Compresión de Audio Basada en Codificación Subbanda


An eight channels subband audio codec is implemented for signals with 44.1 KHz and 16 bits per sample using Matlab. To achieve perfect reconstruction, a two channels QMF filter bank with cutoff frequency ω=π/2 is designed, based on an equiriple filter of 99 order. Seven stages of this bank are used to split the input into eight signals with sample rates from 2.76 to 11 KHz, which are coded from 1 to 16 bits depending on the band energy. To evaluate performance for three tracks in terms of similarity of input and output signals, a Mean Opinion Score (MOS) experiment with fifteen subjects was performed. The Euclidean Distance between spectrums was also measured. Results showed a fair similitude for two tracks and excellent for one. Compression factors above 96% were achieved.

Keywords: subband coding, mean opinion score MOS, QMF filter banks, audio compression

[1] Anbarjafari, G., and Demirel, H. (2010). “Image super resolution based on interpolation of wavelet domain high frequency subbands and the spatial domain input image”. ETRI J., Vol. 32, No. 3, pp 390–394.

[2] April, M. (2015). “Sub-band Coding of Speech Signals using Multirate Signal Processing and comparing the various parameter of different speech signals”. IJETTCS, Vol. 4, No. 2, pp 217–221.

[3] Bosi, M., and Goldberg, R.E. (2003). Introduction to Digital Audio Coding and Standards, 1st edition, Springer, USA.

[4] ITU-T. (2016). Recommendation ITU-T P.800.1,, 06/15/2017. (date accessed)

[5] Kevric, J., and Subasi, A. (2017). “Comparison of signal decomposition methods in classification of EEG signals for motor-imagery BCI system”. Biomed. Signal Process. Control, Vol. 31, pp 398–406.

[6] Oosugi, N., Kitajo, K., Hasegawa, N., Nagasaka, Y., Okanoya, K., and Fujii, N. (2017). “A new method for quantifying the performance of EEG blind source separation algorithms by referencing a simultaneously recorded ECoG signal”. Neural Networks, Vol. 93, pp 1–6.

[7] Poornachandra, S. (2008). “Wavelet-based denoising using subband dependent threshold for ECG signals”. Digit. Signal Process. A Rev. J., Vol. 18, No. 1, pp 49–55.

[8] Proakis, J.G., and Manolakis, D.G. (1996). Digital Signal Processing, 3rd edition, Prentice Hall, USA.

[9] Vaidyanathan, P.P. (1990). “Multirate Digital Filters, Fiter Banks, Polyphase Networks, and Applications: A Tutorial”. Proceedings of the IEEE, Vol. 78, No. 1, pp 56–93.

[10] Winkler, S., and Faller, C. (2005). “Maximizing Audiovisual Quality at Low Bitrates”. Electron. Imaging 2005, Vol. 2005, pp 139–148.