Masood Parwez Shabnam , Assistant Manager , Broadcast Technical, Dish TV India Ltd.

The robust and standalone hardware-based solution allows for easy integration within any live feed including production and playout center workflows.

The process of embedding the electronic identifier into a video or audio file which is inaudible to the human ear is called watermarking.

An audio watermark is a unique electronic identifier embedded in an audio signal, typically used to identify ownership of copyright. It is present in the audio signal without consuming much bandwidth of the embedded signal. Audio watermarking (encoding) embeds a series of codes, beyond the range of the human ear, in the soundtrack of a TV program or commercial. These are collected by the metering technology in the homes of the audience panel to register what is being watched. The watermark is inserted at the broadcaster end in the playout chain using a watermark encoder card. It can easily be detected and decoded using dedicated hardware or software.

Watermarking is mainly used for the protection of intellectual property rights, especially protection against music piracy where it provides information about content ownership and can be used to track the original source of material.

Types of Watermarking Techniques

Multimedia can be defined as multiple forms of media (text, graphics, images, animation, audio, and video) that are used together in the same application. Important properties of a watermarking system include perceptual transparency, robustness, and high data capacity. Robustness is the resistance of the watermark against intentional attacks such as addition of noise, filtering, lossy compression, scaling and likewise. Watermarks and watermarking techniques can be divided into various categories.

There are two techniques in which frequency domain methods are more robust than the spatial domain techniques. Frequency domain techniques incorporate the watermark into transforms and include: DCT (discrete cosine transform) and DWT (discrete wave transform). DCT domain allows an image to break up into different frequency bands, making it much easier to embed watermarking information into the appropriate frequency bands of the signal.

The robust and standalone hardware-based solution allows for easy integration within any live feed including production and playout center workflows.

The software measure what media people actually consume, to give advertisers, agencies, broadcasters, and content owners a true understanding of the merits of individual media and to help them optimize their media strategies.

For the TRP calculation the watermark encoder cards provided a reference and NTP which synchronize with the UTC to follow the correct time stamp at which time this program has been watched.

TRP Calculation

There are BAR-o-meters installed at some selected households in urban and rural areas. In those STBs a chip is installed through which the watermark monitoring station receives the data that at a particular time, for example, in prime time say 7 PM to 9 PM xyz program has been watched. They provide the data to the broadcaster that this program has been watched at this point of time and TRP is high for this program. Advertisers want to show their commercial during the high TRP program. This gives content owners unprecedented visibility into when and where their content is broadcast, who has viewed it, etc.

As the watermark is part of the content, any attempt to destroy or remove it will also ruin the quality of the material in which it is embedded. This increases the integrity of the data generated by TRP calculator 'ratings.

How is the TRP Data Calculated?

Audio watermarking embeds audio watermarks in video content prior to upload and broadcast. The watermark is part of the content and present in every audio track like stereo, mono, and Dolby(5.1+2). The watermark ID is broadcasted along with the content. Viewing details are recorded by the BAR-O-meters, so are the watermarks. The raw data is cleaned, merged with the channel, program, language, and broadcast schedule details.