media-processing（媒体处理）

Media Processing

Tools and workflows for working with images, audio, and video in a repeatable, scriptable way using standard CLI tools (FFmpeg, ImageMagick) and Python helpers.

When to Use

• Working with image batches (thumbnails, resizing, format conversion)
• Converting media between formats (video ↔ audio ↔ image)
• Optimizing video size while maintaining acceptable quality
• Preparing assets for web, mobile, or archival use
• Designing or refining CLI workflows around FFmpeg/ImageMagick

Key Principles

• CLI-first workflows: Prefer command-line tools (FFmpeg, ImageMagick) and scripts that can be automated in CI or local tooling.
• Deterministic scripts: Scripts should be safe to run repeatedly with predictable output paths and options.
• Non-destructive defaults: Default to writing outputs to new files/directories rather than overwriting originals.
• Cross-platform friendly: Keep examples and scripts usable on Linux, macOS, and Windows where possible.
• Agent-agnostic: Guidance should work with any coding agent (Cursor, Claude, Copilot, etc.), not one specific environment.

Capabilities

• Image workflows

- Batch resize and thumbnail generation - Aspect-ratio–aware resizing (fit, fill, cover, exact) - Optional watermarking - Format conversion (e.g., PNG → WebP, JPEG)

• Media conversion

- Detects media type (video, audio, image) from extension - Uses FFmpeg for video/audio, ImageMagick for images - Quality presets for web, archive, and mobile use cases - Batch conversion with dry-run and verbose modes

• Video optimization

- Resolution and frame-rate adjustments - Single-pass (CRF) or two-pass encoding - Audio bitrate tuning - Basic before/after comparison (size, bitrate, resolution, FPS)

Scripts

Scripts live in scripts/ and are intended to be run directly from a shell:

• batch_resize.py

- Batch image resizing with multiple strategies (fit, fill, cover, exact, thumbnail) - Optional watermark overlay - Supports parallel processing and dry-run mode

• media_convert.py

- Unified conversion tool for video, audio, and images - Automatically picks FFmpeg or ImageMagick - Uses quality presets (web, archive, mobile) - Supports batch conversion and format changes (e.g., .mov → .mp4, .wav → .mp3)

• video_optimize.py

- Focused on video size/quality trade-offs - Resolution caps, FPS reduction, CRF tuning, optional two-pass encoding - Optional comparison summary between original and optimized outputs

See scripts/requirements.txt for environment expectations (Python 3.10+, FFmpeg, ImageMagick) and system installation hints.

Usage Guidelines

• Check dependencies first

- Ensure ffmpeg and ffprobe are installed and on PATH for video/audio tasks. - Ensure magick (ImageMagick) is installed and on PATH for image tasks.

• Prefer dry-runs when exploring

- Use --dry-run and/or --verbose flags on scripts to inspect generated commands before running them.

• Keep originals

- Point outputs to a separate directory on first runs (e.g., --output./out/) to avoid accidental overwrites.

• Document workflows

- When you find good command lines or script invocations, promote them into project scripts (e.g., just, npm scripts, or CI jobs) so they’re repeatable.

References

For deeper tool-specific notes (placeholders for now, extend as needed), see:

• references/ffmpeg-encoding.md – FFmpeg encoding patterns and flags
• references/ffmpeg-filters.md – Common filter graphs (scale, crop, audio filters)
• references/ffmpeg-streaming.md – Streaming-friendly settings and HLS/DASH tips
• references/format-compatibility.md – Container/codec compatibility notes (web, mobile, desktop)
• references/imagemagick-batch.md – Batch image processing patterns with ImageMagick
• references/imagemagick-editing.md – Image editing operations (crop, resize, composite, text, etc.)