Daily Video Output: 8 Videos Breakdown

Video Structure (Per Day)

Amcrest Camera (4 videos)

amcrest_day_20250827.mp4 – 8:00am to 4:00pm
amcrest_evening_20250827.mp4 – 4:00pm to 12:00am
amcrest_night_20250827.mp4 – 12:00am to 8:00am
amcrest_sunset_20250827.mp4 – 30min before sunset → 30min after sunset

Reolink Camera (4 videos)

reolink_day_20250827.mp4 – 8:00am to 4:00pm
reolink_evening_20250827.mp4 – 4:00pm to 12:00am
reolink_night_20250827.mp4 – 12:00am to 8:00am
reolink_sunset_20250827.mp4 – 30min before sunset → 30min after sunset

Total: 8 videos per day

Sunset Video Special Characteristics

Timing (Using Douglas, MI coordinates)

// Already in your script:
private $latitude = 42.5596;
private $longitude = -86.2355;

private function getGoldenHourWindow($timestamp = null) {
    $sun_info = date_sun_info($timestamp, $this->latitude, $this->longitude);
    $sunset_timestamp = $sun_info['sunset'];
    
    return [
        'start' => $sunset_timestamp - (30 * 60),  // 30min before
        'end' => $sunset_timestamp + (30 * 60),    // 30min after
        'sunset' => $sunset_timestamp
    ];
}

Cross-Period Collection

Sunset videos span period boundaries:

Example August 27, 2025:
Sunset: 7:45 PM
Golden Hour: 7:15 PM → 8:15 PM

Segments collected from:
├── 7:15-8:00 PM (end of "evening" period)  
└── 8:00-8:15 PM (start of "night" period)

Current Script Advantage

Your script already identifies golden hour segments:

Tags them with _gh suffix
Stores them in the same period directories
Calculates the exact golden hour window

Append Strategy for Sunset Videos

Challenge: Time-Based vs Period-Based

Period videos: Append every 15 minutes predictably
Sunset videos: Only append during golden hour window (~1 hour per day)

Implementation Approach

public function receiveSegment() {
    $is_golden_hour = $this->isSegmentGoldenHour($timestamp);
    
    // Always append to period video
    $this->appendToPeriodVideo($camera, $period, $segment);
    
    // Also append to sunset video if golden hour
    if ($is_golden_hour) {
        $this->appendToSunsetVideo($camera, $segment);
    }
}

private function appendToSunsetVideo($camera, $segment) {
    $today = date('Ymd');
    $sunset_video = "/final_videos/{$camera}_sunset_{$today}.mp4";
    $temp_video = "/temp_build/{$camera}_sunset_{$today}_building.mp4";
    
    if (!file_exists($sunset_video)) {
        // First golden hour segment of the day
        copy($segment, $sunset_video);
    } else {
        // Append to existing sunset video
        $this->fastAppend($sunset_video, $segment, $temp_video);
        rename($temp_video, $sunset_video);
    }
}

File Naming Convention

/final_videos/
├── amcrest_day_20250827.mp4      ← 8am-4pm, ~480 min
├── amcrest_evening_20250827.mp4  ← 4pm-12am, ~480 min  
├── amcrest_night_20250827.mp4    ← 12am-8am, ~480 min
├── amcrest_sunset_20250827.mp4   ← Sunset±30min, ~60 min
├── reolink_day_20250827.mp4      ← 8am-4pm, ~480 min
├── reolink_evening_20250827.mp4  ← 4pm-12am, ~480 min
├── reolink_night_20250827.mp4    ← 12am-8am, ~480 min
└── reolink_sunset_20250827.mp4   ← Sunset±30min, ~60 min

Sunset Video Timing Examples

Date	Sunset Time	Golden Hour Window	Expected Duration
June 21	8:15 PM	7:45 PM – 8:45 PM	~60 minutes
August 27	7:45 PM	7:15 PM – 8:15 PM	~60 minutes
December 21	5:30 PM	5:00 PM – 6:00 PM	~60 minutes

Duration = ~60 min = 4 segments (15-min intervals)

Processing Efficiency Gains

Current Script Waste

Builds 3 video types per period (regular/complete/golden_only)
Re-concatenates everything every 20 minutes
~432 rebuilds per day

Your Append Approach

4 videos per camera, append-only
Constant 2-3 second processing per segment
~96 appends per day (24 hrs × 4 segments/hr × 2 cameras)

Result: 98% reduction in processing overhead

Revised timelapse method