Ad Insertion

Ad Insertion Technology

The existing MPEG-2 ad insertion technology has been designed and developed using another popular technology, rate-shaping (re-quantization) as its starting point. Rate-shaping is widely used by service providers looking to groom a set of channels into a fixed bandwidth pipe. It is therefore no surprise that the majority of ad insertion deployments to date have been within the cable industry whose HFC architecture requires delivering video in fixed bandwidth pipes known as QAMs.

The re-quantization technology allowed cable service providers to deliver a bouquet of broadcast channels to a regional hub and insert local ads into these channels without exceeding the overall total bandwidth of the pipe. This technology has significantly impacted the cable industry and has tremendously assisted in pushing forward the digital ad insertion business model. However, this technology does have one major drawback -- the video quality is often negatively affected during complex video sequences.

Fortunately, as video networks of all types are now continuously evolving towards a more IP-centric infrastructure, utilizing H.264 codecs and constant bit-rates (CBR), the need for re-quantization technology has diminished.

As the once live variable bit-rate (VBR) content is now more commonly available in CBR, the technology required to splice a channel, or in other words seamlessly insert one stream into another, has been simplified. The focus has shifted from bandwidth management towards ensuring seamless transitions on CBR channels. This trend has enabled new technologies such as PES-level splicing to take effect.

PES-level splicing is a simple and minimal power consuming process used often to merge two compressed files together without hampering their video quality. Harmonic has used this technology in various platforms including its CLEARcut™ Offline Encoding solution, which offers the ability to merge multiple files together seamlessly while retaining their MPEG compliance.

Harmonic also offers the ProStream™ 2000 Digital Ad Splicer, a solution designed from the ground up to fit the next generation video networks heavily based on H.264 codecs, IP delivery and CBR networks. The ProStream 2000 is based on years of research in stream processing technology and is capable of inserting ads in a seamless manner using PES-level splicing technology while not hampering or affecting the incoming video quality.