From d2257fd8a36bf6bac162db09c07895d1d024cbd0 Mon Sep 17 00:00:00 2001 From: Stanislaw Grams Date: Sat, 14 Mar 2026 21:55:30 +0100 Subject: [PATCH] [fix](trx-rs): widen FT4 candidate timing search window Use a wider FT4 time-offset search range in candidate acquisition\nso decode remains robust with current pipeline latency.\n\nCo-authored-by: OpenAI Codex Signed-off-by: Stanislaw Grams --- external/ft8_lib/ft8/decode.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/external/ft8_lib/ft8/decode.c b/external/ft8_lib/ft8/decode.c index 3536024..c05022b 100644 --- a/external/ft8_lib/ft8/decode.c +++ b/external/ft8_lib/ft8/decode.c @@ -253,6 +253,17 @@ int ftx_find_candidates(const ftx_waterfall_t* wf, int num_candidates, ftx_candi time_offset_max = time_offset_min + 1; } } + else if (wf->protocol == FTX_PROTOCOL_FT4) + { + // Keep roughly the same +/- seconds search span used by FT8. + // FT4 symbols are much shorter, so it needs a wider symbol-index window. + time_offset_min = -34; + time_offset_max = wf->num_blocks - FT4_NN + 34; + if (time_offset_max <= time_offset_min) + { + time_offset_max = time_offset_min + 1; + } + } int heap_size = 0; ftx_candidate_t candidate;