# ffmpeg

### Installing

```bash
sudo apt install ffmpeg
```

### Compress a video to h265

```bash
 ffmpeg -i example_h264.mp4 -c:v libx265 -crf 24 -preset fast -c:a aac -b:a 128k example_h265.mp4
```

<div id="bkmrk-">  
</div>### CRF Info

For H.264 (x264):

The typical CRF range is 18-28.

CRF 18: Near lossless quality (very high quality, larger file size).

CRF 23: Default value, good balance between quality and file size.

CRF 28: Noticeable quality loss, much smaller file size.

<div id="bkmrk--1">  
</div>### Overwright a videos audio with a new audio track

```bash
 ffmpeg -i video_to_overwright.mkv -i audio_input.mp3 -c:v copy -map 0:v:0 -map 1:a:0 output.mp4
```


### MP4 to MP3

```bash
 ffmpeg -i filename.mp4 filename.mp3
```

### Change video format

```bash
ffmpeg -i input.m4v -c copy output.mp4
```