Video Translation

Video Translation

Create a new localized video asset from an existing project video. Treat speech translation, dubbing, voice preservation, lip synchronization, captions, quality, authorization, generation, and verification as one workflow.

Lip-synced translation starts with source-transcript review in an editable ChatCut Widget. The recognized source wording is never treated as final until the user has edited or approved that form and submitted it. Audio-only translation keeps the existing direct-submit flow and skips this review.

When to Use

Use this skill when the user wants an existing video to:

• Make its speakers speak another language.
• Produce a dubbed or localized version.
• Preserve the original speakers' vocal identity across languages.
• Synchronize visible mouth movements with translated speech.
• Translate only the spoken audio while keeping the original picture.
• Generate a translated video with optional translated captions.
• Create a language-specific version for another market.

Typical triggering requests include:

• "让视频里这个人说英语。"
• "把中文口播做成英文版，口型也对上。"
• "把这段采访译制成日语，保留每个人的声音。"
• "做一个西班牙语配音版。"
• "只把声音翻译成英语，画面不要变。"
• "把这个中文数字人成片改成英文。"

Route adjacent requests elsewhere:

• Only translate, add, edit, or export captions: use caption translation.
• Translate a script before generating a new avatar video: translate the text, then use the Digital Human Skill.
• Generate speech with a chosen replacement voice: use the Voice Skill.
• Transcribe spoken content without changing it: use the Transcription Skill.
• Edit pauses, mistakes, framing, or B-roll in talking-head footage: use the Talking Head Guide.
• Generate new footage rather than localize an existing video: use Video Gen.

Treat these requests as ambiguous:

• "把这个视频翻译成英文。"
• "帮我做一个英文版。"
• "中文改成英语。"
• "做一个海外版。"
• "把这个视频国际化一下。"

For an ambiguous request, ask one treatment question with text choices. Keep the wording natural for the conversation, and include all applicable paths:

• Lip-sync translation: continue through the editable source-transcript review and submit with audioOnly: false or omit audioOnly.
• Audio-only translation: keep the existing direct-submit path and submit with audioOnly: true.
• Subtitle-only translation: use caption translation and do not submit a video translation job.

Keep user-facing terminology in one language. These are localized concept names, not fixed full option sentences; descriptions may stay natural for the context:

The target translation language does not control this copy; the user's conversation language does. Never append a second-language gloss such as (lip-sync) to a localized label.

Do not omit lip-sync when the source has a visible speaker. Do not relabel audio-only translation as generic "AI voice replacement"; choosing a new synthetic voice is a separate Voice Skill workflow. If the user already stated one treatment, skip this question and follow that route directly.

Do not submit a paid video-translation job until changing the spoken audio is explicitly requested or confirmed.

Workflow

1. Resolve the source video. It must be an imported project video asset; use the exact asset id from the attachment, selection, or browse_assets. Local or external media must be imported first.

2. Resolve the target language as an English language name (for example "English", "Spanish", "Japanese"). Confirm it when the user only implied a market ("海外版") rather than a language.

3. Pick the treatment:

   • Lip-sync: mode: "speed" — translated dubbing that preserves the speakers' vocal identity, plus synchronized mouth movements. Continue through the source-transcript review below.
   • audioOnly: true — translate the audio only and keep the picture untouched. Use for screen recordings, voice-over footage, or when the user says the picture must not change. Prefer this for transparent WebM when preserving the alpha channel matters. Skip steps 4–6 and keep the existing direct-submit flow; do not require or pass reviewedSourceTranscript.

4. Prepare the source transcript for lip-sync only. If word-level transcription is not complete, call trigger_transcript, wait for it with track_progress, and retry only when it is ready. Call read_script, then read the matching library/<filename>.md source transcript. Do not use the editable timeline.md cut as the translation source. Do not substitute inspect_asset transcript ranges for read_script; the range result may be partial and is not the canonical complete source transcript.

5. Render the editable source-text review for lip-sync only. Load the widget-forms Skill and reuse the same <form-textarea> confirmation pattern used by the Digital Human Skill. Strip the library's [sN] addresses and speaker-rendering rows, but keep exactly one recognized transcript segment per line, in source order. Put that complete text in the textarea's default; use a localized label that asks the user to check and correct the recognized original text. Do not expose segment ids, word indices, file syntax, or timestamps.

   Hard preflight before emitting the Widget:

   • The field id is exactly reviewedSourceTranscript.
   • The prefill attribute is exactly default, never default-value, defaultValue, value, or placeholder.
   • default contains the actual complete non-empty recognized transcript, not a placeholder or an omitted value. If the transcript text has not been read successfully, do not render the Widget; read the canonical library document first.
   • Preserve one recognized source segment per line. Verify that the first and last non-empty source segments are both present before sending the form.
   • In the embedded raw-tag route, apply the widget-forms XML attribute escaping rule to the complete transcript before placing it in default. Never put unescaped recognized text inside the tag.

   Embedded ChatCut example (localize visible copy):

   请检查识别出的原文，有错字可以直接修改：
   
   <widget>
     <form-textarea id="reviewedSourceTranscript" label="请确认并修正原文" rows="12" required="true" default="<recognized source text; one segment per line>"/>
   </widget>
   

   Follow widget-forms for the active host rather than emitting raw tags in a host that does not support the embedded protocol. Do not add a separate yes/no question or a handwritten submit button. Stop here and wait. Never submit a translation in the same turn that first presents the Widget.

6. Use the submitted revision exactly. The Widget submission is explicit confirmation. Read the complete reviewedSourceTranscript textarea answer from the user's next message and preserve its wording, punctuation, and order exactly. Pass through the returned line breaks when present, but do not reject or rewrite normal line-break edits made inside the textarea; the tool realigns them to the source timing. Do not paraphrase the text and do not ask the user to confirm the same text again. If the user replies outside the Widget with further corrections, reopen the same editable Widget with those corrections applied rather than reverting to a prose transcript.

7. Duration behavior. By default the output may run slightly longer or shorter than the source so the translated speech keeps a natural pace. Pass keepDuration: true only when the user needs the exact original length (for example to swap it into an existing timeline slot), and mention that pacing may sound faster.

8. Submit with submit_video_translation. For lip-sync, pass reviewedSourceTranscript as the exact complete textarea value returned in step 6; the tool combines those reviewed lines with the original segment timestamps and creates source subtitles. For audioOnly: true, omit reviewedSourceTranscript and preserve the pre-existing direct-submit path. The tool shows the user a paid confirmation before the job starts; do not resubmit after a denial.

9. Track with track_progress(action="wait") until the translated video asset lands in the library, then hand it back (place on the timeline only when asked).

Constraints and cost

• The whole source video is translated and billed by its full duration. To localize only a section, trim/export that section into its own asset first, then translate the shorter asset.
• Optional translated captions: enableCaption: true burns subtitles into the output video.
• ChatCut always requests preservation of the source resolution and bitrate. This is best-effort for lip-sync because the picture is re-rendered. A transparent WebM may become opaque, and 4K or >30 fps media may be re-encoded. The tool confirmation calls these cases out; never promise that lip-sync will preserve the container, alpha channel, HDR, codec, bitrate, or frame rate exactly.
• When the picture must not be lip-synced, choose audioOnly: true; this avoids facial re-rendering and is the safest treatment for transparent sources, but do not promise byte-for-byte container preservation. After completion ChatCut compares the source and output resolution, frame rate, and alpha pixel format when media probing is available, and reports detected changes in generation status.
• Multiple speakers are supported; pass speakerCount when the user states it.
• For lip-sync, the editable review starts with one source segment per line so the submitted text can reuse the original word-level timing. Pass the complete Widget value directly to the tool; do not merge, split, reorder, or silently normalize it in the conversation layer. Do not invoke this review for audioOnly: true.
• Indicative cost: ≈ 8 credits per minute of source video.
• Speech is dubbed with voices matched to the original speakers; it is a translation of the recorded voice, so confirm the user has rights to the footage and its speakers when the material is clearly someone else's.
• Never reveal or discuss the underlying provider; present this as ChatCut's AI video translation.