---
name: "SDL_SetAudioStreamFrequencyRatio"
section: "3"
platform: "linux"
package: "libsdl3-doc"
version: "3.2.10+ds-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/SDL_SetAudioStreamFrequencyRatio"
---

# SDL\_SetAudioStreamFrequencyRatio(3)

Change the frequency ratio of an audio stream.

## NAME

SDL\_SetAudioStreamFrequencyRatio - Change the frequency ratio of an audio stream.

## HEADER FILE

Defined in SDL3/SDL\_audio.h

## SYNOPSIS

```
#include "SDL3/SDL.h"
```

**bool SDL\_SetAudioStreamFrequencyRatio(SDL\_AudioStream \*stream, float ratio);**

## DESCRIPTION

The frequency ratio is used to adjust the rate at which input data is consumed. Changing this effectively modifies the speed and pitch of the audio. A value greater than 1.0 will play the audio faster, and at a higher pitch. A value less than 1.0 will play the audio slower, and at a lower pitch.

This is applied during  **SDL\_GetAudioStreamData** , and can be continuously changed to create various effects.

## FUNCTION PARAMETERS

- *stream*

  the stream the frequency ratio is being changed.

- *ratio*

  the frequency ratio. 1.0 is normal speed. Must be between 0.01 and 100.

## RETURN VALUE

Returns true on success or false on failure; call

**SDL\_GetError** () for more information.

## THREAD SAFETY

It is safe to call this function from any thread, as it holds a stream-specific mutex while running.

## AVAILABILITY

This function is available since SDL 3.2.0.

## SEE ALSO

**•**(3), [**SDL\_GetAudioStreamFrequencyRatio**(3)](/SDL_GetAudioStreamFrequencyRatio/3.md), **•**(3), [**SDL\_SetAudioStreamFormat**(3)](/SDL_SetAudioStreamFormat/3.md)