Audio and Video

Mains power EMI noise filtering

Because of the presence of mains current in mains-powered audio equipment as well as ubiquitous AC electromagnetic fields from nearby appliances and wiring, 50/60 Hz electrical noise can get into audio systems, and is heard as mains hum from their speakers. In addition to mains frequency humming, the mains power can also contain higher frequency

VideoLAN 20 years

VideoLAN (VLC) is a free, open source multi-platform media player and environment that plays most media files and DVD-VCDs as well as Audio CDs and various streaming protocols. VLC media player (previously the VideoLAN Client and commonly known as simply VLC) is a free and open-source, portable, cross-platform media player software, and streaming media server

Dirt cheap frame grabber

This is a story of a a video digitizing circuit I built early 1990′s. It kind of worked, but was not practical then and much less useful nowadays. It is an interesting how simple circuit could be used for converting analogue composite video signal to digital for computer processing. This is the story of Dirt

USB cameras connected to Android 10 device do not work

I used to use some external cameras like microscope and endoscope connected to my Android phone with OTG cable. Google Android documentation says that many standard USB cameras should generally work with Android: The Android platform supports the use of plug-and-play USB cameras (that is, webcams) using the standard Android Camera2 API and the camera

Audio cable testing articles

Here are two articles that could be interesting and entertaining to read. In this first article the writer uses audio analyzing tools to to debunk spurious claims made by audiophiles, HiFi journalists, and the high-end audio industry about the quality of their products. This article covers using audio analyzers and also using SDR software to

Signal processing tips from Hackaday

Signal processing is an electrical engineering subfield that focuses on analysing, modifying and synthesizing signals such as sound, images and biological measurements. Electronic signal processing was first revolutionized by the MOSFET and then single-chip digital signal processor (DSP). Digital signal processing is the processing of digitized discrete-time sampled signals. Processing is done by general-purpose computers