Издательство: | Книга по требованию |
Дата выхода: | июль 2011 |
ISBN: | 978-6-1329-2328-8 |
Объём: | 80 страниц |
Масса: | 141 г |
Размеры(В x Ш x Т), см: | 23 x 16 x 1 |
High Quality Content by WIKIPEDIA articles! Pre-echo is a digital audio compression artifact where a sound is heard before it occurs (hence the name). It is most noticeable in impulsive sounds from percussion instruments such as castanets or cymbals. It occurs in transform-based audio compression algorithms – typically based on the modified discrete cosine transform (MDCT) – such as MP3, MPEG-4 AAC, and Vorbis, and is due to quantization noise being spread over the entire transform-window of the codec. The psychoacoustic component of the effect is that one hears only the echo preceding the transient, not the one following – because this latter is drowned out by the transient. Formally, forward temporal masking is much stronger than backwards temporal masking, hence one hears a pre-echo, but no post-echo.
Данное издание не является оригинальным. Книга печатается по технологии принт-он-деманд после получения заказа.