switch_camera

switch_camera is a Dart library that provides a Dart FFI interface to interact with camera and audio recording functionalities from Rust. It supports video capturing, frame streaming, and video writing, as well as audio recording and merging video with audio. I used the switch_camera library to build a desktop application named Zed Camera, and you can watch a demonstration of it on YouTube. This library is particularly useful in IoT, CCTV, and industrial contexts where multiple camera inputs and reliable audio-visual recording are essential.

Features

• List available camera devices
• Open and release camera devices
• Capture video frames (with and without flip)
• Stream video frames (with and without flip)
• Start video writer
• Write video frames (with and without flip)
• Audio recording (start, stop, pause, resume)
• Merge audio and video

Platform Support

• Linux

Installation

To install switch_camera, use flutter pub add:

Flutter

flutter pub add switch_camera

Dependencies

Linux - Ubuntu:

• sudo apt-get update
• Getting OpenCV: sudo apt-get install libopencv-dev clang libclang-dev
• Install JACK development files: sudo apt-get install libjack-jackd2-dev
• Install ALSA development files: sudo apt-get install libasound2-dev
• Install FFmpeg: sudo apt-get install ffmpeg

Usage

Camera

import 'package:switch_camera/switch_camera.dart';

void main() {
  final camera = Camera();

  // List available 10 devices
  final devices = camera.getDevices(10);
  print('Available devices: $devices');

  // Open a camera device
  camera.open(0);

  // Capture a frame
  final frame = camera.captureFrame();
  print('Captured frame: ${frame.length} bytes');

  // Capture a flipped frame
  final flippedFrame = camera.captureFrameFlip();
  print('Captured flipped frame: ${flippedFrame.length} bytes');

  // Stream frames
  camera.streamFrames();

  // Stream flipped frames
  camera.streamFramesFlip();

  // Start video writer
  camera.startVideoWriter('output.mp4', 30.0, 1920, 1080);

  // Write a frame
  camera.writeFrame();

  // Write a flipped frame
  camera.writeFrameFlip();

  // Release the camera
  camera.release();

  // Dispose the camera
  camera.dispose();
}

Audio Recorder

import 'package:switch_camera/switch_camera.dart';

void main() {
  final recorder = RustAudioRecorder();

  // Start recording
  recorder.startRecording();

  // Pause recording
  recorder.pauseRecording();

  // Resume recording
  recorder.resumeRecording();

  // Stop recording
  recorder.stopRecording();
}

Merge Audio and Video

import 'package:switch_camera/switch_camera.dart';

void main() {
  final result = mergeCamAudioVideo('output_with_audio.mp4');
  print('Merge result: $result');
}

NB: Prepare Linux apps for distribution

To build flutter applciation as release run the following command:

flutter build linux --release

After that, go to build/linux/release/bundle/ and run the application using the following command:

./projectname

"By runnung the application in the directory, a file will be automatically copied to lib folder with the following directory src/rust_native/librust_camera.so. This file is responsible for this library to work in your application."

API Reference

Camera

• List<int> getDevices(int limit)

  • Lists available camera devices up to the specified limit.

• void open(int index)

  • Opens a camera device by index.

• void release()

  • Releases the currently opened camera device.

• Uint8List captureFrame()

  • Captures a single video frame.

• Uint8List captureFrameFlip()

  • Captures a single flipped video frame.

• Stream<Uint8List> streamFrames()

  • Streams video frames.

• Stream<Uint8List> streamFramesFlip()

  • Streams flipped video frames.

• void startVideoWriter(String filename, double fps, int width, int height)

  • Starts video writing to the specified file.

• void startAVideoWriter(double fps, int width, int height)

  • Starts a video writer without specifying a filename.

• void writeFrame()

  • Writes a video frame.

• void writeFrameFlip()

  • Writes a flipped video frame.

• void dispose()

  • Disposes the camera resources.

RustAudioRecorder

• void startRecording()
  • Starts audio recording.
• void stopRecording()
  • Stops audio recording.
• void pauseRecording()
  • Pauses audio recording.
• void resumeRecording()
  • Resumes audio recording.

Merge Functions

• String mergeCamAudioVideo(String outputFilePath)
  • Merges the recorded camera video and audio into the specified output file.

Author

Zacchaeus Oluwole

LinkedIn: www.linkedin.com/in/zacchaeus-oluwole/

X: x.com/ZTechPlus

Email: zacchaeusoluwole@gmail.com

Github: github.com/Zacchaeus-Oluwole