react-native-vision-camera/docs/docs/guides/PERFORMANCE.mdx
2023-10-03 11:31:37 +02:00

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---
id: performance
title: Performance
sidebar_label: Performance
---
import Tabs from '@theme/Tabs'
import TabItem from '@theme/TabItem'
import useBaseUrl from '@docusaurus/useBaseUrl'
## Performance of VisionCamera
VisionCamera is highly optimized to be **as fast as a native Camera app**, and is sometimes even faster than that.
I am using highly efficient native GPU buffer formats (such as YUV 4:2:0, or lossless compressed YUV 4:2:0), running the video pipelines in parallel, using C++ for the Frame Processors implementation, and other tricks to make sure VisionCamera is as efficient as possible.
## Making it faster
There are a few things you can do to make your Camera faster which requires a core understanding of how Cameras work under the hood:
### Simpler Camera Device
Selecting a "simpler" Camera Device (i.e. a Camera Device with _less physical cameras_) allows the Camera to initialize faster as it does not have to start multiple devices at once.
You can prefer a simple wide-angle Camera (`['wide-angle-camera']`) over a triple camera (`['ultra-wide-angle-camera', 'wide-angle-camera', 'telephoto-camera']`) to significantly speed up initialization time.
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groupId="component-style"
defaultValue="hooks"
values={[
{label: 'Hooks API', value: 'hooks'},
{label: 'Imperative API', value: 'imperative'}
]}>
<TabItem value="hooks">
```ts
const fasterDevice = useCameraDevice('back', {
physicalDevices: ['wide-angle-camera']
})
const slowerDevice = useCameraDevice('back', {
physicalDevices: ['ultra-wide-angle-camera', 'wide-angle-camera', 'telephoto-camera']
})
```
</TabItem>
<TabItem value="imperative">
```ts
const devices = Camera.getAvailableCameraDevices()
const fasterDevice = getCameraDevice(devices, 'back', {
physicalDevices: ['wide-angle-camera']
})
const slowerDevice = getCameraDevice(devices, 'back', {
physicalDevices: ['ultra-wide-angle-camera', 'wide-angle-camera', 'telephoto-camera']
})
```
</TabItem>
</Tabs>
See ["Camera Devices"](devices) for more information.
Note: By default (when not passing the options object), a simpler device is already chosen.
### No HDR
HDR uses 10-bit formats and/or additional processing steps that come with additional computation overhead. Disable HDR (don't pass `hdr` to the `<Camera>`) for higher efficiency.
### Buffer Compression
Enable Buffer Compression ([`enableBufferCompression`](/docs/api/interfaces/CameraProps#enablebuffercompression)) to use lossless-compressed buffers for the Camera's video pipeline. These buffers can use less memory and are more efficient.
Note: When not using a `frameProcessor`, buffer compression is automatically enabled.
### Video Stabilization
Video Stabilization requires additional overhead to start the algorithm, so disabling [`videoStabilizationMode`](/docs/api/interfaces/CameraProps#videostabilizationmode) can significantly speed up the Camera initialization time.
### Pixel Format
By default, the `native` [`PixelFormat`](/docs/api#pixelformat) is used, which is much more efficient than `rgb`.
- On iOS, `native` is `yuv`
- On Android `native` is some kind of vendor specific format, which might be `yuv`
### Disable unneeded pipelines
Only enable [`photo`](/docs/api/interfaces/CameraProps#photo) and [`video`](/docs/api/interfaces/CameraProps#video) if needed.
### Fast Photos
If you need to take photos as fast as possible, use a [`qualityPrioritization`](/docs/api/interfaces/TakePhotoOptions#qualityprioritization) of `'speed'` to speed up the photo pipeline:
```ts
camera.current.takePhoto({
qualityPrioritization: 'speed'
})
```
### Appropriate Format resolution
Choose formats efficiently. If your backend can only handle 1080p videos, don't select a 4k format if you have to downsize it later anyways - instead use 1080p already for the Camera:
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groupId="component-style"
defaultValue="hooks"
values={[
{label: 'Hooks API', value: 'hooks'},
{label: 'Imperative API', value: 'imperative'}
]}>
<TabItem value="hooks">
```ts
const format = useCameraFormat(device, [
{ videoResolution: { width: 1920, height: 1080 } }
])
```
</TabItem>
<TabItem value="imperative">
```ts
const format = getCameraFormat(device, [
{ videoResolution: { width: 1920, height: 1080 } }
])
```
</TabItem>
</Tabs>
### Appropriate Format FPS
Same as with format resolutions, also record at the frame rate you expect. Setting your frame rate higher can use more memory and heat up the battery.
If your backend can only handle 30 FPS, there is no need to record at 60 FPS, instead set the Camera' [`fps`](/docs/api/interfaces/CameraProps#fps) to 30:
```jsx
return <Camera {...props} fps={30} />
```
<br />
#### 🚀 Next section: [Camera Errors](errors)