Cap Export Benchmark Results

This document tracks performance benchmarks for Cap's export system over time. Each benchmark run is timestamped, enabling comparison across different versions, configurations, and hardware.

Quick Reference

Performance Targets

Metric	Target	Notes
Export Render FPS (1080p)	>= 30 fps	For 1080p and below
Export Render FPS (4K)	>= 15 fps	For 4K resolution
Export Completion	No errors	All presets must complete
Size Estimation Accuracy	< 50% error	Initial target, tighten with data

Export Presets Tested

MP4:

720p / 30fps / Maximum, Social, Web
1080p / 30fps / Maximum, Social, Web
1080p / 60fps / Maximum
4K / 30fps / Maximum, Social

GIF:

720p / 15fps
720p / 30fps

Running Benchmarks

bash

# Quick benchmark (3 core presets)
cargo run -p cap-export --example export-benchmark-runner -- quick

# Full benchmark (all presets, writes to this file)
cargo run -p cap-export --example export-benchmark-runner -- full --benchmark-output

# MP4 only
cargo run -p cap-export --example export-benchmark-runner -- mp4-only --benchmark-output

# GIF only
cargo run -p cap-export --example export-benchmark-runner -- gif-only --benchmark-output

# Custom duration (default: 30s)
cargo run -p cap-export --example export-benchmark-runner -- full --duration 60 --benchmark-output

Benchmark History

Benchmark Run: 2026-02-16 11:02:26 UTC

Local time: 2026-02-16 11:02:26

Overall Result: ALL PASS (9/9)

Test Video: 72s at 1920x1080 30fps

Notes: Final calibration: encoder_efficiency=0.5 applied, FPS tapering, real-world data

Command: cargo run -p cap-export --example export-benchmark-runner -- mp4-only --duration 72 --recording-path /Users/richie/Library/Application Support/so.cap.desktop.dev/recordings/Odyssey G93SC (Display) 2026-02-16 10.06 AM.cap --benchmark-output

<details> <summary>System Information</summary>

OS: macos
Arch: aarch64

</details>

Export Results

Preset	Time(s)	FPS	Size(MB)	Estimated(MB)	Size Err(%)	Time Est(s)	Time Err(%)	Status
MP4 720p/30fps/Maximum	7.58	283.4	35.79	36.22	+1.2	7.41	-2.3	PASS
MP4 720p/30fps/Social	7.78	276.2	18.93	18.52	-2.2	7.41	-4.8	PASS
MP4 720p/30fps/Web	7.03	305.6	12.13	10.26	-15.4	7.41	+5.4	PASS
MP4 1080p/30fps/Maximum	7.66	280.3	80.27	80.46	+0.2	7.41	-3.4	PASS
MP4 1080p/30fps/Social	8.62	249.2	41.19	40.64	-1.3	7.41	-14.1	PASS
MP4 1080p/30fps/Web	7.50	286.3	23.37	22.06	-5.6	7.41	-1.3	PASS
MP4 1080p/60fps/Maximum	15.15	283.5	127.65	128.25	+0.5	14.81	-2.2	PASS
MP4 4K/30fps/Maximum	20.22	106.3	319.82	319.39	-0.1	12.27	-39.3	PASS
MP4 4K/30fps/Social	12.26	175.2	161.26	160.11	-0.7	12.27	+0.1	PASS

Estimation Accuracy

MP4 Size: avg error -2.6%, avg |error| 3.0%
MP4 Time: avg error -6.9%, avg |error| 8.1%

Calibration Data

Use these actual-vs-estimated ratios to tune the estimation algorithm:

Preset	Actual(MB)	Estimated(MB)	Ratio (actual/est)	Suggested BPP Multiplier
MP4 720p/30fps/Maximum	35.79	36.22	0.9882	0.2965 (current: 0.30)
MP4 720p/30fps/Social	18.93	18.52	1.0224	0.1534 (current: 0.15)
MP4 720p/30fps/Web	12.13	10.26	1.1827	0.0946 (current: 0.08)
MP4 1080p/30fps/Maximum	80.27	80.46	0.9976	0.2993 (current: 0.30)
MP4 1080p/30fps/Social	41.19	40.64	1.0134	0.1520 (current: 0.15)
MP4 1080p/30fps/Web	23.37	22.06	1.0593	0.0847 (current: 0.08)
MP4 1080p/60fps/Maximum	127.65	128.25	0.9953	0.2986 (current: 0.30)
MP4 4K/30fps/Maximum	319.82	319.39	1.0013	0.3004 (current: 0.30)
MP4 4K/30fps/Social	161.26	160.11	1.0072	0.1511 (current: 0.15)

Notes

Test videos are generated synthetically using FFmpeg testsrc for deterministic results
Source video is 1920x1080 at 30fps; exports at different resolutions test upscaling/downscaling
Size estimation uses the same algorithm as apps/desktop/src-tauri/src/export.rs
Calibration data in each run shows actual-vs-estimated ratios for tuning the estimation algorithm