simulstream.server.speech_processors.sliding_window_retranslation

Classes

SlidingWindowRetranslator(config)

A speech processor that applies a fixed-length sliding window retranslation with deduplication to mitigate overlapping outputs when processing unsegmented audio streams.
class simulstream.server.speech_processors.sliding_window_retranslation.SlidingWindowRetranslator(config: SimpleNamespace)

A speech processor that applies a fixed-length sliding window retranslation with deduplication to mitigate overlapping outputs when processing unsegmented audio streams.

This class implements the algorithm introduced in:

S. Sen, et al. 2025. “Simultaneous Translation for Unsegmented Input: A Sliding Window Approach” (https://arxiv.org/pdf/2210.09754)

The approach relies on detecting the longest common subsequence between the current window and the previous one, in order to prevent repeating tokens caused by overlapping audio windows.

Parameters:

config (SimpleNamespace) –

Configuration object. The following attributes are expected:

  • window_len (int): Length of the sliding window (in seconds).

  • matching_threshold (float, optional): Minimum fraction of the current tokens that must match the previous history to be considered aligned. Default = 0.1.

  • override_on_failed_match (bool, optional): If True, the previous history is deleted from the output when no sufficient match is found. Otherwise, previous history is kept and the new output is appended to the end of the previous history. Default = False.

  • max_tokens_per_second (int, optional): Maximum output tokens allowed per second of audio. Default = 10.

clear() → None

Clear internal states, such as history of cached audio and/or tokens, in preparation for a new stream or conversation.

end_of_stream() → IncrementalOutput

This method is called at the end of audio chunk processing. It can be used to emit hypotheses at the end of the speech to conclude the output.

Returns:

The incremental output (new and deleted tokens/strings).

Return type:

IncrementalOutput