如何用FFmpeg批量提取MKV文件中的印尼SRT字幕？

Got it, let's tackle this batch subtitle extraction problem. Since you already know how to pull Indonesian subtitles from a single file with FFmpeg, scaling this to your 17 files in the dots folder is straightforward with a bash loop. Here are two reliable approaches:

方法1：基于语言代码的批量提取（推荐） #

This method is more robust because it targets subtitles by their language code (ind for Indonesian) instead of a fixed stream index—stream numbers can vary between different MKV files, so this avoids errors if some files have different stream layouts.

1. First, navigate to your dots folder:

   cd /home/jaac/torrents/rtorrent/dots
   

2. Run this bash loop to process all MKV files:

   for file in *.mkv; do
     ffmpeg -i "$file" -map 0:s:m:language:ind "${file%.mkv}_indo.srt" -y
   done
   

Let's break down the key parts:

• "$file": Quotes ensure the command handles filenames with spaces or special characters correctly.
• -map 0:s:m:language:ind: Tells FFmpeg to pick the subtitle stream (s) from the input file (0) that matches (m) the Indonesian language code ind.
• ${file%.mkv}_indo.srt: Creates a subtitle filename that matches the original MKV (e.g., Title.NF.WEB-DL.DDP2.0.x264-Ao.mkv becomes Title.NF.WEB-DL.DDP2.0.x264-Ao_indo.srt).
• -y: Automatically overwrites existing .srt files if they exist. Remove this flag if you want FFmpeg to prompt you before overwriting.

方法2：固定流索引的批量提取（仅当所有文件的印尼语字幕都是第7个流） #

If you're absolutely certain every MKV in your folder has the Indonesian subtitle at stream index 0:7, you can reuse your original command in a loop:

cd /home/jaac/torrents/rtorrent/dots
for file in *.mkv; do
  ffmpeg -i "$file" -map 0:7 "${file%.mkv}_indo.srt" -y
done

额外小贴士：验证字幕流信息 #

Before running the batch command, you can double-check the subtitle streams in any file to confirm the language or index. Use ffprobe (included with FFmpeg) for this:

ffprobe -v error -select_streams s -show_entries stream=index:stream_tags=language -of csv=p=0 "YourFile.mkv"

This will output something like:

5,eng
7,ind

Which confirms stream 7 is Indonesian (ind), so your original single-file command works for that specific file.

内容的提问来源于stack exchange，提问作者jaac