Techniques for generating a target digital media item based on a source digital media item are described. A digital media item may be a song, a video clip, an album, or any length of audio or video. When adjusting the bit count for a portion of the target digital media item, instead of using the same set of parameter values used in a perceptual model for each portion of the source media item, the set of parameter values may be modified to encode the portion of the source digital media item. In this way, how audio or video is perceived is taken into account when adjusting a proposed bit count for a given portion of the target digital media item. Thus, while maintaining the same statistical bitrate as before increased digital media quality is achieved.