markdown FFmpeg的

Posted 2021-05-05

### Duplicate frames /w wrong 

Fixing to be 10fps

```ffmpeg -i INPUT.flv -r 10 -vf "mpdecimate,setpts=N/(10*TB)" OUTPUT.mp4```

> `N`→ The count of the input frame for video or the number of consumed samples, not including the current frame for audio, starting from 0.  
  `TB`→ The timebase of the input timestamps.

[source](http://ffmpeg.org/ffmpeg-all.html#toc-setpts_002c-asetpts)

### Extract bluray audio
```
ffmpeg -i VIDEO.m2ts -map 0:<stream> -acodec <pcm_s24le|libmp3lame> audio.<wav|mp3>
```

### Copy chapters from one file to another
```
ffmpeg -i video_w_chapters.mp4 -i video.mp4 -map 1 -map_metadata 0 -c copy output.mp4
```
> `-map 1`→ Select `video.mp4` as source  
  `-map_metadata 0`→ Select `video_w_chapters.mp4` as metadata (chapters) source