The evolution from analog to digital TV has added some complexity to Close Captioning (CC). With one standard way of broadcasting/transmitting, decoding and displaying content NTSC or PAL, depending on region, analog TV made enabling CC fairly easy across CE devices since the TV was able to do all the CC decoding.
With the advent of digital TV and the introduction of digital HDTV services (cable, satellite, etc.) the responsibility of decoding CC has been taken away from the TVs and put into the various Set Top Boxes (STB) that are required for the majority of the digital HDTV services. Additionally, these STBs now have different ways of enabling CC making it complicated and creating confusion for consumers. All set-top boxes are required to support CC, however the implementation of CC can vary from one product to another. Enabling CC on a specific set-top box can be simple, or more difficult, depending on the implementation.
HDMI, LLC recommends contacting your TV service provider (cable, satellite, etc.) for the correct way to switch on its CC feature as a first step to resolve this issue. The second step is to contact the manufacturers directly for the correct way to enable the CC feature within your product.
HDMI and Close Captioning
All HDMI specifications support Close Captioning (CC) and enable the rendering of CC signals between CE devices. HDMI carries and delivers all the rendered data, in its entirety (including CC), produced from the source device to the display device.
HDMI, LLC is working with all CE vendors and service providers (cable, satellite, etc.) to make them aware of this issue. In addition, we are also encouraging these vendors and service providers to take steps that will address this CC problem which will deliver a more user friendly way for consumers to activate the CC feature.
