name: chm-translate description: "Translate CHM (Compiled HTML Help) documentation files into another language. Covers the complete workflow: decompile CHM with 7-Zip, translate HTML/HHC/HHK content using DeepSeek API with concurrent chunking, rebuild HHC/HHK with GBK encoding for correct Chinese TOC display, generate a correct HHP project file with all images included, recompile with hhc.exe, and binary-patch #WINDOWS to restore navigation panels and toolbar buttons. This skill should be used when the user wants to translate a .chm help file, localize CHM documentation, or convert CHM content to another language. Triggers: translate chm, 翻译chm, localize chm, CHM翻译, 帮助文档翻译, chm to chinese." agent_created: true

CHM Translate

Overview

Translate Microsoft CHM (Compiled HTML Help) documentation files into another language (typically Chinese). This skill handles the complete pipeline: decompile → translate → fix encoding → recompile, with critical attention to the encoding incompatibilities of the legacy hhc.exe compiler.

When to Use

• User wants to translate a .chm help file to another language
• User wants to localize CHM documentation
• User says "翻译CHM", "translate chm", "chm to chinese", etc.

Prerequisites

This skill depends on two other skills — load both before starting:

1. chm-decompile-compile — provides 7-Zip extraction, hhc.exe location, and HHP format reference
2. manual-translation — provides DeepSeek API configuration and translation strategy

Critical Pitfalls (Read Before Starting)

These pitfalls were discovered through hard experience. Ignoring them will cause compilation failures or broken CHM navigation:

Pitfall 1: HHC/HHK Encoding — Use GBK, NOT HTML Entities

Previous approach (HTML entities) is WRONG. Earlier documentation recommended converting Chinese to HTML numeric entities (简) and saving as windows-1252. Testing revealed this causes garbled text in the TOC panel:

• hhc.exe stores HHC content as-is — it does NOT decode &#xxxx; entities
• The CHM viewer (hh.exe) TOC panel renderer does NOT decode HTML entities either
• Result: the TOC shows literal 简 text or garbled characters instead of Chinese

Correct approach: GBK encoding. On Chinese Windows (code page 936), hhc.exe can compile GBK-encoded HHC/HHK files without errors. The GBK bytes are stored as-is and correctly rendered by hh.exe's TOC panel.

UTF-8 still does NOT work — it causes HHC5003 errors because hhc.exe's parser interprets multi-byte UTF-8 sequences as windows-1252, breaking HTML tags.

Solution: Save HHC/HHK files with GBK encoding (raw Chinese characters, not entities):

# Read translated HHC (UTF-8)
with open('translated.hhc', 'r', encoding='utf-8') as f:
    text = f.read()

# Write as GBK
with open('output.hhc', 'wb') as f:
    f.write(text.encode('gbk'))

If some characters can't be encoded in GBK (rare), use errors='replace' as fallback.

Pitfall 2: HHP File Must Be Pure ASCII

Any non-ASCII character in the HHP file (including the Title field) causes silent compilation failure.

Solution: Use English-only text in the HHP file. For the Title, use ASCII text like POV-Ray 3.7 Documentation (Chinese).

Pitfall 3: HHP [WINDOWS] Line Comma Count Must Be Exact

The [WINDOWS] line is a comma-separated field list. Between the default topic (field 5) and the toolbar flags (field 10), there must be exactly 6 commas (5 empty fields: home, jump1url, jump1text, jump2url, jump2text). If there are only 5 commas, the toolbar flags value is parsed as jump2text instead, leaving the actual toolbar flags empty — this causes the CHM to open with NO navigation panel and NO toolbar buttons.

Correct format (count the commas carefully):

main="Title","toc.hhc","index.hhk","default.html",,,,,,0x77F3E,220,0x10384e,[0,0,1024,768],0,0

Fields: caption, toc, index, default, home, jump1url, jump1text, jump2url, jump2text, toolbar_flags, nav_width, win_props, win_rect, show_state, valid_info

Pitfall 4: Toolbar Flags Must Include All Desired Panels/Buttons

Use 0x77F3E to enable all standard navigation panels and toolbar buttons:

Pitfall 5: API May Return Markdown Code Block Wrappers

DeepSeek API sometimes wraps translated HTML content in markdown code blocks (html ...). These must be stripped from all translated files before compilation.

Pitfall 6: Large Files Need Chunking with Fallback Strategy

Files over ~20KB should be split by heading tags (<h2>-<h4>). Files without headings (e.g., table-of-contents pages) should be split by ` — stylesheets and scripts -images/` — image resources

Step 2: Analyze File Structure

Count files and estimate total text size:

cd extracted_dir
echo "HTML files:" && find . -name "*.html" -o -name "*.htm" | wc -l
echo "HHC/HHK:" && find . -name "*.hhc" -o -name "*.hhk"
echo "Images:" && find . \( -name "*.png" -o -name "*.gif" -o -name "*.jpg" \) | wc -l
echo "Total text:" && find . -name "*.html" -exec cat {} \; | wc -c

If total text exceeds ~50KB, use the API translation script. If smaller, consider manual translation.

Step 3: Translate Content

Use scripts/translate_chm.py for the main translation. This script: - Reads all HTML/HHC/HHK files with automatic encoding detection - Splits large files by heading tags into chunks (~20KB each) - Translates all chunks concurrently using DeepSeek API - Reassembles translated chunks into complete files - Fixes charset and lang attributes - Writes output as UTF-8

Configuration (edit the script before running):

DEEPSEEK_API_KEY = "sk-..."           # API key
MODEL = "deepseek-v4-flash"           # Model name
INPUT_DIR = Path(r"path/to/extracted")  # Extracted CHM directory
OUTPUT_DIR = Path(r"path/to/translated") # Output directory
CHUNK_THRESHOLD = 30000               # Files larger than this get chunked
TARGET_CHUNK_SIZE = 20000             # Target chunk size in characters
CONCURRENCY = 15                      # Concurrent API calls

Translation system prompt (designed for technical documentation):

You are a professional translator. Translate the following text from English to Chinese (Simplified).

Translation rules:
1. Preserve ALL formatting: HTML tags, attributes, structure, lists, tables, etc.
2. Do NOT translate code, variable names, function names, CLI commands, or file paths.
3. Do NOT translate the content of HTML attributes like href, src, name, class, id.
4. Only translate visible text content between HTML tags.
5. Maintain the original document structure and line breaks.
6. Use industry-standard terminology for technical terms.
7. If unsure about a term, keep the original and add translation in parentheses.
8. Keep section numbers (like 3.4.1.1) as-is.
9. Output ONLY the translated text — no explanations, no notes, no preamble.

Running the script:

PYTHONUNBUFFERED=1 python -u translate_chm.py

oreets and scripts - images/ — image resources

Step 2: Analyze File Structure

Count files and estimate total text size:

cd extracted_dir
echo "HTML files:" && find . -name "*.html" -o -name "*.htm" | wc -l
echo "HHC/HHK:" && find . -name "*.hhc" -o -name "*.hhk"
echo "Images:" && find . \( -name "*.png" -o -name "*.gif" -o -name "*.jpg" \) | wc -l
echo "Total text:" && find . -name "*.html" -exec cat {} \; | wc -c

If total text exceeds ~50KB, use the API translation script. If smaller, consider manual translation.

Step 3: Translate Content

Use scripts/translate_chm.py for the main translation. This script: - Reads all HTML/HHC/HHK files with automatic encoding detection - Splits large files by heading tags into chunks (~20KB each) - Translates all chunks concurrently using DeepSeek API - Reassembles translated chunks into complete files - Fixes charset and lang attributes - Writes output as UTF-8

Configuration (edit the script before running):

DEEPSEEK_API_KEY = "sk-..."           # API key
MODEL = "deepseek-v4-flash"           # Model name
INPUT_DIR = Path(r"path/to/extracted")  # Extracted CHM directory
OUTPUT_DIR = Path(r"path/to/translated") # Output directory
CHUNK_THRESHOLD = 30000               # Files larger than this get chunked
TARGET_CHUNK_SIZE = 20000             # Target chunk size in characters
CONCURRENCY = 15                      # Concurrent API calls

Translation system prompt (designed for technical documentation):

You are a professional translator. Translate the following text from English to Chinese (Simplified).

Translation rules:
1. Preserve ALL formatting: HTML tags, attributes, structure, lists, tables, etc.
2. Do NOT translate code, variable names, function names, CLI commands, or file paths.
3. Do NOT translate the content of HTML attributes like href, src, name, class, id.
4. Only translate visible text content between HTML tags.
5. Maintain the original document structure and line breaks.
6. Use industry-standard terminology for technical terms.
7. If unsure about a term, keep the original and add translation in parentheses.
8. Keep section numbers (like 3.4.1.1) as-is.
9. Output ONLY the translated text — no explanations, no notes, no preamble.

Running the script:

PYTHONUNBUFFERED=1 python -u translate_chm.py

` tags. If a chunk returns empty from the API, retry with a smaller chunk size (5KB).

Pitfall 7: Empty API Responses for Certain Content Types

The API may return empty content for files that are primarily link tables with little translatable text. Always check if the translated output is empty and retry with smaller chunks. If still empty after retry, use the original content as fallback.

Pitfall 8: hhc.exe Produces Wrong #WINDOWS Binary Data (Navigation Panel + Toolbar Missing)

This is the most critical pitfall. Even with a perfectly correct HHP file, hhc.exe always writes fsWinProperties=0x6E into the compiled #WINDOWS binary, completely ignoring the windowstyles value in the HHP [WINDOWS] line.

The value 0x6E contains two fatal flag bits: - 0x20 (NO_TOOLBAR) — hides the entire toolbar (隐藏/查找/上一步/下一步/前进/停止/刷新/主页/字体/打印/选项 buttons) - 0x08 (NODEF_STYLES) — prevents default window styles, hiding the navigation panel (目录/索引/搜索/收藏夹 tabs)

The correct value (from the original CHM) is 0x516, which does NOT contain these bits.

Minimal patch (fsWinProperties only) is NOT sufficient. Testing showed that patching only fsWinProperties from 0x6E to 0x516 restores the left navigation panels (目录/索引/搜索/收藏夹) but does NOT restore the toolbar buttons. The full fix requires copying ALL non-string-offset fields from the original CHM's #WINDOWS into the compiled CHM's #WINDOWS.

Solution: Binary-patch the compiled CHM's #WINDOWS after compilation. See Step 9 and references/windows_binary_patch.md for the complete procedure.

Pitfall 9: Image Files Must Be Listed in HHP [FILES] Section

hhc.exe only includes files explicitly listed in the HHP [FILES] section. If images are not listed, hhc.exe may auto-include some images referenced by <img> tags, but it flattens their paths (e.g., images/3/34/DocImgPovlogotext.jpg becomes DocImgPovlogotext.jpg), causing path mismatches with HTML references.

Solution: The gen_hhp.py script must collect ALL files (HTML + images + CSS + JS) with their full relative paths and include them in the [FILES] section. See the updated scripts/gen_hhp.py.

Workflow

Step 1: Decompile the CHM

Use 7-Zip to extract the CHM file:

"/c/Program Files/7-Zip/7z.exe" x "input.chm" -o"extracted_dir" -y

Verify the extracted contents: - *.html — content pages - *.hhc — table of contents - *.hhk — index file - *.css, *.js — stylesheets and scripts - images/ — image resources

Step 2: Analyze File Structure

Count files and estimate total text size:

cd extracted_dir
echo "HTML files:" && find . -name "*.html" -o -name "*.htm" | wc -l
echo "HHC/HHK:" && find . -name "*.hhc" -o -name "*.hhk"
echo "Images:" && find . \( -name "*.png" -o -name "*.gif" -o -name "*.jpg" \) | wc -l
echo "Total text:" && find . -name "*.html" -exec cat {} \; | wc -c

If total text exceeds ~50KB, use the API translation script. If smaller, consider manual translation.

Step 3: Translate Content

Use scripts/translate_chm.py for the main translation. This script: - Reads all HTML/HHC/HHK files with automatic encoding detection - Splits large files by heading tags into chunks (~20KB each) - Translates all chunks concurrently using DeepSeek API - Reassembles translated chunks into complete files - Fixes charset and lang attributes - Writes output as UTF-8

Configuration (edit the script before running):

DEEPSEEK_API_KEY = "sk-..."           # API key
MODEL = "deepseek-v4-flash"           # Model name
INPUT_DIR = Path(r"path/to/extracted")  # Extracted CHM directory
OUTPUT_DIR = Path(r"path/to/translated") # Output directory
CHUNK_THRESHOLD = 30000               # Files larger than this get chunked
TARGET_CHUNK_SIZE = 20000             # Target chunk size in characters
CONCURRENCY = 15                      # Concurrent API calls

Translation system prompt (designed for technical documentation):

小葱技能站7w4.net，专业的AI技能分享平台。

You are a professional translator. Translate the following text from English to Chinese (Simplified).

Translation rules:
1. Preserve ALL formatting: HTML tags, attributes, structure, lists, tables, etc.
2. Do NOT translate code, variable names, function names, CLI commands, or file paths.
3. Do NOT translate the content of HTML attributes like href, src, name, class, id.
4. Only translate visible text content between HTML tags.
5. Maintain the original document structure and line breaks.
6. Use industry-standard terminology for technical terms.
7. If unsure about a term, keep the original and add translation in parentheses.
8. Keep section numbers (like 3.4.1.1) as-is.
9. Output ONLY the translated text — no explanations, no notes, no preamble.

Running the script:

PYTHONUNBUFFERED=1 python -u translate_chm.py

Use PYTHONUNBUFFERED=1 and -u flag to avoid Python output buffering issues when running in background.

Step 4: Check for Empty Outputs and Retry

After translation, check for empty output files:

cd translated_dir
for f in *.html *.hhc *.hhk; do
    size=$(wc -c < "$f" 2>/dev/null)
    if [ "$size" -lt 10 ]; then
        echo "EMPTY: $f ($size bytes)"
    fi
done

For empty files, retry translation with smaller chunk size (5KB) and split by scripts/gen_hhp.py or create manually:

[OPTIONS]
Compatibility=1.1 or later
Compiled file=output_zh.chm
Contents file=toc.hhc
Index file=index.hhk
Default Topic=index.html
Display compile progress=Yes
Language=0x804
Title=Document Title (English Only)

[WINDOWS]
main="Title","toc.hhc","index.hhk","index.html",,,,,,0x77F3E,220,0x10384e,[0,0,1024,768],0,0

[FILES]
index.html
page1.html
page2.html

[INFOTYPES]

Critical requirements: - Language=0x804 for Simplified Chinese - Title must be ASCII only (no Chinese characters) - [WINDOWS] line must have exactly 6 commas between default topic and toolbar flags - Toolbar flags = 0x77F3E for full navigation panel + toolbar - [FILES] section must list ALL HTML files

Auto-generating [FILES] section (must include ALL files — HTML, images, CSS, JS — with full relative paths):

from pathlib import Path

FILE_EXTENSIONS = {'.html', '.htm', '.css', '.js',
                   '.jpg', '.jpeg', '.png', '.gif', '.bmp', '.ico',
                   '.svg', '.webp'}

output_dir = Path("translated_dir")
all_files = []
for f in sorted(output_dir.rglob("*")):
    if f.is_file() and f.suffix.lower() in FILE_EXTENSIONS:
        rel_path = f.relative_to(output_dir).as_posix()  # use forward slashes
        all_files.append(rel_path)
files_section = "\n".join(all_files)

or line boundaries instead of heading tags. Usescripts/retry_empty.py` as a template.

Step 5: Post-Translation Cleanup

Run scripts/fix_translated.py to clean up common issues:

1. Remove markdown code block wrappers — Strip html and markers that the API may have added
2. Fix charset meta tags — Change charset=windows-1252 to charset=utf-8
3. Fix lang attribute — Change lang="en" to lang="zh-CN"
4. Clean excess blank lines — Collapse 3+ consecutive newlines to 2

Step 6: Rebuild HHC/HHK with GBK Encoding

This is a critical step. Do NOT skip it.

The translation script outputs HHC/HHK as UTF-8, but hhc.exe cannot compile UTF-8 HHC files (HHC5003 error). Use scripts/rebuild_hhc_hhk.py to:

1. Read the original HHC/HHK file (preserving exact structure and formatting)
2. Build a translation mapping from the translated HHC/HHK (using Local URL values as keys)
3. Replace Name values in the original file with translated values
4. Write the result as GBK encoding (NOT HTML entities — see Pitfall 1)

This approach preserves the original file structure perfectly while injecting translated text.

Running the script:

python rebuild_hhc_hhk.py --input-dir extracted_dir --output-dir translated_dir

The script automatically detects HHC and HHK files by extension.

Why GBK, not entities: Testing showed that HTML entities (简) are stored as literal text by hhc.exe and displayed garbled in the CHM viewer's TOC panel. GBK-encoded Chinese characters are stored and rendered correctly on Chinese Windows systems.

Step 7: Generate HHP Project File

Create a pure ASCII HHP file. Use scripts/gen_hhp.py or create manually:

[OPTIONS]
Compatibility=1.1 or later
Compiled file=output_zh.chm
Contents file=toc.hhc
Index file=index.hhk
Default Topic=index.html
Display compile progress=Yes
Language=0x804
Title=Document Title (English Only)

[WINDOWS]
main="Title","toc.hhc","index.hhk","index.html",,,,,,0x77F3E,220,0x10384e,[0,0,1024,768],0,0

[FILES]
index.html
page1.html
page2.html

[INFOTYPES]

Critical requirements: - Language=0x804 for Simplified Chinese - Title must be ASCII only (no Chinese characters) - [WINDOWS] line must have exactly 6 commas between default topic and toolbar flags - Toolbar flags = 0x77F3E for full navigation panel + toolbar - [FILES] section must list ALL HTML files

Auto-generating [FILES] section (must include ALL files — HTML, images, CSS, JS — with full relative paths):

from pathlib import Path

FILE_EXTENSIONS = {'.html', '.htm', '.css', '.js',
                   '.jpg', '.jpeg', '.png', '.gif', '.bmp', '.ico',
                   '.svg', '.webp'}

output_dir = Path("translated_dir")
all_files = []
for f in sorted(output_dir.rglob("*")):
    if f.is_file() and f.suffix.lower() in FILE_EXTENSIONS:
        rel_path = f.relative_to(output_dir).as_posix()  # use forward slashes
        all_files.append(rel_path)
files_section = "\n".join(all_files)

Critical: If images are not listed in [FILES], hhc.exe flattens their paths (e.g., images/3/34/xxx.jpg → xxx.jpg), causing broken images. See Pitfall 9.

Step 8: Compile the CHM

cd translated_dir && "/path/to/hhc.exe" project.hhp

Verify compilation success: - Exit code 0 = success - "未编译文件" (uncompiled files) list should be empty - Check that the output .chm file exists and has reasonable size

Common compilation errors:

Step 9: Binary Patch #WINDOWS (Mandatory)

This step is mandatory. Without it, the compiled CHM will have no navigation panel and no toolbar buttons (see Pitfall 8).

The challenge: hhc.exe stores #WINDOWS inside the LZX-compressed section (section 1) of the CHM, so it cannot be directly modified in the binary file. The solution is to migrate #WINDOWS from the compressed section to the uncompressed section (section 0), then patch it there.

Use scripts/patch_windows.py to perform the patch automatically. The script:

1. Parses the CHM's ITSF/ITSP/PMGL structure to locate the /#WINDOWS entry
2. Extracts the compiled #WINDOWS data (204 bytes)
3. Copies ALL non-string-offset fields from the original CHM's #WINDOWS into the compiled #WINDOWS
4. Appends the patched #WINDOWS at the end of section 0 (uncompressed area)
5. Updates the PMGL directory entry: section 1→0, offset → new location
6. Updates the HST (Header Section Table) file size to include the appended data

Prerequisites: You need the original CHM file to extract the correct #WINDOWS field values.

python patch_windows.py \
  --compiled-chm translated.chm \
  --original-chm original.chm \
  --output patched.chm

Key fields patched (offsets within the 204-byte #WINDOWS structure):

String-offset fields NOT patched (offsets 0x1C, 0x68, 0x6C, 0x70, 0x74): These point into the compiled CHM's #STRINGS table, which differs from the original. They must keep the compiled values.

Verification:

# 7-zip should open without warnings
"/c/Program Files/7-Zip/7z.exe" l patched.chm

# Extract and verify #WINDOWS
"/c/Program Files/7-Zip/7z.exe" x -o/tmp/verify patched.chm "#WINDOWS"
python -c "import struct; d=open('/tmp/verify/#WINDOWS','rb').read(); print(f'fsWinProperties: 0x{struct.unpack_from(\"<I\",d,0x14)[0]:X}')"

See references/windows_binary_patch.md for the full technical details.

Step 10: Verify the Result

1. Open the compiled CHM file
2. Verify left panel shows: 目录 (Contents) / 索引 (Index) / 搜索 (Search) / 收藏夹 (Favorites)
3. Verify toolbar shows: 后退 / 前进 / 停止 / 刷新 / 主页 / 选项 / 打印
4. Click through several TOC entries to verify navigation works
5. Check a few pages for translation quality
6. Verify images render correctly (paths must match HTML references)

Scripts

scripts/translate_chm.py

Main translation script. Reads all HTML/HHC/HHK files, chunks large files by heading tags, translates concurrently via DeepSeek API, writes UTF-8 output. Configure API key, model, input/output directories, chunk size, and concurrency at the top of the script.

scripts/retry_empty.py

Retry translation for files that returned empty output. Uses smaller chunk size (5KB) and splits by </tr> tags or line boundaries instead of heading tags. Includes fallback to original content if API still returns empty.

scripts/fix_translated.py

Post-translation cleanup. Removes markdown code block wrappers (html /), fixes charset meta tags (windows-1252 → utf-8), fixes lang attribute (en → zh-CN), and cleans excess blank lines.

scripts/rebuild_hhc_hhk.py

Rebuilds HHC/HHK files with GBK encoding. Reads original HHC/HHK to preserve structure, extracts translated Name values from the translated version, replaces Name values in the original, and writes as GBK encoding (NOT HTML entities — entities cause garbled TOC text, see Pitfall 1). This is the critical step that makes hhc.exe able to compile Chinese HHC/HHK files.

scripts/gen_hhp.py

Generates a pure-ASCII HHP project file with correct [WINDOWS] line (6 commas, full toolbar flags) and auto-generated [FILES] section. Now includes ALL files (HTML + images + CSS + JS) with their full relative paths, not just top-level HTML files.

scripts/patch_windows.py

Binary-patches the compiled CHM's #WINDOWS to fix navigation panel and toolbar display. Migrates #WINDOWS from the LZX-compressed section (section 1) to the uncompressed section (section 0), copies all non-string-offset fields from the original CHM's #WINDOWS, and updates the PMGL directory and HST table. This is the mandatory post-compilation step (see Step 9).

References

references/encoding_pitfalls.md

Detailed explanation of all encoding-related pitfalls discovered during CHM translation, including why hhc.exe fails with UTF-8, why HTML entity encoding does NOT work (causes garbled TOC), how GBK encoding is the correct approach, and the exact HHP [WINDOWS] field layout with correct comma positions.

references/windows_binary_patch.md

Complete technical reference for the #WINDOWS binary patching procedure, including: CHM file structure (ITSF/ITSP/PMGL), #WINDOWS 204-byte layout, why hhc.exe produces wrong values, the section-migration technique, ENCINT encoding, and field-by-field patching guide.

Workflow Summary

CHM file
  ↓ 7-Zip extract
Extracted files (HTML + HHC + HHK + images)
  ↓ translate_chm.py (DeepSeek API, concurrent chunking)
Translated files (UTF-8)
  ↓ fix_translated.py (strip ```html, fix charset/lang)
Cleaned translated files
  ↓ rebuild_hhc_hhk.py (GBK encoding for Chinese TOC text)
HHC/HHK ready for compilation
  ↓ gen_hhp.py (pure ASCII, correct [WINDOWS], ALL files in [FILES])
HHP project file
  ↓ hhc.exe compile
Compiled CHM (navigation panel + toolbar MISSING)
  ↓ patch_windows.py (binary patch #WINDOWS from original CHM)
Patched CHM (navigation panel + toolbar WORKING)

这个 Skill 质量很好，文档写得很详细清楚，遇到的坑和解决方案都讲得很明白，代码逻辑清晰、容易理解。优点是功能完整、教程详尽、技术专业；不足是脚本里有硬编码的 API 密钥存在安全风险，建议开发者改进。总体推荐使用。