Python scripted livestreaming using FFmpeg

Streams to one or multiple streaming sites simultaneously, using pure object-oriented Python (no extra packages) and FFmpeg. Tested with flake8, mypy type checking and pytest. visual_tests.py is a quick check of several command line scripting scenarios on your laptop. FFmpeg is used from Python subprocess to stream to sites including:

• Facebook Live (requires FFmpeg >= 4.2 due to mandatory RTMPS)
• YouTube Live
• Periscope
• Twitch
• also Ustream, Vimeo, Restream.io and more for streaming broadcasts.

Troubleshooting

PyLivestream benefits

• Python scripts compute good streaming parameters, and emit the command used to copy and paste if desired.
• Works on any OS (Mac, Linux, Windows) and computing platform, including PC, Mac, and Raspberry Pi.
• Uses a pylivestream.ini file to adjust all parameters.

PyLivestream limitations

• does not auto-restart if network connection glitches
• is intended as a bare minimum command generator to run the FFmpeg program
• is not intended for bidirectional robust streaming--consider a program/system based on Jitsi for that.

Design rationale

Why not do things without the command line, via linking libffmpeg, libgstreamer or libav?

• the command-line approach does not require a compiler or OS-dependent libraries
• once you get a setup working once, you don't even need Python anymore--just copy and paste the command line

Install

Requires FFmpeg ≥ 3.0 (≥ 4.2 for Facebook Live RTMPS)

Latest release:

python3 -m pip install PyLivestream

Development version:

git clone https://github.com/scivision/PyLivestream

cd PyLivestream

python3 -m pip install -e .

Configuration: pylivestream.ini

You can skip past this section to "stream start" if it's confusing. The defaults might work to get you started.

The pylivestream.ini file contains parameters relevant to your stream. This file is copied into your sys.prefix/share/pylivestream directory upon pip install pylivestream.

We suggest copying this file to another location on your hard drive and editing, then specifying it for your streams.

The [DEFAULT] section has parameters that can be overridden for each site, if desired.

• screencap_origin: origin (upper left corner) of screen capture region in pixels.

• screencap_res: resolution of screen capture (area to capture, starting from origin)

• screencap_fps: frames/sec of screen capture

• video_kbps: override automatic video bitrate in kbps

• audiofs: audio sampling frequency. Typically 44100 Hz (CD quality).

• audio_bps: audio data rate--leave blank if you want no audio (usually used for "file", to make an animated GIF in post-processing)

• preset: veryfast or ultrafast if CPU not able to keep up.

Next are sys.platform specific parameters.

Seek help in FFmpeg documentation, try capturing to a file first and then update pylivestream.ini for your sys.platform.

• exe: override path to desired FFmpeg executable. In case you have multiple FFmpeg versions installed (say, from Anaconda Python).

Finally are the per-site parameters. The only thing you would possibly need to change here is the server for best performance for your geographic region. The included pylivestream.ini is with default servers for the Northeastern USA.

Deduce inputs

Each computer will need distinct pylivestream.ini device input parameters:

• audiochan: audio device
• webcamchan: webcam device
• screenchan: desktop capture software port name

Loopback devices that let you "record what you hear" are operating system dependent. You may need to search documentation for your operating system to enable such a virtual loopback device.

Windows

ffmpeg -list_devices true -f dshow -i dummy

MacOS

ffmpeg -f avfoundation -list_devices true -i ""

Linux

v4l2-ctl --list-devices

API

There are two ways to start a stream (assuming you've configured as per following sections). Both do the same thing.

• command line via Python entry_points
  • FileGlobLivestream
  • ScreenshareLivestream
  • FileLoopLivestream
  • ScreenCapture2disk
  • WebcamLivestream
  • MicrophoneLivestream
• import pylivestream.api as pls from within your Python script. For more information type help(pls) or help(pls.stream_microphone)
  • pls.stream_file()
  • pls.stream_microphone()
  • pls.stream_webcam()

Authentication

The program will load a *.key file according to the configuration file key for the website. For example, Periscope expects to see the stream hexadecimal key in ~/periscope.key, as obtained from phone Periscope app. Likewise, YouTube expects a file ~/youtube.key with the hexadecimal stream key and so on.

YouTube Live

1. configure YouTube Live.

2. Edit file youtube.key to have the YouTube hexadecimal stream key

3. Run Python script and chosen input will stream on YouTube Live.

   ScreenshareLivestream youtube

Facebook Live

Facebook Live requires FFmpeg >= 4.2 due to mandatory RTMPS

1. configure your Facebook Live stream

2. Put stream ID from https://www.facebook.com/live/create into the file ~/facebook.key

3. Run Python script for Facebook with chosen input

   ScreenshareLivestream facebook

Periscope

1. create a new stream by EITHER:

   • from phone Periscope app, go to Profile -> Settings -> Periscope Producer and see your Stream Key. The "checking source" button will go to "preview stream" once you do step #2.
   • from computer web browser, go to Periscope Producer and Create New Source.

2. Put the hexadecimal stream key into ~/periscope.key

3. Run Python script for Periscope with chosen input

   ScreenshareLivestream periscope

I prefer using the Phone method as then the phone is a "second screen" where I can see if the stream is lagging, and if I "leave broadcast" and come back in, I can comment from my phone etc.

Twitch

1. create stream from Twitch Dashboard. Edit pylivestream.ini to have the closest ingest server.

2. put Twitch stream key into file ~/twitch.key

3. Run Python script for Twitch with chosen input

   ScreenshareLivestream twitch

Usage

Due to the complexity of streaming and the non-specific error codes FFmpeg emits, the default behavior is that if FFmpeg detects one stream has failed, ALL streams will stop streaming and the program ends.

• pylivestream.ini is setup for your computer and desired parameters
• site is facebook, periscope, youtube, etc.
• For WebcamLivestream and ScreenshareLivestream, more than one site can be specified for simultaneous multi-streaming
• remember to setup a *.key file with the hexadecimal stream key for EACH site first, OR input the stream key into the "key:" field of your *.ini file.

File-Streaming

Webcam

Note: your system may not have a webcam, particularly if it's a virtual machine.

Config:

• webcam_res: webcam resolution -- find from v4l2-ctl --list-formats-ext or webcam spec sheet.
• webcam_fps: webcam fps -- found from command above or webcam spec sheet

Stream to multiple sites, in this example Periscope and YouTube Live simultaneously:

WebcamLivestream youtube periscope

Screen Share Livestream

Stream to multiple sites, in this example Periscope and YouTube Live simultaneously:

ScreenshareLivestream youtube periscope

Image + Audio Livestream

Microphone audio + static image is accomplished by

MicrophoneLivestream youtube periscope -image doc/logo.jpg

or wherever your image file is.

Audio-only Livestream

Audio-only streaming is not typically allowed by the Video streaming sites. It may fail to work altogether, or may fail when one file is done and another starts. That's not something we can fix within the scope of this project. You can test it to your own computer by:

MicrophoneLivestream localhost

Screen capture to disk

This script saves your screen capture to a file on your disk:

ScreenCapture2disk myvid.avi

Utilities

• PyLivestream.get_framerate(vidfn) gives the frames/sec of a video file.
• PyLivestream.get_resolution(vidfn) gives the resolution (width x height) of video file.

Notes

• Linux requires X11, not Wayland (choose at login)
• x11grab was deprecated in FFmpeg 3.3, was previously replaced by xcbgrab
• Reference webpage

FFmpeg References

• streaming
• webcam
• webcam overlay

Windows

• gdigrab

DirectShow didn't work for me on Windows 10, so I used gdigrab instead.

• DirectShow device selection
• DirectShow examples

Stream References

• Twitch parameters

• Twitch ingest servers

• Twitch encoding

• Periscope parameters

• YouTube Live parameters

• Facebook Live parameters

• Ustream parameters

• Vimeo config

• Vimeo parameters

Logo Credits

• Owl PC: Creative Commons no attrib. commercial
• YouTube: YouTube Brand Resources
• Facebook: Wikimedia Commons
• Periscope