so currently I'm trying to make a Python script which reads the ALSA Mixer's output (or rather the general audio output) for the volumes/amplitudes of the current playing audio frequencies to trigger the GPIO ports on my Raspberry Pi, so I can effectively make an EQ out of LEDs responding to the current audio output. I want to create a real-time analysis (which is not bounded to the ALSA Mixer, whatever works, works), so I can stream my music from my iPhone via Airplay to the Raspberry Pi or watch a YouTube video and the LED-EQ is, well, doing what it's supposed to do.
My problem is that I coudn't found any library or function in python on the Internet, which let's me get the current audio output or rather the frequency amplitudes. Does anybody have an idea of how to make this thing going?
P.S.: I tried Lightshowpi but I couldn't figure out how to use Shairport-sync with it, so if anyone has an answer to that, let me know it. :)
Edit:
If there's a way to get the wave form from the e.g. the last 8 Bytes of the audio stream I may do a fourier transformation (could a fourier transformation really work in a real-time environment, because of the heavy maths load on the CPU?)
Related
I am currently trying to write a program that will detect a notification sound from an app and press some keys in response. I want it to be able to detect a specific sound from a sound file. This app also has background noise coming from it.
My research has been less than successful in finding an audio recognition software. If worst comes to worst I can also just use something that pulls audio from input and finagle OBS.
Background
I'm working on a music player, and want any sort of audio visualizer to be part of it. I've already made a previous post specifically targeting python-vlc, but I guess not too many people know about it. Here is the post in question: How to get audio samples from python-VLC
What I need
I need a way to listen to audio output, preferably by application although it is not completely necessary. It must be a python module.
What I found
A bunch of tutorials regarding audio input from the microphone, which is NOT what I need
Two swhardware.com tutorials with audio visualizers
https://swharden.com/blog/2016-07-19-realtime-audio-visualization-in-python/
Another one from 2013 but I can't find the link
PyAudio tutorials also using the microphone
Listening audio output with python
terminatorX on Linux; it uses the microphone
squishyball on Linux; it doesn't support all audio files
livefft; uses pyqt4 so I couldn't even test it
Alternatives
Any python module or linux terminal that can provide a list of audio samples from any audio file. Similar to pydub.AudioSegement.get_array_of_samples()
What I don't need
More suggestions to use pydub's get_array_of_samples()
Pydub doesn't read the audio file correctly and quickly gets out of sync from already playing audio
More tutorials of how to get audio from the microphone
Answers on how to strip audio from a video file with ffmpeg
import speech_recognition as sr
r = sr.Recognizer()
with sr.Microphone() as source:
audio = r.listen(source)
print(r.recognize_sphinx(audio))
When I run this code in Python in raspberry pi 3 (model B), it gives the following error.
OSError: No Default Input Device Available
what is the reason for this? do I need to have a USB microphone to get the audio signals in rather than using the microphone in earphones?
< /Hey >
As designed by the Raspberry Pi's circuit layout, in short:
The 3.5mm Audio Jack on the Raspberry Pi models cannot be used as an audio input.
I'm not sure if you would want to anyways.
This means you have a couple of options on how you want to set up your microphone setup.
1. Using a small mic array (Like Alexa Echo or Google Home)
A lot of the time these kind of systems are prototyped on Raspberry Pi's or similar (see the official Alexa development kit). You can find similar replicas to the microphone arrays found on google home etc. , specifically fitted for the Raspberry Pi. These include some added advanced features such as Noise Suppression, Direction of Sound Source and other neat features I'll leave for you to explore yourself.
Here's 3 I found after googling (I'm sure if you look you can find more):
ReSpeaker 4-mic array
ReSpeaker 7-mic array
Matrix Creator
If you wanted high quality results for speech recognition I'd probably begin to look more down this route.
2. Using a normal USB microphone
Probably the most common approach is to get a standard USB microphone that has Raspberry Pi drivers and use this. I found one from Adafruit which I'm sure is just plug and play which could be nice and easy to get going with.
Again I'm sure you'll find plenty of other options online, these were just suggestions to get you started.
Hopefully this helps! :-)
What you could use is a USB microphone, these tend to install the required drivers and work out of the box more easily.
Source: https://www.raspberrypi.org/forums/viewtopic.php?t=188108
We have a python program which outputs specific waveforms over the audio to drive an LED, for an easy and cheap robot programming device.
With the windows systems that we've tested everything works fine, but on some systems the waveform seems to be altered. We've used the control panel to disable any 'enhancements' for the audio output endpoint but it doesn't seem to help.
So, is it possible, using python, to instruct Windows to play audio unchanged? Or do some of the audio gurus here have another theory of what could be affecting the audio?
Sound cards are for playing audio, not sending data. You can't rely on an arbitrary signal not being altered by the hardware, much less the software. For example, many sound cards have a capacitor in series with the output to filter out DC bias. If you try to pass a DC-biased (or very low frequency) signal through such a sound card, it will be distorted. And there's nothing you can do about it at the software level.
Background
I'm attempting to craft a simple video playback script for a small cinema that automates the playing of videos and control of the projector, sound and lighting systems. I have two video outputs, one goes to a monitor in the projection booth, and the other directly to the projector. I desire to play video (and only video) fullscreen to the projector while putting controls and a small (~1/4 screen) preview on the monitor. This will allow the projectionist to view the video being output and control the playback from the monitor in the booth while all the audience ever sees is the video output.
Problem
I am currently using Python to control VLC player (with libvlc Python bindings) to playback videos. I have everything working fine except that I can't figure out how to get a preview (direct copy) of the video being played fullscreen on the projector output into my GUI.
I have tried using the clone filter, but I cant get the cloned window to automagically appear full screen nor in my GUI. The clone filter seems like the logical choice but it seems to be VERY inflexible when it comes to specifying destination screens, fullscreen, etc. I must be able to open video windows full screen on the projector monitor. Professionalism is key and it would look bad if the projectionist had to drag a window over and double click on it when the movie started.
Currently Using:
Debian Linux
Python 2.7
wxPython
libvlc
I would like to continue using Python as I already have the code for controlling the projector, sound processor, lighting and curtain written and tested. I chose VLC because it really seems bulletproof when it comes to video playback but am not committed to it's continued use. I also chose wxWidgets for my GUI as a result of past experience but I am not stuck on that either.
This describes the direct solution and does not concentrate on any alternative or the overall design of your application.
As Your Application and VLC media player are separate processes, you will not be able to get what you want directly because there is no "shared memory" between those 2 applications. The best shot to "copy" the decoded frames from VLC will be to e.g. send a RAW Video .mts stream (ts is usually used for this kind of usecase) and send e.g. to udp://localhost:1234.
In your application, you will need to be able to receive the ts stream, "decode" it and display at the spot of interest.
For start, i would try if you are able to do this using 2 vlc players that you control manually. When you achieved that the first VLC streams to udp and outputs on the main display at the same time, and the other VLC player receives and plays the udp stream you can go on:
Find a player library that you can use directly in your wxpython application and check if it can receive the udp stream as well E.g.
https://wxpython.org/Phoenix/docs/html/wx.media.MediaCtrl.html
This player lib for example requires gstreamer as a base.
As a result, main display and the picture in your applicatoin might have a latency of some seconds. To come around this latency, the best way that i currently know is using WebRTC but this is a lot more complex setup than the above.
https://www.sipwise.org/news/technical/tv-over-webrt/
Sure in case you do some "encoding" for WebRTC or even for UDP, you would need to utilize some hardware encoder, e.g. Nvidia NVENC in order to be able to guarantee the needed resources are always there.