ytptube/app/features/streaming/library/segments.py
2026-05-28 19:07:11 +03:00

284 lines
10 KiB
Python

import asyncio
import os
import subprocess # type: ignore
import sys
import tempfile
from pathlib import Path
from secrets import token_hex
from typing import TYPE_CHECKING, ClassVar
from aiohttp import web
from app.features.streaming.library.ffprobe import ffprobe
from app.features.streaming.library.segment_encoders import (
detect_qsv_capabilities,
encoder_fallback_chain,
get_builder_for_codec,
has_dri_devices,
select_encoder,
)
from app.library.config import SUPPORTED_CODECS, Config
from app.library.log import get_logger
if TYPE_CHECKING:
from asyncio.subprocess import Process
from .ffprobe import FFProbeResult
from .segment_encoders import EncoderBuilder
LOG = get_logger()
class Segments:
"""
Build and stream MPEG-TS segments using ffmpeg with optional on-the-fly
transcoding. The class can auto-detect an available hardware encoder on the
first video segment and cache that choice for subsequent segments to avoid
repeated probing.
"""
# Cache of selected video encoder across all segment instances
_cached_vcodec: ClassVar[str | None] = None
_cache_initialized: ClassVar[bool] = False
def __init__(self, download_path: str, index: int, duration: float, vconvert: bool, aconvert: bool):
config: Config = Config.get_instance()
self.download_path: str = download_path
"The path where files are downloaded."
self.index = int(index)
"The index of the segment."
self.duration = float(duration)
"The duration of the segment."
self.vconvert = bool(vconvert)
"Whether to convert video."
self.aconvert = bool(aconvert)
"Whether to convert audio."
# Default to configured codec; can be replaced by auto-detection
self.vcodec: str = config.streamer_vcodec
"The video codec to use."
self.acodec: str = config.streamer_acodec
"The audio codec to use."
# sadly due to unforeseen circumstances, we have to convert the video for now.
self.vconvert = True
"Whether to convert video."
self.aconvert = True
"Whether to convert audio."
self.attempted: set[str] = set()
"The set of attempted codecs."
def _make_stream_input(self, file: Path) -> Path:
while True:
stream_input = Path(tempfile.gettempdir()).joinpath(f"ytptube_stream.{token_hex(8)}")
try:
stream_input.symlink_to(file, target_is_directory=False)
return stream_input
except FileExistsError:
continue
async def build_ffmpeg_args(self, file: Path, s_codec: str, *, stream_input: Path | None = None) -> list[str]:
try:
ff: FFProbeResult = await ffprobe(file)
except UnicodeDecodeError:
pass
input_path = stream_input or file
startTime: str = f"{0:.6f}" if self.index == 0 else f"{self.duration * self.index:.6f}"
ctx = {
"is_linux": sys.platform.startswith("linux"),
"has_dri": has_dri_devices(),
"vaapi_device": Config.get_instance().vaapi_device,
"qsv": {"full": False, "lp": False},
}
caps: dict[str, dict[str, bool]] = detect_qsv_capabilities()
base_codec: str = s_codec.split("_", maxsplit=1)[0]
codec_caps: dict[str, bool] = caps.get(base_codec, {"full": False, "lp": False})
ctx["qsv"] = codec_caps
if self.vconvert and ff and hasattr(ff, "has_video") and ff.has_video():
builder: EncoderBuilder = get_builder_for_codec(s_codec)
else:
builder = None
ctx: dict = {}
# Collect encoder-specific input/global flags that must precede the input
input_args: list[str] = []
if builder:
input_args = builder.input_args(ctx)
fargs: list[str] = [
"-xerror",
"-hide_banner",
"-loglevel",
"error",
# input trimming before the input file
"-ss",
str(startTime),
"-t",
str(f"{self.duration:.6f}"),
"-copyts",
# hardware/global input options must come before -i
*input_args,
"-i",
f"file:{input_path}",
"-map_metadata",
"-1",
]
v_args: list[str] = []
if builder:
v_args = builder.add_video_args(["-g", "52", "-map", "0:v:0", "-strict", "-2"], ctx)
else:
v_args += ["-codec:v", "copy"]
fargs += v_args
if ff and ff.has_audio():
fargs += ["-map", "0:a:0", "-codec:a", self.acodec if self.aconvert else "copy"]
fargs += ["-sn", "-muxdelay", "0", "-f", "mpegts", "pipe:1"]
return fargs
async def _run(self, resp: web.StreamResponse, file: Path, args: list[str]) -> tuple[bool, int, bool, str]:
proc: Process = await asyncio.create_subprocess_exec(
"ffmpeg",
*args,
stdin=asyncio.subprocess.DEVNULL,
stdout=asyncio.subprocess.PIPE,
stderr=asyncio.subprocess.PIPE,
creationflags=subprocess.CREATE_NO_WINDOW if os.name == "nt" else 0,
)
client_disconnected_local = False
wrote_any = False
stderr_buf = bytearray()
async def _drain_stderr() -> None:
try:
assert proc.stderr is not None
while True:
chunk: bytes = await proc.stderr.read(4096)
if not chunk:
break
stderr_buf.extend(chunk)
except Exception:
# best-effort only
pass
stderr_task: asyncio.Task[None] = asyncio.create_task(_drain_stderr())
LOG.debug(
"Streaming segment %s for '%s'.",
self.index,
file,
extra={"file": str(file), "segment_index": self.index, "ffmpeg_args": args},
)
try:
while True:
chunk: bytes = await proc.stdout.read(1024 * 64)
if not chunk:
break
wrote_any = True
try:
await resp.write(chunk)
except (asyncio.CancelledError, ConnectionResetError, BrokenPipeError, ConnectionError):
LOG.warning("Client disconnected or connection reset while writing.")
client_disconnected_local = True
break
except asyncio.CancelledError:
LOG.warning("Client disconnected. Terminating ffmpeg.")
client_disconnected_local = True
proc.terminate()
try:
await asyncio.wait_for(proc.wait(), timeout=5)
except TimeoutError:
LOG.warning(
"Segment stream for '%s' did not stop ffmpeg in time after the client disconnected; killing it.",
file,
)
proc.kill()
raise
except ConnectionResetError:
LOG.warning("Connection reset by peer. Skipping further writes.")
client_disconnected_local = True
finally:
# Ensure process is stopped when client disconnected, to avoid hangs
if client_disconnected_local:
proc.terminate()
try:
rc: int = await asyncio.wait_for(proc.wait(), timeout=5)
except TimeoutError:
LOG.warning(
"Segment stream for '%s' did not stop ffmpeg in time after the client disconnected; killing it.",
file,
)
proc.kill()
try:
rc = await asyncio.wait_for(proc.wait(), timeout=5)
except Exception:
rc = -1
else:
# Normal termination path with a safety timeout
try:
rc = await asyncio.wait_for(proc.wait(), timeout=30)
except TimeoutError:
LOG.warning("Segment stream for '%s' did not stop ffmpeg in time; killing the process.", file)
proc.kill()
try:
rc = await asyncio.wait_for(proc.wait(), timeout=5)
except Exception:
rc = -1
try:
await asyncio.wait_for(stderr_task, timeout=1)
except Exception:
pass
return (wrote_any, rc, client_disconnected_local, stderr_buf.decode("utf-8", errors="ignore").strip())
async def stream(self, file: Path, resp: web.StreamResponse) -> None:
codec: str = Segments._cached_vcodec if Segments._cache_initialized else self.vcodec
if not codec or codec not in SUPPORTED_CODECS:
codec: str = select_encoder(self.vcodec or "")
LOG.debug("Selected video codec '%s' for segment streaming.", codec, extra={"codec": codec})
if Segments._cached_vcodec and Segments._cache_initialized:
codecs: list[str] = [Segments._cached_vcodec]
else:
codecs: list[str] = [codec, *list(encoder_fallback_chain(codec))]
stream_input = self._make_stream_input(file)
try:
for s_codec in codecs:
if s_codec in self.attempted:
continue
ffmpeg_args: list[str] = await self.build_ffmpeg_args(file, s_codec, stream_input=stream_input)
_, rc, client_disconnected, stderr_text = await self._run(resp, file, ffmpeg_args)
if 0 == rc:
Segments._cached_vcodec = s_codec
Segments._cache_initialized = True
return
if client_disconnected:
return
if 0 != rc:
err: str = stderr_text[:500] if stderr_text else "no error output"
LOG.warning(
"Retrying segment %s for '%s' because hardware encoder '%s' failed: %s.",
self.index,
file,
s_codec,
err,
extra={"ffmpeg_args": ffmpeg_args, "returncode": rc, "stderr": err, "codec": s_codec},
)
self.attempted.add(s_codec)
finally:
if stream_input.is_symlink():
stream_input.unlink()