According to the present invention, methods and apparatus for updating reduction ratios are provided. An input bit sequence can be altered to provide modified output bit sequence. The input bit sequence may represent information in a portion of data such as a video sequence, a picture, or an audio stream. In one example, the bit sequence is an MPEG-2 video sequence. The input bit sequence is altered using a reduction ratio to provide a modified output bit sequence. The reduction ratio can be continually updated using rate control information to achieve a target reduction ratio for the input bit sequence.