Pre-processing of bit rate allocation in a multi-channel video encoder
US6259733A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 16, 1998 |
| Grant date | Jul 10, 2001 |
| Priority date | — |
| Expiry date | Jun 16, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/15
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for bit rate allocation, or statistical multiplexing, in a multi-channel video data encoder. A pre-processor in each channel determines a bit rate need prior to compression and encoding. A control processes the bit rate need in each channel to arrive at an allocated bit rate for each channel. The video data is then compressed and encoded according to the allocated bit rate. The bit rate demand accounts for various characteristics of the current picture data in each channel, including spatial activity, temporal activity, image size, frame rate, scene change, brightness, flash, fade, and horizontal pixel resolution. The system also biases the bit rate allocation according to inter-frame distance, whether the average spatial activity level is below a lower threshold, whether the inter-frame distance is above an upper threshold or below a lower threshold, whether the quantization of previous frames is above an upper threshold, the length of the Group of Pictures (GOP), and a user-selectable priority factor. The system also allocates any surplus bit rate among the channels to avoid having unused bandwidth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.