Worldwide television tuning system with object-based tuning control modules

摘要

A worldwide television tuning system is configurable to the television standards and channel frequencies of multiple different countries based on a country's ITU long-distance country code. The television tuning system is architected in parallel hardware and software components. The hardware components include tuner circuitry to tune to various television frequencies carrying television video signals and video decoder circuitry coupled to receive a television video signal from the tuner circuitry and to convert the television video signal to digital video data. The software components include a tuner module coupled to adjust the tuner circuitry to a particular television frequency and a video decoder module to decode the digital video data according to a particular video standard. A driver interface layer interfaces the software layer and the hardware circuitry. When a new channel is requested, the tuner module generates and sends a beginning tuning packet to inform the video decoder module of an impending change to the new channel. In addition to the video decoder module, this tuning packet also propagates to all downstream modules (e.g., audio decoder module, VBI decoders, etc.). The tuner module then controls the tuner circuitry to tune to a new television frequency that corresponds to the new channel. Afterward, the tuner module generates and sends an ending tuning packet to inform the video decoder module that the channel change is complete. The tuning packet includes a designation of country within which the tuning system is configured to receive television signals, a channel to be tuned, the particular video standard, and flags indicating whether the tuning packet represents a beginning of a tuning operation or an ending of the tuning operation.