TG: digital (cassete sonoro)(por)
UP (abreviatura de): digital compact cassete(eng)
UP (abreviatura de): casete compacta digital(spa)
UP (variação de): casete compacto digital(spa)
UP (abreviatura de): digital compact cassete(eng)
UP (abreviatura de): casete compacta digital(spa)
UP (variação de): casete compacto digital(spa)
Definição do conceito
[POR] digital compact cassete (DCC) é um formato de mídia de aúdio digital desenvolvido pela empresa holandesa Philips em 1992, que pode ser considerado o sucessor da fita cassete. | Os aparelhos DCC tinham a particularidade de tanto trabalharem com as novas cassetes DCC como com as antigas analógicas. Após uma guerra comercial com as cassetes DAT, da concorrente Sony, ambas perderam o mercado para o novo formato MiniDisc (também conhecido como MD), também da Sony. A perda foi possível pela praticidade e segurança do MiniDisc, apesar da superior qualidade do DCC e do DAT que utilizavam fitas, estes por sua vez se tornaram frágeis em seu armazenamento.Por exemplo, uma fita DAT mantida em um gravador por um certo tempo dentro de um ambiente com ar condicionado causava humidificação nas cabeças. Já o MiniDisc trabalha em ATRAC 3 com excessiva compressão DIGITAL e dependendo da pressão sonora do ambiente se perdem harmônicos importantes e o som registrado se torna estranho. | FONTE: DIGITAL COMPACT CASSETTE(sic) (DCC). Wikipédia. Disponível em : https://pt.wikipedia.org/wiki/Digital_Compact_Cassette Acesso em : 02 ago. 2022
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[SPA] casete compacta digital (DCC) : Soporte digital paralelo a la casete analógica, desarollado por Philips. No ha tenido éxito en el mercado. | FUENTE : IASA. Regflas de catalogación de IASA. Madrid : ANABAD, 2005. (Apéndice D. GLOSARIO) p. 233
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[SPA] casete compacto digital (DCC) : El casete compacto digital, o Digital Compact Cassette en inglés (DCC), fue un formato de cinta magnética de audio, de casete compacto, con base de óxido de cromo, que se utiliza como soporte para la grabación magnética digital y en la reproducción de sonido presentado por las empresas Philips y Matsushita al final de 1992 y comercializado como el sucesor del casete analógico convencional. Fue también competidor del formato MiniDisc de Sony. Otro formato competidor, la cinta de audio digital (DAT) había fracasado en 1992 en venderse en grandes cantidades. DCC compartió un factor de forma similar a los casetes analógicos, y los equipos de DCC podían reproducir cualquier tipo de casete. Esta compatibilidad permitió a los usuarios adoptar la grabación digital sin necesidad de generar sus colecciones obsoletas de cintas existentes. | FORMATO DCC : El casete del formato de DCC comparte características físicas del casete de audio convencional:
* Tamaño cartucho: 100 x 65 x 12 mm | * Longitud de cinta: 60,35m (60 minutos). | * Anchura de la cinta: 3,81 mm || Los DCC eran grabados con una frecuencia de muestreo de 44,1 kHz y una resolución de 16 bits, aunque también se admitían las frecuencias de muestreo de 32 y 48 kHz. En función del teorema de Nyquist, si se utilizaba la frecuencia de muestreo más baja (32 kHz), la respuesta en frecuencia bajaba hasta los 16.000 Hz (16x2=32). La velocidad de transmisión de datos del DCC era de 1,54 Mbps, superior a la del CD que es de 1,4 Mbps. | El DCC, como el formato S-DAT, es un sistema de grabación multipista con cabezal estacionario ya que lo único que se mueve es la cinta. En las cintas de video y en los R-DAT, las cabezas rotan en un tambor y la cinta también se desplaza. La velocidad de desplazamiento de la cinta es de 4,75 mm/s como los Casetes Compactos analógicos y los dos formatos DAT. | Como el DCC es un formato multipista, puesto que permite 16 pistas de audio (8 por cara), posee varias cabezas de reproducción y grabación que pueden sincronizarse. Las pistas se graban helicoidalmente y es la anchura de las pistas (185 nanómetros), la que determina la distancia entre los cabezales. Las pistas de la cinta S-DAT son más anchas. Consecuentemente, la capacidad de almacenamiento de información de un DCC es mucho menor que la de un DAT. La anchura del paso de pista es de 10 nanómetros. Además de las 16 pistas señaladas, el DCC en cada cara, introduce una pista auxiliar en la cual se graba una señal inaudible de control que permite entre otras cosas: | * Indicar el inicio de la cinta. | * Facilitar la localización de contenidos introduciendo marcas. | * Señalizar el final de la grabación y el propio final de la cinta, lo que permite saber el tiempo de grabación disponible. || FUENTE : CASETE COMPACTO DIGITAL in: Wikipedia. Disponible en : https://es.wikipedia.org/wiki/Casete_compacto_digital Acceso en : 10 ago. 2022
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[ENG] digital compact cassette (DCC) : A digital format parallel to the analogue compact cassette, developed by Philips. No longer successful on the market. | SOURCE : IASA. The IASA Cataloguing Rules (IASA 1999) Ed. by Mary Miliano. (Appendix D. Glossary) Available at : https://www.iasa-web.org/cataloguing-rules/appendix-d-glossary Accessed : 10 aug. 2022
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[ENG] The Digital Compact Cassette (DCC) is a magnetic tape sound recording format introduced by Philips and Matsushita Electric in late 1992 and marketed as the successor to the standard analog Compact Cassette. It was also a direct competitor to Sony´s MiniDisc (MD), but neither format toppled the then-ubiquitous analog cassette despite their technical superiority, and DCC was discontinued in October 1996. | Another competing format, the Digital Audio Tape (DAT), had by 1992 also failed to sell in large quantities to consumers, although it was popular as a professional digital audio storage format. The DCC form factor is similar to the analog compact cassette (CC), and DCC recorders and players can play back either type: analog as well as DCC. This backward compatibility was intended to allow users to adopt digital recording without rendering their existing tape collections obsolete, but because DCC recorders couldn´t record (only play back) analog cassettes, it effectively forced consumers to either replace their cassette deck with a DCC recorder and give up analog recording, or keep the existing cassette deck and make space to add the DCC recorder to their setup. | Tape specifications and PASC audio compression : DCC tape is the same 0.15 inches (3.8 mm) width as in analog compact cassettes, and operates at the same speed: 1+7?8 inches (4.8 cm) per second. The tape that was used in production cassettes was chromium dioxide- or cobalt-doped ferric oxide, 3–4 µm thick in a total tape thickness of 12 µm,[9] identical to the tape that was widely in use for video tapes. | ... | Because of the low tape speed, the achievable bit rate of DCC is limited. To compensate, DCC uses Precision Adaptive Sub-band Coding (PASC) for audio data compression. PASC was later integrated into the ISO/IEC 11172-3 standard as MPEG-1 Audio Layer I (MP1). Though MP1 allows various bit rates, PASC is fixed at 384 kilobits per second. The bandwidth of a CD recording of approximately 1.4 megabits per second is reduced to 384 kilobits per second, a compression ratio of around 3.68:1. The difference in quality between PASC and the 5:1 compression used by early versions of ATRAC in the original MiniDisc is largely a subjective matter. | After adding system information (such as emphasis settings, SCMS information, and time code) as well as adding Reed-Solomon error correction bits to the 384 kbit/s data stream, followed by 8b/10b encoding, the resulting bit rate on the eight main data tracks tape ends up being twice the rate of the original PASC data: 768 kbit/s, which is recorded onto the eight main data tracks at 96 kbit/s per track in an interleaved pattern. According to the Philips webpage,[9] it is possible for a DCC player to recover all missing data from a tape, even if one of the 8 audio tracks is completely unreadable, or if all tracks are unreadable for 1.45 mm (about 0.03 seconds). || Cassettes and cases : The DCC cassette and the case that Philips (but not some other cassette manufacturers) used were designed by Peter Doodson who also designed the CD jewel case. || DCCs are similar to analog compact cassettes, except that there are no "bulges" where the tape-access holes are located. DCC cassettes are flat and there are no access holes for the hubs on the top side (they are not required because auto-reverse is a standard feature on all DCC decks), so this side can be used for a larger label than can be used on an analog compact cassette. A spring-loaded metal shutter similar to the shutters on 3.5 inch floppy disks and MiniDiscs covers the tape access holes and locks the hubs while the cassette is not in use. Cassettes provide several extra holes and indentations so that DCC recorders can tell a DCC apart from an analog compact cassette, and so they can tell what the length of a DCC tape is. Also, there is a sliding write-protect tab on the DCC to enable and disable recording. Unlike the break-away notches on analog compact cassettes and VHS tapes, this tab makes it easier to make a tape recordable again, and unlike on analog compact cassettes, the marker protects the entire tape rather than just one side. | SOURCE : DIGITAL COMPACT CASSETTE. in: Wikipedia : https://en.wikipedia.org/wiki/Digital_Compact_Cassette Accessed : 10 aug. 2022.
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