US 9,812,136 B2
Audio processing system
Kristofer Kjoerling, Solna (SE); Heiko Purnhagen, Sundyberg (SE); and Lars Villemoes, Jarfalla (SE)
Assigned to Dolby International AB, Amsterdam (NL)
Filed by DOLBY INTERNATIONAL AB, Amsterdam Zuidoost (NL)
Filed on Sep. 1, 2016, as Appl. No. 15/255,009.
Application 15/255,009 is a continuation of application No. 14/781,232, granted, now 9,478,224, previously published as PCT/EP2014/056857, filed on Apr. 4, 2014.
Claims priority of provisional application 61/809,019, filed on Apr. 5, 2013.
Claims priority of provisional application 61/875,959, filed on Sep. 10, 2013.
Prior Publication US 2016/0372123 A1, Dec. 22, 2016
This patent is subject to a terminal disclaimer.
Int. Cl. G10L 21/00 (2013.01); G10L 19/008 (2013.01); G10L 19/04 (2013.01); G10L 19/20 (2013.01); G10L 19/032 (2013.01); G10L 25/00 (2013.01); G10L 25/93 (2013.01); H03G 5/00 (2006.01); H04R 5/00 (2006.01); H04R 5/02 (2006.01); H04L 27/00 (2006.01); G06F 17/00 (2006.01)
CPC G10L 19/008 (2013.01) [G10L 19/032 (2013.01); G10L 19/04 (2013.01); G10L 19/20 (2013.01)] 12 Claims
OG exemplary drawing
 
1. An audio processing apparatus configured to accept an audio bitstream, the audio processing apparatus comprising:
an audio decoder adapted to receive the bitstream and to output quantized spectral coefficients;
a first processor that includes:
a dequantizer adapted to receive the quantized spectral coefficients and to output a first frequency-domain representation of an intermediate signal; and
an inverse transformer for receiving the first frequency-domain representation of the intermediate signal and synthesizing, based thereon, a time-domain representation of the intermediate signal;
a second processor that includes:
an analysis filterbank for receiving the time-domain representation of the intermediate signal and outputting a second frequency-domain representation of the intermediate signal;
an adjuster for receiving said second frequency-domain representation of the intermediate signal and outputting a frequency-domain representation of a processed audio signal; and
a synthesis filterbank for receiving the frequency-domain representation of the processed audio signal and outputting a time-domain representation of the processed audio signal; and
a sample rate converter for receiving said time-domain representation of the processed audio signal and outputting a reconstructed audio signal sampled at a target sampling frequency,
wherein the respective internal sampling rates of the time-domain representation of the intermediate audio signal and of the time-domain representation of the processed audio signal are equal, and wherein said at least one processing component includes:
a parametric upmixer for receiving a downmix signal with M channels and outputting, based thereon, a signal with N channels, wherein the parametric upmixer is operable at least in a mode where 1≤M<N, associated with a delay, and a mode where 1≤M=N; and
a first delay configured to incur a delay, when the parametric upmixer is in the mode where 1≤M=N, to compensate for the delay associated with the mode where 1≤M<N in order for the adjuster to have a constant total delay independently of a current operating mode of the parametric upmixer.