Init: 导入源码

backend/app/services/video_service.py

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+"""
+视频合成服务
+"""
+import os
+import subprocess
+import json
+from pathlib import Path
+from loguru import logger
+from typing import Optional
+
+class VideoService:
+    def __init__(self):
+        pass
+
+    def _run_ffmpeg(self, cmd: list) -> bool:
+        cmd_str = ' '.join(f'"{c}"' if ' ' in c or '\\' in c else c for c in cmd)
+        logger.debug(f"FFmpeg CMD: {cmd_str}")
+        try:
+            # Synchronous call for BackgroundTasks compatibility
+            result = subprocess.run(
+                cmd_str,
+                shell=True,
+                capture_output=True,
+                text=True,
+                encoding='utf-8',
+            )
+            if result.returncode != 0:
+                logger.error(f"FFmpeg Error: {result.stderr}")
+                return False
+            return True
+        except Exception as e:
+            logger.error(f"FFmpeg Exception: {e}")
+            return False
+
+    def _get_duration(self, file_path: str) -> float:
+        # Synchronous call for BackgroundTasks compatibility
+        cmd = f'ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 "{file_path}"'
+        try:
+            result = subprocess.run(
+                cmd,
+                shell=True,
+                capture_output=True,
+                text=True,
+            )
+            return float(result.stdout.strip())
+        except Exception:
+            return 0.0
+
+    async def compose(
+        self,
+        video_path: str,
+        audio_path: str,
+        output_path: str,
+        subtitle_path: Optional[str] = None
+    ) -> str:
+        """合成视频"""
+        # Ensure output dir
+        Path(output_path).parent.mkdir(parents=True, exist_ok=True)
+        
+        video_duration = self._get_duration(video_path)
+        audio_duration = self._get_duration(audio_path)
+        
+        # Audio loop if needed
+        loop_count = 1
+        if audio_duration > video_duration and video_duration > 0:
+            loop_count = int(audio_duration / video_duration) + 1
+            
+        cmd = ["ffmpeg", "-y"]
+        
+        # Input video (stream_loop must be before -i)
+        if loop_count > 1:
+            cmd.extend(["-stream_loop", str(loop_count)])
+        cmd.extend(["-i", video_path])
+        
+        # Input audio
+        cmd.extend(["-i", audio_path])
+        
+        # Filter complex
+        filter_complex = []
+        
+        # Subtitles (skip for now to mimic previous state or implement basic)
+        # Previous state: subtitles disabled due to font issues
+        # if subtitle_path: ...
+        
+        # Audio map
+        cmd.extend(["-c:v", "libx264", "-c:a", "aac", "-shortest"])
+        # Use audio from input 1
+        cmd.extend(["-map", "0:v", "-map", "1:a"])
+        
+        cmd.append(output_path)
+        
+        if self._run_ffmpeg(cmd):
+            return output_path
+        else:
+            raise RuntimeError("FFmpeg composition failed")