Stop monotonic

Author: WyattBlue

auto_editor/make_layers.py

@@ -13,6 +13,7 @@
 from auto_editor.timeline import ASpace, TlAudio, TlVideo, VSpace, v1, v3
 from auto_editor.utils.func import mut_margin
 from auto_editor.utils.types import Args, CoerceError, time
+from math import ceil
 
 if TYPE_CHECKING:
     from numpy.typing import NDArray
@@ -234,16 +235,30 @@ def echunk(
     clips: list[Clip] = []
     i = 0
     start = 0
+
+    last_i = 0
+
     for chunk in echunk(speed_index, src_index):
         if chunk[3] != 99999:
-            dur = round((chunk[2] - chunk[1]) / chunk[3])
+            dur = int((chunk[2] - chunk[1]) / chunk[3])
             if dur == 0:
                 continue
 
-            offset = int(chunk[1] / chunk[3])
+            offset = ceil(chunk[1] / chunk[3])
+
+            if (clips and clips[-1].start == round(start)):
+                raise ValueError("")
+
+            max_end = start + dur - 1
+            this_i = round((offset + max_end - start) * chunk[3])
+
+            if this_i < last_i:
+                raise ValueError("")
+                # import pdb; pdb.set_trace()
+            last_i = this_i
+
+            clips.append(Clip(start, dur, offset, chunk[3], chunk[0]))
 
-            if not (clips and clips[-1].start == round(start)):
-                clips.append(Clip(start, dur, offset, chunk[3], chunk[0]))
             start += dur
             i += 1
 
@@ -281,4 +296,23 @@ def chunkify(arr: NDArray, smap: dict[int, float]) -> Chunks:
     else:
         v1_compatiable = None
 
-    return v3(inp, tb, sr, res, args.background, vtl, atl, v1_compatiable)
+    tl = v3(inp, tb, sr, res, args.background, vtl, atl, v1_compatiable)
+
+    # Assert monotonic here because
+    #  1. non-monotonic timelines cause performance problems in video rendering.
+    #  2. it should be linear here.
+
+    last_i = 0
+    for index in range(tl.end):
+        for layer in tl.v:
+            for lobj in layer:
+                assert isinstance(lobj, TlVideo)
+                if index >= lobj.start and index < (lobj.start + lobj.dur):
+                    _i = round((lobj.offset + index - lobj.start) * lobj.speed)
+                    #print(f"{_i=}, {index=}, {lobj.start=} {lobj.dur=}, {lobj.offset=}, {lobj.speed=}")
+                    if (_i < last_i):
+                        print(_i, last_i)
+                        raise ValueError("not monotinic")
+
+                    last_i = _i
+    return tl