# CMD for FFmpeg AAC Encoding

##### From a video file, convert only the audio stream, video direct copy:

`ffmpeg -i input.mp4 -c:v copy -c:a libfdk_aac -b:a 128k output.mp4`

`ffmpeg -i input.mp4 -c:v copy -c:a libfdk_aac -vbr 3 output.mp4`

###### ▩ HIGH-EFFICIENCY AAC

##### HE-AAC version 1:
`ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he -b:a 64k output.m4a`

##### HE-AAC version 2:
`ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he_v2 -b:a 32k output.m4a`

##### Native FFmpeg AAC Encoder:
`ffmpeg -i input.wav -c:a aac -b:a 160k output.m4a`

##### source:
https://trac.ffmpeg.org/wiki/Encode/AAC

##### online:
https://rentry.co/aac

##### Modos VBR

| VRR | kbps/channel | AOTs |
|-----|----------------|------------|
| 1 | 20-32 | LC,HE,HEv2 |
| 2 | 32-40 | LC,HE,HEv2 |
| 3 | 48-56 | LC,HE,HEv2 |
| 4 | 64-72 | LC |
| 5 | 96-112 | LC |