# UxPlay 1.56: AirPlay-Mirror and AirPlay-Audio server for Linux, macOS, and Unix.

### Now developed at the GitHub site <https://github.com/FDH2/UxPlay> (where all user issues should be posted).

Highlights:

-   GPLv3, open source.
-   Originally supported only AirPlay Mirror protocol, now has added
    support for AirPlay Audio-only (Apple Lossless ALAC) streaming from
    current iOS/iPadOS 15.5 clients. **There is no support for Airplay2
    video-streaming protocol, and none is planned.**
-   macOS computers (2011 or later, both Intel and "Apple Silicon" M1
    systems) can act either as AirPlay clients, or as the server running
    UxPlay. Using AirPlay, UxPlay can emulate a second display for macOS
    clients.
-   Support for older iOS clients (such as 32-bit iPad 2nd gen. and
    iPhone 4S, when upgraded to iOS 9.3.5 or later), plus a Windows
    AirPlay-client emulator, AirMyPC.
-   Uses GStreamer plugins for audio and video rendering (with options
    to select different hardware-appropriate output "videosinks" and
    "audiosinks", and a fully-user-configurable video streaming
    pipeline).
-   Support for server behind a firewall.
-   **New**: Support for Raspberry Pi, with hardware video acceleration
    using Video4Linux2 (vl42), which supports both 32- and 64-bit
    systems, unlike deprecated OpenMAX (omx), which is being dropped by
    RPi distributions in favor of v4l2. (For GStreamer \< 1.22, a
    [patch](https://github.com/FDH2/UxPlay/wiki/Gstreamer-Video4Linux2-plugin-patches)
    to the GStreamer Video4Linux2 plugin, available in the [UxPlay
    Wiki](https://github.com/FDH2/UxPlay/wiki), is required, unless your
    distribution has made a backport of changes from the development
    branch.) See [success
    reports](https://github.com/FDH2/UxPlay/wiki/UxPlay-on-Raspberry-Pi:-success-reports:).

This project is a GPLv3 open source unix AirPlay2 Mirror server for
Linux, macOS, and \*BSD. It was initially developed by
[antimof](http://github.com/antimof/Uxplay) using code from
OpenMAX-based [RPiPlay](https://github.com/FD-/RPiPlay), which in turn
derives from [AirplayServer](https://github.com/KqsMea8/AirplayServer),
[shairplay](https://github.com/juhovh/shairplay), and
[playfair](https://github.com/EstebanKubata/playfair). (The antimof site
is no longer involved in development, but periodically posts updates
pulled from the new main [UxPlay site](https://github.com/FDH2/UxPlay)).

UxPlay is tested on a number of systems, including (among others) Debian
10.11 "Buster" and 11.2 "Bullseye", Ubuntu 20.04 and 22.04, Linux Mint
20.3, Pop!\_OS 22.04 (NVIDIA edition), Rocky Linux 8.6 (a CentOS
successor), OpenSUSE 15.4, Arch Linux 5.16.8, macOS 12.3 (Intel and M1),
FreeBSD 13.1. On Raspberry Pi, it is tested on Raspberry Pi OS
(Bullseye) (32- and 64-bit), Ubuntu 22.04, and Manjaro RPi4 22.04.

Its main use is to act like an AppleTV for screen-mirroring (with audio)
of iOS/iPadOS/macOS clients (iPhones, iPads, MacBooks) in a window on
the server display (with the possibility of sharing that window on
screen-sharing applications such as Zoom) on a host running Linux,
macOS, or other unix. UxPlay supports Apple's AirPlay2 protocol using
"Legacy Pairing", but some features are missing. (Details of what is
publically known about Apple's AirPlay 2 protocol can be found
[here](https://openairplay.github.io/airplay-spec/),
[here](https://github.com/SteeBono/airplayreceiver/wiki/AirPlay2-Protocol)
and [here](https://emanuelecozzi.net/docs/airplay2)).

The UxPlay server and its client must be on the same local area network,
on which a **Bonjour/Zeroconf mDNS/DNS-SD server** is also running (only
DNS-SD "Service Discovery" service is strictly necessary, it is not
necessary that the local network also be of the ".local" mDNS-based
type). On Linux and BSD Unix servers, this is usually provided by
[Avahi](https://www.avahi.org), through the avahi-daemon service, and is
included in most Linux distributions (this service can also be provided
by macOS, iOS or Windows servers).

Connections to the UxPlay server by iOS/MacOS clients can be initiated
both in **AirPlay Mirror** mode (which streams lossily-compressed AAC
audio while mirroring the client screen, or in the alternative **AirPlay
Audio** mode which streams Apple Lossless (ALAC) audio without screen
mirroring. In **Audio** mode, metadata is displayed in the uxplay
terminal; if UxPlay option `-ca <name>` is used, the accompanying cover
art is also output to a periodically-updated file `<name>`, and can be
viewed with a (reloading) graphics viewer of your choice such as `feh`:
run "`uxplay -ca <name> &`" in the background, then run
"`feh -R 1 <name>`" in the foreground; terminate with
"`ctrl-C fg ctrl-C`". *Switching between* **Mirror** *and* **Audio**
*modes during an active connection is possible: in* **Mirror** *mode,
stop mirroring (or close the mirror window) and start an* **Audio**
*mode connection, switch back by initiating a* **Mirror** *mode
connection; cover-art display stops/restarts as you leave/re-enter*
**Audio** *mode.*

-   **Note that Apple video-DRM (as found in AppleTV.app content on the
    client) cannot be decrypted by UxPlay, and (unlike a true AppleTV),
    the UxPlay server does not allow the Apple client to run a http
    connection on the server that directly streams content from the
    internet to the server, instead of streaming it to the client, and
    then re-streaming to the server. Unlike AppleTV.app, DRM-free apps
    like youtube.app can be viewed and listened to in Mirror mode, but
    using the youtube.app icon for AirPlay video will only send ALAC
    sound without the accompanying video.**

### Possibility for using hardware-accelerated h264 video-decoding, if available.

UxPlay uses [GStreamer](https://gstreamer.freedesktop.org) "plugins" for
rendering audio and video. This means that video and audio are supported
"out of the box", using a choice of plugins. AirPlay streams video in
h264 format: gstreamer decoding is plugin agnostic, and uses accelerated
GPU hardware h264 decoders if available; if not, software decoding is
used.

-   **VAAPI for Intel and AMD integrated graphics, NVIDIA with "Nouveau"
    open-source driver**

    With an Intel or AMD GPU, hardware decoding with the open-source
    VAAPI gstreamer plugin is preferable. The open-source "Nouveau"
    drivers for NVIDIA graphics are also in principle supported: see
    [here](https://nouveau.freedesktop.org/VideoAcceleration.html), but
    this requires VAAPI to be supplemented with firmware extracted from
    the proprietary NVIDIA drivers.

-   **NVIDIA with proprietary drivers**

    The `nvh264dec` plugin (included in gstreamer1.0-plugins-bad since
    GStreamer-1.18.0) can be used for accelerated video decoding on the
    NVIDIA GPU after NVIDIA's CUDA driver `libcuda.so` is installed.
    (This plugin should be used with options
    `uxplay -vd nvh264dec -vs glimagesink`.) For GStreamer-1.16.3 or
    earlier, replace `nvh264dec` by the older plugin `nvdec`, which must
    be built by the user: See [these
    instructions](https://github.com/FDH2/UxPlay/wiki/NVIDIA-nvdec-and-nvenc-plugins).

-   **Video4Linux2 support for the Raspberry Pi Broadcom GPU**

    Raspberry Pi (RPi) computers can run UxPlay with software decoding
    of h264 video but this usually has unacceptable latency, and
    hardware-accelerated GPU decoding should be used. UxPlay accesses
    the GPU using the GStreamer plugin for Video4Linux2 (v4l2), which
    replaces unmaintained 32-bit-only OpenMax used by RPiPlay. Fixes to
    the v4l2 plugin that allow it to work with UxPlay on RPi are now in
    the GStreamer development branch, and will appear in the upcoming
    GStreamer-1.22 release. A (partial) backport (as
    `gstreamer1.0-plugins-good-1.18.4-2+~rpt1`) has already appeared in
    RPi OS updates. Until the full update appears, or for other
    distributions, you can find [patching instructions for
    GStreamer](https://github.com/FDH2/UxPlay/wiki/Gstreamer-Video4Linux2-plugin-patches)
    in the [UxPlay Wiki](https://github.com/FDH2/UxPlay/wiki) for
    GStreamer 1.18.4 and later.

### Note to packagers: OpenSSL-3.0.0 solves GPL v3 license issues.

Some Linux distributions such as Debian do not allow distribution of
compiled GPL code linked to OpenSSL-1.1.1 because its license has some
incompatibilities with GPL code, unless all authors have given an
"exception" to allow such linking (the historical origins of UxPlay make
this impossible to obtain). Other distributions treat OpenSSL as a
"System Library" to which the GPL allows linking.

For "GPL-strict" distributions, UxPlay can be built using OpenSSL-
3.0.0, which has a new [GPLv3-compatible
license](https://www.openssl.org/blog/blog/2021/09/07/OpenSSL3.Final/).

# Getting UxPlay:

Either download and unzip
[UxPlay-master.zip](https://github.com/FDH2/UxPlay/archive/refs/heads/master.zip),
or (if git is installed): "git clone https://github.com/FDH2/UxPlay".
You can also download a recent or earlier version listed in
[Releases](https://github.com/FDH2/UxPlay/releases).

-   Current UxPlay is also a pull request on the original site
    https://github.com/antimof/UxPlay ; that original project is
    inactive, but the pull requests are now being periodically merged
    with the antimof tree (thank you antimof!).

## Building UxPlay on Linux (or \*BSD):

### Debian-based systems:

-   Note that the current Debian "testing" distribution (for eventual
    release as Debian 12/Bookworm) now includes uxplay, so future
    Debian-based distributions may offer a pre-built uxplay package.

(Instructions for Debian/Ubuntu; adapt these for other Linuxes; for
macOS, see below). See [Troubleshooting](#troubleshooting) below for
help with any difficulties.

You need a C/C++ compiler (e.g. g++) with the standard development
libraries installed. Debian-based systems provide a package
"build-essential" for use in compiling software. You also need
pkg-config: if it is not found by "`which pkg-config`", install
pkg-config or its work-alike replacement pkgconf. Also make sure that
cmake\>=3.4.1 is installed: "`sudo apt-get install cmake`" (add
`build-essential` and `pkg-config` (or `pkgconf`) to this if needed).

Make sure that your distribution provides OpenSSL 1.1.1 or later, and
libplist 2.0 or later. (This means Debian 10 "Buster", Ubuntu 18.04 or
later.) If it does not, you may need to build and install these from
source (see instructions at the end of this README). If you have a
non-standard OpenSSL installation, you may need to set the environment
variable OPENSSL_ROOT_DIR (*e.g.* ,
"`export OPENSSL_ROOT_DIR=/usr/local/lib64`" if that is where it is
installed).

In a terminal window, change directories to the source directory of the
downloaded source code ("UxPlay-\*", "\*" = "master" or the release tag
for zipfile downloads, "UxPlay" for "git clone" downloads), then follow
the instructions below:

**Note:** By default UxPlay will be built with optimization for the
computer it is built on; when this is not the case, as when you are
packaging for a distribution, use the cmake option
`-DNO_MARCH_NATIVE=ON`.

1.  `sudo apt-get install libssl-dev libplist-dev` (unless you need to
    build OpenSSL and libplist from source).
2.  `sudo apt-get install libavahi-compat-libdnssd-dev libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev`.
3.  `sudo apt-get install libx11-dev` (only needed if you invoke the
    "ZOOMFIX" X11 display-name fix in the next step)
4.  `cmake .` (or "`cmake -DZOOMFIX=ON .`" to get a screen-sharing fix
    to make X11 mirror display windows visible to screen-sharing
    applications such as Zoom, see [ZOOMFIX compile-time
    option](#zoomfix-compile-time-option) below). **ZOOMFIX is only
    needed for GStreamer-1.18.x or earlier**.
5.  `make`
6.  `sudo make install` (you can afterwards uninstall with
    `sudo make uninstall` in the same directory in which this was run).
7.  Install GStreamer plugins that you need:
    `sudo apt-get install gstreamer1.0-<plugin>`; values of `<plugin>`
    needed are: "**plugins-base**", "**libav**" (for sound),
    "**plugins-good**" (for v4l2 hardware h264 decoding) and
    "**plugins-bad**" (for h264 decoding). Also needed may be "**gl**"
    for OpenGL support (which may be useful, and should be used with
    h264 decoding by the NVIDIA GPU), and "**x**" for X11 support,
    although these may already be installed; "**vaapi**" is needed for
    hardware-accelerated h264 video decoding by Intel or AMD graphics
    (but not for use with NVIDIA using proprietary drivers). Also
    install "**tools**" to get the utility gst-inspect-1.0 for examining
    the GStreamer installation.

*If you intend to modify the code, use a separate "build" directory:
replace* "`cmake  [ ] .`" *by*
"`mkdir build ; cd build ; cmake [ ] ..`"; *you can then clean the build
directory with* "`rm -rf build/*`" *(run from within the UxPlay source
directory) without affecting the source directories which contain your
modifications*.

The above script installs the executable file "`uxplay`" to
`/usr/local/bin`, (and installs a manpage to somewhere like
`/usr/local/share/man/man1` and README files to somewhere like
`/usr/local/share/doc/uxplay`). The uxplay executable can also be found
in the build directory after the build processs, if you wish to test
before installing.

**Finally, run uxplay in a terminal window**. Use Ctrl-C (or close the
window) to terminate it when done. If it is not seen by the iOS client's
drop-down "Screen Mirroring" panel, check that your DNS-SD server
(usually avahi-daemon) is running: do this in a terminal window with
`systemctl status avahi-daemon`. If this shows the avahi-daemon is not
running, control it with
`sudo systemctl [start,stop,enable,disable] avahi-daemon` (or
avahi-daemon.service). If UxPlay is seen, but the client fails to
connect when it is selected, there may be a firewall on the server that
prevents UxPlay from receiving client connection requests unless some
network ports are opened. See [Troubleshooting](#troubleshooting) below
for help with this or other problems.

**One common problem involves GStreamer attempting to use
incorrectly-configured or absent accelerated hardware h264 video
decoding (e.g., VAAPI). Try "`uxplay -avdec`" to force software video
decoding; if this works you can then try to fix accelerated hardware
video decoding if you need it, or just uninstall the GStreamer VAAPI
plugin. If your system uses the Wayland compositor for graphics, use
"`uxplay -vs waylandsink`".** See [Usage](#usage) for more run-time
options.

### **Special instructions for Raspberry Pi (only tested on model 4B)**:

-   For good performance, the Raspberry Pi needs the GStreamer
    Video4linux2 plugin to use its Broadcom GPU hardware for decoding
    h264 video. You can also test UxPlay with software-only video
    decoding using option `-avdec`.

-   The upcoming GStreamer-1.22 release will work well, but older
    releases of GStreamer will not work unless patched with backports of
    the improvements from GStreamer-1.22. Patches for GStreamer-1.18.4
    and later are [available with instructions in the UxPlay
    Wiki](https://github.com/FDH2/UxPlay/wiki/Gstreamer-Video4Linux2-plugin-patches).

The basic uxplay options for R Pi are `uxplay -v4l2 [-vs <videosink>]`.
The choice `<videosink>` = `glimagesink` is sometimes useful. On a
system without X11 (like R Pi OS Lite) with framebuffer video, use
`<videosink>` = `kmssink`. With the Wayland video compositor (as in
recent Ubuntu for R Pi) use `<videosink>` = `waylandsink`. For
convenience, these options are also available combined in options
`-rpi`, `-rpigl` `-rpifb`, `-rpiwl`, respectively provided for X11, X11
with OpenGL, framebuffer, and Wayland systems. You may find the simple
"uxplay", (which lets GStreamer try to find the best video solution by
itself) provides the best results.

-   **If you are not using the latest patches from the wiki, you will
    also need to add the `-bt709` option**: previously the GStreamer
    v4l2 plugin could not recognise Apple's color format (an unusual
    "full-range" variant of the bt709 HDTV standard), which -bt709
    fixes.

-   Tip: to start UxPlay on a remote host (such as a Raspberry Pi) using
    ssh:

```{=html}
<!-- -->
```
       ssh user@remote_host
       export DISPLAY=:0
       nohup uxplay [options] > FILE &

Sound and video will play on the remote host; "nohup" will keep uplay
running if the ssh session is closed.\
Terminal output is saved to FILE (which can be /dev/null to discard it).

### Non-Debian-based Linux or \*BSD

-   **Red Hat, Fedora, CentOS (now continued as Rocky Linux or Alma
    Linux):** (sudo yum install) openssl-devel libplist-devel
    avahi-compat-libdns_sd-devel (some from the "PowerTools" add-on
    repository) (+libX11-devel for ZOOMFIX). The required GStreamer
    packages (some from [rpmfusion.org](https://rpmfusion.org)) are:
    gstreamer1-devel gstreamer1-plugins-base-devel gstreamer1-libav
    gstreamer1-plugins-bad-free (+ gstreamer1-vaapi for intel graphics).

-   **OpenSUSE:** (sudo zypper install) libopenssl-devel libplist-devel
    avahi-compat-mDNSResponder-devel (+ libX11-devel for ZOOMFIX). The
    required GStreamer packages are: gstreamer-devel
    gstreamer-plugins-base-devel gstreamer-plugins-libav
    gstreamer-plugins-bad (+ gstreamer-plugins-vaapi for Intel
    graphics); in some cases, you may need to use gstreamer packages for
    OpenSUSE from
    [Packman](https://ftp.gwdg.de/pub/linux/misc/packman/suse/)
    "Essentials".

-   **Arch Linux** (sudo pacman -Syu) openssl libplist avahi
    gst-plugins-base gst-plugins-good gst-plugins-bad gst-libav (+
    gstreamer-vaapi for Intel graphics). (**Also available as a package
    in AUR**).

-   **FreeBSD:** (sudo pkg install) libplist gstreamer1,
    gstreamer1-libav, gstreamer1-plugins, gstreamer1-plugins-\* (\* =
    core, good, bad, x, gtk, gl, vulkan, pulse ...), (+ gstreamer1-vaapi
    for Intel graphics). Either avahi-libdns or mDNSResponder must also
    be installed to provide the dns_sd library. OpenSSL is already
    installed as a System Library. "ZOOMFIX" is untested; don't try to
    use it on FreeBSD unless you need it.

## Building UxPlay on macOS: **(Intel X86_64 and "Apple Silicon" M1 Macs)**

*Note: A native AirPlay Server feature is included in macOS 12 Monterey,
but is restricted to recent hardware. UxPlay can run on older macOS
systems that will not be able to run Monterey, or can run Monterey but
not AirPlay.*

These instructions for macOS asssume that the Xcode command-line
developer tools are installed (if Xcode is installed, open the Terminal,
type "sudo xcode-select --install" and accept the conditions).

It is also assumed that CMake \>= 3.13 is installed: this can be done
with package managers [MacPorts](http://www.macports.org),
[Fink](http://finkproject.org) or [Homebrew](http://brew.sh), or by a
download from <https://cmake.org/download/>.

First install OpenSSL and libplist: static versions of these libaries
will be used, so they can be uninstalled after UxPlay is built. These
are available in MacPorts and Homebrew, or they can easily be built from
source (see instructions at the end of this README; this requires
development tools autoconf, automake, libtool, which can be installed
using MacPorts, HomeBrew, or Fink).

Next get the latest macOS release of GStreamer-1.0.

-   recommended: install the "official" GStreamer release for macOS from
    <https://gstreamer.freedesktop.org/download/>. The alternative is to
    install it from Homebrew (MacPorts also supplies it, but compiled to
    use X11).

**For the "official" release**: install both the macOS runtime and
development installer packages. Assuming that the latest release is
1.20.2. install `gstreamer-1.0-1.20.2-universal.pkg` and
`gstreamer-1.0-devel-1.20.2-universal.pkg`. (If you have an
Intel-architecture Mac, and have problems with the "universal" packages,
you can also use `gstreamer-1.0-1.18.6-x86_64.pkg` and
`gstreamer-1.0-devel-1.18.6-x86_64.pkg`.) Click on them to install (they
install to /Library/FrameWorks/GStreamer.framework).

**For Homebrew**: pkgconfig is needed ("brew install pkgconfig"). Then
"brew install gst-plugins-base gst-plugins-good gst-plugins-bad
gst-libav". This appears to be functionally equivalent to using
GStreamer.framework, but causes a large number of extra packages to be
installed by Homebrew as dependencies. **You may need to set the
environment variable GST_PLUGIN_PATH=/usr/local/lib/gstreamer-1.0 to
point to the Homebrew GStreamer installation.**

Finally, build and install uxplay (without ZOOMFIX): open a terminal and
change into the UxPlay source directory ("UxPlay-master" for zipfile
downloads, "UxPlay" for "git clone" downloads) and build/install with
"cmake . ; make ; sudo make install" (same as for Linux).

-   On macOS with this installation of GStreamer, the only videosinks
    available seem to be glimagesink (default choice made by
    autovideosink) and osxvideosink. The window title does not show the
    Airplay server name, but the window is visible to screen-sharing
    apps (e.g., Zoom). The only available audiosink seems to be
    osxaudiosink.

-   The option -t *timeout* is currently suppressed, and the option -nc
    is always used, whether or not it is selected. This is a workaround
    for a problem with GStreamer videosinks on macOS: if the GStreamer
    pipeline is destroyed while the mirror window is still open, a
    segfault occurs.

-   In the case of glimagesink, the resolution settings "-s wxh" do not
    affect the (small) initial OpenGL mirror window size, but the window
    can be expanded using the mouse or trackpad. In contrast, a window
    created with "-vs osxvideosink" is initially big, but has the wrong
    aspect ratio (stretched image); in this case the aspect ratio
    changes when the window width is changed by dragging its side.

***Using GStreamer installed from MacPorts (not recommended):***

To install: "sudo port install pkgconfig"; "sudo port install
gstreamer1-gst-plugins-base gstreamer1-gst-plugins-good
gstreamer1-gst-plugins-bad gstreamer1-gst-libav". **The MacPorts
GStreamer is built to use X11**, so uxplay must be run from an XQuartz
terminal, can use ZOOMFIX, and needs option "-vs ximagesink". On an
unibody (non-retina) MacBook Pro, the default resolution wxh = 1920x1080
was too large, but using option "-s 800x600" worked. The MacPorts
GStreamer pipeline seems fragile against attempts to change the X11
window size, or to rotations that switch a connected client between
portrait and landscape mode while uxplay is running. Using the MacPorts
X11 GStreamer seems only possible if the image size is left unchanged
from the initial "-s wxh" setting (also use the iPad/iPhone setting that
locks the screen orientation against switching between portrait and
landscape mode as the device is rotated).

# Usage

Options:

**-n server_name** (Default: UxPlay); server_name@\_hostname\_ will be
the name that appears offering AirPlay services to your iPad, iPhone
etc, where *hostname* is the name of the server running uxplay. This
will also now be the name shown above the mirror display (X11) window.

**-nh** Do not append "@_hostname_" at the end of the AirPlay server
name.

**-s wxh** (e.g. -s 1920x1080 , which is the default ) sets the display
resolution (width and height, in pixels). (This may be a request made to
the AirPlay client, and perhaps will not be the final resolution you
get.) w and h are whole numbers with four digits or less. Note that the
**height** pixel size is the controlling one used by the client for
determining the streaming format; the width is dynamically adjusted to
the shape of the image (portrait or landscape format, depending on how
an iPad is held, for example).

**-s wxh@r** As above, but also informs the AirPlay client about the
screen refresh rate of the display. Default is r=60 (60 Hz); r must be a
whole number less than 256.

**-o** turns on an "overscanned" option for the display window. This
reduces the image resolution by using some of the pixels requested by
option -s wxh (or their default values 1920x1080) by adding an empty
boundary frame of unused pixels (which would be lost in a full-screen
display that overscans, and is not displayed by gstreamer).
Recommendation: **don't use this option** unless there is some special
reason to use it.

**-fs** uses fullscreen mode, but only works with Wayland or VAAPI
plugins.

**-p** allows you to select the network ports used by UxPlay (these need
to be opened if the server is behind a firewall). By itself, -p sets
"legacy" ports TCP 7100, 7000, 7001, UDP 6000, 6001, 7011. -p n (e.g. -p
35000) sets TCP and UDP ports n, n+1, n+2. -p n1,n2,n3 (comma-separated
values) sets each port separately; -p n1,n2 sets ports n1,n2,n2+1. -p
tcp n or -p udp n sets just the TCP or UDP ports. Ports must be in the
range \[1024-65535\].

If the -p option is not used, the ports are chosen dynamically
(randomly), which will not work if a firewall is running.

**-avdec** forces use of software h264 decoding using Gstreamer element
avdec_h264 (libav h264 decoder). This option should prevent
autovideosink choosing a hardware-accelerated videosink plugin such as
vaapisink.

**-vp *parser*** choses the GStreamer pipeline's h264 parser element,
default is h264parse. Using quotes "..." allows options to be added.

**-vd *decoder*** chooses the GStreamer pipeline's h264 decoder element,
instead of letting decodebin pick it for you. Software decoding is done
by avdec_h264; various hardware decoders include: vaapih264dec, nvdec,
nvh264dec, v4l2h264dec (these require that the appropriate hardware is
available). Using quotes "..." allows some parameters to be included
with the decoder name.

**-vc *converter*** chooses the GStreamer pipeline's videoconverter
element, instead of the default value "videoconvert". When using
Video4Linux2 hardware-decoding by a GPU,`-vc  v4l2convert` will also use
the GPU for video conversion. Using quotes "..." allows some parameters
to be included with the converter name.

**-vs *videosink*** chooses the GStreamer videosink, instead of letting
autovideosink pick it for you. Some videosink choices are: ximagesink,
xvimagesink, vaapisink (for intel graphics), gtksink, glimagesink,
waylandsink, osximagesink (for macOS), kmssink (for systems without X11,
like Raspberry Pi OS lite) or fpsdisplaysink (which shows the streaming
framerate in fps). Using quotes "..." allows some parameters to be
included with the videosink name. For example, **fullscreen** mode is
supported by the vaapisink plugin, and is obtained using
`-vs "vaapisink fullscreen=true"`; this also works with `waylandsink`.
The syntax of such options is specific to a given plugin, and some
choices of videosink might not work on your system.

**-vs 0** suppresses display of streamed video, but plays streamed
audio. (The client's screen is still mirrored at a reduced rate of 1
frame per second, but is not rendered or displayed.) This feature (which
streams audio in AAC audio format) is now probably unneeded, as UxPlay
can now stream superior-quality Apple Lossless audio without video in
Airplay non-mirror mode.

**-v4l2** Video settings for hardware h264 video decoding in the GPU by
Video4Linux2. Equivalent to `-vd v4l2h264dec -vc v4l2convert`.

**-bt709** A workaround for the failure of the older Video4Linux2 plugin
to recognize Apple's use of an uncommon (but permitted) "full-range
color" variant of the bt709 color standard for digital TV. This is no
longer needed by GStreamer-1.20.4 and backports from it.

**-rpi** Equivalent to "-v4l2". Use for "Desktop" Raspberry Pi systems
with X11.

**-rpigl** Equivalent to "-v4l2 -vs glimagesink". Sometimes better for
"Desktop" Raspberry Pi systems with X11.

**-rpifb** Equivalent to "-rpi -vs kmssink" (use for Raspberry Pi
systems using the framebuffer, like RPi OS Bullseye Lite).

**-rpiwl** Equivalent to "-rpi -vs waylandsink", for Raspberry Pi
"Desktop" systems using the Wayland video compositor (use for Ubuntu
21.10 for Raspberry Pi 4B).

**-as *audiosink*** chooses the GStreamer audiosink, instead of letting
autoaudiosink pick it for you. Some audiosink choices are: pulsesink,
alsasink, osssink, oss4sink, and osxaudiosink (for macOS). Using quotes
"..." might allow some parameters to be included with the audiosink
name. (Some choices of audiosink might not work on your system.)

**-as 0** (or just **-a**) suppresses playing of streamed audio, but
displays streamed video.

**-ca *filename*** provides a file (where *filename* can include a full
path) used for output of "cover art" (from Apple Music, *etc.*,) in
audio-only ALAC mode. This file is overwritten with the latest cover art
as it arrives. Cover art (jpeg format) is discarded if this option is
not used. Use with a image viewer that reloads the image if it changes,
or regularly (*e.g.* once per second.). To achieve this, run
"`uxplay -ca [path/to/]filename &`" in the background, then run the the
image viewer in the foreground. Example, using `feh` as the viewer: run
"`feh -R 1 [path/to/]filename`" (in the same terminal window in which
uxplay was put into the background). To quit, use `ctrl-C fg ctrl-C` to
terminate the image viewer, bring `uxplay` into the foreground, and
terminate it too.

**-reset n** sets a limit of n consecutive timeout failures of the
client to respond to ntp requests from the server (these are sent every
3 seconds to check if the client is still present). After n failures,
the client will be presumed to be offline, and the connection will be
reset to allow a new connection. The default value of n is 5; the value
n = 0 means "no limit" on timeouts.

**-nc** maintains previous UxPlay \< 1.45 behavior that does **not
close** the video window when the the client sends the "Stop Mirroring"
signal. *This option is currently used by default in macOS, as the
window created in macOS by GStreamer does not terminate correctly (it
causes a segfault) if it is still open when the GStreamer pipeline is
closed.*

**-FPSdata** Turns on monitoring of regular reports about video
streaming performance that are sent by the client. These will be
displayed in the terminal window if this option is used. The data is
updated by the client at 1 second intervals.

**-fps n** sets a maximum frame rate (in frames per second) for the
AirPlay client to stream video; n must be a whole number less than 256.
(The client may choose to serve video at any frame rate lower than this;
default is 30 fps.) A setting below 30 fps might be useful to reduce
latency if you are running more than one instance of uxplay at the same
time. *This setting is only an advisory to the client device, so setting
a high value will not force a high framerate.* (You can test using "-vs
fpsdisplaysink" to see what framerate is being received, or use the
option -FPSdata which displays video-stream performance data
continuously sent by the client during video-streaming.)

**-f {H\|V\|I}** implements "videoflip" image transforms: H = horizontal
flip (right-left flip, or mirror image); V = vertical flip ; I = 180
degree rotation or inversion (which is the combination of H with V).

**-r {R\|L}** 90 degree Right (clockwise) or Left (counter-clockwise)
rotations; these image transforms are carried out after any **-f**
transforms.

**-m** generates a random MAC address to use instead of the true
hardware MAC number of the computer's network card. (Different
server_name, MAC addresses, and network ports are needed for each
running uxplay if you attempt to run two instances of uxplay on the same
computer.) If UxPlay fails to find the true MAC address of a network
card, (more specifically, the MAC address used by the first active
network interface detected) a random MAC address will be used even if
option **-m** was not specifed. (Note that a random MAC address will be
different each time UxPlay is started).

**-t *timeout*** will cause the server to relaunch (without stopping
uxplay) if no connections have been present during the previous
*timeout* seconds. You may wish to use this if the Server is not visible
to new Clients that were inactive when the Server was launched, and an
idle Bonjour registration eventually becomes unavailable for new
connections (this is a workaround for what may be due to a problem with
your DNS-SD or Avahi setup). *This option is currently disabled in
macOS, for the same reason that requires the -nc option.*

**-vdmp** Dumps h264 video to file videodump.h264. -vdmp n dumps not
more than n NAL units to videodump.x.h264; x= 1,2,... increases each
time a SPS/PPS NAL unit arrives. To change the name *videodump*, use
-vdmp \[n\] *filename*.

**-admp** Dumps audio to file audiodump.x.aac (AAC-ELD format audio),
audiodump.x.alac (ALAC format audio) or audiodump.x.aud (other-format
audio), where x = 1,2,3... increases each time the audio format changes.
-admp *n* restricts the number of packets dumped to a file to *n* or
less. To change the name *audiodump*, use -admp \[n\] *filename*.

**-d** Enable debug output. Note: this does not show GStreamer error or
debug messages. To see GStreamer error and warning messages, set the
environment variable GST_DEBUG with "export GST_DEBUG=2" before running
uxplay. To see GStreamer debug messages, set GST_DEBUG=4; increase this
to see even more of the GStreamer inner workings.

# Troubleshooting

Note: `uxplay` is run from a terminal command line, and informational
messages are written to the terminal.

### 0. Problems in compiling UxPlay.

One user (on Ubuntu) found compilation failed with messages about
linking to "usr/local/lib/libcrypto.a" and "zlib". This was because (in
addition to the standard ubuntu installation of libssl-dev), the user
was unaware that a second installation with libcrypto in /usr/local was
present. Solution: when more than one installation of OpenSSL is
present, set the environment variable OPEN_SSL_ROOT_DIR to point to the
correct one; on 64-bit Ubuntu, this is done by running
`export OPENSSL_ROOT_DIR=/usr/lib/X86_64-linux-gnu/` before running
cmake.

### 1. uxplay starts, but stalls after "Initialized server socket(s)" appears, *without any server name showing on the client*.

Stalling this way, with *no* server name showing *on the client* as
available, probably means that your network **does not have a running
Bonjour/zeroconf DNS-SD server.** On Linux, make sure Avahi is
installed, and start the avahi-daemon service on the system running
uxplay (your distribution will document how to do this). Some systems
may instead use the mdnsd daemon as an alternative to provide DNS-SD
service. *(FreeBSD offers both alternatives, but only Avahi was tested:
one of the steps needed for getting Avahi running on a FreeBSD system is
to edit `/usr/local/etc/avahi/avahi-daemon.conf` to uncomment a line for
airplay support.*)

After starting uxplay, use the utility `avahi-browse -a -t` in a
different terminal window on the server to verify that the UxPlay
AirTunes and AirPlay services are correctly registered (only the
AirTunes service is used in the "Legacy" AirPlay Mirror mode used by
UxPlay). If the UxPlay service is listed by avahi-browse, but is not
seen by the client, the problem is likely to be a problem with the local
network.

### 2. uxplay starts, but stalls after "Initialized server socket(s)" appears, *with the server name showing on the client* (but the client fails to connect when the UxPlay server is selected).

This shows that a *DNS-SD* service is working, but a firewall on the
server is probably blocking the connection request from the client. (One
user who insisted that the firewall had been turned off turned out to
have had *two* active firewalls (*firewalld* and *ufw*) *both* running
on the server!) If possible, either turn off the firewall to see if that
is the problem, or get three consecutive network ports, starting at port
n, all three in the range 1024-65535, opened for both tcp and udp, and
use "uxplay -p n" (or open UDP 6000, 6001, 6011 TCP 7000,7001,7100 and
use "uxplay -p").

### 3. Problems *after* the client-server connection has been made:

If you do *not* see the message `raop_rtp_mirror starting mirroring`,
something went wrong before the client-server negotiations were
finished. For such problems, use "uxplay -d" (debug log option) to see
what is happening: it will show how far the connection process gets
before the failure occurs. You can compare your debug output to that
from a successful start of UxPlay in the [UxPlay
Wiki](https://github.com/FDH2/UxPlay/wiki).

**If UxPlay reports that mirroring started, but you get no video or
audio, the problem is probably from a GStreamer plugin that doesn't work
on your system** (by default, GStreamer uses the "autovideosink" and
"autoaudiosink" algorithms to guess what are the "best" plugins to use
on your system).

**Raspberry Pi** devices (-rpi option) only work with hardware GPU
decoding if the Video4Linux2 plugin in GStreamer v1.20.x or earlier has
been patched (see the UxPlay
[Wiki](https://github.com/FDH2/UxPlay/wiki/Gstreamer-Video4Linux2-plugin-patches)
for patches). This may be fixed in the future when GStreamer-1.22 is
released, or by backport patches in distributions such as Raspberry Pi
OS (Bullseye).

Sometimes "autovideosink" may select the OpenGL renderer "glimagesink"
which may not work correctly on your system. Try the options "-vs
ximagesink" or "-vs xvimagesink" to see if using one of these fixes the
problem.

Other reported problems are connected to the GStreamer VAAPI plugin (for
hardware-accelerated Intel graphics, but not NVIDIA graphics). Use the
option "-avdec" to force software h264 video decoding: this should
prevent autovideosink from selecting the vaapisink videosink.
Alternatively, find out if the gstreamer1.0-vaapi plugin is installed,
and if so, uninstall it. (If this does not fix the problem, you can
reinstall it.)

There are some reports of other GStreamer problems with
hardware-accelerated Intel HD graphics. One user (on Debian) solved this
with "sudo apt install intel-media-va-driver-non-free". This is a driver
for 8'th (or later) generation "\*-lake" Intel chips, that seems to be
related to VAAPI accelerated graphics.

If you *do* have Intel HD graphics, and have installed the vaapi plugin,
but `-vs vaapisink` does not work, check that vaapi is not "blacklisted"
in your GStreamer installation: run `gst-inspect-1.0 vaapi`, if this
reports `0 features`, you need to `export GST_VAAPI_ALL_DRIVERS=1`
before running uxplay, or set this in the default environment.

You can try to fix audio problems by using the "-as *audiosink*" option
to choose the GStreamer audiosink , rather than have autoaudiosink pick
one for you. The command "gst-inspect-1.0 \| grep Sink \| grep Audio" "
will show you which audiosinks are available on your system. (Replace
"Audio" by "Video" to see videosinks). Some possible audiosinks are
pulsesink, alsasink, osssink, oss4sink, and osxaudiosink (macOS).

If you ran cmake with "-DZOOMFIX=ON", check if the problem is still
there without ZOOMFIX. ZOOMFIX is only applied to the default videosink
choice ("autovideosink") and the two X11 videosinks "ximagesink" and
"xvimagesink". ZOOMFIX is only designed for these last two; if
autovideosink chooses a different videosink, ZOOMFIX is now ignored. If
you are using the X11 windowing system (standard on Linux), and have
trouble with screen-sharing on Zoom, use ZOOMFIX and "-vs xvimagesink"
(or "-vs ximagesink" if the previous choice doesn't work).

As other videosink choices are not affected by ZOOMFIX, they may or may
not be visible to screen-sharing apps. Cairo-based windows created on
Linux with "-vs gtksink" are visible to screen-sharing aps without
ZOOMFIX; windows on macOS created by "-vs glimagesink" (default choice)
and "-vs osximagesink" are also visible.

The "OpenGL renderer" window created on Linux by "-vs glimagesink"
sometimes does not close properly when its "close" button is clicked.
(this is a GStreamer issue). You may need to terminate uxplay with
Ctrl-C to close a "zombie" OpenGl window. If similar problems happen
when the client sends the "Stop Mirroring" signal, try the no-close
option "-nc" that leaves the video window open.

### 4. GStreamer issues (missing plugins, etc.):

To troubleshoot GStreamer execute "export GST_DEBUG=2" to set the
GStreamer debug-level environment-variable in the terminal where you
will run uxplay, so that you see warning and error messages; see
[GStreamer debugging
tools](https://gstreamer.freedesktop.org/documentation/tutorials/basic/debugging-tools.html)
for how to see much more of what is happening inside GStreamer. Run
"gst-inspect-1.0" to see which GStreamer plugins are installed on your
system.

Some extra GStreamer packages for special plugins may need to be
installed (or reinstalled: a user using a Wayland display system as an
alternative to X11 reported that after reinstalling Lubuntu 18.4, UxPlay
would not work until gstreamer1.0-x was installed, presumably for
Wayland's X11-compatibility mode). Different distributions may break up
GStreamer 1.x into packages in different ways; the packages listed above
in the build instructions should bring in other required GStreamer
packages as dependencies, but will not install all possible plugins.

The GStreamer video pipeline, which is shown in the initial output from
`uxplay -d`, has the default form

    appsrc name=video_source ! queue ! h264parse ! decodebin ! videoconvert ! autovideosink name=video_sink sync=false

The pipeline is fully configurable: default elements "h264parse",
"decodebin", "videoconvert", and "autovideosink" can respectively be
replaced by using uxplay options `-vp`, `-vd`, `-vc`, and `-vs`, if
there is any need to modify it (entries can be given in quotes "..." to
include options).

### 5. Mirror screen freezes:

This can happen if the TCP video stream from the client stops arriving
at the server, probably because of network problems (the UDP audio
stream may continue to arrive). At 3-second intervals, UxPlay checks
that the client is still connected by sending it a request for a NTP
time signal. If a reply is not received from the client within a 0.3 sec
time-window, an "ntp timeout" is registered. If a certain number
(currently 5) of consecutive ntp timeouts occur, UxPlay assumes that the
client is "dead", and resets the connection, becoming available for
connection to a new client, or reconnection to the previous one.
Sometimes the connection may recover before the timeout limit is
reached, and if the default limit is not right for your network, it can
be modified using the option "-reset *n*", where *n* is the desired
timeout-limit value (*n* = 0 means "no limit"). If the connection starts
to recover after ntp timeouts, a corrupt video packet from before the
timeout may trigger a "connection reset by peer" error, which also
causes UxPlay to reset the connection. When the connection is reset, the
"frozen" mirror screen of the previous connection is left in place, and
will be taken over by a new client connection when it is made.

### 6. Protocol issues, such as failure to decrypt ALL video and audio streams from old or non-Apple clients:

A protocol failure may trigger an unending stream of error messages, and
means that the audio decryption key (also used in video decryption) was
not correctly extracted from data sent by the client. This should not
happen for iOS 9.3 or later clients. However, if a client uses the same
older version of the protocol that is used by the Windows-based AirPlay
client emulator *AirMyPC*, the protocol can be switched to the older
version by the setting `OLD_PROTOCOL_CLIENT_USER_AGENT_LIST` in
`UxPlay/lib/global.h`. UxPlay reports the client's "User Agent" string
when it connects. If some other client also fails to decrypt all audio
and video, try adding its "User Agent" string in place of "xxx" in the
entry "AirMyPC/2.0;xxx" in global.h and rebuild uxplay.

Note that Uxplay declares itself to be an AppleTV3,2 with a
sourceVersion 220.68; this can also be changed in global.h. It had been
thought that it was necessary for UxPlay to claim to be an older 32 bit
AppleTV model that cannot run modern 64bit tvOS, in order for the client
to use a "legacy" protocol for pairing with the server (see the *"Notes
on AirPlay protocol versions"* at the end of this README). However,
UxPlay still works if it declares itself as an AppleTV6,2 with
sourceVersion 380.20.1 (an AppleTV 4K 1st gen, introduced 2017, running
tvOS 12.2.1); it seems that the use of "legacy" protocol just requires
bit 27 (listed as "SupportsLegacyPairing") of the "features" plist code
(reported to the client by the AirPlay server) to be set. The "features"
code and other settings are set in `UxPlay/lib/dnssdint.h`.

# ChangeLog

1.56 2022-07-30 Remove -bt709 from -rpi, -rpiwl, -rpifb as GStreamer is
now fixed.

1.55 2022-07-04 Remove the bt709 fix from -v4l2 and create a new -bt709
option (previous "-v4l2" is now "-v4l2 -bt709"). This allows the
currently-required -bt709 option to be used on its own on RPi without
-v4l2 (sometimes this give better results).

1.54 2022-06-25 Add support for "Cover Art" display in Audio-only (ALAC)
mode. Reverted a change that caused VAAPI to crash with AMD POLARIS
graphics cards. Minor internal changes to plist code and uxplay option
parsing.

1.53 2022-06-13 Internal changes to audio sync code, revised
documentation, Minor bugfix (fix assertion crash when resent audio
packets are empty).

1.52 2022-05-05 Cleaned up initial audio sync code, and reformatted
streaming debug output (readable aligned timestamps with decimal points
in seconds). Eliminate memory leaks (found by valgrind). Support for
display of ALAC (audio-only) metadata (soundtrack artist names, titles
etc.) in the uxplay terminal.

1.51 2022-04-24 Reworked options forVideo4Linux2 support (new option
-v4l2) and short options -rpi, -rpifb, -rpiwl as synonyms for -v4l2,
-v4l2 -vs kmssink, and -v4l2 -vs waylandsink. Reverted a change from
1.48 that broke reconnection after "Stop Mirroring" is sent by client.

1.50 2022-04-22 Added -fs fullscreen option (for Wayland or VAAPI
plugins only), Changed -rpi to be for framebuffer ("lite") RPi systems
and added -rpigl (OpenGL) and -rpiwl (Wayland) options for RPi Desktop
systems. Also modified timestamps from "DTS" to "PTS" for latency
improvement, plus internal cleanups.

1.49 2022-03-28 Addded options for dumping video and/or audio to file,
for debugging, etc. h264 PPS/SPS NALU's are shown with -d. Fixed
video-not-working for M1 Mac clients.

1.48 2022-03-11 Made the GStreamer video pipeline fully configurable,
for use with hardware h264 decoding. Support for Raspberry Pi.

1.47 2022-02-05 Added -FPSdata option to display (in the terminal)
regular reports sent by the client about video streaming performance.
Internal cleanups of processing of video packets received from the
client. Added -reset n option to reset the connection after n ntp
timeouts (also reset after "connection reset by peer" error in video
stream).

1.46 2022-01-20 Restore pre-1.44 behavior (1.44 may have broken hardware
acceleration): once again use decodebin in the video pipeline; introduce
new option "-avdec" to force software h264 decoding by libav h264, if
needed (to prevent selection of vaapisink by autovideosink). Update
llhttp to v6.0.6. UxPlay now reports itself as AppleTV3,2. Restrict
connections to one client at a time (second client must now wait for
first client to disconnect).

1.45 2022-01-10 New behavior: close video window when client requests
"stop mirroring". (A new "no close" option "-nc" is added for users who
wish to retain previous behavior that does not close the video window).

1.44 2021-12-13 Omit hash of aeskey with ecdh_secret for an AirMyPC
client; make an internal rearrangement of where this hash is done. Fully
report all initial communications between client and server in -d debug
mode. Replace decodebin in GStreamer video pipeline by h264-specific
elements.

1.43 2021-12-07 Various internal changes, such as tests for successful
decryption, uniform treatment of informational/debug messages, etc.,
updated README.

1.42 2021-11-20 Fix MAC detection to work with modern Linux interface
naming practices, MacOS and \*BSD.

1.41 2021-11-11 Further cleanups of multiple audio format support
(internal changes, separated RAOP and GStreamer audio/video startup)

1.40 2021-11-09 Cleanup segfault in ALAC support, manpage location fix,
show request Plists in debug mode.

1.39 2021-11-06 Added support for Apple Lossless (ALAC) audio streams.

1.38 2021-10-8 Add -as *audiosink* option to allow user to choose the
GStreamer audiosink.

1.37 2021-09-29 Append "@hostname" to AirPlay Server name, where
"hostname" is the name of the server running uxplay (reworked change in
1.36).

1.36 2021-09-29 Implemented suggestion (by @mrbesen and @PetrusZ) to use
hostname of machine runing uxplay as the default server name

1.35.1 2021-09-28 Added the -vs 0 option for streaming audio, but not
displaying video.

1.35 2021-09-10 now uses a GLib MainLoop, and builds on macOS (tested on
Intel Mac, 10.15 ). New option -t *timeout* for relaunching server if no
connections were active in previous *timeout* seconds (to renew Bonjour
registration).

1.341 2021-09-04 fixed: render logger was not being destroyed by
stop_server()

1.34 2021-08-27 Fixed "ZOOMFIX": the X11 window name fix was only being
made the first time the GStreamer window was created by uxplay, and not
if the server was relaunched after the GStreamer window was closed, with
uxplay still running. Corrected in v. 1.34

### ZOOMFIX compile-time option

In GStreamer-1.18.6 and earlier, if UxPlay is using an X11 window for
screen mirroring, this window is not visible to screen-sharing apps like
ZOOM. OpenGL-based windows (use `-vs glimagesink` or `-vs gtksink`,
*etc.*) do not have this problem.

A workaround is to manually make the X11 window visible to
screen-sharing apps with the X11 utility xdotool, if it is installed,
with: `xdotool selectwindow set_window --name <name>` (where `<name>` is
your choice of name), and then select the uxplay window by clicking on
it with the mouse.

However, if "`cmake -DZOOMFIX=ON .`" is run before compiling, the
mirrored window is visible to screen-sharing applications, without this
procedure. To compile with ZOOMFIX=ON, the X11 development libraries
must be installed. (Without ZOOMFIX, UxPlay has no dependence on X11).

**ZOOMFIX is not needed in GStreamer-1.20 or later.** Thanks to David
Ventura https://github.com/DavidVentura/UxPlay for the fix and also for
getting a fix into gstreamer-1.20.

### Building OpenSSL \>= 1.1.1 from source.

If you need to do this, note that you may be able to use a newer version
(OpenSSL-3.0.1 is known to work). You will need the standard development
toolset (autoconf, automake, libtool). Download the source code from
<https://www.openssl.org/source/>. Install the downloaded openssl by
opening a terminal in your Downloads directory, and unpacking the source
distribution: ("tar -xvzf openssl-3.0.1.tar.gz ; cd openssl-3.0.1").
Then build/install with "./config ; make ; sudo make install_dev". This
will typically install the needed library `libcrypto.*`, either in
/usr/local/lib or /usr/local/lib64.

*(Ignore the following for builds on MacOS:)* On some systems like
Debian or Ubuntu, you may also need to add a missing entry
`/usr/local/lib64` in /etc/ld.so.conf (or place a file containing
"/usr/local/lib64/libcrypto.so" in /etc/ld.so.conf.d) and then run "sudo
ldconfig".

### Building libplist \>= 2.0.0 from source.

*(Note: on Debian 9 "Stretch" or Ubuntu 16.04 LTS editions, you can
avoid this step by installing libplist-dev and libplist3 from Debian 10
or Ubuntu 18.04.)* As well as the usual build tools (autoconf, automake,
libtool), you may need to also install some libpython\*-dev package.
Download the latest source from
<https://github.com/libimobiledevice/libplist>: get
[libplist-master.zip](https://github.com/libimobiledevice/libplist/archive/refs/heads/master.zip),
then ("unzip libplist-master.zip ; cd libplist-master"), build/install
("./autogen.sh ; make ; sudo make install"). This will probably install
libplist-2.0.\* in /usr/local/lib.

*(Ignore the following for builds on MacOS:)* On some systems like
Debian or Ubuntu, you may also need to add a missing entry
`/usr/local/lib` in /etc/ld.so.conf (or place a file containing
"/usr/local/lib/libplist-2.0.so" in /etc/ld.so.conf.d) and then run
"sudo ldconfig".

# Disclaimer

All the resources in this repository are written using only freely
available information from the internet. The code and related resources
are meant for educational purposes only. It is the responsibility of the
user to make sure all local laws are adhered to.

This project makes use of a third-party GPL library for handling
FairPlay. The legal status of that library is unclear. Should you be a
representative of Apple and have any objections against the legality of
the library and its use in this project, please contact me and I'll take
the appropriate steps.

Given the large number of third-party AirPlay receivers (mostly
closed-source) available for purchase, it is my understanding that an
open source implementation of the same functionality wouldn't violate
any of Apple's rights either.

# UxPlay authors

*\[adapted from fdraschbacher's notes on RPiPlay antecedents\]*

The code in this repository accumulated from various sources over time.
Here is an attempt at listing the various authors and the components
they created:

UxPlay was initially created by **antimof** from RPiPlay, by replacing
its Raspberry-Pi-adapted OpenMAX video and audio rendering system with
GStreamer rendering for desktop Linux systems (antimof's work on code in
`renderers/` was later backported to RPiPlay).

The previous authors of code included in UxPlay by inheritance from
RPiPlay include:

-   **EstebanKubata**: Created a FairPlay library called
    [PlayFair](https://github.com/EstebanKubata/playfair). Located in
    the `lib/playfair` folder. License: GNU GPL
-   **Juho Vähä-Herttua** and contributors: Created an AirPlay audio
    server called [ShairPlay](https://github.com/juhovh/shairplay),
    including support for Fairplay based on PlayFair. Most of the code
    in `lib/` originally stems from this project. License: GNU LGPLv2.1+
-   **dsafa22**: Created an AirPlay 2 mirroring server
    [AirplayServer](https://github.com/dsafa22/AirplayServer) (seems
    gone now), for Android based on ShairPlay. Code is preserved
    [here](https://github.com/jiangban/AirplayServer), and [see
    here](https://github.com/FDH2/UxPlay/wiki/AirPlay2) for the
    description of the analysis of the AirPlay 2 mirror protocol that
    made RPiPlay possible, by the AirplayServer author. All code in
    `lib/` concerning mirroring is dsafa22's work. License: GNU
    LGPLv2.1+
-   **Florian Draschbacher** (FD-) and contributors: adapted dsafa22's
    Android project for the Raspberry Pi, with extensive cleanups,
    debugging and improvements. The project
    [RPiPlay](https://github.com/FD-/RPiPlay) is basically a port of
    dsafa22's code to the Raspberry Pi, utilizing OpenMAX and OpenSSL
    for better performance on the Pi. License GPL v3. FD- has written an
    interesting note on the history of [Airplay protocol
    versions](http://github.com/FD-/RPiPlay#airplay-protocol-versions),
    available at the RPiPlay github repository.

Independent of UxPlay, but used by it and bundled with it:

-   **Fedor Indutny** (of Node.js, and formerly Joyent, Inc) and
    contributors: Created an http parsing library called
    [llhttp](https://github.com/nodejs/llhttp). Located at
    `lib/llhttp/`. License: MIT
