and court testimony on decoded evidence.
Expert witness services →
Get expert advice
Find out whether your file can be decoded
Tell us what the file is, where it came from and what happens when you try to play it. We will give you a candid view of what can be recovered before you commit to any work.
Freecall
1800 865 190
Hours
Monday to Friday, 9.00 am to 5.30 pm
All enquiries are treated in strict confidence. Please contact us before sending any footage so we can advise on the most appropriate transfer method. If you do share footage with us, always use a secure method to protect the integrity of your evidence.