[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 <codex@openai.com> Signed-off-by: Stanislaw Grams <stanislawgrams@gmail.com>
2026-03-14 21:55:30 +01:00
parent 7c08e12870
commit d2257fd8a3
1 changed files with 11 additions and 0 deletions
@@ -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;