The design of the MPEG compression standard ensures all receivers receiving the same compressed bit stream exhibit identical buffer occupancy levels. However, files that will be spliced are generally encoded independently. The encoder used for the current file assumes a particular buffer occupancy level at the precise time of the splice, while the encoder utilized for the next program may well assume another. A technician therefore cannot assume that a transition between the two programs will not trigger an overflow or underflow. Unless the two occupancy levels are identical, overflow or underflow becomes possible.
Several solutions are available.
Such an approach also requires the purchase of an encoder, a costly piece of equipment used to digitize and compressed both the analog feed and the ad that has been inserted. From a quality perspective, the phenomenon of generational loss a discernible degradation in picture quality that occurs each time video content is converted from digital to analog and back accompanies any approach that relies on currently existing analog-based switching equipment to insert advertising spots into a digital video program stream. In such a case, the picture quality would degrade when the content changes format from digital to analog and back. Clearly, only a seamless splicing system may overcome these challenges. Seamless splicing produces an invisible splice between the program material being delivered and a particular ad being spliced into it.