Rate control for bitstream re-encoding
US6763067B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 9, 2001 |
| Grant date | Jul 13, 2004 |
| Priority date | — |
| Expiry date | Jul 26, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/44004
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Processing is applied to convert an input compressed video bitstream into an output compressed video bitstream having a different bit rate and/or representing different imagery from the input bitstream. The bitstream conversion processing is adjusted based on control parameters that are generated by comparing analogous measurements made to the input and output bitstreams so that subsequent measurements of the output bitstream will more closely match subsequent measurements of the input bitstream. In certain embodiments, the bitstream conversion processing involves decoding the input bitstream, optionally applying image processing functions to the resulting decoded video data, and re-encoding the resulting processed video data to generate the output bitstream. In one embodiment, the quantization data used during quantization of DCT coefficients during the re-encoding process are scaled using quantization re-scale factors (QRFs) generated by comparing the arrival margin for each frame in the input bitstream to the arrival margin for the corresponding frame in the output bitstream, where the arrival margin is defined as the amount of time between when the last bit of a frame has enter…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.