ZL1WTT Software-based DATV System and Experimentation
Description
ZL1WTT details a software-based Digital Amateur Television (DATV) system. The page describes an experimental setup capable of multiplexing multiple standard-definition (SD) and high-definition (HD) channels using h264 compression. The author discusses challenges with data bandwidth, peak data rates up to 32 Mbit/s, and the adoption of Freeview and Sky settings (22.5M Sym/s 3/4FEC). The system utilizes four computers on a LAN, with a laptop acting as the multiplexer to re-code PIDs for six channels. Channels include looped MPEG2 playlists, MPEG2 encoder card input from a VCR, satellite feeds, and an off-air UHF receiver. The flexibility of the DVB transport stream is highlighted, supporting MPG2, h264, AC3, and AAC formats. Advantages of a software-defined system include no video quality loss and easy reconfiguration of settings for MPEG2 encoder cards (size, bit-rate, frame rate, video input, coding format) and satellite receiver cards (frequency, LNB volts, symbol rate, FEC).