- Add new brightness-deadband property (default 10.0, range 0.0-50.0)
- Implements deadband/tolerance zone around target brightness
- When brightness is within ±deadband, no adjustments are made
- Prevents oscillation at fast update rates (10-100ms)
- Allows fast corrections when brightness significantly deviates
- Enables fast ramp rates without flicker/oscillation
- Updated README with detailed deadband documentation and usage examples
- Solves exposure fluctuation issue at high frame rates with fast updates
Implements YASS-inspired automatic exposure control for IDS uEye cameras.
The intervalometer filter analyzes video brightness in real-time and
smoothly ramps camera exposure and gain settings during changing light
conditions - ideal for sunset/sunrise time-lapse photography.
Key features:
- Automatic exposure ramping (0.85-1.24ms configurable range)
- Automatic gain control (0-52 configurable range)
- Real-time brightness analysis (GRAY8, GRAY16, RGB, BGR, BGRA)
- YASS-inspired ramping algorithm (exposure priority, then gain)
- Configurable ramp rates (VSlow/Slow/Medium/Fast/VFast)
- Exposure compensation (±4 stops)
- CSV logging of exposure parameters
- Direct GObject property control (no message bus overhead)
Technical implementation:
- GstBaseTransform filter for in-place processing
- Discovers upstream camera element by name
- Controls camera via g_object_set() for synchronous updates
- Frame-by-frame brightness calculation with format support
Files added:
- gst/intervalometer/gstintervalometer.c: Main implementation (734 lines)
- gst/intervalometer/gstintervalometer.h: Header with structure definitions
- gst/intervalometer/CMakeLists.txt: Build configuration
- gst/intervalometer/README.md: Comprehensive documentation
Files modified:
- gst/CMakeLists.txt: Added intervalometer subdirectory
- build.ps1: Added intervalometer to build and deployment pipeline
Usage example:
gst-launch-1.0 idsueyesrc name=cam ! \\
intervalometer enabled=true camera-element=cam \\
exposure-min=0.85 exposure-max=1.24 \\
gain-min=0 gain-max=52 ramp-rate=medium ! \\
autovideosink
Inspired by YASS (Yet Another Sunset Script) for CHDK cameras by
waterwingz, based on work by Fbonomi and soulf2.
