Bitstream Transcoding in the Studio

One of the benefits of carrying video in the studio as compressed bitstreams is the great flexibility in trading off various compression parameters to optimize the bitstream for the task at hand, For example, when live switching is required, we may require frequent I frames and thus a high bit rate, but when the bit rate must be low, as when distributing video by satellite, the I-frame density must be reduced. Thus there is a need for studio devices that perform this bitstream transcoding. This paper will examine the requirements for bit rate transcoding and possible cost/performance enhancements that may be achieved in such devices.