语言支持：字体和文本转语音
我的博客现在支持九种语言：日语（ja）、西班牙语（es）、印地语（hi）、中文（zh）、英语（en）、法语（fr）、德语（de）、阿拉伯语（ar）和繁体中文（hant）。你可以在https://lzwjava.github.io找到本站。
在计算机环境中处理多种语言时，需要考虑以下几个方面。
字体处理
不同的语言需要特定的字体才能正确渲染，尤其是在使用LaTeX生成PDF时。以下Python代码展示了如何根据操作系统和语言选择合适的字体：
if platform.system() == "Darwin":
if lang == "hi":
CJK_FONT = "Kohinoor Devanagari"
elif lang == "ar":
CJK_FONT = "Geeza Pro"
elif lang in ["en", "fr", "de", "es"]:
CJK_FONT = "Helvetica"
elif lang == "zh":
CJK_FONT = "PingFang SC"
elif lang == "hant":
CJK_FONT = "PingFang TC"
elif lang == "ja":
CJK_FONT = "Hiragino Sans"
else:
CJK_FONT = "Arial Unicode MS"
else:
if lang == "hi":
CJK_FONT = "Noto Sans Devanagari"
elif lang == "ar":
CJK_FONT = "Noto Naskh Arabic"
elif lang in ["en", "fr", "de", "es"]:
CJK_FONT = "DejaVu Sans"
elif lang == "zh":
CJK_FONT = "Noto Sans CJK SC"
elif lang == "hant":
CJK_FONT = "Noto Sans CJK TC"
elif lang == "ja":
CJK_FONT = "Noto Sans CJK JP"
else:
CJK_FONT = "Noto Sans"
command = [
'pandoc',
input_markdown_path,
'-o', output_pdf_path,
'-f', 'markdown',
'--pdf-engine', 'xelatex',
'-V', f'romanfont={CJK_FONT}',
'-V', f'mainfont={CJK_FONT}',
'-V', f'CJKmainfont={CJK_FONT}',
'-V', f'CJKsansfont={CJK_FONT}',
'-V', f'CJKmonofont={CJK_FONT}',
'-V', f'geometry:{GEOMETRY}',
'-V', 'classoption=16pt',
'-V', 'CJKoptions=Scale=1.1',
'-V', 'linestretch=1.5'
]
需要注意的是，这个解决方案并不是完美的。例如，代码块注释中的印地语文本可能无法正常渲染。
文本转语音
我使用Google文本转语音为博客文章生成音频版本。以下代码片段展示了如何为文本转语音引擎选择合适的语言代码：
synthesis_input = texttospeech.SynthesisInput(text=chunk)
if language_code == "en-US":
voice_name = random.choice(["en-US-Journey-D", "en-US-Journey-F", "en-US-Journey-O"])
elif language_code == "cmn-CN":
voice_name = random.choice(["cmn-CN-Wavenet-A", "cmn-CN-Wavenet-B", "cmn-CN-Wavenet-C", "cmn-CN-Wavenet-D"])
elif language_code == "es-ES":
voice_name = random.choice(["es-ES-Journey-D", "es-ES-Journey-F", "es-ES-Journey-O"])
elif language_code == "fr-FR":
voice_name = random.choice(["fr-FR-Journey-D", "fr-FR-Journey-F", "fr-FR-Journey-O"])
elif language_code == "yue-HK":
voice_name = random.choice(["yue-HK-Standard-A", "yue-HK-Standard-B", "yue-HK-Standard-C", "yue-HK-Standard-D"])
elif language_code == "ja-JP":
voice_name = random.choice(["ja-JP-Neural2-B", "ja-JP-Neural2-C", "ja-JP-Neural2-D"])
elif language_code == "hi-IN":
voice_name = random.choice(["hi-IN-Wavenet-A", "hi-IN-Wavenet-B", "hi-IN-Wavenet-C", "hi-IN-Wavenet-D", "hi-IN-Wavenet-E", "hi-IN-Wavenet-F"])
elif language_code == "de-DE":
voice_name = random.choice(["de-DE-Journey-D", "de-DE-Journey-F", "de-DE-Journey-O"])
elif language_code == "ar-XA":
voice_name = random.choice(["ar-XA-Wavenet-A", "ar-XA-Wavenet-B", "ar-XA-Wavenet-C", "ar-XA-Wavenet-D"])
text_to_speech(
text=article_text,
output_filename=output_filename,
task=task,
language_code=language_code,
dry_run=dry_run,
progress=progress
)
目前，只为中文和英文内容生成音频。要扩展支持其他语言，需要配置相应的语言代码。
总结
语言在两个主要方面有所不同：其书写表示（形状）和其口头表达（发音）。字体选择和文本转语音配置分别处理了这两个方面。