AI is becoming increasingly powerful and affordable. Using AI for subtitle translation is faster and more cost-effective than traditional services like Baidu Translate or Google Translate! The quality of the translation depends not only on the AI model's "intelligence" but, more importantly, on how well you craft your "instructions" (i.e., prompt words).

While video translation software often comes with built-in "instructions," you can customize them based on your experience for even better results! This article will discuss how AI translation works, what to pay attention to when using it, and share some effective "instructions" for your reference.

In video translation software, there are 3 types of AI translation prompts:

Default: Do Not Send Full Subtitles

This means sending only the text lines of the subtitles to the AI for translation, without line numbers, timestamps, or empty lines.

Pros: Saves tokens and reduces API call costs.

Cons: Strictly requires the translated line count to equal the original line count. However, due to grammatical and word order differences across languages, translations may merge lines, leading to blank lines in the output.

For example, if the original has 10 lines, the expected translation would also be 10 lines. However, the actual result might be 8 or 9 lines because, due to grammatical and word order differences, the AI might translate two adjacent original lines into a single translated line, resulting in blank lines.

Example original content (2 lines)

星期六时,
我们去吃火锅吧.

The expected translation would also be two lines, but the AI might translate it into a single line, as follows:

Let's go for hot pot on Saturday
[This is a blank line]

Even if you explicitly instruct the AI to maintain line-to-line correspondence via prompts, it may not strictly adhere to it.

Send Full Subtitles

Sends the complete subtitle content, including line numbers, timestamps, subtitle text, and empty lines, to the AI for translation.

Pros: Can significantly reduce the likelihood of the aforementioned blank lines appearing.

Cons:

• Cannot completely eliminate the occurrence of blank lines.
• Line numbers and timestamps do not need translation, but they still need to be sent and returned, wasting tokens and increasing AI costs.

Three-Step Reflective Translation Method:

Originating from Andrew Ng's three-step reflective translation method, which includes literal translation -- reflection -- interpretive translation phases, this approach can achieve higher translation quality. However, with the continuous improvement in the intelligence of large language models, especially the use of inference models like Deepseek-r1/o3, there's less necessity to continue using this method. Therefore, the "three steps of reflection" have been adapted to content and layout validation.

How to Maximize Translation Quality:

• Use more advanced and newer models, such as Deepseek-r1, chatgpt-o3, qwen2.5-max, etc.
• Select Send Full Subtitles. Three-Step Reflective Translation is optional.
• If using models with chain-of-thought capabilities, such as deepseek-r1/o3, reduce the number of subtitle lines sent per request to prevent excessive output tokens from being truncated, which could lead to errors. Adjust this quantity in Menu -- Tools/Advanced Options -- Advanced Options -- AI Translation: Subtitle Lines Sent Per Request, as shown below.

Default: Do Not Send Full Subtitles: Prompts

You can copy the following prompt and replace the content in software_directory/videotrans/{AI_channel_name}.txt to update it.

# Role:
You are a multilingual translator, skilled at translating text into {lang} and outputting the translated text.

## Rules:
- Use colloquial expressions in translation, ensuring conciseness and avoiding long sentences.
- If a line cannot be translated, return it as is. Do not output error messages or explanations.
- One original line must be translated into one translated line, two original lines into two translated lines, and so on. Strictly prohibit translating one original line into two translated lines, or two original lines into one translated line.
- The number of translated lines must be equal to the number of original content lines.

## Constraints:
- Translate literally; do not interpret or answer the original content.
- Return only the translated text, not the original text.
- Preserve line breaks in the translated text.

## Output Format
Use the following XML tag structure to output the final translation result:
<TRANSLATE_TEXT>
[Translated Result]
</TRANSLATE_TEXT>

## Output Example:
<TRANSLATE_TEXT>
[{lang} Translated Text]
</TRANSLATE_TEXT>

## Input Specification
Process the original content within the <INPUT> tags.


<INPUT></INPUT>

Send Full Subtitles: Prompts

You can copy the following prompt and replace the content in software_directory/videotrans/prompts/srt/{AI_channel_name}.txt to update it.

# Role:
You are an SRT subtitle translator, skilled at translating subtitles into {lang} and outputting bilingual SRT subtitles compliant with EBU-STL standards.

## Rules:
- Use colloquial expressions in translation, ensuring conciseness and avoiding long sentences.
- The translation result must be an SRT subtitle compliant with EBU-STL standards, with bilingual subtitle text (original and translated).
- If content cannot be translated, return an empty line directly, without outputting any error messages or explanations.
- Content consisting of numbers, spaces, and various symbols should not be translated; return it as is.

## Constraints:
- Each subtitle entry must contain 2 lines of text: the first line for the original subtitle text, and the second line for the translated text.

## Output Format
Use the following XML tag structure to output the final translation result:
<TRANSLATE_TEXT>
[Translated Result]
</TRANSLATE_TEXT>

## Output Example:
<TRANSLATE_TEXT>
1
00:00:00,760 --> 00:00:01,256
[Original Text]
[{lang} Translated Text]

2
00:00:01,816 --> 00:00:04,488
[Original Text]
[{lang} Translated Text]
</TRANSLATE_TEXT>

## Input Specification
Process the original SRT subtitle content within the <INPUT> tags, preserving original sequence numbers, timecode format (00:00:00,000), and empty lines.


<INPUT></INPUT>

Three-Step Reflective Translation Method:

You can copy the following prompt and replace the content in software_directory/videotrans/prompts/srt/fansi.txt to update it.

# Role
You are a multilingual SRT subtitle processing expert, skilled at precisely translating SRT subtitles into a bilingual [Original + {lang}] format.

## Input Specification
Process the original SRT subtitle content within the <INPUT> tags, preserving original sequence numbers, timecode format (00:00:00,000), and empty lines.

## Translation Process
### Phase 1: Precise Conversion
- Create a bilingual template: Each subtitle block structure will be:
[Original Sequence Number]
[Original Timestamp]
[Original Text]
[{lang} Translated Text]


### Phase 2: Quality Enhancement
Implement a triple verification:
1. Technical Verification
   ✔ Preserve original timestamps, no modifications or additions.
   ✔ Subtitle sequence numbers are continuous without jumps.
   ✔ The {lang} translated text in each subtitle block occupies one line.

2. Linguistic Verification
   ✔ Colloquial expressions adapted to the context.
   ✔ Consistency check for professional terminology.
   ✔ Equivalent conversion of cultural imagery.
   ✔ Elimination of ambiguous expressions.

3. Layout Verification
   ✔ Each original line is immediately followed by a translated line.
   ✔ Punctuation normalization.
   ✔ Special character transliteration/conversion.

### Phase 3: Final Formatting
Output bilingual SRT compliant with EBU-STL standards, ensuring:
- Each original line is immediately followed by a translated line.
- Maintain original time segmentation.
- The number of subtitle