Platform Targets

OpenReels supports three platform targets that control the output video's dimensions, frame rate, and duration constraints. The platform is specified with the --platform flag (default: youtube).

Platform configurations

All three platforms currently use the same 9:16 vertical resolution and 30fps frame rate. The key differences are in duration constraints.

How platform config is used

The platform configuration affects two parts of the pipeline:

Assembly stage

During Remotion rendering, the platform config controls:

• Width and height -- passed to renderMedia as the composition dimensions
• FPS -- used for frame rate in both composition selection and rendering
• Codec -- H.264 for all platforms (broad compatibility)

const platformConfig = getPlatformConfig(opts.platform);

await renderMedia({
  composition: {
    ...composition,
    width: platformConfig.width,
    height: platformConfig.height,
    fps: platformConfig.fps,
    durationInFrames: totalFrames,
  },
  codec: "h264",
  // ...
});

Duration calculation

The FPS value from the platform config is used throughout the score-to-props mapper for converting seconds to frames:

const durationInFrames = Math.round(durationSeconds * fps);

Duration limits

The maxDurationSeconds and recommendedDurationSeconds fields are available for validation and guidance but are not currently hard-enforced by the rendering pipeline. The actual video duration is determined by the voiceover length, which is controlled by the Creative Director's word budget (driven by the pacing tier).

For YouTube Shorts, the 60-second hard limit is the most important constraint. The pacing tiers are calibrated to keep total word counts under 140 words, which at ~150 words per minute produces videos in the 40-55 second sweet spot.

Usage

# Default (YouTube Shorts)
pnpm start "topic"

# TikTok (allows longer videos)
pnpm start "topic" --platform tiktok

# Instagram Reels
pnpm start "topic" --platform instagram

Source files