Linux-audio-dev August 2019

linux-audio-dev@lists.linuxaudio.org

5 participants
7 discussions

Xputty - damn tiny abstraction Layer to create X11 window/widgets with cairo surfaces

by Hermann Meyer

For creating LV2 UI's I end up more and more writing the same code, so I decided to wrote a Layer for it. It's supposed to create, manage, draw, and destroy X11 widgets with a cairo surface to draw. Additional to subscribe to and handle events. I decided to put it in the Public Domain, so everyone could do what ever he /she want's with it. The repository contain a example folder showing some of the features supported by the layer. It's a tiny, but powerful abstraction of the X11 low level API to easier the process to create nice GUI's. Documentation is included in the source code, it's a single header and a single c file. All together just 654 lines, were most lines taken by documentation. So, here you go: https://github.com/brummer10/Xputty

3 years, 5 months

Web Audio Conference 2019 - Call for Diversity Tickets

by Gerard Roma

*Apologies for cross-postings* # Web Audio Conference 2019 - Call For Diversity Tickets https://www.ntnu.edu/wac2019/call-for-diversity We have a limited number of diversity tickets available to attend the Web Audio Conference 2019 in Trondheim (4-6 December, 2019), thanks to our sponsors (https://ntnu.edu/wac2019/sponsors). This may cover your conference ticket and/or travels as an author or other attender. We have also tried to keep the conference fees as low as possible to encourage interested attendees to come (https://www.ntnu.edu/wac2019/registration). The diversity tickets will be prioritized for attenders from lower-income countries and backgrounds, and underrepresented communities in web audio. To be eligible, you need to fill in the following online survey telling us how we can help you, which should take 5-10 minutes: http://tiny.cc/WAC19-call-diversity An expert diversity committee is constituted who will decide from the candidates by September 15, 2019. ## Important dates * September 8, 2019 (Anywhere on Earth): Deadline diversity tickets application. * September 15, 2019: Notification of grantees. * September 22, 2019: Deadline early-bird ticket. * December 4-6, 2019: The conference. Please do not hesitate to contact the diversity committee, diversity(a)wac2019.ntnu.no, if you have questions. You can find more information about the diversity theme here: https://www.ntnu.edu/wac2019/diversity-theme Also, you can find a preliminary draft of the programme and a list of conference venues on our website: https://www.ntnu.edu/wac2019/programme https://www.ntnu.edu/wac2019/venues-and-maps

3 years, 7 months

IRT gets it: open-source libraries for object-based audio

by Jörn Nettingsmeier

Hi *! Haven't checked this out in any detail, but the German Institut für Rundfunktechnik (a sort of science outsourcing provider for public broadcast over here, with an impressive track record of ground-breaking work) have released a substantial body of code on object-based audio under an Apache open-source license: https://lab.irt.de/more-open-source-for-open-object-based-audio-workflows/ If anyone gets interested and finds it useful, please give them a little shout-out - I guess our fellow open-source enthusiasts within those institutions can use some support! All best, Jörn -- Jörn Nettingsmeier Tuinbouwstraat 180, 1097 ZB Amsterdam, Nederland Tel. +49 177 7937487 Meister für Veranstaltungstechnik (Bühne/Studio), Tonmeister VDT http://stackingdwarves.net

3 years, 7 months

Proscenion

by Benoît Rouits

Hello list, old reader of the LAU list, i decided to subscribe to the LAD to present a little project i wrote, proscenion. Proscenion is a (GPL) software that renders true phase stereo with Jack by placing jack sources into a graphical canvas and reap the stereo capture rendered on the fly. The software is not perfect and not very well written, but it is functionnal. It is written upon Gtk3 and GooCanvas: http://brouits.free.fr/proscenion/ https://gitlab.gnome.org/be1/proscenion/ Hope you will like it and ban panpot stereo from your next tune ;-) Cheers, Benoît

3 years, 7 months

Berlin Linux Audio meeting @ c-base 2019-08-13

by Daniel Swärd

Hi all. As usual the second Tuesday of the month is upon us. I'll be in the mainhall from 20:00. See you there. Suggested discussion topic: Anyone going to Chaos Communication Camp? Should we do a LAU thing there? Cheers /Daniel

3 years, 7 months

Writing a driver for a device which clears the buffer on the start trigger

by Paul Pawlowski

Hello, I'm writing a driver for a device which clears the BAR DMA buffer if I send the Start IO command to it. I'm not sure how to workaround this issue. I have got the driver working to some extent by moving the Start IO command code to the open() callback instead of the trigger(SNDRV_PCM_TRIGGER_START) however that's obviously a hack and causes issues (the first ~0.1s of audio is lost). I also tried to memcpy() the memory to a temporary buffer in the SNDRV_PCM_TRIGGER_START trigger, however that turned out to be a performance bottleneck (it took about ~300ms to copy that memory back, which is ~the period size, probably related). I'm also aware that using some sort of a copy buffer could work, but that sounds like a performance waste as it's not needed after the playback is started. I tried to search for existing kernel drivers utilizing a similar mechanism (there's the SNDRV_PCM_INFO_DOUBLE flag after all), but could not find any results that made sense. Any help is appreciated. Thank you, Paul Pawlowski

3 years, 7 months

jack meterbridge 0.9.2 update / maintenance

by Stephan Bourgeois

Hi there, I have been tinkering with Steve Harris' meterbridge 0.9.2 for jack. cf. https://github.com/stephanb2/jack-meterbridge 1. Refactored global variables so that the code builds on Debian 9.2. 2. Improved (?) the dpm IEC scale and ballistics. 3. Changed the PPM ballistics to use Fons Adriaensen's JMeters algorithm. I do however have a deeper question: what is the point of jack meterbridge? Given that the broadcast and podcast industry has moved to EBU-R128 and Ebumeter offers EBU R-128 metering. JMeters offers "nostalgia" PPM and VU meters with correct ballistics, more options, better graphics. The only thing missing would be a 4x oversampling true peak meter. Should meterbridge be maintained or should another metering app de bundled with jack? Note that I am not a C engineer, my background is Java and Python. Please send code review comments and shout if you see anything horrific. Let me know your thoughts. Cheers, Stephan. -- Sent from: http://linux-audio.4202.n7.nabble.com/linux-audio-dev-f58952.html

3 years, 7 months

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Linux-audio-dev August 2019