reels-app/scripts/subtitle.py

315 lines
11 KiB
Python

#!/usr/bin/env python3
"""
subtitle.py — Generiraj podnapise iz videa in jih burn-in v output.
Uporablja faster-whisper za transkripcijo, FFmpeg za burn-in.
Primer:
python3 subtitle.py video.mp4 video_sub.mp4
python3 subtitle.py video.mp4 video_sub.mp4 --lang sl --model small
python3 subtitle.py video.mp4 video_sub.mp4 --style reels # velik beli centriran tekst
"""
import argparse
import subprocess
import sys
import tempfile
import os
from pathlib import Path
def detect_language_robust(video, model):
"""2-step detekcija jezika za auto mode:
1. Vzemi 3 vzorce po 30s iz različnih delov pesmi (start/middle/end refrena)
2. Vsak vzorec transkribiraj z auto-detect
3. Vrne najpogostejši jezik z največjo skupno verjetnostjo
To prepreči, da Whisper sredi pesmi spremeni jezik.
"""
import subprocess
duration_proc = subprocess.run(
["ffprobe", "-v", "error", "-show_entries", "format=duration",
"-of", "default=nw=1:nokey=1", str(video)],
capture_output=True, text=True
)
try:
duration = float(duration_proc.stdout.strip())
except Exception:
duration = 180.0
# 3 vzorci po 30s — začetek (po intru), sredina, proti koncu
sample_starts = [
max(15, duration * 0.15), # po intru, kjer je verjetno verz 1
duration * 0.45, # približno sredina, refren
duration * 0.75, # zadnji refren
]
lang_votes = {} # lang → cumulative_prob
for ss in sample_starts:
if ss + 5 > duration:
continue
# Extract 30s sample
sample = tempfile.NamedTemporaryFile(suffix=".wav", delete=False)
sample.close()
subprocess.run(
["ffmpeg", "-y", "-ss", str(ss), "-i", str(video),
"-t", "30", "-vn", "-ac", "1", "-ar", "16000",
"-c:a", "pcm_s16le", sample.name],
check=True, capture_output=True
)
try:
_, sample_info = model.transcribe(sample.name, language=None, vad_filter=False)
lang = sample_info.language
prob = float(sample_info.language_probability)
lang_votes[lang] = lang_votes.get(lang, 0) + prob
print(f" sample @ {ss:.0f}s: {lang} (p={prob:.2f})")
except Exception as e:
print(f" sample @ {ss:.0f}s: failed ({e})")
finally:
try:
os.unlink(sample.name)
except Exception:
pass
if not lang_votes:
return None
best_lang = max(lang_votes.items(), key=lambda x: x[1])
print(f" 🎯 Locked language: {best_lang[0]} (cumulative p={best_lang[1]:.2f})")
return best_lang[0]
def transcribe(video, lang=None, model_size="small"):
"""Vrne pot do .srt datoteke."""
from faster_whisper import WhisperModel
print(f"🧠 Whisper model: {model_size}, lang={lang or 'auto'}")
model = WhisperModel(model_size, device="cpu", compute_type="int8")
# Auto-detect z robust 3-sample voting (preprečuje preklop jezika sredi pesmi)
if not lang:
print(" 🔍 Robust auto-detect (3 sampli)...")
lang = detect_language_robust(video, model)
if lang:
print(f" ✅ Lang lock: {lang}")
else:
print(" ⚠️ Detection failed, fallback na auto per-segment")
segments, info = model.transcribe(
str(video),
language=lang, # fixed za cel video
word_timestamps=True,
# VAD filter kdaj izpusti vokal med glasbo — pri pesmi bolje brez
vad_filter=False,
# Anti-halucinacije:
# - condition_on_previous_text: ne predaja napak naprej
# - temperature=0: deterministično (brez "kreativnega" ugibanja)
# - compression_ratio_threshold: zazna ponavljajoče halucinacije
# - log_prob_threshold: zavrne segmente z nizko verjetnostjo
# - no_speech_threshold: agresivneje preskoči tihe dele
condition_on_previous_text=False,
temperature=0.0,
compression_ratio_threshold=2.4,
log_prob_threshold=-1.0,
no_speech_threshold=0.6,
)
print(f" Detekcija: {info.language} (p={info.language_probability:.2f})")
srt_path = tempfile.NamedTemporaryFile(suffix=".srt", delete=False, mode="w", encoding="utf-8")
def fmt_ts(s):
h = int(s // 3600)
m = int((s % 3600) // 60)
sec = s % 60
return f"{h:02d}:{m:02d}:{sec:06.3f}".replace(".", ",")
# Generiramo word-level chunked podnapise: 3-4 besede naenkrat,
# max 2.5s na chunk za hiter pacing v reels stil.
# Vse v VELIKIH TISKANIH ČRKAH.
MAX_CHUNK_DURATION = 2.5 # sekund
def write_chunk(idx, start, end, text):
# Če je chunk daljši od MAX, razdeli ga na N enakih kosov z istim tekstom
duration = end - start
if duration <= MAX_CHUNK_DURATION:
srt_path.write(f"{idx}\n{fmt_ts(start)} --> {fmt_ts(end)}\n{text}\n\n")
return idx + 1
# Razdeli na N enakih kosov
n_parts = int(duration / MAX_CHUNK_DURATION) + 1
chunk_dur = duration / n_parts
for i in range(n_parts):
chunk_start = start + i * chunk_dur
chunk_end = start + (i + 1) * chunk_dur
srt_path.write(f"{idx}\n{fmt_ts(chunk_start)} --> {fmt_ts(chunk_end)}\n{text}\n\n")
idx += 1
return idx
idx = 1
for seg in segments:
words = seg.words or []
if not words:
idx = write_chunk(idx, seg.start, seg.end, seg.text.strip().upper())
continue
# Združi v skupine po ~4 besede
group = []
for w in words:
group.append(w)
if len(group) >= 4 or w.word.strip().endswith((".", "?", "!")):
start = group[0].start
end = group[-1].end
text = "".join(g.word for g in group).strip().upper()
idx = write_chunk(idx, start, end, text)
group = []
if group:
start = group[0].start
end = group[-1].end
text = "".join(g.word for g in group).strip().upper()
idx = write_chunk(idx, start, end, text)
srt_path.close()
print(f"📝 SRT: {srt_path.name} ({idx - 1} segmentov)")
return srt_path.name
SUBTITLE_STYLES = {
"reels": (
# Velike bele črke z debelim črnim outline-om, na spodnji tretjini
"FontName=Arial,FontSize=42,Bold=1,"
"PrimaryColour=&HFFFFFF,OutlineColour=&H000000,"
"Outline=4,Shadow=1,Alignment=2,MarginV=120,BorderStyle=1"
),
"yellow": (
"FontName=Arial,FontSize=42,Bold=1,"
"PrimaryColour=&H00FFFF,OutlineColour=&H000000,"
"Outline=4,Shadow=1,Alignment=2,MarginV=120,BorderStyle=1"
),
"minimal": (
"FontName=Arial,FontSize=28,"
"PrimaryColour=&HFFFFFF,OutlineColour=&H000000,"
"Outline=2,Shadow=0,Alignment=2,MarginV=80,BorderStyle=1"
),
}
def burn_subtitles(video, srt, output, style="reels"):
"""Burn-in podnapisov. Najprej pretvorimo SRT v ASS z eksplicitnim stylom, ker
FFmpeg force_style je ne-zanesljivo in pogosto silently ignore-an."""
# Pretvorimo SRT → ASS s pravim stylom
ass_path = srt.replace(".srt", ".ass") if srt.endswith(".srt") else srt + ".ass"
# Style nastavitve glede na izbiro
if style == "yellow":
primary = "&H0000FFFF" # rumeno
else:
primary = "&H00FFFFFF" # belo
# ASS PlayResY 1920 → MarginV je v pikslih 1:1
# FontSize=56 = ~3% širine ekrana, MarginV=400 = spodnja tretjina (safe zone)
# WrapStyle=0 → smart wrap, MarginL/R=80 = 7.4% z vsake strani
ass_header = f"""[Script Info]
ScriptType: v4.00+
PlayResX: 1080
PlayResY: 1920
WrapStyle: 0
ScaledBorderAndShadow: yes
[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Default,DejaVu Sans,56,{primary},&H00FFFFFF,&H00000000,&H00000000,1,0,0,0,100,100,0,0,1,5,1,2,80,80,400,1
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
"""
# Parse SRT in convert v ASS dialogue lines
with open(srt, "r", encoding="utf-8") as f:
srt_content = f.read()
def srt_to_ass_time(t):
# 00:00:09,520 → 0:00:09.52
h, m, rest = t.split(":")
s, ms = rest.split(",")
return f"{int(h)}:{int(m):02d}:{int(s):02d}.{int(ms)//10:02d}"
dialogue_lines = []
blocks = srt_content.strip().split("\n\n")
for block in blocks:
lines = block.strip().split("\n")
if len(lines) < 3:
continue
# lines[0] = idx, lines[1] = timecode, lines[2:] = text
timecode = lines[1]
text = " ".join(lines[2:]).replace("\n", " ")
if " --> " not in timecode:
continue
start_t, end_t = timecode.split(" --> ")
ass_start = srt_to_ass_time(start_t.strip())
ass_end = srt_to_ass_time(end_t.strip())
dialogue_lines.append(f"Dialogue: 0,{ass_start},{ass_end},Default,,0,0,0,,{text}")
with open(ass_path, "w", encoding="utf-8") as f:
f.write(ass_header)
f.write("\n".join(dialogue_lines))
f.write("\n")
print(f"📝 ASS: {ass_path} ({len(dialogue_lines)} dialogov)")
# Burn-in z ass filtrom (boljši kot subtitles za naš primer)
ass_escaped = ass_path.replace("\\", "\\\\").replace(":", "\\:").replace("'", r"\'")
# setsar=1 + setdar=9/16: zagotovi 1:1 piksel + 9:16 display ratio v finalnem output-u
vf = f"ass='{ass_escaped}',setsar=1"
cmd = [
"ffmpeg", "-y", "-i", str(video),
"-vf", vf,
"-c:v", "libx264", "-preset", "medium", "-crf", "21",
"-pix_fmt", "yuv420p", # web/mobile compat (Instagram/FB/web players)
"-c:a", "copy",
"-movflags", "+faststart",
str(output),
]
print("🔥 Burn-in podnapisov...")
result = subprocess.run(cmd, capture_output=True, text=True)
if result.returncode != 0:
print("❌ FFmpeg napaka:", file=sys.stderr)
print(result.stderr[-2000:], file=sys.stderr)
sys.exit(1)
print(f"{output}")
def main():
ap = argparse.ArgumentParser()
ap.add_argument("input")
ap.add_argument("output")
ap.add_argument("--lang", default=None, help="Jezik (sl, de, en, ...) ali auto")
ap.add_argument("--model", default="large-v3", choices=["tiny", "base", "small", "medium", "large-v3"])
ap.add_argument("--style", default="reels", choices=list(SUBTITLE_STYLES.keys()))
ap.add_argument("--keep-srt", action="store_true", help="Ohrani .srt poleg output")
ap.add_argument("--srt", default=None, help="Že-pripravljen SRT (preskoči Whisper transkripcijo)")
args = ap.parse_args()
src = Path(args.input)
if not src.exists():
print(f"{src} ne obstaja", file=sys.stderr)
sys.exit(1)
if args.srt and Path(args.srt).exists():
print(f"📄 Uporabljam že-pripravljen SRT: {args.srt}")
srt = args.srt
srt_was_provided = True
else:
srt = transcribe(src, lang=args.lang, model_size=args.model)
srt_was_provided = False
burn_subtitles(src, srt, args.output, style=args.style)
if args.keep_srt and not srt_was_provided:
keep_path = Path(args.output).with_suffix(".srt")
os.rename(srt, keep_path)
print(f"💾 SRT shranjen: {keep_path}")
elif not srt_was_provided:
os.unlink(srt)
if __name__ == "__main__":
main()