VLC: Set a different playback speed for dialog and not-dialog scenes (using subtitles)

vlc-speed-sub.py

#!/usr/bin/env python3

# This changes the playback speed to a different speed when there is and when there isn't subtitles.
# You need to activate the Lua HTTP interface in VLC and
# configure the password here, then run the script with a .srt as first argument.
# Ended up not being very nice because VLC janks for a few milliseconds when the playback speed changes

import requests
import pysrt
import sys
import time
import re

PASSWORD = '1234'
SUB_RATE = 0.75
NOSUB_RATE = 1.25

sub = pysrt.open(sys.argv[1])


def get(url):
    return requests.get(url, auth=('', PASSWORD)).text


play_time = 0
play_time_at = time.time()


def set_speed(rate):
    global play_time, play_time_at
    resp = get('http://127.0.0.1:8080/requests/status.xml?command=rate&val=%s' % rate)
    play_time_at = time.time()
    position = float(re.search('<position>([^<]+)</position>', resp).group(1))
    length = float(re.search('<length>([^<]+)</length>', resp).group(1))
    play_time = position * length


current_rate = 1
set_speed(NOSUB_RATE)
while True:
    current_time = play_time + (time.time() - play_time_at) * current_rate
    have_sub = len(sub.at(int(current_time * 1000))) > 0
    new_rate = SUB_RATE if have_sub else NOSUB_RATE
    if current_rate != new_rate:
        current_rate = new_rate
        set_speed(new_rate)
    time.sleep(0.1)