Method and apparatus for pyramid vector quantization indexing and de-indexing of audio/video sample vectors

A method for pyramid vector quantization indexing of audio/video samples, wherein said method comprises the steps of:

• obtaining an integer input vector;
• said integer input vector representing said audio/video signal samples;
• said integer input vector having a number of integer-valued coefficients;
• extracting a leading sign from said integer input vector;
• said leading sign being a sign of a last non-zero coefficient in said integer input vector in a direction of encoding;
• indexing said integer input vector with a modified pyramid vector quantization enumeration scheme into an output index, which output index together with said leading sign representing said audio/video signal samples;
• said modified pyramid vector quantization enumeration scheme neglecting said leading sign by shifting a sign of each non-zero coefficient such that said shifted sign is encoded in association with next non-zero coefficient in the direction of encoding;
• and
• outputting said leading sign as a first codeword and said output index as a second codeword into an outgoing bit stream.