The Vector Quantised codec
The Vector Quantised (VQ) codec is known as the optimum quantisation method which maps vectors onto a finite number of bits. I
developed two VQ based codecs Codec 1, maximising the compression ratio, whereas the output of Codec 2 is more
robust. For both codecs, the bitrate is programmable and remains CONSTANT, in contrast to the above mentioned
standard codecs, where intra frames exceed ten times the inter frame size and therefore delays of seconds are
possible. This is the reason why the codecs need to run for about 10 to 20 frames to establish the quality.
Example sequences for Codec one at 6.7, 8, 9.6 and 13 kbps and for Codec 2 at 11.36 kbs is shown here:
The Claire Sequence
The codecs are proposed as a direct replacement of voice channels in second generation mobile systems such as
the Pan-European GSM, the American IS-54 and IS-95 as well as Japanese systems.
- The Claire Sequence at 6.7 kbps , VQ Codec 1,
- The Claire Sequence at 8 kbps, VQ Codec 1,
- The Claire Sequence at 9.6 kbps, VQ Codec 1,
- The Claire Sequence at 13 kbps, VQ Codec 1,
- The Claire Sequence at 11.4 kbps, VQ Codec 2.
The following two sequences are Coded with Codec 1:
The Miss America Sequence
- The Missa Sequence , at 150 byte per frame
- The Missa Sequence , at 125 byte per frame
- The Missa Sequence , at 100 byte per frame
The 'Lab' Sequence
- The Lab Sequence , at 12 kbps
- The Lab Sequence , at 10 kbps
- The Lab Sequence , at 8 kbps.
- H263 The Lab Sequence 10kb/s average (First Frame at 110kb/s !!)
- H263 The Lab Sequence 5kb/s average (First Frame at 110kb/s !!)