Human-Centered Multimedia Computing (HCMC) has emerged as a field of computational science where human-centered principles of design are core to the creation of multimedia systems. Today's multimedia technologies still largely cater to the "able" population, largely ignoring those with disabilities or "adding-on" accessibility features after development rather than incorporating the principles as an integral system component at the conceptualization and design stages. We propose a methodology to enrich HCMC through inspirations from disabilities, deficits and impairments. We propose a three dimension model, and illustrate how disabilities research can result in a broader impact. Although HCMC does address adaptability to some extent, continuous co-adaptation between the user and machine is important for improved effectiveness and efficiency. We therefore introduce the concept of personcenteredness and Person-Centered Multimedia Computing (PCMC). Through understanding individual users' needs, we can better design and facilitate seamless and implicit co-adaptation in next-generation multimedia technologies. We present three case studies that illustrate the usefulness of the person-centeredness approach.