Multi-speaker dubbing works best when speaker turns are clear and voices do not overlap. TransCast uses speaker-labeled transcript segments, extracts reference speech, and synthesizes each line from the corresponding reference before aligning the audio. Review speaker boundaries, names, interruptions, and fast exchanges carefully. There is currently no manual speaker-assignment editor.
Why interviews are harder than monologues
An interview adds several failure points to ordinary translation: the system must find speaker changes, preserve the meaning of short replies, keep names consistent, and place translated speech inside turns that may already be tight.
Overlapping speech is the hardest case. If two people talk at once, transcription, speaker attribution, and clean voice-reference extraction all have less distinct material to work with.
Prepare audio with distinct turns
Use the cleanest available mix. Reduce background music where possible, avoid cutting off the start of a response, and choose a recording in which each participant has several uninterrupted sentences.
TransCast accepts local MP4, MOV, WebM, and MKV files up to 500 MB and one hour. It does not import a meeting or video URL.
How speaker-aware references work
The transcript contains timed segments and speaker labels. TransCast selects reference audio for detected speakers, translates each segment, generates voice-matched synthetic speech, and aligns the result to the original time window.
Voice matching is not the original recording speaking another language. Use it only with the necessary rights and participant consent. The voice-matched video translation guide explains the distinction.
Prepare names, titles, and recurring terms
Add participant names, organizations, products, job titles, and industry terms to the glossary before processing. Define exactly what viewers should read and how the generated voice should pronounce it. Follow the technical glossary workflow for acronyms and unusual names.
Review every handoff
Watch the full video and pause at every speaker change. Check that the voice changes with the person, short acknowledgements were not assigned incorrectly, interruptions keep their meaning, and translated lines do not run into the next turn.
Audio dubbing leaves the original picture intact. If mouth alignment is a project requirement, compare audio dubbing with lip-sync dubbing; TransCast does not currently alter facial motion.
Multi-speaker QA checklist
- Every participant has authorized use of their source and voice.
- Speaker turns are distinct in the source recording.
- Names, titles, and technical terms use the approved glossary.
- Every interruption, overlap, and rapid exchange has been reviewed.
- The translated line and source line in the SRT match the correct turn.
- A fluent reviewer has watched the complete export.