fix(intro): precompose alpha-adjusted logo PNG and overlay to respect transparency across ffmpeg builds

movmaker.py

@@ -31,11 +31,15 @@ IMAGE_EXTS = {".jpg", ".jpeg", ".png", ".webp", ".bmp", ".tif", ".tiff"}
 VIDEO_EXTS = {".mp4", ".mov", ".mkv", ".avi", ".webm", ".m4v"}
 AUDIO_EXTS = {".mp3", ".wav", ".m4a", ".aac", ".flac", ".ogg"}
 DATA_NAMES = {"data.txt", "info.txt", "title.txt"}
+
 BASE_DIR = Path(__file__).resolve().parent
 FFMPEG = BASE_DIR / "ffmpeg" / "ffmpeg"
 FFPROBE = BASE_DIR / "ffmpeg" / "ffprobe"
 INTRO_LOGO_NAME = "intro.png"
 DEFAULT_INTRO_LOGO = BASE_DIR / "img" / "moto_travel.png"
+JAMENDO_ENV = Path.home() / ".config" / "movmaker" / "jamendo.env"
+LOG_PATH: Path | None = None
+
 INTRO_LOGO_TARGET_HEIGHT_RATIO = 0.99
 INTRO_LOGO_EXTRA_HOLD = 6.0
 INTRO_LOGO_FADE_OFFSET = 3.0
@@ -56,8 +60,6 @@ CLIP_AUDIO_SIDECHAIN_THRESHOLD = 0.04
 CLIP_AUDIO_SIDECHAIN_RATIO = 8.0
 CLIP_AUDIO_SIDECHAIN_ATTACK = 5.0
 CLIP_AUDIO_SIDECHAIN_RELEASE = 250.0
-JAMENDO_ENV = Path.home() / ".config" / "movmaker" / "jamendo.env"
-LOG_PATH: Path | None = None
 
 
 def tool_path(local_path: Path, fallback: str) -> str:
@@ -707,6 +709,11 @@ def drawtext_escape(text: str) -> str:
 def render_intro_logo_frame(logo: Path, out: Path, width: int, height: int, alpha: float) -> None:
     """Build a single black frame with the intro logo centered and scaled.
 
+    This implementation first renders a temporary PNG of the logo with the
+    requested alpha applied, then overlays that precomposed PNG onto a black
+    background. This avoids passing problematic options to the overlay filter
+    and works reliably across ffmpeg builds.
+
     Args:
         logo: Source PNG to overlay.
         out: Destination PNG path for the composed frame.
@@ -718,17 +725,30 @@ def render_intro_logo_frame(logo: Path, out: Path, width: int, height: int, alph
         raise ValueError("intro logo frame must have positive width/height")
     alpha = min(1.0, max(0.0, alpha))
     target_logo_height = max(1, int(round(height * INTRO_LOGO_TARGET_HEIGHT_RATIO)))
-    filters = (
+
-        f"[1:v]scale=w={width}:h={target_logo_height}:force_original_aspect_ratio=decrease,"
+    ffmpeg_exe = tool_path(FFMPEG, "ffmpeg")
-        f"format=rgba,colorchannelmixer=aa={alpha:.3f}[logo];"
+
-        f"[0:v]format=rgba[bg];"
+    # Prepare a temporary logo PNG with the requested alpha applied.
-        f"[bg][logo]overlay=x=(W-w)/2:y=(H-h)/2:format=rgba[vout]"
+    tmp_logo = out.with_name(out.stem + "_alpha.png")
-    )
+    cmd_logo = [
-    cmd = [
+        ffmpeg_exe, "-y",
-        tool_path(FFMPEG, "ffmpeg"), "-y",
-        "-f", "lavfi", "-i", f"color=c=black:s={width}x{height}",
         "-i", str(logo),
-        "-filter_complex", filters,
+        "-vf", (
+            f"scale=w={width}:h={target_logo_height}:force_original_aspect_ratio=decrease,"
+            f"format=rgba,colorchannelmixer=aa={alpha:.3f}"
+        ),
+        "-frames:v", "1",
+        "-pix_fmt", "rgba",
+        str(tmp_logo),
+    ]
+    run(cmd_logo)
+
+    # Overlay the precomposed logo onto a black background and write the single frame.
+    cmd = [
+        ffmpeg_exe, "-y",
+        "-f", "lavfi", "-i", f"color=c=black:s={width}x{height}",
+        "-i", str(tmp_logo),
+        "-filter_complex", "[0:v][1:v]overlay=x=(W-w)/2:y=(H-h)/2:format=auto[vout]",
         "-map", "[vout]",
         "-frames:v", "1",
         "-pix_fmt", "rgba",
@@ -736,7 +756,14 @@ def render_intro_logo_frame(logo: Path, out: Path, width: int, height: int, alph
         "-update", "1",
         str(out),
     ]
-    run(cmd)
+    try:
+        run(cmd)
+    finally:
+        try:
+            if tmp_logo.exists():
+                tmp_logo.unlink()
+        except Exception:
+            pass
 
 
 def normalize_clip(item: MediaItem, out: Path, width: int, height: int, fps: int, preset: str, crf: int) -> None: