Generate Thai subtitles for your Vietnamese videos

From Latin with tone diacritics to the Thai script

Vietnamese is written in Latin with tone diacritics and Thai in the Thai script, so the exported file uses a different writing system from the audio that produced it. The subtitle formats handle that — SRT and VTT are plain text and carry any script — but the font in whatever plays the file has to cover it.

This is the most common reason a Thai subtitle track looks correct in an editor and shows boxes or blanks on a device. Test on the target platform before you publish a batch.

How Vietnamese audio becomes Thai subtitles

Audio in Vietnamese (Tiếng Việt) is transcribed first, then translated into Thai (ไทย). Because the translation runs on the transcript rather than on the audio, the Thai subtitle file keeps the timings of the original Vietnamese speech — each line appears at the moment it was actually said.

Register in Thai subtitles

Thai marks politeness grammatically, so a translator has to choose a level of formality that the Vietnamese original may not have stated. The same sentence can be rendered casually or deferentially and both are accurate translations of the words.

Check the register before publishing anything with a clear audience — an interview, a lecture, a customer-facing video. It reads as a mistake to a native speaker far more readily than an awkward word choice does.

Tone in the Vietnamese audio

Vietnamese uses tone to distinguish words that are otherwise identical, so recognition depends on pitch as well as on the sounds themselves. Background music is unusually costly here — it competes with exactly the cue the recogniser needs.

Where tone was misheard, the Thai translation follows the wrong word rather than producing obvious nonsense, so errors read as plausible. A pass over the transcript before translating is worth more on Vietnamese than on most languages.

Why translate Vietnamese video into Thai

Vietnamese is spoken principally in Vietnam; Thai in Thailand. A Thai subtitle track is what lets one recording reach both audiences without re-recording, re-editing or dubbing it.

Because subtitles are a separate file rather than part of the picture, you can attach several language tracks to the same video and let viewers pick.

About the Vietnamese audio

Vietnamese uses the Latin alphabet with a dense set of tone and vowel diacritics, and those marks are not decorative — dropping them changes the word. The transcript keeps them, so check that whatever you load the subtitle file into handles the full character set.

About the Thai subtitles

Thai is written without spaces between words and is tonal, so segmentation happens during recognition rather than afterwards. The script has no capital letters and no full stops, which makes sentence boundaries in the transcript a judgement call worth reviewing.

What a Vietnamese to Thai subtitle file looks like

Four lines of Vietnamese speech, transcribed and translated, as they come out of the exported SRT. The timings are the Vietnamese speaker's — translation does not move them, which is why the file drops onto the original video unchanged.

1
00:00:01,000 --> 00:00:03,240
เรามาเริ่มกันที่คำถามแรก

2
00:00:03,600 --> 00:00:06,120
ทุกคนได้ยินผมชัดไหม

3
00:00:06,480 --> 00:00:09,300
ผมจะแบ่งปันรายละเอียดในอีกสักครู่

4
00:00:09,700 --> 00:00:12,040
วันนี้ก็มีเพียงเท่านี้

What to check before publishing

• Names and places, which translation handles less reliably than ordinary prose.
• Idiom — a phrase that is natural in Vietnamese may need loosening to read well in Thai.
• That the Thai script renders in your player, not just in the editor you exported from.
• The level of formality, which Thai states grammatically whether or not the Vietnamese original did.
• Timing on fast exchanges, where two speakers overlap.