use tail end of longer contexts

app.py

@@ -141,20 +141,19 @@ def apply_micro_fades(wav: au.Waveform, ms: int = 5) -> None:
         wav.samples[:n]  *= env
         wav.samples[-n:] *= env[::-1]
 
-def take_bar_aligned_tail(wav: au.Waveform,
-                          bpm: float,
-                          beats_per_bar: int,
-                          ctx_seconds: float) -> au.Waveform:
+def take_bar_aligned_tail(wav, bpm, beats_per_bar, ctx_seconds, max_bars=None):
     """
     Return the LAST N bars whose duration is as close as possible to ctx_seconds,
     anchored to the end of `wav`, and bar-aligned.
     """
-    spb = (60.0 / bpm) * beats_per_bar               # seconds per bar
+    spb = (60.0 / bpm) * beats_per_bar
+    print(f"[MRT] bpm={bpm}, spb={spb:.4f}, ctx_frames={mrt.config.context_length_frames}, fps={mrt.codec.frame_rate}")
     bars_needed = max(1, int(round(ctx_seconds / spb)))
-    tail_seconds = bars_needed * spb                  # exact multiple of bars
+    if max_bars is not None:
+        bars_needed = min(bars_needed, max_bars)
+    tail_seconds = bars_needed * spb
     n = int(round(tail_seconds * wav.sample_rate))
     if n >= wav.samples.shape[0]:
-        # Input shorter than desired tail: keep whole thing (your existing behavior will tile)
         return wav
     return au.Waveform(wav.samples[-n:], wav.sample_rate)
 
@@ -187,6 +186,8 @@ def generate_loop_continuation_with_mrt(
         beats_per_bar=beats_per_bar,
         ctx_seconds=ctx_seconds
     )
+    print(f"[MRT] context tail: {ctx_seconds:.2f}s ≈ {loop_for_context.samples.shape[0]/loop_for_context.sample_rate:.2f}s, "
+      f"sr={loop_for_context.sample_rate}")
 
     # Encode ONLY the tail (so we condition on recent audio)
     tokens_full = mrt.codec.encode(loop_for_context).astype(np.int32)