# CAMERA_I2CFrameRate*

## Syntax

  `#include <twl/camera.h>`
  `CAMERAResult CAMERA_I2CFrameRate(CAMERASelect camera, CAMERAFrameRate rate);`
  `CAMERAResult CAMERA_I2CFrameRateAsync(CAMERASelect camera, CAMERAFrameRate rate, CAMERACallback callback, void *arg);`

## Arguments

camera | Camera to configure (`CAMERA_SELECT_IN`, `CAMERA_SELECT_OUT`, or `CAMERA_SELECT_BOTH`).
rate | Frame rate.
callback | Function that is called when asynchronous processing has completed.
arg | Arguments when the callback function is invoked.

## Return Values

Returns `CAMERA_RESULT_SUCCESS` if configuration was successful.

## Description

Changes the camera's frame rate.
Unlike `CAMERA_I2CFrameRate`, the `CAMERA_I2CFrameRateAsync` function returns control immediately and runs asynchronously. Use callback to confirm that processing has completed.
Do not set `CAMERA_FRAME_RATE_30_TO_10`, `CAMERA_FRAME_RATE_30_TO_5`, or `CAMERA_FRAME_RATE_30` with this function while either `CAMERA_SIZE_VGA` or `CAMERA_SIZE_DS_LCDx4` is specified with the `CAMERA_I2CSize*` functions. Capture data becomes impossible to receive if these settings are used at the same time.
Also,
Note:
If camera settings are changed using any of the `CAMERA_I2C*` functions, the changes may be delayed for approximately one frame before they are applied. If camera settings are changed during image capture, therefore, an application's timing may make it impossible to get an image with the changes applied.
Occasional Shifting of Captured Images
The captured image may shift if this function is called during image capture.
Before calling this function, first stop the image capture with `CAMERA_StopCapture`. Then call this function. After this function completes execution, restart the image capture with `CAMERA_StartCapture`.

## See Also

`CAMERASelect`
`CAMERACallback`
`CAMERAResult`
`CAMERAFrameRate`
`CAMERA_I2CSize*`

## Revision History

2009/11/11 Explained occasional shifting of captured images.
2009/07/03 Updated information about conditions of use.
2008/10/30 Added that `CAMERA_SELECT_BOTH` can also be specified.
2008/01/23 Added a description that 30 fps capture is impossible at VGA resolution.
2007/11/12 Initial version.

CONFIDENTIAL