Initial commit: auto-video-cut project

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

auto_video_cut/audio.py

@@ -0,0 +1,116 @@
+"""Hintergrundmusik-Mixing und Audio-Logik."""
+
+from __future__ import annotations
+
+import random
+import subprocess
+from pathlib import Path
+
+from .config import MUSIC_EXTENSIONS, get_music_files
+
+
+def _run(cmd: list[str]) -> subprocess.CompletedProcess:
+    return subprocess.run(cmd, capture_output=True, text=True, check=False)
+
+
+def pick_music_file(
+    music_files: list[Path],
+    mode: str = "random",
+) -> Path:
+    """Musikdatei nach Modus auswählen."""
+    if not music_files:
+        raise FileNotFoundError("Keine Musikdateien gefunden.")
+
+    if mode == "random":
+        return random.choice(music_files)
+    elif mode in ("alphabetical", "loop"):
+        return sorted(music_files)[0]
+    else:
+        raise ValueError(f"Unbekannter Musik-Modus: {mode}")
+
+
+def mix_music(
+    video_path: Path,
+    output_path: Path,
+    music_file: Path,
+    volume_original: float = 1.0,
+    volume_music: float = 0.3,
+) -> Path:
+    """Hintergrundmusik in Video mixen."""
+    output_path.parent.mkdir(parents=True, exist_ok=True)
+
+    # Prüfen ob Video Audio-Stream hat
+    probe_cmd = [
+        "ffprobe", "-v", "error",
+        "-select_streams", "a",
+        "-show_entries", "stream=codec_type",
+        "-of", "default=noprint_wrappers=1:nokey=1",
+        str(video_path),
+    ]
+    probe = _run(probe_cmd)
+    has_audio = bool(probe.stdout.strip())
+
+    if has_audio:
+        filter_complex = (
+            f"[0:a]volume={volume_original}[v1];"
+            f"[1:a]volume={volume_music}[v2];"
+            f"[v1][v2]amix=inputs=2:duration=first[a]"
+        )
+        cmd = [
+            "ffmpeg", "-y",
+            "-i", str(video_path),
+            "-stream_loop", "-1",
+            "-i", str(music_file),
+            "-filter_complex", filter_complex,
+            "-c:v", "copy",
+            "-c:a", "aac",
+            "-map", "0:v:0",
+            "-map", "[a]",
+            "-shortest",
+            str(output_path),
+        ]
+    else:
+        # Kein Original-Audio → Musik direkt als Track
+        cmd = [
+            "ffmpeg", "-y",
+            "-i", str(video_path),
+            "-stream_loop", "-1",
+            "-i", str(music_file),
+            "-filter_complex", f"[1:a]volume={volume_music}[a]",
+            "-c:v", "copy",
+            "-c:a", "aac",
+            "-map", "0:v:0",
+            "-map", "[a]",
+            "-shortest",
+            str(output_path),
+        ]
+
+    result = _run(cmd)
+    if result.returncode != 0:
+        raise RuntimeError(f"ffmpeg Fehler beim Musik-Mixing: {result.stderr}")
+
+    return output_path
+
+
+def add_music_from_config(
+    video_path: Path,
+    output_path: Path,
+    config: dict,
+) -> Path:
+    """Musik aus Konfiguration auswählen und mixen."""
+    music_files = get_music_files(config)
+    if not music_files:
+        raise FileNotFoundError(
+            f"Keine Musikdateien in: {config['resources']['folder']}/music/"
+        )
+
+    mode = config["music"]["mode"]
+    music_file = pick_music_file(music_files, mode)
+
+    return mix_music(
+        video_path=video_path,
+        output_path=output_path,
+        music_file=music_file,
+        volume_original=config["music"]["volume_original"],
+        volume_music=config["music"]["volume_music"],
+    )