Export Settings

Export Overview

VideoBuff can export video up to 4K resolution with H.264 or H.265 codecs. Bitrate and frame rate are also selectable to match your needs, from high-quality productions to lightweight files for social media.

All export processing is performed by the WebCodecs API within the browser, with no server upload involved. Progress is displayed in real time during export, and you can cancel at any time if needed.

Completed files are saved through the browser's download function.

Resolution Selection

Resolution presets are available for each aspect ratio. For 16:9 (landscape), choose from 4K (3840x2160), 1080p (1920x1080), 720p (1280x720), and 480p (854x480). For 9:16 (portrait/short video), options range from 4K (2160x3840) to 480p (480x854).

Square (1:1, ideal for Instagram) and 4:3 (traditional ratio) also have four resolution presets each. Select the optimal aspect ratio and resolution for your intended use.

Since 4K export takes longer to process, using a lower resolution for test exports is recommended.

Codec Selection

H.264 is the most widely supported video codec, playable on virtually all devices and platforms. It offers a good balance of file size and quality, and is recommended when uploading to social media or targeting a broad range of viewing environments.

H.265 (HEVC) is the successor to H.264, achieving similar quality at a much smaller file size (roughly 30-50% reduction), but browser and device support is more limited.

VideoBuff detects codec support at runtime when the app starts, showing only available codecs as options.

Bitrate and Frame Rate

Bitrate presets come in three levels: High (best quality), Standard, and Light (smaller file). Dedicated 4K presets offer 30Mbps (high), 16Mbps (standard), and 8Mbps (light). Higher bitrate improves visual quality but increases file size.

Frame rate options include 24fps (cinematic feel), 30fps (general video), and 60fps (smooth motion). 60fps is best for sports and gaming footage, 30fps for general vlogs, and 24fps for cinematic productions.

Export Process Phases

Export proceeds through multiple phases. The Preparing phase analyzes the project structure and builds the export pipeline. The Demuxing phase separates video and audio streams from source files.

The Rendering phase composites each frame on an OffscreenCanvas, applying effects and transitions. The Encoding Audio phase encodes the audio processed by the Web Audio API.

The Muxing phase packages the video and audio streams into an MP4 container. A progress bar shows the status of each phase, and you can cancel at any point during the process.

Technical Note: Export Pipeline

Export uses the WebCodecs API's VideoEncoder and AudioEncoder. Each frame is composited on an OffscreenCanvas — combining all video, text, and image layers — before being passed to the VideoEncoder for hardware-accelerated encoding.

Audio uses Web Audio API offline rendering to produce effects-processed PCM data, which is then encoded by the AudioEncoder. The final MP4 container is assembled using the mp4-muxer library, combining video and audio streams into a downloadable file.

All encoding processing is completed client-side with absolutely no server upload.