Next |
Prev |
Top
|
JOS Index |
JOS Pubs |
JOS Home |
Search
- Original MPEG subbands were about 687 Hz wide.
- Finer frequency resolution was needed.
- A Princen-Bradley filter bank with 12 to 36 sub-bands is
appended after each subband of the 32-channel PQMF cosine modulated
analysis filter bank.
- The number of sub-bands and window shape are signal dependent:
- Transients use 12 subbands, which gives better time resolution
and poorer frequency resolution.
- Steady-state tones use 36 subbands, which gives better
frequency resolution and poorer time resolution.
- The encoder generates a function called the perceptual
entropy (PE), which tells the coder when to switch resolutions.
Next |
Prev |
Top
|
JOS Index |
JOS Pubs |
JOS Home |
Search
Download JFB.pdf
Download JFB_2up.pdf
Download JFB_4up.pdf
[Comment on this page via email]