Difference From The Non--hf Repository
The source repository is intended for the qwen-asr wrapper / original Qwen3-ASR
layout. This repository is intended for native Hugging Face Transformers loading.
The conversion keeps the fine-tuned weights unchanged and only rewrites the
repository layout to match Qwen/Qwen3-ASR-1.7B-hf:
- config / processor / tokenizer files come from the official
-hf template.
- safetensors keys are rewritten as:
thinker.audio_tower.* -> model.audio_tower.*
thinker.audio_tower.proj1.* -> model.multi_modal_projector.linear_1.*
thinker.audio_tower.proj2.* -> model.multi_modal_projector.linear_2.*
thinker.model.* -> model.language_model.*
- tensor count after conversion:
707.
- converted tensor bytes:
4076104960.
Requirements
Requires the stable transformers >= 5.13.0 release for native Qwen3-ASR support:
pip install "transformers>=5.13.0"
With uv:
uv pip install "transformers>=5.13.0"
Usage
from transformers import AutoModelForMultimodalLM, AutoProcessor
model_id = "jaykwok/Qwen3-ASR-1.7B-JA-Anime-Galgame-hf"
processor = AutoProcessor.from_pretrained(model_id)
model = AutoModelForMultimodalLM.from_pretrained(
model_id,
torch_dtype="auto",
device_map="auto",
)
inputs = processor.apply_transcription_request(
audio="path/to/audio.wav",
language="Japanese",
).to(model.device, model.dtype)
output_ids = model.generate(**inputs, max_new_tokens=256)
generated_ids = output_ids[:, inputs["input_ids"].shape[1]:]
text = processor.decode(generated_ids, return_format="transcription_only")[0]
print(text)
CTC Alignment Heads
The original general-purpose head remains available under its original name.
The JAV/non-semantic-vocalisation head is a separate file, not an in-place
replacement:
Table with columns: JAV vocalisation variant, Original general head | JAV vocalisation variant | Original general head |
|---|
| File | ctc_aligner_jav_vocalisation_v2.pt | ctc_aligner.pt |
| Intended use | JAV or other Japanese audio with frequent non-semantic vocalisation | General anime / galgame alignment and reproducing existing results |
| Training domains | Galgame + anime SFW + anime NSFW/JAV | Galgame with sparse word-timestamp supervision |
| Vocabulary | Acoustic characters only (acoustic_only=True); punctuation has zero acoustic width | Character vocabulary including punctuation |
Choose the JAV variant when non-semantic moans are being transcribed as words or
when punctuation classes fragment otherwise continuous blank runs. Choose the
original head for its original domain or when exact compatibility with existing
timelines matters. Both heads are encoder-specific and both preserve all audio:
blank runs are used to choose chunk boundaries, never to delete samples.
What the heads do
ASR gives you text and a segment window. It does not tell you when inside that
window each character was spoken, so a subtitle writer has to spread the text
across the window in proportion to character count and hope. This head replaces
that guess with a measurement.
It is a small CTC classifier over the frozen audio encoder of this model.
It brings no acoustic model of its own — that is the point. General-purpose
Japanese forced aligners are not adapted to this domain, so pairing one with a
domain-fine-tuned ASR makes the aligner the bottleneck. Sitting on the encoder
that was already fine-tuned means the domain adaptation is paid for once, and
only a 3.8 M-parameter head has to be learned.
It is encoder-specific. It is trained against the features this fine-tune's
encoder produces and will not transfer to Qwen/Qwen3-ASR-1.7B-hf or to another
fine-tune. That is why it ships here, next to the encoder it belongs to, rather
than in the application that consumes it.
Table | |
|---|
| The architecture below is shared. The concrete dimensions in this table describe | |
the original ctc_aligner.pt; the variant table above gives the fields that | |
differ for ctc_aligner_jav_vocalisation_v2.pt. | |
Table | |
|---|
| File | ctc_aligner.pt (14.7 MB, torch.save payload, weights_only=False) |
| Schema | asr_ctc_alignment_head_v1 |
| Input | (B, T, 2048) encoder hidden states, 13 fps (76.9 ms per frame) |
| Output | (B, T*2, 2328) log-probabilities, 38.5 ms resolution |
| Parameters | 3,840,280 |
| Vocabulary |
Two design choices differ from the obvious ones:
- Characters, not kana or phonemes. Kana needs g2p (
pyopenjtalk), which
adds a dependency and, worse, a reading-error source on kanji. Characters need
neither, and the density works out better: the training corpus runs 4.67
chars/s against a 13 fps encoder, i.e. ~2.8 frames per character, where kana
would be nearer 2.
- The encoder is upsampled before the classifier. It adds no information,
but CTC cannot emit more tokens than it has frames, and timestamp resolution
is bounded by frame duration — 76.9 ms natively. A ×2 transposed convolution
is cheap and buys back both.
Two readings of the same tensor
The head is run once per audio chunk; the resulting log-probabilities are read
two different ways.
- Character timestamps. CTC forced alignment (Viterbi over the standard
blank-interleaved target lattice) of the known transcript against the
log-probs yields a start/end frame per character. This is what gives subtitle
cues real in-segment timing and real word gaps to split lines at.
- Blank runs. A stretch the head covers entirely with blank is a stretch
with no character evidence in it — read straight off the argmax, with no
tuned threshold and no free parameter beyond a minimum run length. These are
the natural pause locations, useful for choosing where to cut long audio into
chunks.
Reading (2) is a gate on cut points only. Deciding that a stretch is silence
and therefore deleting the audio would make a false blank unrecoverable; using
it to choose where to cut leaves every sample in the stream either way.
Loading a variant
The payload is self-contained: architecture hyper-parameters, vocabulary and
weights all travel in the same file.
import torch
from huggingface_hub import hf_hub_download
filename = "ctc_aligner_jav_vocalisation_v2.pt"
path = hf_hub_download(
repo_id="jaykwok/Qwen3-ASR-1.7B-JA-Anime-Galgame-hf",
filename=filename,
)
payload = torch.load(path, map_location="cpu", weights_only=False)
payload["schema"]
payload["input_dim"]
payload["hidden_dim"]
payload["upsample"]
payload["blocks"]
payload["vocab"]
payload["vocab"].get("acoustic_only", False)
payload["state_dict"]
The module it belongs to:
from torch import nn
class ResidualConvBlock(nn.Module):
"""Dilated depthwise-separable conv, pre-norm, residual.
Convolutional rather than attentional on purpose: alignment is a monotonic,
local problem, and a conv stack cannot learn to reorder time the way
self-attention can.
"""
def __init__(self, channels, dilation):
super().__init__()
self.norm = nn.LayerNorm(channels)
self.depthwise = nn.Conv1d(
channels, channels, kernel_size=5,
padding=2 * dilation, dilation=dilation, groups=channels,
)
self.pointwise = nn.Conv1d(channels, channels, kernel_size=1)
self.activation = nn.GELU()
self.dropout = nn.Dropout(0.0)
def forward(self, x):
y = self.norm(x).transpose(1, 2)
y = self.pointwise(self.activation(self.depthwise(y)))
return x + self.dropout(y.transpose(1, 2))
class CtcAlignmentHead(nn.Module):
def __init__(self, vocab_size, input_dim=2048, hidden_dim=512,
upsample=2, blocks=4):
super().__init__()
self.upsample = upsample
self.input_norm = nn.LayerNorm(input_dim)
self.project = nn.Linear(input_dim, hidden_dim)
self.expand = nn.ConvTranspose1d(
hidden_dim, hidden_dim, kernel_size=upsample, stride=upsample
) if upsample > 1 else None
self.blocks = nn.ModuleList(
[ResidualConvBlock(hidden_dim, dilation=2**i) for i in range(blocks)]
)
self.output_norm = nn.LayerNorm(hidden_dim)
self.classifier = nn.Linear(hidden_dim, vocab_size)
def forward(self, features):
"""(B, T, input_dim) -> (B, T*upsample, vocab) log-probabilities."""
x = self.project(self.input_norm(features))
if self.expand is not None:
x = self.expand(x.transpose(1, 2)).transpose(1, 2)
for block in self.blocks:
x = block(x)
return nn.functional.log_softmax(
self.classifier(self.output_norm(x)), dim=-1
)
head = CtcAlignmentHead(
vocab_size=payload["vocab"]["size"],
input_dim=payload["input_dim"],
hidden_dim=payload["hidden_dim"],
upsample=payload["upsample"],
blocks=payload["blocks"],
)
head.load_state_dict(payload["state_dict"])
head.eval()
For the acoustic-only JAV variant, punctuation in the known ASR transcript is
retained as zero-width text metadata rather than assigned an acoustic frame. A
consumer must keep those zero-width punctuation spans when rebuilding text; it
must not drop them as malformed timestamps.
Running it
Feed it the audio encoder's output for the same audio, then read the result.
import unicodedata
import torch
from transformers import AutoModelForMultimodalLM, AutoProcessor
model_id = "jaykwok/Qwen3-ASR-1.7B-JA-Anime-Galgame-hf"
processor = AutoProcessor.from_pretrained(model_id)
model = AutoModelForMultimodalLM.from_pretrained(model_id, torch_dtype="auto")
inputs = processor.apply_transcription_request(
audio="path/to/audio.wav", language="Japanese",
).to(model.device, model.dtype)
with torch.inference_mode():
encoded = model.get_audio_features(
input_features=inputs["input_features"],
input_features_mask=inputs["input_features_mask"],
)
features = encoded.pooler_output.float().cpu()
log_probs = head(features.unsqueeze(0))[0]
Note that pooler_output is the batch's valid frames concatenated, not a
padded (B, T, 2048) tensor. With a batch of one it is exactly that clip's
frames; for a real batch, slice it with the per-item frame count:
def audio_output_lengths(input_lengths):
"""Mel frames -> encoder frames, 13 per 100."""
leave = input_lengths % 100
feat = (leave - 1) // 2 + 1
return ((feat - 1) // 2 + 1 - 1) // 2 + 1 + (input_lengths // 100) * 13
lengths = audio_output_lengths(inputs["input_features_mask"].sum(dim=1))
Character indices, for building CTC targets:
chars = payload["vocab"]["chars"]
lookup = {ch: i + 2 for i, ch in enumerate(chars)}
def encode(text):
folded = unicodedata.normalize("NFKC", text)
folded = "".join(ch for ch in folded if not ch.isspace())
return [lookup.get(ch, 1) for ch in folded]
Out-of-vocabulary characters map to <unk> rather than being dropped: they
still consume audio, and dropping them would shift every later timestamp.
Frame f of the output starts at f * (1 / 13) / upsample seconds. Blank runs
need no extra machinery:
blank = log_probs.argmax(dim=-1).eq(0)
For character timestamps, run a standard CTC forced alignment (Viterbi over the
blank-interleaved target lattice, backtracked to per-character frame spans)
against encode(transcript). torchaudio.functional.forced_align does this if
you have a torchaudio build for your Python/CUDA combination; otherwise it is
about a hundred lines to implement directly, and doing so removes the dependency
entirely.
Treat the head as a measured improvement over proportional timing, not as
ground truth.
Conversion
This repository was produced with:
uv run python -m tools.asr.convert_qwen3_asr_to_hf `
--source-model-dir models/jaykwok-Qwen3-ASR-1.7B-JA-Anime-Galgame `
--output-dir agents/temp/20260630_123000_qwen3_asr_hf_conversion `
--template-repo Qwen/Qwen3-ASR-1.7B-hf `
--max-shard-size 768MB
Notes
This model is specialized for Japanese anime / galgame style speech. It should
be evaluated on your own data before production use.