Uma anÃlise comparativa dos codificadores/ decodificadores de voz para comunicaÃÃes digitais

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

This work proposes an analysis of signal processing by intervals containing Portuguese phonemes for encoders utilized in digital communications, specially in VoIP calls. The focus of this work is the adaptation capacity of encoders to vocal tract changes in these intervals during the signal processing. To make the analysis closer to the real time situation, it was used periods containing all the basic Portuguese phonemes. It was extracted information about fundamental frequency and the three first formants for each interval for a group formed by men and women with different ages. These intervals were created using the software Praat, which was also used to extract all the parameters. The obtained results showed a subtle difference in signal processing of the formants frequencies between sexes. It was observed a phenomenon of pitch correction in some intervals with a variant phoneme for both sexes. The encoders G.722, G.723.1, G.726, G.728, G.729A, iLBC and Speex were analyzed

ASSUNTO(S)

g.726 codecs g.722. g.723.1 g.729a comunicacao g.728 speex speex g.726 ilbc g.728 codificaÃÃo de voz g.722. g.723.1 ilbc g.729a

ACESSO AO ARTIGO

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