Added comment, changed output to arrays of SRTsegment

Former-commit-id: 97fea915a8272bdfd5a632e672dfe8e9709c4188

evaluation/alignment.py

@@ -3,69 +3,87 @@ import numpy as np
 sys.path.append('../src')
 from srt_util.srt import SrtScript
 
+
+# Helper method
+# Align sub anchor segment pair via greedy approach
+# Input: anchor segment, SRT segments, output array of sub, index of current sub
+# Output: updated index of sub
 def procedure(anchor, subsec, S_arr, subidx):
     cache_idx = 0
-    while subidx != cache_idx:
+    while subidx != cache_idx:  # Terminate when alignment stablizes
         cache_idx = subidx
-        if subidx >= len(subsec):
+        # if sub segment runs out during the loop, terminate
+        if subidx >= len(subsec): 
             break
         sub = subsec[subidx]
         if anchor.end < sub.start:
             continue
+        # If next sub has a heavier overlap compartment, add to current alignment
         if (anchor.start <= sub.start) and (sub.end <= anchor.end) or anchor.end - sub.start > sub.end - anchor.start:
-            S_arr[-1] += sub.source_text
+            S_arr[-1] += sub#.source_text
             subidx += 1
-    return subidx - 1
 
+    return subidx - 1  # Reset last invalid update from loop
+
+
+# Input: path1, path2
+# Output: aligned array of SRTsegment corresponding to path1 path2
+# Note: Modify comment with .source_text to get output array with string only
 def alignment(pred_path, gt_path):
     pred = SrtScript.parse_from_srt_file(pred_path).segments
     gt = SrtScript.parse_from_srt_file(gt_path).segments
     pred_arr, gt_arr = [], []
-    idx_p, idx_t = 0, 0
+    idx_p, idx_t = 0, 0  # idx_p: current index of pred segment, idx_t for ground truth
 
     while idx_p < len(pred) or idx_t < len(gt):
+        # Check if one srt file runs out while reading
         ps = pred[idx_p] if idx_p < len(pred) else None
         gs = gt[idx_t] if idx_t < len(gt) else None
-
+        
         if not ps:
-            gt_arr.append(gs.source_text)
+            # If ps runs out, align gs segment with filler one by one
+            gt_arr.append(gs)#.source_text
             pred_arr.append('')
             idx_t += 1
             continue
 
         if not gs:
-            pred_arr.append(ps.source_text)
+            # If gs runs out, align ps segment with filler one by one
+            pred_arr.append(ps)#.source_text 
             gt_arr.append('')
             idx_p += 1
             continue
 
         ps_dur = ps.end - ps.start
         gs_dur = gs.end - gs.start
-
+        
+        # Check for duration to decide anchor and sub
         if ps_dur <= gs_dur:
+            # Detect segment with no overlap
             if ps.end < gs.start:
-                pred_arr.append(ps.source_text)
-                gt_arr.append('')
-                idx_t -= 1
+                pred_arr.append(ps)#.source_text
+                gt_arr.append('')  # append filler
+                idx_t -= 1  # reset ground truth index
             else:
-                gt_arr.append(gs.source_text)
+                gt_arr.append(gs)#.source_text
                 if gs.end >= ps.start:
-                    pred_arr.append(ps.source_text)
+                    pred_arr.append(ps)#.source_text
                     idx_p = procedure(gs, pred, pred_arr, idx_p + 1)
-                else:
+                else:  # filler pairing
                     pred_arr.append('')
                     idx_p -= 1
         else:
+            # same overlap checking procedure
             if gs.end < ps.start:
-                gt_arr.append(gs.source_text)
-                pred_arr.append('')
-                idx_p -= 1
+                gt_arr.append(gs)#.source_text
+                pred_arr.append('')  # filler
+                idx_p -= 1  # reset
             else:
-                pred_arr.append(ps.source_text)
+                pred_arr.append(ps)#.source_text
                 if ps.end >= gs.start:
-                    gt_arr.append(gs.source_text)
+                    gt_arr.append(gs)#.source_text
                     idx_t = procedure(ps, gt, gt_arr, idx_t + 1)
-                else:
+                else:  # filler pairing
                     gt_arr.append('')
                     idx_t -= 1