mirror of
https://github.com/YusufB5/ASCILINE.git
synced 2026-06-17 22:35:13 +02:00
81 lines
3 KiB
Python
81 lines
3 KiB
Python
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"""
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ytdl.py — Resolve YouTube (and other yt-dlp-supported) URLs to a local file.
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ASCILINE downscales every frame to a tiny character grid, so there is no point
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pulling high resolution. We cap at <=480p and mux to a single mp4 with audio
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(the /audio endpoint runs ffmpeg on the same file). Downloads are cached in
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videos/ by video id so re-runs are instant.
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"""
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import os
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import sys
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import subprocess
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_URL_HINTS = ("http://", "https://", "youtube.com", "youtu.be")
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def is_url(s: str) -> bool:
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s = s.lower()
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return s.startswith(("http://", "https://")) or "youtube.com" in s or "youtu.be" in s
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def _ytdlp(*args: str) -> subprocess.CompletedProcess:
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# Use the running interpreter's yt_dlp so it always matches the venv.
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return subprocess.run([sys.executable, "-m", "yt_dlp", *args],
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capture_output=True, text=True)
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def download(url: str, cache_dir: str = "videos") -> str:
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"""Download `url` (<=480p, muxed mp4) into cache_dir and return the path."""
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os.makedirs(cache_dir, exist_ok=True)
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probe = _ytdlp("--no-playlist", "--print", "id", url)
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if probe.returncode != 0 or not probe.stdout.strip():
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raise RuntimeError(f"yt-dlp could not read {url!r}: {probe.stderr.strip()[:200]}")
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video_id = probe.stdout.strip().splitlines()[0]
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out = os.path.join(cache_dir, f"{video_id}.mp4")
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if os.path.exists(out):
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print(f"[YT] cached: {out}")
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return out
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print(f"[YT] downloading {url} (<=480p) ...")
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# Prefer H.264 (avc1): OpenCV decodes it everywhere, unlike AV1/VP9 which
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# need hardware support. Fall back to anything <=480p, then re-encode below.
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fmt = ("bv*[vcodec^=avc1][height<=480]+ba/"
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"b[vcodec^=avc1][height<=480]/"
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"bv*[height<=480]+ba/b[height<=480]/b")
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res = _ytdlp("--no-playlist", "-f", fmt,
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"--merge-output-format", "mp4", "-o", out, url)
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if res.returncode != 0 or not os.path.exists(out):
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raise RuntimeError(f"yt-dlp download failed: {res.stderr.strip()[-300:]}")
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if not _decodable(out):
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print("[YT] codec not decodable (likely AV1/VP9) — re-encoding to H.264 ...")
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_reencode_h264(out)
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print(f"[YT] saved: {out}")
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return out
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def _decodable(path: str) -> bool:
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"""True if OpenCV can actually read the first frame."""
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try:
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import cv2
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except ImportError:
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return True # can't check; assume fine
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cap = cv2.VideoCapture(path)
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ok, _ = cap.read()
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cap.release()
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return ok
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def _reencode_h264(path: str) -> None:
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"""Transcode in place to H.264 + AAC so OpenCV/ffmpeg can read it."""
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tmp = path + ".h264.mp4"
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res = subprocess.run(
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["ffmpeg", "-y", "-i", path, "-c:v", "libx264", "-preset", "veryfast",
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"-crf", "23", "-c:a", "aac", "-b:a", "128k", "-loglevel", "error", tmp],
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capture_output=True, text=True)
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if res.returncode != 0 or not os.path.exists(tmp):
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raise RuntimeError(f"re-encode failed: {res.stderr.strip()[-300:]}")
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os.replace(tmp, path)
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