firefox drama!
cmd := exec.Command("/usr/bin/ffmpeg",
"-y",
"-i", temp,
// LIMIT DURATION
"-t", "4.0",
// VIDEO SIZE (stable + no distortion)
"-vf", "scale=720:720:force_original_aspect_ratio=increase,crop=720:720",
// VIDEO ENCODING (balanced)
"-c:v", "libx264",
"-profile:v", "baseline",
"-level", "3.1",
"-crf", "23",
"-preset", "fast", // ⚡ better than medium for server load
// KEYFRAMES (CRITICAL for Firefox + scrolling)
"-g", "30",
"-keyint_min", "30",
"-sc_threshold", "0",
// PIXEL FORMAT (browser compatibility)
"-pix_fmt", "yuv420p",
// AUDIO (light + stable)
"-c:a", "aac",
"-b:a", "64k",
"-ac", "2",
// FAST START (important for streaming feel)
"-movflags", "+faststart",
fPath,
)