Two-pass MPEG-2 variable-bit-rate encoding

Abstract

A two-pass encoding system that has the objective of producing an optimized variable-bit-rate (VBR) data stream in a second pass is described. In a first pass, the video sequence is encoded with constant-bit-rate (CBR), while statistics concerning coding complexity are gathered. Following this, the first-pass data is processed to prepare the control parameters for the second pass, which performs the actual VBR compression. During the running of the second pass, a run-time bit-production control mechanism monitors the accuracy and validity of the first-pass data, correcting errors in prediction and observing the buffer boundaries.