NAVE¶
Encoding of television signals, such as in the Nielsen system, is used for audience measurement (e.g., to accurately identify television distributors, including broadcast stations or cable networks). The Nielsen Media approach installs metering devices at the user’s premises. This device identifies stations and networks to which the end user tunes in. By encoding content with a NAVE unit, ratings data for programming can be provided whether it is received in a digital, analog or combined viewing environment. Reading the aforementioned watermarks, or other codes, inserted into the television signal at the distribution source through the NAVE unit captures this end user data.
Figure: NAVE watermarking¶
The NAVE is a system capable of inserting Nielsen Media Research proprietary NAVE source identification watermarking directly into the audio portion of compressed digital ATSC Transport Streams prior to broadcast. NAVE devices can simultaneously insert watermarking data on multiple independent digital television programs being broadcast, whether they are standard-definition (SDTV) or high-definition (HDTV). The watermark is capable of identifying the Provider Content (PC), the network on which the content was distributed (NT) and the final distributor (FD), say in the case of local broadcast station or cable channel. The watermarks include a timestamp, so if the content viewed is time-shifted (VOD) within a reasonable time frame, that usage data is also captured.
If any station’s NAVE encoder is interrupted, the meter device installed in Nielsen sample premises collects and stores passive signatures for all non- encoded programming viewed. These signatures are downloaded each night to Nielsen’s operations center. To identify viewing, the passive signatures collected from the meter device in the premises are matched against the signatures in the library.
The feature allows you to define the watermarks to be accepted, and the faults/recoveries to occur, by configuring the watermark’s creation time and the number of good watermarks that should be received per period.
Figure: Encoder features – NAVE¶
Enable |
Enable/disable Nielsen Audio Video Encoder monitoring; requires a subscription to Nielsen service |
Score line |
Percentage of good watermarks in the monitored window; labeled “Error percent” in early versions of Volicon Media Intelligence service |
Levels |
Filters watermarks by their levels |
FD |
Final Distributor: Entity that delivered content to customer |
PC |
Provider Content: Entity that originated content |
VOD |
Video on Demand: Time-shifted viewing |
NT |
Network that delivered the content |
Minimum good watermarks |
If number of good watermarks during sliding window are lower than minimum value, fault detected |
Station IDs |
List of good watermarks you intend to accept; if field left empty, all watermarks will be detected; if some channels support more than one station ID (SID), insert into SID array all IDs you intend to accept; single SID sufficient to satisfy minimum good watermarks and watermark percentage recovery variables to avoid faults and stay recovered |
Warning percent |
If value greater than score line but less than warning percent, warning message will be sent; other cases to result in recovery |
Watermark age |
The watermark’s time from its creation |
Watermark max age |
Filters out watermarks older than threshold and reports no faults on these; if left at 0, variable watermark age taken; e.g., if watermark is 10 days old, any older watermarks to be ignored; if the watermark’s age is less than threshold, it will be processed as regular watermark |
Window interval |
Faults detected and recoveries enabled during sliding window interval; e.g., if you define 30-second window for each second, 30-second window will be checked (0-30, 1-31, 2-32…) against various parameters used |