fix: harden arabic terminal rtl rendering

history.md

@@ -152,3 +152,11 @@ The project now features a high-performance, Apple Silicon-optimized pipeline th
     - Implemented comment/blank-line support and invalid-line skipping with line-level warnings.
     - Merged file-based glossary entries with repeatable `--glossary-pair` CLI entries for runtime overrides.
 - **Outcome:** English caption correction can now use a maintained glossary file automatically, while preserving ad-hoc CLI term fixes.
+
+## Phase 19: Arabic Terminal Rendering Hardening
+- **Goal:** Improve readability of Arabic captions in terminal environments with mixed LTR/RTL output.
+- **Approach:**
+    - Switched Arabic output to a strict two-line format (`[AR]:` label line + dedicated RTL content line).
+    - Wrapped Arabic caption content in explicit RTL embedding marks for better bidirectional layout stability.
+    - Added punctuation normalization for Arabic display (`،`, `؛`, `؟`) to reduce LTR punctuation artifacts.
+- **Outcome:** Arabic captions render more consistently in terminal output, especially when adjacent to English/French/Spanish caption lines.

transcribe.py

@@ -229,6 +229,30 @@ def maybe_merge_recent_caption(recent_en_lines, current_text, now_ts, window_sec
     previous["ts"] = now_ts
     return old, merged
 
+def normalize_arabic_punctuation(text):
+    """Convert common Latin punctuation to Arabic-friendly equivalents."""
+    updated = text.replace(",", "،").replace(";", "؛")
+    # Convert question mark only when there are Arabic letters present.
+    if re.search(r"[\u0600-\u06FF]", updated):
+        updated = updated.replace("?", "؟")
+    return updated
+
+def format_caption_lines(lang_key, text):
+    """Format caption output lines for terminal display."""
+    key = lang_key.lower()
+    if key == "ar":
+        cleaned = normalize_arabic_punctuation(text)
+        # Put label on separate line and force RTL embedding for the content line.
+        return ["[AR]:", f"\u202B{cleaned}\u202C"]
+    return [f"[{lang_key.upper()}]: {text}"]
+
+def print_caption(lang_key, text, leading_newline=False):
+    lines = format_caption_lines(lang_key, text)
+    if leading_newline and lines:
+        lines[0] = "\n" + lines[0]
+    for line in lines:
+        print(line)
+
 def is_hallucination(text):
     """Detect common Whisper hallucinations or high repetition."""
     if not text: return False
@@ -517,7 +541,7 @@ def main():
                                 recent_en_lines.clear()
 
                             if original_text:
-                                print(f"\n[{detected_lang.upper()}]: {original_text}")
+                                print_caption(detected_lang, original_text, leading_newline=True)
                                 last_change_time = time.time() # Successfully transcribed full segment
 
                                 # Prepare payload
@@ -588,7 +612,7 @@ def main():
                                         # Skip if we already filled this (e.g. detected lang was 'es')
                                         if lang_key in payload:
                                             if lang_key != detected_lang: # Already printed original
-                                                print(f"[{lang_key.upper()}]: {payload[lang_key]}")
+                                                print_caption(lang_key, payload[lang_key])
                                             continue
 
                                         translated_parts = []
@@ -608,7 +632,7 @@ def main():
 
                                         translated_text = " ".join(part for part in translated_parts if part).strip()
                                         payload[lang_key] = translated_text
-                                        print(f"[{lang_key.upper()}]: {translated_text}")
+                                        print_caption(lang_key, translated_text)
                                 
                                 # Queue for background ingestion if enabled
                                 if args.ingest: