LOLA
Read the Lola User Manual
Lola is an Audio Visual Streaming System developed by “Conservatorio di Musica G. Tartini”, Trieste, Italy, in collaboration with GARR, the Italian Academic and Research Network. LOLA goal is to provide a tool for real-time audio/video “natural” distance human interaction. It was originally conceived for distance music performances, education and production, but can be used for any other scenario where real-time interaction is required. A special attention has been paid to the optimization of the signal processing and transmission in order to keep the system latency as low as possible, below the human delay perception threshold. Both Standard Definition video (SD) and High Definition video (HD) modes are supported from version 1.4.x
The system is based on high performance audio/video acquisition hardware, and on the integration and optimization of audio/video stream acquisition, presentation and transmission. The LOLA system also requires very high performance Wide Area and Local Area Networks: 1 Gigabit per second end-to-end connection is the minimum suggested configuration when running the system with uncompressed video signals; lower bandwidth can be used when running the LOLA system with video compression on. (From the Lola Manual)
The Lola system requires very specific hardware to be able to work. Here we will list audio/video hardware that works with Lola.
– RME HDSPe-AIO (PCI-Express internal card)
– RME Hammerfall HDSP 9632 (PCI internal card)
– RME Multiface II (PCI/PCIe host card + external ADC/DAC box)
– Imperx: CXP-B1410C, CXP-B1411C and ICX-B1410C (old Gen 1 model)
– Ximea xiQ line: MQ013CG-E2
– Grasshopper3 series:
GS3-U3-41C6C (Color camera) and GS3-U3-41C6M (Monochrome camera)
– Flea3 series:
FL3-U3-13S2C-CS (Color camera)
Use a fast LCD monitor with real low latency/response time (equal to or less than 2 or 3 milliseconds) or an old style, but faster, CRT monitor/projector.
The way you connect the monitor to the PC may also cause additional latency. Use VGA, DVI-D or RGB connectors, avoid HDMI.
The following LOLA audio setup was tested on 28.08:
Stereo setup with two Genelec monitors placed in line with an C414 XLS microphone from AKG.
The microphone polar pattern was set to figure-of-eight. Low sensitivity to sounds arriving 90 degrees of axis allows to cancel out the sound from the speakers placed in line with the microphone. The figure-of-eight pattern was used to avoid the microphone-speaker feedback of the signal sent back and forth between Oslo and Trondheim.
The microphone-speaker setup was placed approximately 1m away from a sound absorbing surface (wall draped with heavy curtains) to counter the high rear sensitivity of the figure-of-eight polar pattern.
A slight low-frequency cut-off at 80 Hz was introduced to avoid “muddy” and bass-heavy signal and increase speech intelligibility. Attenuation level was set to 0 dB.
There is a running LOLA machine at Uninett (the Norwegian internet provider for universities), which can best tested on the IP 158.38.100.101 (mm-echo.uninett.no). It runs with LOLA version 1.5, with sampling rate 48khz and compressed video.