RTSP-AVBridge

RTSP-AVBridge is an open-source project that offers a cross-platform solution for implementing virtual cameras and virtual microphones using RTSP for audio and video transmission.

Resolution	Frame Rate	Encoding Side (M3Pro 4-core, whole machine)	Decoding Side (Win32, whole machine)	Visual Latency (Average of three measurements)
640x480	30	Frame time: 8~20ms; Max CPU usage: 14.5% (whole machine); Memory: 70MB	Frame time: 30~50ms; Very low CPU usage; 43MB memory	238ms
1280x720	30	Frame time: 8~20ms; Max CPU usage: 20.9% (whole machine); Memory: 123MB	Frame time: 30~50ms; Very low CPU usage; 45MB memory	160ms
1760x1328	30	Frame time: 15~25ms; Max CPU usage: 24% (whole machine); Memory: 247MB	Frame time: 30~50ms; Very low CPU usage; 61MB memory	209ms
1920x1080	30	Frame time: 9~25ms; Max CPU usage: 31% (whole machine); Memory: 225MB	Frame time: 30~50ms; Very low CPU usage; 59MB memory	172ms

Microphone usage was not tested.

Features

• Bypasses the signed driver requirement for virtual device construction
• Recognized by popular applications such as Tencent Meeting
• Supports reconnection and retransmission
• Ensures stable transmission of high-definition video and audio

TODO

• [] Improve Documentation

Setup

• With Physical Device (Server) (e.g., Moonlight)
  1. Download and run the mediamtx service
• Without Physical Device (Client) (e.g., Sunshine-host)
  1. For virtual camera, download and configure Softcam. You can try examples of Softcam.
  2. For virtual microphone, download and configure PortAudio (optional); Install Virtual Audio Cable (VAC) software

Virtual Camera

Implementation: The virtual camera is constructed using a DirectShow driver, based on Softcam.

Installation

• With Physical Device (Server) (Moonlight)

  gcc video.c -o video -I /usr/local/include -L /usr/local/lib -lavdevice -lavformat -lavcodec -lavutil -lswscale
  
  ./video -u [rtsp_url] [-w width] [-h height] [-f fps]
  ./video

• Without Physical Device (Client) (Sunshine-host)

  • SoftCam

Running

• With Physical Device (Server) (Moonlight)
  • Start the mediamtx service
  • Run the binary file
• Without Physical Device (Client) (Sunshine-host)
  • Set up RTSP_URL
  • Build the Visual Studio project
  • Run the executable

Virtual Microphone

Implementation: Real-time audio is transmitted to a virtual speaker, which forwards the audio to the virtual microphone.

Installation

• With Physical Device (Server) (Moonlight)

  gcc audio1.c -o audio1 -I /usr/local/include -L /usr/local/lib -lavdevice -lavformat -lavcodec -lavutil -lswscale -lswresample -lpthread
  
  ./audio

• Without Physical Device (Client) (Sunshine-host)

  • virtual audio cable
  • Connect the RTSP audio stream to a virtual speaker

Running

• With Physical Device (Server) (Moonlight)
  • Start the mediamtx service
  • Run the binary file
• Without Physical Device (Client) (Sunshine-host)
  • Run the Python script (less stable, low latency)
  • Run the Visual Studio project (more stable, higher latency, need portaudio)

Related Projects

• PortAudio
• Softcam
• Mediamtx

License

MIT