Downloading a TTML file is only the first step. The real challenge is understanding its structure, converting it for practical use, and avoiding common pitfalls like missing styling or overlapping timings.
If you’ve ever tried to grab captions from a streaming service like HBO Max, Paramount+, or even some corporate video platforms, you’ve likely run into a file format that isn’t .srt or .vtt . Instead, you saw .xml or .ttml . Welcome to the world of Timed Text Markup Language (TTML)—a powerful, verbose, and often misunderstood standard.
ffmpeg -i input.ttml output.vtt If you have seg_1.ttml , seg_2.ttml , etc.: ttml download
import glob from lxml import etree combined = etree.Element("tt", nsmap={None: "http://www.w3.org/ns/ttml"}) body = etree.SubElement(combined, "body") div = etree.SubElement(body, "div")
for f in sorted(glob.glob("seg_ .ttml")): tree = etree.parse(f) for p in tree.xpath("// [local-name()='p']"): div.append(p) Downloading a TTML file is only the first step
if not convert_to_srt: return
GET /api/captions/video123?format=ttml Authorization: Bearer <token> You can find these endpoints by inspecting the tab in DevTools. 3. Understanding TTML Structure (A Quick Reference) Here’s a minimal TTML file: Instead, you saw
with open("captions.srt", "w", encoding="utf-8") as f: f.write("\n".join(cues))