mirror of
https://github.com/unshackle-dl/unshackle.git
synced 2026-11-13 12:35:05 +00:00
imSp4rky
d7a2bb6b8e
Merge cues at the string level instead of round-tripping through pycaption, which dropped inline tags and cue settings. STYLE and REGION blocks are kept, duplicate boundary cues splice correctly, and a bad timing line now skips the cue instead of crashing. Also rank pysubs2 above SubtitleEdit for ASS to TTML/VTT since SubtitleEdit flattens inline styling there. Documented the measured backend fidelity table and added regression tests for the merge.
114 lines
4.7 KiB
Python
114 lines
4.7 KiB
Python
"""Regression tests for segmented-WebVTT merging (``core/utils/webvtt.py``).
|
|
|
|
The merge used to round-trip cues through pycaption's reader/writer (and a pysubs2
|
|
pre-normalization step), both of which silently dropped inline formatting despite
|
|
``preserve_formatting=True``. It is now a pure string-level splice: cue
|
|
timing lines, settings, and payload are kept verbatim, so span tags
|
|
(``<i>``/``<u>``/``<b>``), ASS-style overrides (``{\\an8}``), and entities all
|
|
survive, while duplicate headers collapse and boundary-duplicate cues dedupe.
|
|
"""
|
|
|
|
from __future__ import annotations
|
|
|
|
from unshackle.core.utils.webvtt import merge_segmented_webvtt
|
|
|
|
# Two segments, each a full WebVTT document with its own X-TIMESTAMP-MAP header,
|
|
# as they arrive concatenated from a DASH/HLS subtitle stream. The first cue carries
|
|
# span tags, an {\an8} override, a cue setting, and a literal < entity.
|
|
SEGMENTED_VTT = (
|
|
"WEBVTT\n"
|
|
"X-TIMESTAMP-MAP=MPEGTS:900000,LOCAL:00:00:00.000\n\n"
|
|
"00:00:01.000 --> 00:00:03.000 line:10% align:center\n"
|
|
"<i>Hello</i> {\\an8}world <u>und</u> <b>bold</b> 5 < 6\n\n"
|
|
"WEBVTT\n"
|
|
"X-TIMESTAMP-MAP=MPEGTS:1800000,LOCAL:00:00:00.000\n\n"
|
|
"00:00:04.000 --> 00:00:06.000\n"
|
|
"<i>Second</i> cue\n"
|
|
)
|
|
|
|
|
|
def test_merge_preserves_inline_formatting():
|
|
out = merge_segmented_webvtt(SEGMENTED_VTT, segment_durations=[900000, 900000], timescale=1)
|
|
for tag in ("<i>", "</i>", "<u>", "</u>", "<b>", "</b>", "{\\an8}"):
|
|
assert tag in out, f"{tag!r} was stripped from merged output:\n{out}"
|
|
|
|
|
|
def test_merge_preserves_cue_settings_and_entities():
|
|
out = merge_segmented_webvtt(SEGMENTED_VTT, segment_durations=[900000, 900000], timescale=1)
|
|
assert "line:10% align:center" in out # cue positioning survives
|
|
assert "<" in out # a literal entity is not turned into a stray tag
|
|
|
|
|
|
def test_merge_collapses_headers_into_single_document():
|
|
out = merge_segmented_webvtt(SEGMENTED_VTT, segment_durations=[900000, 900000], timescale=1)
|
|
assert out.count("WEBVTT") == 1
|
|
assert "X-TIMESTAMP-MAP" not in out
|
|
|
|
|
|
def test_merge_dedupes_boundary_duplicate_cues():
|
|
# A cue that spans a segment boundary is emitted in both segments; the merge
|
|
# should collapse the adjacent identical pair into one.
|
|
dup = SEGMENTED_VTT + (
|
|
"\nWEBVTT\n"
|
|
"X-TIMESTAMP-MAP=MPEGTS:2700000,LOCAL:00:00:00.000\n\n"
|
|
"00:00:04.000 --> 00:00:06.000\n"
|
|
"<i>Second</i> cue\n"
|
|
)
|
|
out = merge_segmented_webvtt(dup, segment_durations=[900000, 900000, 900000], timescale=1)
|
|
assert out.count("<i>Second</i> cue") == 1, f"boundary duplicate not deduped:\n{out}"
|
|
|
|
|
|
def test_merge_keeps_timing_lines_verbatim():
|
|
# String-level merge must not re-render timestamps (pycaption shortened
|
|
# 00:00:01.000 -> 00:01.000) and must keep the settings tail untouched.
|
|
out = merge_segmented_webvtt(SEGMENTED_VTT, segment_durations=[900000, 900000], timescale=1)
|
|
assert "00:00:01.000 --> 00:00:03.000 line:10% align:center" in out
|
|
assert "00:00:04.000 --> 00:00:06.000" in out
|
|
|
|
|
|
def test_merge_splices_triple_duplicate_into_one():
|
|
# A cue spanning two boundaries appears in three consecutive segments; the
|
|
# kept cue must be extended each time (latent bug: extending the dropped one).
|
|
vtt = (
|
|
"WEBVTT\n\n00:00:01.000 --> 00:00:02.000\nSame cue\n\n"
|
|
"WEBVTT\n\n00:00:02.000 --> 00:00:03.000\nSame cue\n\n"
|
|
"WEBVTT\n\n00:00:03.000 --> 00:00:04.000\nSame cue\n"
|
|
)
|
|
out = merge_segmented_webvtt(vtt)
|
|
assert out.count("Same cue") == 1
|
|
assert "00:00:01.000 --> 00:00:04.000" in out
|
|
|
|
|
|
def test_merge_drops_cue_ids_and_notes_keeps_style():
|
|
vtt = (
|
|
"WEBVTT\n\n"
|
|
"STYLE\n::cue { color: red }\n\n"
|
|
"NOTE a comment\n\n"
|
|
"some-cue-id-42\n00:00:01.000 --> 00:00:02.000\nHello\n"
|
|
)
|
|
out = merge_segmented_webvtt(vtt)
|
|
assert "Hello" in out
|
|
assert "some-cue-id-42" not in out
|
|
assert "NOTE" not in out
|
|
assert "STYLE\n::cue { color: red }" in out # kept; players without STYLE support ignore it
|
|
|
|
|
|
def test_merge_dedupes_repeated_style_blocks_before_cues():
|
|
# Every segment repeats the same STYLE block; keep exactly one, before the first cue.
|
|
style = "WEBVTT\n\nSTYLE\n::cue { color: red }\n\n"
|
|
vtt = style + "00:00:01.000 --> 00:00:02.000\nOne\n\n" + style + "00:00:03.000 --> 00:00:04.000\nTwo\n"
|
|
out = merge_segmented_webvtt(vtt)
|
|
assert out.count("STYLE") == 1
|
|
assert out.index("STYLE") < out.index("-->")
|
|
|
|
|
|
def test_merge_skips_malformed_timing_line():
|
|
vtt = (
|
|
"WEBVTT\n\n"
|
|
"garbage --> not-a-time\nBroken\n\n"
|
|
"00:00:01.000 --> 00:00:02.000\nGood\n"
|
|
)
|
|
out = merge_segmented_webvtt(vtt)
|
|
assert "Good" in out
|
|
assert "Broken" not in out
|