File size: 4,466 Bytes
53ed7ea | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 | """Rebuild the link-only clips of 4DCodeBench-RealWorld from their public sources.
Each clip in `link_only_clips.json` is its source and the chain of steps that
turned the source into the benchmark video. A step is one of
encode one ffmpeg pass to H.264:
input options placed before -i (-ss, -t)
vf the filter graph
output options placed after the filter (-t, -r, -vsync)
crf, preset x264 settings (defaults 18, medium)
retime rewrite the timestamps to `fps` without touching a frame
(29.97 -> 30, 23.976 -> 24)
stabilize virtual-tripod lock with tripod_lock.py; `args` are its CLI flags
Usage:
python scripts/prepare_videos.py [--downloads downloads] [--out videos] [case ...]
Sources are fetched into --downloads. Requires ffmpeg/ffprobe on PATH, numpy
and opencv-python.
"""
import argparse
import json
import subprocess
import tempfile
import urllib.request
from fractions import Fraction
from pathlib import Path
import tripod_lock
HERE = Path(__file__).resolve().parent
ROOT = HERE.parent
def fetch(clip, downloads):
path = downloads / clip["file"]
if path.exists():
return path
print(f" downloading {clip['download']}")
req = urllib.request.Request(clip["download"], headers={"User-Agent": "Mozilla/5.0"})
part = path.with_suffix(".part")
with urllib.request.urlopen(req) as r, open(part, "wb") as f:
while chunk := r.read(1 << 20):
f.write(chunk)
part.rename(path)
return path
def ffmpeg(*args):
subprocess.run(["ffmpeg", "-nostdin", "-v", "error", "-y", *map(str, args)], check=True)
def encode(src, dst, input=(), vf=None, output=(), crf=18, preset="medium"):
ffmpeg(*input, "-i", src, "-map", "0:v:0", *(["-vf", vf] if vf else []), *output,
"-an", "-c:v", "libx264", "-preset", preset, "-crf", crf, "-pix_fmt", "yuv420p",
"-movflags", "+faststart", dst)
def retime(src, dst, fps):
rate = subprocess.run(["ffprobe", "-v", "error", "-select_streams", "v:0", "-show_entries",
"stream=r_frame_rate", "-of", "csv=p=0", str(src)],
capture_output=True, text=True, check=True).stdout.strip()
ffmpeg("-itsscale", float(Fraction(rate) / Fraction(fps)), "-i", src, "-map", "0:v:0", "-c", "copy",
"-movflags", "+faststart", dst)
def stabilize(src, dst, args):
ap = argparse.ArgumentParser()
for flag in ("--crop-left", "--crop-right", "--crop-top", "--crop-bottom"):
ap.add_argument(flag, type=int, default=0)
ap.add_argument("--ref-frame", default="0")
a = ap.parse_args(args)
extra = (a.crop_left, a.crop_right, a.crop_top, a.crop_bottom)
raw, _, _ = tripod_lock.process(src, dst.parent, "similarity", extra, ref_frame=a.ref_frame)
ffmpeg("-i", raw, "-c:v", "libx264", "-crf", 18, "-pix_fmt", "yuv420p", dst)
raw.unlink()
def build(clip, downloads, out_dir):
current = fetch(clip, downloads)
with tempfile.TemporaryDirectory() as tmp:
for i, step in enumerate(clip["steps"]):
(kind, params), = step.items()
last = i == len(clip["steps"]) - 1
dst = out_dir / f"{clip['case']}.mp4" if last else Path(tmp) / f"{i}.mp4"
if kind == "encode":
encode(current, dst, **params)
elif kind == "retime":
retime(current, dst, params["fps"])
else:
stabilize(current, dst, params["args"])
current = dst
print(f" {current}")
def main():
ap = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
ap.add_argument("cases", nargs="*", help="cases to build (default: all)")
ap.add_argument("--downloads", type=Path, default=ROOT / "downloads")
ap.add_argument("--out", type=Path, default=ROOT / "videos")
args = ap.parse_args()
clips = json.loads((HERE / "link_only_clips.json").read_text())
unknown = set(args.cases) - {c["case"] for c in clips}
if unknown:
raise SystemExit(f"not link-only cases: {sorted(unknown)}")
args.downloads.mkdir(parents=True, exist_ok=True)
args.out.mkdir(parents=True, exist_ok=True)
for clip in clips:
if not args.cases or clip["case"] in args.cases:
print(clip["case"])
build(clip, args.downloads, args.out)
if __name__ == "__main__":
main()
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