xiaoxia-saas/apps/worker/video_processing/processor.py

"""Video processing module with proper temp file cleanup."""

import os
import tempfile
from dataclasses import dataclass
from typing import List, Tuple

import ffprobe


@dataclass
class VideoResult:
    """Video processing result."""

    output_path: str
    thumbnail_path: str
    duration: float
    width: int
    height: int
    fps: float
    file_size: int


class VideoProcessor:
    """Video processor with proper temp file cleanup."""

    def __init__(self, temp_dir: str = None):
        """
        Initialize video processor.

        Args:
            temp_dir: Temporary directory for intermediate files.
                     Uses system temp dir if not specified.
        """
        self.temp_dir = temp_dir or tempfile.gettempdir()

    def concatenate_videos(
        self,
        input_paths: List[str],
        output_path: str,
        resolution: Tuple[int, int] = (1920, 1080),
        fps: int = 25,
    ) -> VideoResult:
        """
        Concatenate multiple videos into one.

        Args:
            input_paths: List of input video paths
            output_path: Output video path
            resolution: Target resolution (width, height)
            fps: Target frame rate

        Returns:
            VideoResult with processing details
        """
        if not input_paths:
            raise ValueError("input_paths cannot be empty")

        # Ensure output directory exists
        os.makedirs(os.path.dirname(output_path), exist_ok=True)

        # P2-6: Use NamedTemporaryFile with cleanup for concat list file
        concat_file = None
        try:
            # Create concat file in temp directory with auto cleanup
            concat_file = tempfile.NamedTemporaryFile(
                mode='w',
                suffix='.txt',
                dir=self.temp_dir,
                delete=True,
            )
            
            # Write concat list
            for path in input_paths:
                concat_file.write(f"file '{os.path.abspath(path)}'\n")
            concat_file.flush()

            # Run ffmpeg concat
            width, height = resolution
            (
                ffprobe.input(concat_file.name, format="concat", safe=0)
                .output(
                    output_path,
                    vcodec="libx264",
                    acodec="aac",
                    s=f"{width}x{height}",
                    r=fps,
                    preset="medium",
                    crf=23,
                )
                .overwrite_output()
                .run(capture_stdout=True, capture_stderr=True)
            )

            # Clean up concat file explicitly (will be cleaned on context exit anyway)
            concat_file.close()

            # Generate thumbnail
            thumbnail_path = self.generate_thumbnail(output_path)

            # Get video info
            probe = ffprobe.probe(output_path)
            video_info = next(s for s in probe["streams"] if s["codec_type"] == "video")

            duration = float(probe["format"]["duration"])
            width = int(video_info["width"])
            height = int(video_info["height"])

            # Get FPS
            fps_str = video_info.get("r_frame_rate", "25/1")
            fps_parts = fps_str.split("/")
            fps_value = float(fps_parts[0]) / float(fps_parts[1]) if len(fps_parts) == 2 else float(fps_parts[0])

            file_size = os.path.getsize(output_path)

            return VideoResult(
                output_path=output_path,
                thumbnail_path=thumbnail_path,
                duration=duration,
                width=width,
                height=height,
                fps=fps_value,
                file_size=file_size,
            )

        except ffprobe.Error as e:
            stderr = e.stderr.decode() if e.stderr else ""
            raise RuntimeError(f"FFmpeg error: {stderr}")
        finally:
            # Ensure concat file is cleaned up even on exception
            if concat_file is not None:
                try:
                    concat_file.close()
                except Exception:
                    pass

    def generate_thumbnail(
        self,
        video_path: str,
        timestamp: float = 1.0,
        output_path: str = None,
    ) -> str:
        """
        Generate thumbnail from video.

        Args:
            video_path: Path to video file
            timestamp: Time in seconds to capture frame
            output_path: Output thumbnail path. Defaults to video_path + '.jpg'

        Returns:
            Path to generated thumbnail
        """
        if output_path is None:
            output_path = f"{os.path.splitext(video_path)[0]}_thumb.jpg"

        try:
            (
                ffprobe.input(video_path, ss=timestamp)
                .output(output_path, vframes=1, format="image2", vcodec="mjpeg")
                .overwrite_output()
                .run(capture_stdout=True, capture_stderr=True)
            )

            return output_path

        except ffprobe.Error as e:
            stderr = e.stderr.decode() if e.stderr else ""
            raise RuntimeError(f"FFmpeg thumbnail error: {stderr}")

    def get_video_info(self, video_path: str) -> dict:
        """
        Get video metadata.

        Args:
            video_path: Path to video file

        Returns:
            Dictionary with video metadata
        """
        try:
            probe = ffprobe.probe(video_path)
            video_info = next(s for s in probe["streams"] if s["codec_type"] == "video")

            duration = float(probe["format"]["duration"])
            width = int(video_info["width"])
            height = int(video_info["height"])

            fps_str = video_info.get("r_frame_rate", "25/1")
            fps_parts = fps_str.split("/")
            fps_value = float(fps_parts[0]) / float(fps_parts[1]) if len(fps_parts) == 2 else float(fps_parts[0])

            return {
                "duration": duration,
                "width": width,
                "height": height,
                "fps": fps_value,
                "codec": video_info.get("codec_name"),
                "bitrate": int(probe["format"].get("bit_rate", 0)),
            }

        except ffprobe.Error as e:
            stderr = e.stderr.decode() if e.stderr else ""
            raise RuntimeError(f"FFmpeg probe error: {stderr}")