deltacast-sdi-recorder/backend/app/recorders/recorder.py

"""Recorder management for Deltacast SDI recording ports."""

import asyncio
import re
import time
import logging
from ..config import Settings
from ..models import RecorderConfig, PortStatus, CodecType
from ..utils.ffmpeg import FFmpegCommandBuilder

logger = logging.getLogger(__name__)


class PortRecorder:
    """Manages FFmpeg recording subprocess for a single Deltacast port."""

    def __init__(self, port_index: int, settings: Settings):
        self.port_index = port_index
        self.settings = settings
        self._process: asyncio.subprocess.Process | None = None
        self._config: RecorderConfig | None = None
        self._start_time: float | None = None
        self._frame_count: int = 0
        self._current_file: str = ""
        self._monitor_task: asyncio.Task | None = None
        self._command_builder = FFmpegCommandBuilder(settings)

    async def start(self, config: RecorderConfig) -> None:
        if self._process is not None:
            raise RuntimeError(f"Port {self.port_index} is already recording")

        self._config = config
        self._current_file = config.recording_path
        self._frame_count = 0
        self._start_time = time.time()

        command = self._command_builder.build_command(config)
        logger.info(f"Port {self.port_index}: Starting FFmpeg: {' '.join(command)}")

        self._process = await asyncio.create_subprocess_exec(
            *command,
            stdin=asyncio.subprocess.PIPE,
            stderr=asyncio.subprocess.PIPE,
        )

        self._monitor_task = asyncio.create_task(self._monitor_process())
        logger.info(f"Port {self.port_index}: Recording started (PID: {self._process.pid})")

    async def stop(self) -> None:
        if self._process is None:
            logger.info(f"Port {self.port_index}: Already stopped")
            return

        logger.info(f"Port {self.port_index}: Stopping recording (PID: {self._process.pid})")

        try:
            if self._process.stdin and not self._process.stdin.is_closing():
                self._process.stdin.write(b"q\n")
                await self._process.stdin.drain()

            try:
                await asyncio.wait_for(self._process.wait(), timeout=3.0)
                self._process = None
                return
            except asyncio.TimeoutError:
                logger.warning(f"Port {self.port_index}: Graceful quit timeout, sending SIGTERM")

            self._process.terminate()

            try:
                await asyncio.wait_for(self._process.wait(), timeout=2.0)
                self._process = None
                return
            except asyncio.TimeoutError:
                logger.warning(f"Port {self.port_index}: SIGTERM timeout, sending SIGKILL")

            self._process.kill()
            await self._process.wait()

        except Exception as e:
            logger.error(f"Port {self.port_index}: Error stopping process: {e}")
        finally:
            self._process = None
            if self._monitor_task and not self._monitor_task.done():
                self._monitor_task.cancel()
                try:
                    await self._monitor_task
                except asyncio.CancelledError:
                    pass
            self._start_time = None

    def get_status(self) -> PortStatus:
        is_recording = self._process is not None and self._process.returncode is None

        uptime_seconds = 0
        if self._start_time is not None:
            uptime_seconds = int(time.time() - self._start_time)

        fps = 0.0
        if uptime_seconds > 0:
            fps = self._frame_count / uptime_seconds

        bitrate_mbps = 0.0
        codec = self._config.codec if self._config else CodecType.H264

        return PortStatus(
            port_index=self.port_index,
            is_recording=is_recording,
            frame_count=self._frame_count,
            fps=fps,
            bitrate_mbps=bitrate_mbps,
            uptime_seconds=uptime_seconds,
            current_file=self._current_file,
            codec=codec,
        )

    async def _monitor_process(self) -> None:
        if self._process is None or self._process.stderr is None:
            return

        try:
            async for line in self._process.stderr:
                try:
                    line_str = line.decode("utf-8", errors="ignore").strip()
                    if not line_str:
                        continue
                    match = re.search(r"frame=\s*(\d+)", line_str)
                    if match:
                        self._frame_count = int(match.group(1))
                except Exception as e:
                    logger.error(f"Port {self.port_index}: Error parsing stderr: {e}")

        except asyncio.CancelledError:
            pass
        except Exception as e:
            logger.error(f"Port {self.port_index}: Monitoring process error: {e}")


class RecorderManager:
    """Manages recording on all Deltacast ports."""

    def __init__(self, settings: Settings):
        self.settings = settings
        self._recorders: dict[int, PortRecorder] = {}

    def initialize(self) -> None:
        for port_index in range(self.settings.deltacast_port_count):
            self._recorders[port_index] = PortRecorder(port_index, self.settings)
        logger.info(f"Initialized {self.settings.deltacast_port_count} port recorders")

    async def start_recording(self, port_index: int, config: RecorderConfig) -> None:
        if port_index not in self._recorders:
            raise ValueError(f"Invalid port index {port_index}.")
        await self._recorders[port_index].start(config)

    async def stop_recording(self, port_index: int) -> None:
        if port_index not in self._recorders:
            raise ValueError(f"Invalid port index {port_index}.")
        await self._recorders[port_index].stop()

    def get_status(self, port_index: int) -> PortStatus:
        if port_index not in self._recorders:
            raise ValueError(f"Invalid port index {port_index}.")
        return self._recorders[port_index].get_status()

    def get_all_status(self) -> list[PortStatus]:
        return [self._recorders[i].get_status()
                for i in range(self.settings.deltacast_port_count)]