Jamulus Workshop 28 th August 2020 Dr Patrick Early https://youtu.be/ymwBwhvEeS8
Jamulus
Sound travels at 1,125 ft per second in 20°C
Jamulus
If Sound travels at 1,125 ft per second in 20°C
Then a 30ms Delay would equate to being about 33ft from the person you are playing music with
This picture was taken about 30 feet away from the players. From hear you hear the sound 30ms after it is made. The 30ms echo was mingled with longer echo's as the sound came back from the walls of nearby buildings. Abby Road rooftop recording session 1969 the Beatles
Latency over the internet produces exactly the same echoed sound as was heard from buildings that are further away and can become a distracting influence when playing online. We are trying to minimise this effect therefor at every stage of the process – the equivalent to being as close to the player as is acoustically possible.
Ironically effects pedals try to deliberately create the ‘Rooftop’ or outdoor effect.
30 ms Demo https://youtu.be/-3jTSw0grXg 30ms as an effect
A delay over 5Oms becomes problematic A delay over 100ms becomes unworkable for string players, as the meter becomes ambiguous without the help of accurate visual direction- the conductor
Case Study: Performing Band Rehearsals on the Internet With Jamulus Volker Fischer Abstract The author of this paper is a member of a rock cover band performing weekly rehearsals on the internet over a period of three years. During that time a lot of practical experience with real time jamming was gained. In this paper the author shares these experiences and gives an overview of the Jamulus software which was used to jam online discussing the most important facts for a successful setup. 1 Introduction Since the quality and speed of internet connec- tions have improved tremendously in the past years, performing distant online jamming in real
‘For the concept of online jamming with various different musicians it is indispensable that the servers are crowded. Therefore Jamulus must be intended for end users and it has to be user friendly. With a straightforward GUI design and an auto detection of the jitter buffer size, Jamulus tries hard to get to this goal’. Fischer (2015)
Unfortunately for the software to work correctly, a lot of other things have to be setup correctly . It starts with the analog audio setup, i.e. an instrument and/or a microphone has to be mixed and connected to the sound card of the PC. The PC hardware must be prepared for real time processing, i.e. no CPU or network demanding software may be run in parallel to Jamulus and things like energy saving techniques of lap- top processors have to be turned off. Correct audio drivers must be installed and the parameters like the buffer period size must be set to a small value to get the lowest latency possible. The internet connection must provide not less than the minimum required bandwidth and, at least equally important, must have a low ping time to the server. If even one of these requirements are not fulfilled, the performance is bad or Jamulus does not work at all’. Fischer (2015)
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https://jimamsden.wordpress.com/2020/04/04/remote- jamming-with-helix-and-jamulus/
Typical Jamulus Window
Typical Connection Options
A Minimalist Control Setup
Minimalist Settings Window
How to change internal microphone volume in Windows 10 https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=w eb&cd=&cad=rja&uact=8&ved=2ahUKEwjFudSi1_fpAhUHSxUIH TrgBYAQwqsBMAB6BAgKEAQ&url=https%3A%2F%2Fwww.yout ube.com%2Fwatch%3Fv%3DmmunTzfs5gY&usg=AOvVaw1dJUD EAlJ9dpWhAQIl6jdS
A server is set up in the vicinity of the players to handle all of the signal processing. Failing this, all participants should connect to the nearest (lowest latency) server.
These are mandatory Requirements for all participants without exception, to reduce overall latency to a tolerable level for everyone in the rehearsal Jamulus software downloaded and installed. Ethernet connection direct to your computer A good internet connection A set of regular headphones. A quality instrument microphone An audio interface
Requirements Jamulus software downloaded and installed. Ethernet connection direct to your computer A good internet connection A set of regular headphones. A quality instrument microphone An audio interface
Requirements Jamulus software downloaded and installed. Ethernet connection direct to your computer A good internet connection A set of regular headphones. A quality instrument microphone An audio interface Wi Fi is unacceptable
Use a dongle if there is no Ethernet connection on your computer
Requirements Jamulus software downloaded and installed. Ethernet connection direct to your computer A good internet connection A set of regular headphones. A quality instrument microphone An audio interface
A relatively small speed requirement is specified in kbps by Sourceforge
Given the low kb speed requirement, a more accurate way of measuring the quality of your internet connection for the purposes of using Jamulus therefor is to assess if there are points along its path to and from the server, where delay variation is taking place - jitter Packets of data which carry the audio information get interrupted by variation. This has the effect for the listener that you would experience if buildings were popping up out of nowhere during an outdoor performance, producing random distracting echo’s of your playing (altering your perception of distance from the other players as it were). Traceroute helps to identify the existence of these blocks by registering variation in round trip times for ‘pings’ in ms
Wider ping time variation indicates a less satisfactory internet service and is the main cause of the audio flow being compromised
Requirements Jamulus software downloaded and installed. Ethernet connection direct to your computer A good internet connection A set of regular headphones. A quality instrument microphone An audio interface Blue tooth and wi-fi will increase the overall delay Use headphones with a cable and single stereo jack
Requirements Jamulus software downloaded and installed. Ethernet connection direct to your computer A good internet connection A set of regular headphones. A quality instrument microphone An audio interface
You have to tailor your investment to your circumstances
Requirements Jamulus software downloaded and installed. Ethernet connection direct to your computer A good internet connection A set of regular headphones. A quality instrument microphone An audio interface
er is the variation in the time between data Ji Jitter packets arriving, caused by network congestion, or route changes. The longer data packets take to transmit, the more jit jitter affects audio quality. Standard jit jitter measurement is in ms
jitter buffer is a temporary storage buf buffer used A jit to capture incoming data packets. It is used in packet-based networks to ensure the continuity of audio streams by smoothing out packet arrival times during periods of network congestion.
‘ Cr kling ’ is due to lost packets. What we've Crackl done in choir to reduce this is to switch the auto-buffer off and manually increase it a bit from the auto-set setting. O’Reilly (2020)
You can try to optimize the latency vs. audio dropouts yourself by turning Jitter Buffer Auto off and following this simple algorithm: 1. While not playing, set the local jitter buffer for the client to balance latency with dropouts of the mixed signal you’re hearing coming from the server. 2. Then play and set the server jitter buffer to balance latency and dropouts of your own signal sent to the server. Do this after you have set the local jitter buffer as these two are cumulative. 3. Reduce the jitter buffer size (reducing latency) until dropouts become unacceptable, then increase the buffer size a little to account for network timing variation. This algorithm attempts to achieve a balance between delay and audio dropouts.’ Amsden (2020)
On Muting the Return Sound ‘To play synchronized with the others, one must only listen to the audio mix coming back from the server.’ Fischer (2015) ‘It makes sense to mute yourself during the session, but when preparing, leave yourself unmuted.’ Mountford (2020) ‘The word in the jamuls circles and from the developer is to not mute your return signal and "train" yourself to play to the slight delay. The reasoning behind this is, everyone else is hearing the return signal at the same time’ O’Reilly (2020)
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