# Advanced Usage

While we strive to make Permute easy to use, we also want to give space to more demanding users. Here are some tips and tricks for more advanced use of Permute.

### Advanced preset options

Permute allows you to set the video and audio format quality to several qualities. The basic 4 automatically adjust the bitrate based on the input file and output size and you can learn more about them in the Presets chapter. The additional two are more advanced and are only recommended to be used by more advanced users.

- Custom - this quality allows you to manually set bitrate, max bitrate and framerate for video, bitrate, channels and frequency for audio. Note that not all combinations of these settings are supported by all formats. Use with caution - when conversions start failing after adjusting these options, you might have set some incompatible combination of values.
- Copy - this is also known as remux or passthrough - it copies the track from original file into the destination. Requires you to know the track’s format in the original file and if the container of the resulting file supports this. Note that Permute already automatically copies tracks that it knows are compatible with the resulting file. This option should only be used in rare cases.
- Disable Size Restrictions - this is an H.264 codec option that disables size restrictions imposed by the level that the preset uses. This allows to convert larger resolutions, but the resulting file may not be compatible with all players. Also, hardware acceleration is not supported when this is enabled.

### Per-group options

Each group can be further customized using the Options button. Several options can appear (they depend on the selected preset and content of the group):

- Stitching - selecting this option merges all the files in the group into one. You can use this with video, audio and images (PDF preset only).
- Restricting size - you can customize the target size of the video. Restricting the size limits the resulting size to specified size while maintaining aspect ratio. For example setting the restriction to 1000x1000 results in a video that’s less than 1000px on either side, but aspect ratio is maintained.
- Transformation - rotate or flip the video.
- Volume Adjustment - increase or decrease volume of the audio tracks.
- Remove All - removes all files from within the group.

### Tips and Tricks

Here are listed some tips and tricks:

- You can stitch multiple images into a single PDF file. To do so, drop the images onto Permute, select the PDF preset and in the group options, check the `Stitch together` option.
- Remuxing is still possible in Permute 3, but isn’t available as a standalone preset. If you are sure that you need remuxing, please, create a custom preset and set the video and/or audio qualities to `Copy`. The `Copy` quality forces Permute to remux that stream into the new file. ⚠️ WARNING: This is an advanced option that requires you to have some knowledge about what containers support what video and audio formats as well as to have some knowledge about the formats used in the input file.