PyLivestream

Python scripted livestreaming using FFmpeg

NOTE: This project is archived effectively. Use OBS Studio etc. for livestreaming.

Emits command to run FFmpeg for livestreaming video services, using pure object-oriented Python. 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
• Twitch
• also IBM Live Video, 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 single JSON file pylivestream.json to adjust 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

Alternatives

Other projects using FFmpeg from Python include:

• python-ffmpeg lower level use of FFmpeg with Python asyncio
• asyncio-subprocess-ffpmeg simple asyncio subprocess example that could also be used as a template for general asyncio subprocess Python use.
• ffmpy FFmpeg subprocess without asyncio

Install

Latest release:

python3 -m pip install PyLivestream

Development version:

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

cd PyLivestream

python3 -m pip install -e .

FFmpeg can be obtained like:

• Windows: winget install ffmpeg
• Linux: sudo apt install ffmpeg
• MacOS: brew install ffmpeg

If errors result from FFmpeg not in PATH environment variable, optionally set environment variable “FFMPEG_ROOT” to the directory containing FFmpeg executable.

Configuration: pylivestream.json

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

The pylivestream.json file you create has parameters relevant to the live stream. We suggest copying the example pylivestream.json and editing, then specify it for your streams.

• screencap_origin: origin (upper left corner) of screen capture region in pixels.
• screencap_size: 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
• audio_rate: 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.
• exe: override path to desired FFmpeg executable. In case you have multiple FFmpeg versions installed (say, from Anaconda Python).

Next are sys.platform specific parameters.

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

Deduce inputs

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

• audio_chan: audio device
• camera_chan: camera device
• screen_chan: 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

• command line
  • python -m pylivestream.fglob
  • python -m pylivestream.screen
  • python -m pylivestream.loopfile
  • python -m pylivestream.screen2disk
  • python -m pylivestream.camera
  • python -m pylivestream.microphone
• 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_camera()

Authentication

The program loads a JSON file with the stream URL and hexadecimal stream key for the website(s) used. The user must specify this JSON file location.

YouTube Live

1. configure YouTube Live.
2. Edit “pylivestream.json” to have the YouTube streamid
3. Run Python script for YouTube with chosen input

python -m pylivestream.screen youtube ./pylivestream.json

Facebook Live

Facebook Live requires FFmpeg ≥ 4.2 due to mandatory RTMPS.

1. configure a Facebook Live stream
2. Put stream ID into the JSON file
3. Run Python script for Facebook with chosen input

python -m pylivestream.screen facebook ./pylivestream.json

Twitch

Create stream from Twitch Dashboard. Edit pylivestream.json file with “url” and “streamid” for Twitch. Run Python script for Twitch with chosen input:

python -m pylivestream.screen twitch ./pylivestream.json

Usage

Setup a pylivestream.json for computer and desired parameters. Copy the provided pylivestream.json and edit with values you determine.

Single video file:

python -m pylivestream.loopfile videofile youtube

Camera

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

JSON:

• camera_size: camera resolution – find from v4l2-ctl --list-formats-ext or camera spec sheet.
• camera_fps: camera fps – found from command above or camera spec sheet

python -m pylivestream.camera youtube ./pylivestream.json

Screenshare Livestream:

python -m pylivestream.screen facebook ./pylivestream.json

Microphone audio + static image is accomplished by:

python -m pylivestream.microphone youtube ./pylivestream.json -image doc/logo.jpg

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.

python -m pylivestream.microphone localhost ./pylivestream.json

Saves screen capture to a file on your disk:

python -m pylivestream.screen2disk myvid.avi ./pylivestream.json

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). If Wayland is required, consider OBS Studio. x11grab is used for screen capture on Linux.

• FFmpeg streaming
• FFmpeg camera
• Camera FFmpeg overlay

Windows

• gdigrab

DirectShow didn’t seem to work on Windows, so we used gdigrab instead.

• DirectShow device selection
• DirectShow examples

Stream References

• X Live doesn’t give any specific settings.

• Twitch ingest servers

• Twitch encoding

• YouTube Live parameters

• Facebook Live parameters

• Owncast parameters

• IBM Cloud Video parameters

• Vimeo

Logo Credits

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