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mediaplayer/sentence_api/tests/test_transcription.py
2026-08-18 20:54:42 +08:00

389 lines
13 KiB
Python

import io
import wave
import numpy as np
import pytest
from sentence_api.transcription import (
MossTranscriber,
TranscriptionSegment,
WordTimestamp,
_parse_json_segments,
_plan_chunks,
_parse_word_timestamps,
split_sentences_at_punctuation,
_wav_bytes,
_wav_duration_seconds,
)
SAMPLE_RATE = 16000
def _speech(seconds: float, sample_rate: int = SAMPLE_RATE) -> np.ndarray:
t = np.arange(int(seconds * sample_rate)) / sample_rate
return 0.25 * np.sin(2 * np.pi * 220 * t)
def _silence(seconds: float, sample_rate: int = SAMPLE_RATE) -> np.ndarray:
return np.zeros(int(seconds * sample_rate))
def _audio(*parts: np.ndarray, sample_rate: int = SAMPLE_RATE) -> np.ndarray:
return np.concatenate([np.asarray(part) for part in parts]).astype(np.float32)
def test_plan_chunks_cuts_at_silence_gaps():
samples = _audio(
_speech(10),
_silence(0.8),
_speech(29.2),
_silence(1.0),
_speech(29.0),
_silence(0.6),
_speech(24.4),
)
chunks = _plan_chunks(samples, SAMPLE_RATE)
assert chunks[0][0] == pytest.approx(0.0)
assert chunks[-1][1] == pytest.approx(95.0)
for (start, end), (next_start, _) in zip(chunks, chunks[1:]):
assert end == pytest.approx(next_start)
assert end - start <= 34.0
assert 10.0 <= chunks[0][1] <= 10.8
assert 40.0 <= chunks[1][1] <= 41.0
assert 70.0 <= chunks[2][1] <= 70.6
def test_plan_chunks_falls_back_to_fixed_windows():
chunks = _plan_chunks(_speech(95), SAMPLE_RATE)
assert chunks == [(0.0, 30.0), (30.0, 60.0), (60.0, 90.0), (90.0, 95.0)]
def test_plan_chunks_merges_short_tail():
chunks = _plan_chunks(_speech(93), SAMPLE_RATE)
assert chunks == [(0.0, 30.0), (30.0, 60.0), (60.0, 93.0)]
def test_parse_json_segments_filters_hallucinated_segments():
raw = [
{"start": 0.0, "end": 3.0, "text": "hello world", "compression_ratio": 1.4},
{"start": 3.5, "end": 6.0, "text": "hello world", "compression_ratio": 12.0},
{"start": 6.5, "end": 9.0, "text": "no ratio field"},
]
filtered = _parse_json_segments(raw, compression_limit=2.4)
assert [segment.text for segment in filtered] == ["hello world", "no ratio field"]
assert len(_parse_json_segments(raw)) == 3
def test_wav_bytes_roundtrip(tmp_path):
samples = _speech(2.0)
data = _wav_bytes(samples, SAMPLE_RATE)
assert data.startswith(b"RIFF")
path = tmp_path / "chunk.wav"
path.write_bytes(data)
assert _wav_duration_seconds(path) == pytest.approx(2.0, abs=0.05)
with wave.open(str(path), "rb") as wav:
assert wav.getnchannels() == 1
assert wav.getsampwidth() == 2
assert wav.getframerate() == SAMPLE_RATE
def test_wav_duration_returns_none_for_non_wav(tmp_path):
path = tmp_path / "note.txt"
path.write_text("not audio")
assert _wav_duration_seconds(path) is None
def test_chunked_transcribe_offsets_timestamps(monkeypatch):
requests = []
call_count = {"n": 0}
def fake_post(endpoint, data=None, files=None, timeout=None):
call_count["n"] += 1
requests.append(data)
audio = files["file"][1].read()
with wave.open(io.BytesIO(audio), "rb") as wav:
duration = wav.getnframes() / wav.getframerate()
if call_count["n"] == 1:
segments = [
{"start": 1.0, "end": 4.0, "text": "first part", "compression_ratio": 1.4},
{"start": 27.0, "end": 30.0, "text": "second part", "compression_ratio": 1.5},
]
elif call_count["n"] == 2:
segments = [
{
"start": 1.0,
"end": 4.0,
"text": "third part",
"compression_ratio": 1.4,
"words": [
{"word": "third", "start": 1.0, "end": 2.5},
{"word": " part", "start": 2.6, "end": 4.0},
],
},
{"start": 27.0, "end": 30.0, "text": "fourth part", "compression_ratio": 1.5},
]
else:
segments = [{"start": 0.5, "end": 3.5, "text": "tail part", "compression_ratio": 1.3}]
assert abs(duration - 30.0) < 1.0 or abs(duration - 5.0) < 1.0
class Response:
status_code = 200
def raise_for_status(self):
pass
def json(self):
return {"text": "", "segments": segments}
return Response()
monkeypatch.setattr("sentence_api.transcription.httpx.post", fake_post)
transcriber = MossTranscriber(endpoint="http://whisper:9000", model="whisper")
result = transcriber._transcribe_chunked(_speech(65), SAMPLE_RATE, None)
assert [(s.start_seconds, s.end_seconds, s.text) for s in result.segments] == [
(1.0, 4.0, "first part"),
(27.0, 30.0, "second part"),
(31.0, 34.0, "third part"),
(57.0, 60.0, "fourth part"),
(60.5, 63.5, "tail part"),
]
assert result.text == "first part second part third part fourth part tail part"
assert [(w.start_seconds, w.end_seconds, w.text) for w in result.segments[2].words] == [
(31.0, 32.5, "third"),
(32.6, 34.0, "part"),
]
assert result.segments[0].words is None
assert len(requests) == 3
assert all(request.get("condition_on_previous_text") == "false" for request in requests)
assert all(request.get("timestamp_granularities[]") == "word" for request in requests)
def test_parse_json_segments_parses_word_timestamps():
raw = [
{
"start": 0.0,
"end": 4.0,
"text": "Hello world. Good day.",
"words": [
{"word": "Hello", "start": 0.0, "end": 0.6},
{"word": " world.", "start": 0.7, "end": 1.5},
{"word": " Good", "start": 1.8, "end": 2.4},
{"word": " day.", "start": 2.5, "end": 3.2},
],
},
{"start": 4.5, "end": 6.0, "text": "no words"},
]
segments = _parse_json_segments(raw)
assert [word.text for word in segments[0].words] == ["Hello", "world.", "Good", "day."]
assert segments[1].words is None
def test_parse_word_timestamps_ignores_invalid_entries():
words = _parse_word_timestamps(
[
{"word": "ok", "start": 0.0, "end": 0.5},
{"word": "bad"},
{"word": "", "start": 1.0, "end": 1.5},
{"word": "flat", "start": 2.0, "end": 2.0},
]
)
assert [(word.text, word.start_seconds, word.end_seconds) for word in words] == [
("ok", 0.0, 0.5)
]
assert _parse_word_timestamps(None) is None
assert _parse_word_timestamps("nope") is None
def test_split_sentences_merges_segments_without_punctuation():
segments = [
TranscriptionSegment(
start_seconds=0.0,
end_seconds=8.0,
text=(
"So I've been single for about four years now and I find it hard "
"to meet a guy especially in"
),
),
TranscriptionSegment(
start_seconds=8.0,
end_seconds=9.5,
text="California.",
words=[WordTimestamp(8.0, 9.5, "California.")],
),
TranscriptionSegment(
start_seconds=9.5,
end_seconds=20.0,
text=(
"I've tried dating apps, I've met friends through friends, "
"I've done online dating"
),
),
TranscriptionSegment(
start_seconds=20.0,
end_seconds=24.0,
text=(
"and I just feel like most of the guys that I meet aren't serious "
"about a relationship."
),
words=[WordTimestamp(20.0, 24.0, "relationship.")],
),
]
sentences = split_sentences_at_punctuation(segments)
assert [(s.text, s.start_seconds, s.end_seconds) for s in sentences] == [
(
"So I've been single for about four years now and I find it hard to meet "
"a guy especially in California.",
0.0,
9.5,
),
(
"I've tried dating apps, I've met friends through friends, I've done "
"online dating and I just feel like most of the guys that I meet aren't "
"serious about a relationship.",
9.5,
24.0,
),
]
def test_split_sentences_uses_word_timestamps_within_segment():
segment = TranscriptionSegment(
start_seconds=0.0,
end_seconds=4.0,
text="Hello world. Good day. Nice to meet you.",
words=[
WordTimestamp(0.0, 0.6, "Hello"),
WordTimestamp(0.7, 1.5, "world."),
WordTimestamp(1.8, 2.4, "Good"),
WordTimestamp(2.5, 3.2, "day."),
WordTimestamp(3.3, 3.8, "Nice"),
WordTimestamp(3.9, 4.0, "you."),
],
)
sentences = split_sentences_at_punctuation([segment])
assert [(s.text, s.start_seconds, s.end_seconds) for s in sentences] == [
("Hello world.", 0.0, 1.5),
("Good day.", 1.5, 3.2),
("Nice to meet you.", 3.2, 4.0),
]
def test_split_sentences_splits_at_question_marks():
segment = TranscriptionSegment(
start_seconds=0.0,
end_seconds=10.0,
text="Really? Wait a minute. What about now?",
)
sentences = split_sentences_at_punctuation([segment])
assert [s.text for s in sentences] == [
"Really?",
"Wait a minute.",
"What about now?",
]
assert sentences[0].start_seconds == 0.0
assert sentences[0].end_seconds == sentences[1].start_seconds
assert sentences[1].end_seconds == sentences[2].start_seconds
assert sentences[2].end_seconds == 10.0
def test_split_sentences_falls_back_to_proportional():
segments = [
TranscriptionSegment(
start_seconds=10.0, end_seconds=14.0, text="This is the first"
),
TranscriptionSegment(
start_seconds=14.0,
end_seconds=18.0,
text="sentence. And this is the second one.",
),
]
sentences = split_sentences_at_punctuation(segments)
assert [s.text for s in sentences] == [
"This is the first sentence.",
"And this is the second one.",
]
assert sentences[0].start_seconds == 10.0
assert sentences[0].end_seconds == sentences[1].start_seconds
assert sentences[1].end_seconds == 18.0
def test_split_sentences_falls_back_when_word_ends_are_invalid():
segment = TranscriptionSegment(
start_seconds=0.0,
end_seconds=2.0,
text="One. Two.",
words=[
WordTimestamp(0.0, 2.5, "One."),
WordTimestamp(2.6, 3.0, "Two."),
],
)
sentences = split_sentences_at_punctuation([segment])
assert [s.text for s in sentences] == ["One.", "Two."]
assert sentences[0].end_seconds == sentences[1].start_seconds
assert sentences[1].end_seconds == 2.0
def test_split_sentences_keeps_incomplete_tail_as_sentence():
segment = TranscriptionSegment(
start_seconds=1.0, end_seconds=2.0, text="no period here"
)
sentences = split_sentences_at_punctuation([segment])
assert [(s.text, s.start_seconds, s.end_seconds) for s in sentences] == [
("no period here", 1.0, 2.0)
]
assert split_sentences_at_punctuation([]) == []
def test_split_sentences_handles_ellipsis_and_dots_only():
segment = TranscriptionSegment(
start_seconds=0.0,
end_seconds=2.0,
text="Wait... What? ...",
)
sentences = split_sentences_at_punctuation([segment])
assert [s.text for s in sentences] == ["Wait...", "What?"]
assert sentences[0].start_seconds == 0.0
assert sentences[0].end_seconds == sentences[1].start_seconds
assert sentences[1].end_seconds == 2.0
assert split_sentences_at_punctuation(
[TranscriptionSegment(0.0, 1.0, "...")]
) == []
def test_post_audio_requests_word_timestamps_and_falls_back(monkeypatch):
calls = []
class RejectedResponse:
status_code = 400
def raise_for_status(self):
pass
def json(self):
return {"error": "unknown parameter"}
class OkResponse:
status_code = 200
def raise_for_status(self):
pass
def json(self):
return {"text": "hi.", "segments": []}
def fake_post(endpoint, data=None, files=None, timeout=None):
calls.append(dict(data))
if "timestamp_granularities[]" in data:
return RejectedResponse()
return OkResponse()
monkeypatch.setattr("sentence_api.transcription.httpx.post", fake_post)
transcriber = MossTranscriber(endpoint="http://whisper:9000", model="whisper")
result = transcriber._post_audio(
io.BytesIO(b"fake-audio"), "clip.wav", "audio/wav", "en"
)
assert result["text"] == "hi."
assert calls[0]["timestamp_granularities[]"] == "word"
assert "timestamp_granularities[]" not in calls[1]