🎬 VideoStudio

A browser-based video editor — trim, convert, adjust, and create. Everything runs locally on your machine via FFmpeg.wasm.

🚀 Quick Start

1. Click 📁 Open in the header, or drag a video file into the preview area.
2. Adjust any settings in the right sidebar — trim, quality, volume, color, and so on. Everything defaults to "no change," so you only change what you need.
3. Click 💾 Export to process and download the result.

📁 Opening Files

VideoStudio supports everything FFmpeg supports, including:

• Video: MP4, MOV, WebM, MKV, AVI, FLV, WMV, MPEG, TS, 3GP, and more
• Audio: MP3, WAV, M4A/AAC, FLAC, OGG, Opus, WMA, AIFF
• Images: JPEG, PNG, WebP, BMP, GIF (for the slideshow feature)

You can either click the Open button or drag a file onto the preview area. The file info (name and size) is shown in the header.

✂️ Trim & Transport

Once a video is loaded, use the bottom-left timeline area to navigate and trim:

• ▶ / ⏸ — Play/pause
• ⏹ — Stop and jump back to the trim-in point
• Scrub slider — jump anywhere in the video
• Trim region — drag the two handles to mark the in/out points
• Set In ⇤ / Set Out ⇥ — set the trim point to the current playhead
• Reset — clear the trim

Only the trimmed portion is included in the exported file. This also means shorter trims use less memory during export — useful on mobile.

📦 Output Format

Choose the container and codec for your export:

🎞️ Video Quality

• Resolution — scale to 360p / 480p / 720p / 1080p / 1440p / 4K, or keep original. Aspect ratio is preserved.
• Quality (CRF) — Constant Rate Factor. Lower is better quality.
  • 18 = visually lossless
  • 23 = default, high quality
  • 28 = noticeable compression
  • 35 = very compressed, small file
• Frame rate — optionally force 15/24/30/60 fps.

🔊 Audio

• Volume — 0–300%. Above 100% boosts volume but can clip. Combine with Normalize to protect against clipping.
• Bitrate — 64 kbps (very small) up to 320 kbps (max quality for MP3).
• Sample rate — 22.05 / 44.1 / 48 kHz, or keep original.
• Mute audio — strip audio from the output entirely.

🎨 Color & Image

Visual adjustments applied during encoding (non-destructive — your source file is never modified):

• Brightness (±100) — additive brightness
• Contrast (±100) — contrast multiplier
• Saturation (0–300%) — 0% is greyscale, 100% is original, 200%+ is vivid
• Gamma (0.10–3.00) — non-linear brightness; 1.00 is original
• Hue shift (±180°) — rotate hues around the color wheel
• Sharpen (±150) — positive sharpens, negative blurs
• Denoise — temporal noise reduction (hqdn3d)
• Transform — flip horizontal/vertical, rotate 90° CW/CCW/180°
• Reset color — return all color controls to defaults

🎛️ Audio FX

• Fade in / Fade out — 0–10 seconds each. Fade out automatically starts near the end of the trimmed region.
• Normalize
  • Dynamic (fast) — real-time level normalization, good for podcasts and voiceovers
  • Broadcast −16 LUFS — EBU R128 broadcast loudness
  • Streaming −14 LUFS — YouTube, Spotify, Apple Music loudness target
• Bass / Treble — ±20 dB shelving filters
• 3-band EQ
  • Low — 200 Hz (warmth, body)
  • Mid — 1 kHz (vocals, presence)
  • High — 8 kHz (air, sparkle)
• Noise reduction — FFT-based denoise (afftdn), great for reducing hiss and steady background noise
• Reset audio FX — return all FX controls to defaults

🎵 Extract Audio

One-click export of the video's audio as a separate file. Choose MP3, WAV, M4A/AAC, FLAC, or OGG Vorbis. The extraction respects:

• The current trim region
• Volume, bitrate, and sample rate from the Audio panel
• All Audio FX (fade, normalize, EQ, etc.)

The output file is named <original>_audio.<ext> and downloaded automatically.

🎚️ Additional Audio Tracks

Mix one or more audio files over (or in place of) your video's audio — great for adding background music, voiceovers, or sound effects.

1. Click ＋ Add audio file and pick one or more audio files.
2. For each track, set:
   • Volume (0–300%)
   • Delay in seconds (when the track starts, relative to the video)
3. Choose a Mix mode:
   • Mix with video audio — all tracks blend with the original audio
   • Replace video audio — original audio is dropped; only your new tracks play
4. Export as usual.

🖼️ Create Video from Images

Build an MP4 from 1–10 still images plus optional audio. No video file needs to be loaded.

1. Click ＋ Add images and pick up to 10 images (JPG, PNG, WebP, etc.).
2. Set the default duration each image will be shown (in seconds). You can override this per image by typing in the "Dur" field next to a thumbnail.
3. Choose an Audio source:
   • None — silent video
   • Upload audio file — click "Choose audio file" and pick an audio file
   Tip: To use your video's audio, first use the Extract Audio feature to save it as a file, then upload that file here.
4. Pick a Resolution (Full HD, HD, 4K, Vertical, Square, SD) and FPS.
5. Check Match audio if you want the video to end when the audio ends.
6. Click 🎬 Create Video to build and download the MP4.

Images are automatically scaled and letterboxed (with black bars) to fit the target resolution, preserving aspect ratio.

📱 Mobile / Android

VideoStudio works on mobile browsers but there are practical limits:

• Memory — mobile browser tabs cap out around 1–2 GB. Large files can crash the tab.
• Speed — processing on a phone CPU is slower. A 5-minute 1080p export can take 10–20 minutes.
• First load — the 30 MB FFmpeg engine download is painful on cellular; use Wi-Fi.

Recommendations for mobile:

• Keep source files under ~150 MB
• Export at 720p or lower
• Trim first — shorter clips need less memory
• Prefer MP4 output (fastest codec path)
• Avoid 4K output and very long GIFs

🛠️ Troubleshooting

"Error: out of memory" or tab crashes

• Use a shorter trim region
• Lower the output resolution
• Close other browser tabs to free memory
• On mobile: try a desktop browser instead

Export is very slow

• H.264 encoding in WebAssembly is single-threaded and slower than native FFmpeg. A rough guide: 1× to 3× real-time on desktop, slower on mobile.
• Higher CRF (e.g., 28) is faster than lower CRF (e.g., 18).
• Lower resolution = faster encoding.
• WebM (VP9) encoding is slower than MP4 (H.264). Use MP4 for fastest results.

FFmpeg failed to load

• Check your internet connection — the FFmpeg engine needs to download on first use.
• Try refreshing the page.
• Make sure your browser supports WebAssembly (all modern browsers do).

Audio is out of sync

• Check for per-track delay values you may have set in Additional Audio.
• Try exporting with "Match audio" enabled for slideshows.

The log panel shows a cryptic error

The log at the bottom of the screen shows raw FFmpeg output. Scroll through it for clues — error lines are marked in red. Common issues:

• "Invalid argument" — usually a conflict between filters; try Reset color / Reset audio FX
• "No such file" — file wasn't loaded properly; reload it
• "Out of memory" — see memory tips above

⌨️ Keyboard Shortcuts

💡 Tips & Tricks

• Everything composes. You can trim, color-correct, add extra audio, and export as a different format all in one pass.
• Defaults are neutral. Every control defaults to "no change," so you only pay the cost of filters you actually tweak.
• Use the log. If something looks wrong, the log panel shows exactly what FFmpeg command was run — useful for debugging.
• Normalize before adding effects. When adding extra audio tracks, consider using Normalize on the main audio first to keep levels consistent.
• Slideshow + Extract Audio combo. To use your video's audio with a slideshow: extract the audio first, then upload it in the slideshow panel.
• Your browser caches FFmpeg. After the first export, the engine is reused — it only re-downloads if you clear your browser cache.

ℹ️ About

VideoStudio is built on FFmpeg.wasm, a WebAssembly port of FFmpeg. All video and audio processing runs entirely in your browser with no server involvement.

Part of the jeffapierson.com journal tools collection.