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Ralf Geiger - One of the best experts on this subject based on the ideXlab platform.

  • fine grain scalable perceptual and lossless audio coding based on intmdct
    International Conference on Acoustics Speech and Signal Processing, 2003
    Co-Authors: Ralf Geiger, Gerald Schuller, A Herre, Thomas Sporer
    Abstract:

    This papers presents an embedded fine grain scalable perceptual and lossless audio coding scheme. The enabling technology for this combined perceptual and lossless audio coding approach is the Integer modified discrete cosine transform (IntMDCT), which is an Integer Approximation of the MDCT based on the lifting scheme. It maintains the perfect reconstruction property and therefore enables efficient lossless coding in the frequency domain. The close Approximation of the MDCT also allows us to build a perceptual coding scheme based on the IntMDCT. In this paper a bitsliced arithmetic coding technique is applied to the IntMDCT values. Together with the encoded shape of the masking threshold a perceptually hierarchical bitstream is obtained, containing several stages of perceptual quality and extending to lossless operation when transmitted completely. A concept of encoding subslices is presented in order to obtain a fine adaptation to the masking threshold especially in the range of perceptually transparent quality.

  • intmdct a link between perceptual and lossless audio coding
    International Conference on Acoustics Speech and Signal Processing, 2002
    Co-Authors: Ralf Geiger, Jürgen Herre, Jürgen Koller, Karlheinz Brandenburg
    Abstract:

    The Modified Discrete Cosine Transform (MDCT) is widely used in modem perceptual audio coding schemes. In this paper we present an Integer Approximation of this lapped transform, called IntMDCT, which is derived from the MDCT using the lifting scheme. This reversible Integer transform inherits most of the attractive properties of the MDCT, exhibiting a good spectral representation of the audio signal, critical sampling and overlapping of blocks. This makes the IntMDCT well suited for both lossless audio coding as well as for combined perceptual and lossless audio coding. A scalable system is presented providing a lossless enhancement of perceptual audio coding schemes, such as MPEG-2 AAC.

Karlheinz Brandenburg - One of the best experts on this subject based on the ideXlab platform.

  • intmdct a link between perceptual and lossless audio coding
    International Conference on Acoustics Speech and Signal Processing, 2002
    Co-Authors: Ralf Geiger, Jürgen Herre, Jürgen Koller, Karlheinz Brandenburg
    Abstract:

    The Modified Discrete Cosine Transform (MDCT) is widely used in modem perceptual audio coding schemes. In this paper we present an Integer Approximation of this lapped transform, called IntMDCT, which is derived from the MDCT using the lifting scheme. This reversible Integer transform inherits most of the attractive properties of the MDCT, exhibiting a good spectral representation of the audio signal, critical sampling and overlapping of blocks. This makes the IntMDCT well suited for both lossless audio coding as well as for combined perceptual and lossless audio coding. A scalable system is presented providing a lossless enhancement of perceptual audio coding schemes, such as MPEG-2 AAC.

Thomas Sporer - One of the best experts on this subject based on the ideXlab platform.

  • fine grain scalable perceptual and lossless audio coding based on intmdct
    International Conference on Acoustics Speech and Signal Processing, 2003
    Co-Authors: Ralf Geiger, Gerald Schuller, A Herre, Thomas Sporer
    Abstract:

    This papers presents an embedded fine grain scalable perceptual and lossless audio coding scheme. The enabling technology for this combined perceptual and lossless audio coding approach is the Integer modified discrete cosine transform (IntMDCT), which is an Integer Approximation of the MDCT based on the lifting scheme. It maintains the perfect reconstruction property and therefore enables efficient lossless coding in the frequency domain. The close Approximation of the MDCT also allows us to build a perceptual coding scheme based on the IntMDCT. In this paper a bitsliced arithmetic coding technique is applied to the IntMDCT values. Together with the encoded shape of the masking threshold a perceptually hierarchical bitstream is obtained, containing several stages of perceptual quality and extending to lossless operation when transmitted completely. A concept of encoding subslices is presented in order to obtain a fine adaptation to the masking threshold especially in the range of perceptually transparent quality.

P J G Teunissen - One of the best experts on this subject based on the ideXlab platform.

  • the least squares ambiguity decorrelation adjustment a method for fast gps Integer ambiguity estimation
    Journal of Geodesy, 1995
    Co-Authors: P J G Teunissen
    Abstract:

    The GPS double difference carrier phase measurements are ambiguous by an unknown Integer number of cycles. High precision relative GPS positioning based on short observational timespan data, is possible, when reliable estimates of the Integer double difference ambiguities can be determined in an efficient manner. In this contribution a new method is introduced that enables very fast Integer least-squares estimation of the ambiguities. The method makes use of an ambiguity transformation that allows one to reformulate the original ambiguity estimation problem as a new problem that is much easier to solve. The transformation aims at decorrelating the least-squares ambiguities and is based on an Integer Approximation of the conditional least-squares transformation. This least-squares ambiguity decorrelation approach, flattens the typical discontinuity in the GPS-spectrum of ambiguity conditional variances and returns new ambiguities that show a dramatic improvement in correlation and precision. As a result, the search for the transformed Integer least-squares ambiguities can be performed in a highly efficient manner.

Jürgen Herre - One of the best experts on this subject based on the ideXlab platform.

  • intmdct a link between perceptual and lossless audio coding
    International Conference on Acoustics Speech and Signal Processing, 2002
    Co-Authors: Ralf Geiger, Jürgen Herre, Jürgen Koller, Karlheinz Brandenburg
    Abstract:

    The Modified Discrete Cosine Transform (MDCT) is widely used in modem perceptual audio coding schemes. In this paper we present an Integer Approximation of this lapped transform, called IntMDCT, which is derived from the MDCT using the lifting scheme. This reversible Integer transform inherits most of the attractive properties of the MDCT, exhibiting a good spectral representation of the audio signal, critical sampling and overlapping of blocks. This makes the IntMDCT well suited for both lossless audio coding as well as for combined perceptual and lossless audio coding. A scalable system is presented providing a lossless enhancement of perceptual audio coding schemes, such as MPEG-2 AAC.