A step-by-step tutorial for live audio streaming with Roc

Table of contents What is Roc? What’s new? Ubuntu desktop Raspberry Pi (ALSA) Raspberry Pi (PulseAudio) macOS Android / Termux What is Roc? Roc is an open-source toolkit for real-time audio streaming over the network. You can learn about the project here: overview, features, usage. Among other things, Roc can be used as …

Roc 0.1 released: real-time streaming over the network

What is Roc? I’m happy to announce the first release of Roc Toolkit, version 0.1.0! Roc provides a C API for real-time audio transport. The user just writes a stream to the one end and reads it from another end. Roc, in turn, performs encoding and decoding, and, more importantly, deals with the problems related to the …

Working on a new network transport for PulseAudio and ALSA

Intro Last few years I was working on Roc Toolkit, an open-source solution for real-time media streaming over the network. Due to lack of free time, we postponed release several times, but now it’s almost ready. This article is, inter alia, some kind of a pre-release announcement. You can read more about the project here. …

Ephemeral ports and SO_REUSEADDR

Ephemeral ports The ephemeral port range is a range of ports used by the kernel when the user wants the socket to be bound to a random unused port. In particular, bind, listen, connect, and sendto may automatically allocate an ephemeral port for AF_INET and AF_INET6 sockets. This behavior is described in the ip_local_port_range …

PulseAudio under the hood

Table of contents Preface About PulseAudio High-level components Key abstractions D-Bus API C API Protocols and networking Device drivers Sound processing Sample cache Stream management Time management Power saving Automatic setup and routing Desktop integrations Compatibility layers Server internals Module list GUI tools …

Using MiniSAPServer and MiniSAPListener for SAP/SDP

MiniSAPServer is a small program that periodically sends SAP/SDP messages, given a config file and destination address. I’ve prepared a complementary MiniSAPListener program which listens for SAP/SDP messages, and prints them to stdout or passes to a shell command. The source code is mostly extracted from PulseAudio RTP …

Reusing UNIX domain socket (SO_REUSEADDR for AF_UNIX)

Unix domain sockets are a networkless version of Internet sockets. They have several advantages: Unix domain sockets are files, so file-system permissions may be used for them when one end is closed (e.g. process exits), SIGPIPE is delivered to another end performance may be up to 2x better See details here. Lack of …