# How to Review a Translated YouTube Video Against Its Original

Compare matching meaning units in the original audio and the localized audio using side-by-side caption records and audio checks. A meaning unit is defined as one complete instruction with its condition. A bilingual reviewer is a person who understands both languages well enough to check the spoken meaning. Captions locate evidence; both audio passages must be checked before assigning a translation error.

## Set up the data collection task

An actor is a hosted data collection program. A task is a saved input preset. For YouTube Transcript public build0.1.43, update the task input JSON to collect clean records for your review. Replace the whole saved three-video sample URL list in startUrls with one intended original video URL in its own run and one intended localized video URL in its own separate run, each using its own ordered preferredLanguages codes. Change outputFormats from [text,llm] to [json] and retain includeFailedInputDetails true.

JSON

```text
{
  "startUrls": [
    "https://www.youtube.com/watch?v=dQw4w9WgXcQ"
  ],
  "preferredLanguages": [],
  "outputFormats": ["json"],
  "includeFailedInputDetails": true
}
```

Set up the data collection task

When no requested language exists, preferredLanguages reports LANGUAGE_UNAVAILABLE rather than silently selecting another language. Leaving preferredLanguages empty uses the best available track. Reader-created manual transcripts have separate provenance. The Actor does not translate, dub, transcribe audio, identify speakers, create captions from audio, find matching videos, or perform automatic alignment.

The actor returns required native reader fields: videoId, videoUrl, transcriptLanguageCode, transcriptLanguageName, requestedLanguageCodes, availableLanguageCodes, languageMatch, isAutoGenerated, status, and segments. Public segment keys are startSeconds, endSeconds, durationSeconds, and text. Keep returned endSeconds and null duration.

The OUTPUT summary fields are inputsReceived, uniqueVideosPlanned, rowsWritten, successfulTranscriptRows, failedInputs, duplicateVideosSkipped, statusCounts, errorCodeCounts, and failedInputDetails. rowsWritten and successfulTranscriptRows count successful transcript rows, not stored failure-detail rows; statusCounts includes processed failed input outcomes.

The current positive English/manual-caption control verifies native caption text, timing, and language structure. It does not certify any particular localized channel, available Italian or Spanish track, bilingual accuracy, or audio quality. Each reader-created alignmentUnitId must retain both videoUrl values, independent start/end ranges, and an alignment reason; unit IDs are not Actor output.

## Complete meaning-review steps

1. Manually confirm the two known urls are the correct original and localized versions of the same content. Check video identities, language tracks, and source times. Matching titles or thumbnails are not enough.
2. Collect available caption tracks using the public contract. Save native language and manual or automatic flags separately. Check the spoken language actually heard. Do not force an original track into a target column if the target track is missing.
3. [Check caption words against each video audio](/en/articles/youtube-quote-ledger/) for the reviewed passages. If a caption is uncertain, record it as caption word uncertain and check the source first. A bad source caption does not automatically mean a translation error.
4. Define a meaning unit as one complete instruction with its condition. Match source units to localized segments using actual content, not index zipping or identical start times. Keep unmatched passages unpaired instead of guessing.
5. Apply a small bilingual checklist covering who does what, negation, required order or condition, numbers and units, technical terms, and qualifiers. A fluent target sentence can reverse a condition or change a quantity.
6. Record a narrow state for each aligned unit: meaning supported, meaning changed, caption word uncertain, alignment uncertain, or unavailable. Keep separate target-only and source-only passage lists. For changed units, state the changed instruction and the needed correction.
7. Keep voice naturalness, emotion, speaker recognition, dubbing cadence, and sound quality outside this caption-supported meaning check. Those need separate audio review criteria.
8. Deliver the aligned ledger with original wording, target wording, checked audio times, state, and correction note. Report reviewed units and unpaired units separately.

## Illustrative worked ledger (original fiction)

Every video, caption, and judgment in this fixture is original fiction. A bilingual reviewer checked the spoken passages against their captions without live audio testing.

| Unit ID | Original Range | Original Wording | Localized Range | Localized Wording | State | Correction Note |
| --- | --- | --- | --- | --- | --- | --- |
| U1 | 0-4 seconds | Do not add 12 milliliters until the green light turns on. | 3-8 seconds | Añada 21 mililitros mientras la luz esté apagada. | meaning changed | Restore negation, condition, and 12 milliliters. |
| U2 | 5-8 seconds | Keep the lid closed for two minutes. | 9-13 seconds | Mantenga la tapa cerrada durante dos minutos. | meaning supported | None needed. |

A later localized outro has no counterpart in the reviewed original range. Keep it unpaired, not a mistranslation. These two units yield one supported unit, one changed unit, and one extra unpaired localized passage.

## Next action

Review your target video by checking one complete instruction in both audio tracks and saving its two source ranges using the [Apify YouTube Transcript Scraper](https://apify.com/chronometrica/youtube-transcript-scraper) and the [YouTube Transcripts for LLM Analysis Task](https://apify.com/chronometrica/youtube-transcript-scraper/examples/youtube-transcripts-for-llm-analysis).

## Sources

- [YouTube Help: Create subtitles and captions](https://support.google.com/youtube/answer/2734796)
- [YouTube Help: Manage automatic captions](https://support.google.com/youtube/answer/6373554)
- [Reddit discussion on localized channel quality](https://www.reddit.com/r/LinusTechTips/comments/1rsupa8/the_localized_ltt_channels_ruins_ltts_reputation/oa9w6y0/)