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)

Opus (audio format) was last modified: June 13th, 2019 by Jovan Stosic

Symphony No. 1 (Schumann)

Although he had made some “symphonic attempts” in the autumn of 1840 soon after he married Clara Wieck, he did not compose his first symphony until early 1841. Until then, Schumann was largely known for his works for the piano and for voice. Clara encouraged him to write symphonic music, noting in her diary, “it would be best if he composed for orchestra; his imagination cannot find sufficient scope on the piano… His compositions are all orchestral in feeling… My highest wish is that he should compose for orchestra—that is his field! May I succeed in bringing him to it!”

Schumann sketched the symphony in four days from 23 to 26 January and completed the orchestration by 20 February. The premiere took place under the baton of Felix Mendelssohn on 31 March 1841 in Leipzig, where the symphony was warmly received. According to Clara’s diary, the title “Spring Symphony” was bestowed upon it due to Adolf Böttger‘s poem Frühlingsgedicht. The symphony’s opening has traditionally been associated with the closing lines of Böttger’s poem, “O wende, wende deinen Lauf/Im Thale blüht der Frühling auf!” (“O, turn, O turn and change your course/In the valley, Spring blooms forth!”). This view has been challenged, and the call of a Leipzig nightwatchman has been mentioned as an alternative source.

https://en.wikipedia.org/wiki/Symphony_No._1_(Schumann)

Symphony No. 1 (Schumann) was last modified: June 13th, 2019 by Jovan Stosic