by Adam Schadle Issue 90 - June 2014
Todays media and entertainment ecosystem relies on interconnections between content originators, who produce programming and deliver it over broadcast networks (including terrestrial, satellite, cable, and IPTV), and secondary content distributors who take that programming and deliver it to the end viewer. Increasingly, the lines between the two are blurring as more companies become both originator and delivery service, but one thing is for certain: there is an ever-increasing number of delivery requirements and regulations to be met. It behooves everyone up and down the chain to ensure the content meets set parameters for video quality, audio quality, loudness, and lip sync. Needs have evolved such that more people within an organization must not only understand and adhere to quality levels, but also be able to demonstrate them to management, so that management can prove it to advertisers and compliance bodies. And that means being able to monitor content in order to catch and correct faults.
In a basic delivery scenario, content is created by the originator and sent as a processed signal to the secondary distributor, who processes it further in order to deliver it to the viewing audience on any number of platforms. When it comes to monitoring, there are products that allow content originators to compare the entire original source signal to the entire processed signal nonstop, in real time (i.e., full reference), so that they can easily spot faults, identify the source, and take immediate action. Content distributors, on the other hand, do not have access to the original source signal, so when their ongoing quality-of-services tests identify an error, they have no way of knowing whether the error occurred upstream or after it arrived at their facility.
Quality control is often just as important to content distributors as it is to originators, with more and more service providers testing for the highest level of ongoing video and audio quality they can provide. Yet because the distributors only see the processed signal, identifying and correcting faults can be a challenge. The process is made even more complicated if the secondary distributor has a content delivery network with multiple geographically dispersed delivery points, because there are that many more possibilities for errors to occur. Several solutions in the market attempt to provide service monitoring with quality measurements on the distributor end, but without being able to refer to the original signal, monitoring effectively can be all but impossible.
These challenges are precisely what Video Claritys RTM reduced reference operating mode was designed to overcome. Just as originators use the RTM real-time audio and video monitoring solution for full-reference comparisons, content distributors can now use RTM to measure their incoming signal against representative picture and audio source data sent from an RTM system located at the originator site (i.e., reduced reference). For the first time, distributors will have a tool to compare their signal to that of geographically removed source channels and that means they can assess signal quality and verify whether errors were caused in transmission or from source processing devices that are outside their facility and control.
When a content originator sends a satellite feed to its secondary distributors, an RTM system on the content originator end sends out data representing the original audio and video signal via the Internet or a dedicated network data path. Secondary distributors can subscribe to that data stream so that when they receive a distributed feed from the content originator, their RTM unit will compare the incoming video signal with the source data from the original signal before any processing takes place. The RTM uses this comparison to test for video and audio quality continuously and then also records error events such as picture breakups, freeze-frames, and black frames. RTM automatically records these faults based on user-set error thresholds so that the content distributor can take appropriate action.
The RTM reduced reference method is unique because it provides the reference data from the content source so that it can then be used to understand the root cause of any lower-than-expected A/V quality event. Another unique benefit is the number of audio performance characteristics that can be monitored and found, such as audio dropout, artifact, and low-quality differences from the source. Moreover, the RTM reduced reference method achieves an accurate lip sync measurement using only standard audio/video signals.
RTM with reduced reference operation is a breakthrough in video quality and service performance testing because it allows originators and service providers to collaborate on picture quality measurements, thus reducing program interruptions or problem segments.
