Subtitle embedding

This is the reason the pack exists: give it a video and a subtitle file, and it gives you back a video with the subtitles in it - either soft (tucked into the container as a toggleable track) or hard (burned into the pixels). No terminal, no hand-typed ffmpeg incantation, no leaving ComfyUI. If you're making videos with subtitles - translated dialogue, captions, karaoke lyrics - this is the node you'll actually reach for.

The two methods are meaningfully different, so pick deliberately:

• Soft muxes the subtitle file in as a separate stream. Viewers can turn it off or swap styles, and it's instant because nothing gets re-encoded. The catch: the node only supports soft embedding into MKV output. Set the format to anything else and it quietly logs an error and returns without doing the job - MKV is the default container for exactly this reason.
• Hard bakes the text into every frame using FFmpeg's subtitles= filter. It works with any output format, and since it renders via libass, ASS styling - fonts, colors, karaoke effects - is respected. You're paying with a real re-encode, which is why you usually only hard-burn when you must (uploading to a site that ignores soft tracks, or you need the text visible everywhere).

The inputs that matter

• video_path / subtitle_path - plain text fields, not file pickers. Type an absolute path, or a path relative to wherever ComfyUI runs. The node checks both files exist before doing anything.
• embed_method - soft or hard, as above.
• filename_prefix (default video/embedded) - the output lands in ComfyUI's output/ folder as <prefix>_<video_name>.<ext>.
• settings (optional) - an FFMPEG_SETTINGS object from the FFMpegSettings node. Leave it unconnected and it falls back to its own sensible defaults (MKV, stream copy).

The single output_path (STRING) it returns is where the finished file was written - wire it into a preview or file node, or just read it from the console.

Troubleshooting

• Soft embed with a non-MKV format: refused by design. Check the console log.
• "No such filter: subtitles": your FFmpeg was built without libass. The subtitles= filter isn't a default in every build - gyan's full Windows builds and typical Linux/macOS distro builds have it; minimal static builds often don't. Swap to a full build.
• The classic trap - hard burn plus a custom resolution silently loses your subtitles. If you hard-burn and the settings node has a resolution other than source, the node appends a second -vf scale=... and FFmpeg honors the last -vf, so the burn filter gets dropped and you get clean, subtitle-less video. Keep resolution at source when hard-burning.
• Windows paths: the node escapes drive colons for the filter, but keep paths simple anyway - commas and special characters inside -vf subtitles='...' will fight you.

Installing

It's part of ComfyUI-ASSSSA: install the pack from ComfyUI Manager (search "ComfyUI-ASSSSA") or manually:

cd ComfyUI/custom_nodes
git clone https://github.com/HighDoping/ComfyUI_ASSSSA

Then restart ComfyUI. No Python packages to install and no models to download - the only hard dependency is FFmpeg on your PATH, with libass if you plan to hard-burn.