1776x / scream Goto Github PK

Scream is a virtual device driver for Windows that provides a discrete sound device. Audio played through this device is published on your local network as a PCM multicast stream.

Receivers on the network can pick up the stream and play it through their own audio outputs. Two simple servers for Linux (interfacing with PulseAudio or ALSA) and one for Windows are provided.

Scream is based on Microsoft's MSVAD audio driver sample code.

A ZIP file containing a signed x64 build is available on the GitHub releases page. The "installer" is a batch file that needs to be run with administrator rights.

The build is supposed to run on all x64 versions of Windows 7 through Windows 10.

Microsoft has recently tightened the rules for signing kernel drivers. These new rules apply to newer Windows 10 installations that were not upgraded from an earlier version. If your installation is subject to these rules, the driver will not install. Workaround: Disable secure boot in BIOS. For more information, see this issue.

All audio played through the Scream device will be put onto the local LAN as a multicast stream. The multicast target address and port is always "239.255.77.77:4010". The audio is a raw PCM stream, always 44100kHz, 16bit, stereo. It is transferred in UDP frames with a payload size of max. 980 bytes, representing 1/180 second of audio. Delay is minimal, since all processing is done on kernel level.

Receivers simply need to read the stream off the network and stuff it into a local audio sink. The receiver system's kernel should automatically do the necessary IGMP signalling, so it's usually sufficient to just open a multicast listen socket and start reading from it. Minimal buffering (~ 4 times the UDP payload size) should be done to account for jitter.

Three receivers are provided:

• Linux/Pulseaudio: Not included in the installer package. Just type 'make' to build it.

• Linux/ALSA: Contributed by @ivan. Not included in the installer package. Just type 'make' to build it.

• Windows: ScreamReader, contributed by @MrShoenel. Included in the installer package as of version 1.2.

All three receivers can be run as unprivileged users.

VS2015 and matching WDK are required. You might also have luck with earlier (or future) VS versions, but I didn't test that.