Video Player

Play survey video alongside the map, geo-linked to the vessel/ROV track so the canvas follows the footage.

A MAREANO towed-camera transect — frame 100 of 67 409, 732.91 m down at 62.69° N. The Frame Metadata panel below the player reads straight out of the survey .log: position, depth, cruise and station, plus the observation fields a reviewer fills in. Geo-link and Show on map are the two controls that tie playback to the canvas; both are off here.

What it does

• Loads a video file and an associated navigation log, decoding frames with PyAV where available and OpenCV otherwise.
• In geo-link mode, pans the map canvas to the GPS position of the current frame (nearest-position lookup), so the map tracks the video.
• Renders the GPS track as a styled line layer on the canvas for context.
• Hosts a per-frame annotation editor (see Annotation).

How to use

1. Set the video file and metadata log in Settings → Video.
2. Open the Video Player from the toolbar; use the transport controls to play / pause / seek.
3. Toggle geo-link to make the map follow playback; the current position is marked on the track.

Inputs (Settings → Video)

Setting	What it is
videofile	Video file (MP4 / H.264 recommended).
videometadata	Cruise-survey navigation CSV — degrees + decimal minutes with N/S/E/W hemisphere codes, converted to signed decimal degrees on load.
videoannotation	Optional per-frame bounding-box annotations (frame_index, bboxes, species, confidences).

Exact column lists for both: Annotations & video.

Two decode backends

PyAV (av) is the preferred backend: unlike OpenCV's FFmpeg path it deinterlaces interlaced sources, which FFmpeg 7/8 otherwise refuses to convert. The player falls back to OpenCV when PyAV is unavailable.

The OpenCV dependency is opencv-python-headless on purpose — it avoids bundling a second copy of Qt that would clash with QGIS's own Qt libraries.