Engineering and technology notes

WordPress table is marked as crashed and last repair failed

(1) Log in to your phpMyAdmin or connect to it via your web hosting (cPanel?) backend.
(2) Select the database with the crashed table.
(3) Put a checkmark next to each crashed table.
(4) Select “Repair table” from the “With selected:” drop down at the bottom of the list.
(5) You’re done!

https://wordpress.org/support/topic/wp_options-table-is-marked-as-crashed-and-last-repair-failed-10/

Col legno – violin bowing technique

Col legno – Occasionally the strings are struck with the stick of the bow (“with the wood.”) This gives a muted percussive sound, and is most effective when employed by a full orchestral violin section. The eerie quality of a violin section playing col legno is exploited in some symphonic pieces, notably the “witches’ dance” of the last movement of Berlioz’ Symphonie Fantastique as well as Frederic Chopin’s Warsaw-era Piano Concerto No. 2, which predates it.

https://en.wikipedia.org/wiki/Violin_technique

Opus (audio format)

Opus is a lossy audio coding format developed by the Xiph.Org Foundation and standardized by the Internet Engineering Task Force, designed to efficiently code speech and general audio in a single format, while remaining low-latency enough for real-time interactive communication and low-complexity enough for low-end embedded processors. Opus replaces both Vorbis and Speex for new applications, and several blind listening tests have ranked it higher-quality than any other standard audio format at any given bitrate until transparency is reached, including MP3, AAC, and HE-AAC.

Opus combines the speech-oriented linear predictive coding SILK algorithm and the lower-latency, MDCT-based CELT algorithm, switching between or combining them as needed for maximal efficiency. Bitrate, audio bandwidth, complexity, and algorithm can all be adjusted seamlessly in each frame. Opus has the low algorithmic delay (26.5 ms by default) necessary for use as part of a real-time communication link, permitting natural conversation, networked music performances, and live lip sync; by trading-off quality or bitrate, the delay can be reduced down to 5 ms. Its delay is exceptionally low compared to competing codecs, which require well over 100 ms, yet Opus performs very competitively with these formats in terms of quality per bitrate.

As an open format standardized through RFC 6716, a reference implementation called libopus is available under the New BSD License. The reference has both fixed-point and floating-point optimizations for low- and high-end devices, with SIMD optimizations on platforms that support them. All known software patents that cover Opus are licensed under royalty-free terms.

https://en.wikipedia.org/wiki/Opus_(audio_format)

TypeScript

TypeScript is an open-source programming language developed and maintained by Microsoft. It is a strict syntactical superset of JavaScript, and adds optional static typing to the language.

TypeScript is designed for development of large applications and transcompiles to JavaScript. As TypeScript is a superset of JavaScript, existing JavaScript programs are also valid TypeScript programs. TypeScript may be used to develop JavaScript applications for both client-side and server-side (Node.js) execution.

There are multiple options available for transcompilation. Either the default TypeScript Checker can be used, or the Babel compiler can be invoked to convert TypeScript to JavaScript.

TypeScript supports definition files that can contain type information of existing JavaScript libraries, much like C++ header files can describe the structure of existing object files. This enables other programs to use the values defined in the files as if they were statically typed TypeScript entities. There are third-party header files for popular libraries such as jQuery, MongoDB, and D3.js. TypeScript headers for the Node.js basic modules are also available, allowing development of Node.js programs within TypeScript.

The TypeScript compiler is itself written in TypeScript and compiled to JavaScript. It is licensed under the Apache 2.0 License.

TypeScript is included as a first-class programming language in Microsoft Visual Studio2013 Update 2 and later, beside C# and other Microsoft languages. An official extension allows Visual Studio 2012 to support TypeScript as well.

Anders Hejlsberg, lead architect of C# and creator of Delphi and Turbo Pascal, has worked on the development of TypeScript.

https://en.wikipedia.org/wiki/TypeScript