Exact frame
Forward and back by one frame or one keyframe, “go to” by number or time. The frame shown is decoded from the original and verified on its timestamp; the system player's position is indicative, and the interface says so.
Analysis
Video player
The Video player opens the recording in a working window and ties it to its exact frame: each still is decoded by FFmpeg from the original and its timestamp is compared with the one requested, and if they do not match it is not delivered. Beside it, the Telemetry window follows the video: map, altitude, attitude and values at the current instant, and a click on the map takes the video back to that point. Frames are extracted as lossless PNG, with their provenance.
Video player and Telemetry window together
What it does
What the Video player module does
Verified extraction
Chosen frames, or one every N frames or seconds, as lossless PNG named with number and position. Next to each a provenance .json file (video, timestamp, hashes), a manifest of the series and the PDF contact sheet. It never overwrites.
Copy with information band
Besides the exact PNG, which stays untouched, a copy with a band under the image: file name, MD5, SHA-1 and SHA-256 of the video recomputed at that moment, frame number and timestamp, telemetry at that instant and a compass with aircraft and gimbal heading.
Synchronised Telemetry window
It opens to the right of the player and receives the position during playback: full path, altitude profile, current values and table, with the map able to follow the aircraft. A click on the map, profile or table takes the video back to that instant. On a DJI video attitude and gimbal are shown too.
Measured playback
Speeds from 0.1× to 4×, frames per second actually displayed measured next to the nominal ones and the dropped ones. For 10-bit 4K HEVC videos the system cannot play smoothly, a playback preview verified frame by frame is used; still frames, extraction and hashes stay on the original.
Step by step
How it works
- Open the video from the Video player module, or from the Video analysis module on a gap or a track point.
- Find the frame through playback, steps or the telemetry map.
- Extract the exact PNG, the banded copy and the PDF contact sheet.
FAQ
Frequently asked questions
How do I know the extracted frame is the right one?
Each frame is decoded from the original and its timestamp compared with the one requested: if they do not match, it is not delivered. The
.json file next to the PNG records number, timestamp and hashes.Is the PNG the original video?
No: it is a decoding derivative, lossless with respect to the decoded image. The original is the video, whose recomputed hashes are shown in the band.
Does telemetry follow playback?
Yes: the Telemetry window receives the video position during playback, and a click on the map or profile takes the video back to that instant.
Related modules