This paper describes the move to a multithreaded implementation of a Recursive Transition Network Viterbi speech decoder, undertaken with the objective of performing low-latency synchronous decoding on live audio streams to support online subtitling. The approach was meant to be independent on any specific hardware, in order to be easily exploitable on common computers, and portable to different operating systems. In the paper, the reference serial algorithm is presented, together with the modifications introduced to distribute most of the load to different threads by means of a dispatcher/collector thread and several worker threads. Results are presented, confirming a performance benefit in accordance with the design goals.
Bibliographic reference. Brugnara, Fabio (2011): "A multithreaded implementation of Viterbi decoding on recursive transition networks", In INTERSPEECH-2011, 2873-2876.