| name | subtitle-burner |
| description | Burn an SRT subtitle file into an MP4 via ffmpeg's subtitles filter (libass). Single-pass re-encode of video; audio copied as-is. Uses a verified managed Noto Sans CJK font when available. Used by meta-short-drama as the final subtitling step after merge. |
| description_zh | 通过 ffmpeg 的 subtitles 滤镜（libass）把 SRT 字幕烧录进 MP4；视频单遍重编码，音频原样复制。可用时使用经过验证的托管 Noto Sans CJK 字体。由 meta-short-drama 在合并后执行最终字幕步骤。 |
| provenance | {"origin":"opensquilla-original","license":"Apache-2.0"} |
| metadata | {"opensquilla":{"risk":"medium","capabilities":["filesystem-write","process-control"],"requires":{"bins":"[Truncated]","anyBins":"[Truncated]"}}} |
| entrypoint | {"command":"python {baseDir}/scripts/burn.py","args":["--input","{{ with.input }}","--subtitles","{{ with.subtitles }}","--output","{{ with.output }}","--font","{{ with.font | default('Noto Sans CJK SC') }}","--fonts-dir","{{ with.fonts_dir | default('') }}","--font-size","{{ with.font_size | default(42) }}","--margin-v","{{ with.margin_v | default(80) }}","--play-res","{{ with.play_res | default('auto') }}","--crf","{{ with.crf | default(20) }}","--preset","{{ with.preset | default('medium') }}","--ffmpeg-path","{{ with.ffmpeg_path | default('ffmpeg') }}","--ffprobe-path","{{ with.ffprobe_path | default('ffprobe') }}"],"parse":"text","timeout":600} |
subtitle-burner
Burns an SRT subtitle stream into an MP4. The video is re-encoded
(H.264 + faststart), the audio is copied untouched. libass renders the
text per ASS-style override flags, so Chinese / Japanese / Korean
characters render through the managed Noto Sans CJK font. The font directory
is supplied through OPENSQUILLA_MEDIA_FONTS_DIR by the managed toolchain.
An empty/whitespace-only SRT is a valid no-subtitle request: the input video is
probed, copied to the requested output, and reported as
SUBTITLES_SKIPPED: empty without invoking libass.
Inputs (with:)
| key | required | default | notes |
|---|
input | yes | — | Source MP4 path. |
subtitles | yes | — | .srt path (UTF-8). |
output | yes | — | Output MP4 path. Parent dir created if missing. |
font | no | Noto Sans CJK SC | One libass FontName; comma-separated names are not a fallback chain. |
fonts_dir | no | managed environment | Directory containing subtitle fonts, normally supplied by OpenSquilla. |
font_size | no | 42 | Font size. When play_res=auto this is in source-video pixels. |
margin_v | no | 80 | Bottom margin in source-video pixels (because play_res=auto sets PlayRes to the input W×H). |
play_res | no | auto | auto probes the input MP4 for resolution; or pass WxH like 720x1280. Setting this makes FontSize/MarginV act in source pixels rather than libass's 384×288 default. |
crf | no | 20 | x264 CRF (0-51, lower = better quality). |
