Research into spatial audio coding includes the
proposed Spatially Squeezed Surround Audio Coding (S3AC), a novel
solution to spatial audio coding that compresses multichannel audio signals
(e.g. 5.1 surround) into a stereo or mono signal. As opposed to many existing
spatial audio coding solutions, S3AC requires no transmission or
storage of side information to enable accurate decoding and synthesis of the
original multichannal audio signals. This
research was conducted with a former PhD student, Bin Cheng.
S3AC is particularly suited to coding spatial audio containing dynamically
localized sound sources. Listed below are example files that were used in
subjective listening tests published at ICASSP2007. These files include the
original and decoded 5 channel surround audio files
and can be played back on a 5 channel audio system using suitable software. In
the S3AC approach, the stereo downmix can be further compressed with
an existing audio coder with little loss in quality when decoding to the
original 5 channel audio signals. For the files
presented here, the stereo downmix signals were compressed using the Advance
Audio Coder (AAC) operating at 128kbps. These files were then decoded and converted
back to 5 channel surround files using the S3AC decoder.
Sound
Scene
Original S3AC Coded
The
entire file collection can be downloaded here
As well as compression of 5 channel surround audio files, S3AC
has also been used for binaural reproduction of compressed surround sound files
as well as coding of Ambisonic B-format audio.
Further details can be found in the publications below.
Relevant
Publications
[1] Cheng, B., Ritz, C. and Burnett, I., “Spatial Audio Coding by Squeezing: Analysis
and Application to Compressing Multiple Soundfields”,
Proc. EUSIPCO2009, August 2009.
[2] Cheng, B., Ritz, C. and Burnett, I.,
Psychoacoustic-Based Quantisation of Spatial Audio
Cues, IET Electronics Letters, vol. 44-18, p. 1098-1099, Aug. 2008.
[3] Cheng, B., Ritz, C., Burnett, I., “Binaural
Reproduction of Spatially Squeezed Surround Audio”, Proc. Of 9th International Conference on Signal
Processing (ICSP’08), Oct. 26-29, 2008, pp. 1-4.
[4] Cheng, B., Ritz, C., Burnett, I., “A
spatial squeezing approach to Ambisonic audio
compression”, to be presented at the IEEE 2008 International
Conference on Acoustics, Speech and Signal Processing (ICASSP'2008), Las
Vegas, USA, Mar 30 – Apr 4, 2008.
[5] Cheng, B., Ritz, C., Burnett, I.,
“Encoding Independent Sources in Spatially Squeezed Surround Audio Coding”, Advances
in Multimedia Information Processing – PCM 2007, Proc. of 8th
Pacific-Rim Conference on Multimedia (PCM2007), Hong-Kong, December 2007, Lecture
Notes in Computer Science 4810, 2007.
[6] Cheng, B., Ritz, C., Burnett, I.,
“Principles and Analysis of the Squeezing Approach to Low Bit Rate Spatial
Audio Coding”, Proc. IEEE 2007 International Conference on Acoustics, Speech
and Signal Processing (ICASSP'2007), Vol. 1, pp. 13-16, Honolulu, USA,
15-20 April 2007.
[7] Cheng, B., Ritz, C.,
Burnett, I., “Squeezing the Auditory Space: A New Approach to Multi Channel
Audio Coding”, Advances in Multimedia Information Processing – PCM2006,
Proc. of the 7th Pacific-Rim Conference on Multimedia (PCM2006), Hangzhou,
China, Nov. 2-4, 2006, Lecture Notes in Computer Science 4261, pp. 572 -
581, Springer-Verlag, 2006.