Exchanging digital video of laryngeal examinations.

Laryngeal examinations, especially stroboscopic examinations, are increasingly recorded using digital video formats on computer media, rather than using analog formats on videotape. It would be useful to share these examinations with other medical professionals in formats that would facilitate reliable and high-quality playback on a personal computer by the recipients. Unfortunately, a personal computer is not well designed for reliable presentation of artifact-free video. It is particularly important that laryngeal video play without artifacts of motion or color because these are often the characteristics of greatest clinical interest. With proper tools and procedures, and with reasonable compromises in image resolution and the duration of the examination, digital video of laryngeal examinations can be reliably exchanged. However, the tools, procedures, and formats for recording, converting to another digital format ("transcoding"), communicating, copying, and playing digital video with a personal computer are not familiar to most medical professionals. Some understanding of digital video and the tools available is required of those wanting to exchange digital video. Best results are achieved by recording to a digital format best suited for recording (such as MJPEG or DV),judiciously selecting a segment of the recording for sharing, and converting to a format suited to distribution (such as MPEG1 or MPEG2) using a medium suited to the situation (such as e-mail attachment, CD-ROM, a "clip" within a Microsoft PowerPoint presentation, or DVD-Video). If digital video is sent to a colleague, some guidance on playing files and using a PC media player is helpful.