Initial commit: image+audio to YouTube MP4 queue

worker.py

@@ -0,0 +1,78 @@
+import os
+import shutil
+import subprocess
+import tempfile
+from pathlib import Path
+
+from PIL import Image
+
+from config import Config
+from models import JobStore
+
+
+def _ffmpeg_available() -> bool:
+    return shutil.which('ffmpeg') is not None
+
+
+def _prepare_image(image_path: Path, output_path: Path, width: int, height: int) -> None:
+    img = Image.open(image_path)
+    img = img.convert('RGB')
+
+    # Fit inside target box, then letterbox/pillarbox with black to exact 16:9
+    img.thumbnail((width, height), Image.LANCZOS)
+
+    canvas = Image.new('RGB', (width, height), (0, 0, 0))
+    x = (width - img.width) // 2
+    y = (height - img.height) // 2
+    canvas.paste(img, (x, y))
+    canvas.save(output_path, 'JPEG', quality=95)
+
+
+def _build_video(image_path: Path, audio_path: Path, output_path: Path, cfg: Config) -> None:
+    if not _ffmpeg_available():
+        raise RuntimeError('ffmpeg is not installed or not on PATH')
+
+    with tempfile.TemporaryDirectory() as tmpdir:
+        tmp = Path(tmpdir)
+        prepared_image = tmp / 'prepared.jpg'
+        _prepare_image(image_path, prepared_image, cfg.VIDEO_WIDTH, cfg.VIDEO_HEIGHT)
+
+        cmd = [
+            'ffmpeg',
+            '-y',
+            '-loop', '1',
+            '-framerate', str(cfg.VIDEO_FPS),
+            '-i', str(prepared_image),
+            '-i', str(audio_path),
+            '-c:v', cfg.VIDEO_CODEC,
+            '-pix_fmt', 'yuv420p',
+            '-preset', 'medium',
+            '-b:v', cfg.VIDEO_BITRATE,
+            '-c:a', cfg.AUDIO_CODEC,
+            '-b:a', cfg.AUDIO_BITRATE,
+            '-movflags', '+faststart',
+            '-shortest',
+            str(output_path),
+        ]
+        result = subprocess.run(cmd, capture_output=True, text=True)
+        if result.returncode != 0:
+            raise RuntimeError(f'ffmpeg failed: {result.stderr}')
+
+
+def process_job(job_id: int, store: JobStore, cfg: Config) -> None:
+    job = store.get_job(job_id)
+    if job is None:
+        return
+
+    image_path = cfg.UPLOAD_FOLDER / job['image_file']
+    audio_path = cfg.UPLOAD_FOLDER / job['audio_file']
+    output_filename = f"job-{job_id}.{cfg.OUTPUT_FORMAT}"
+    output_path = cfg.OUTPUT_FOLDER / output_filename
+
+    try:
+        cfg.OUTPUT_FOLDER.mkdir(parents=True, exist_ok=True)
+        _build_video(image_path, audio_path, output_path, cfg)
+        store.update_status(job_id, 'complete', output_file=output_filename)
+    except Exception as exc:
+        store.update_status(job_id, 'error', error_message=str(exc))
+        raise