FFmpeg：六个真实场景FFmpeg: Six Real Use Cases
学习目标LEARNING OBJECTIVES
学完你知道六个你会真的用到的场景，以及它们的共同点。
概念说明CONCEPTS
- 转格式——MOV / MKV → MP4：一条命令转掉
- 压缩交付——指定码率 / 质量导出
- 截帧与缩略图——某一秒抽一帧
- 裁切与拼接——-c copy 不重编码，零损失
- 音视频分离——抽音轨 / 换音轨
- 推流与录制——配合 OBS 等工具
共同点：重复、批量、要求一致——最该交给命令行。
操作步骤STEPS
- 挑一个场景，把命令敲一遍
- 对照 ffprobe 验证结果
- 把命令存进备忘，下次直接用
练习PRACTICE
动手任务
把一条 MOV 转成 MP4，并用 ffprobe 验证编码变了。
自检清单
做完任务后逐条自查，全部能打勾才算过。
常见问题FAQ
这些都要背命令吗？
不用——存进备忘，用的时候抄；要背的是「该在哪一步做什么」。
什么样的活最适合交给 FFmpeg？
重复、批量、要求一致的活——一次做完，最该交给命令行。
Learning Objectives学习目标
After this card you know six scenarios you will really use, and what they share.
Concepts概念说明
- Convert — MOV / MKV → MP4 in one command
- Compress for delivery — target bitrate / quality without opening an app
- Frames & thumbnails — grab one frame at a given second
- Trim & join — with -c copy: no re-encode, zero loss
- Split audio & video — extract or swap the audio track
- Stream & record — with OBS and friends
The common thread: repeated, batched, must-be-consistent — exactly what belongs on the command line.
Steps操作步骤
- Pick one scenario and run the command once
- Verify with ffprobe
- Save the command into your notes for next time
Practice练习
Hands-on task
Convert one MOV to MP4 and verify the codec changed with ffprobe.
Self-check
Work through the task, then tick every line; all checked means you own this card.
FAQ常见问题
Do I have to memorise the commands?
No — save them and copy when needed; what to memorise is which step does what.
Which jobs suit FFmpeg best?
Repeated, batch, consistency-demanding jobs — done in one go; that's what the command line is for.