Files
2026-07-13 13:33:03 +08:00

752 lines
34 KiB
Python

import torch
from .transformers import Decoder
from .spinner import spinner_run
from .torch_utils import onnx_export
class Audio(torch.nn.Module):
def __init__(self, audio, base):
super().__init__()
self.model_type = base.config.model_type
self.audio = audio
self.embed_ = base.embed
self.tokenizer = base.tokenizer
self.config = base.config.origin_config
self.hidden_size = base.config.hidden_size
self.llm_config = { 'is_audio': True }
self.rope_ratio = 1.0
self.quant_bit = 16
self.init_config()
self.load()
def get_config(self):
return self.llm_config
@staticmethod
def get_audio(model_type):
audio_models = {
'qwen2_audio_encoder': Qwen2Audio,
'qwen2_5_omni_audio_encoder': Qwen2_5OmniAudio,
'funaudiochat_audio_encoder': FunAudioChatAudio,
'lfm2_audio': Lfm2Audio,
'gemma4_audio': Gemma4Audio,
}
if model_type in audio_models:
return audio_models[model_type]
return None
def init_config(self):
pass
def load(self):
raise NotImplementedError
def str_to_ids(self, prompt):
input_ids = self.tokenizer(prompt, return_tensors="pt")['input_ids']
return input_ids
def forward(self, images):
raise NotImplementedError
def embed(self, input_ids, images = None, videos = None):
raise NotImplementedError
def export(self, onnx_path):
raise NotImplementedError
class Qwen2Audio(Audio):
def __init__(self, audio, base):
super().__init__(audio, base)
self.audio_embeds = None
self.audio_pad_id = 151646
self.n_fft = 400
self.sampling_rate = 16000
self.hop_length = 160
self.chunk_length = 30
self.feature_size = 128
self.n_samples = self.chunk_length * self.sampling_rate
self.max_length = self.n_samples // self.hop_length
from transformers.audio_utils import mel_filter_bank
self.mel_filters = mel_filter_bank(
num_frequency_bins=1 + self.n_fft // 2,
num_mel_filters=self.feature_size,
min_frequency=0.0,
max_frequency=8000.0,
sampling_rate=self.sampling_rate,
norm="slaney",
mel_scale="slaney",
)
def load(self):
# model
self.audio_tower = self.audio
self.multi_modal_projector = self.audio.multi_modal_projector
# config
self.llm_config['is_audio'] = True
def str_to_ids(self, prompt):
if '<audio>' in prompt and '</audio>' in prompt:
import re
from io import BytesIO
from urllib.request import urlopen
import librosa
pattern = r'(<audio>.*?</audio>)'
parts = re.split(pattern, prompt)
txt_prompt = ''
for part in parts:
if re.match(pattern, part):
audio_content = re.search(r'<audio>(.*?)</audio>', part).group(1)
if audio_content.startswith('http://') or audio_content.startswith('https://'):
audio_obj = librosa.load(BytesIO(urlopen(audio_content).read()), sr=self.sampling_rate)[0]
else:
# local file
audio_obj = librosa.load(audio_content, sr=self.sampling_rate)[0]
audio_embed_len = self.audio_process(audio_obj)
audio_pad_str = '<|AUDIO|>' * audio_embed_len
txt_prompt += audio_pad_str
else:
txt_prompt += part
else:
txt_prompt = prompt
input_ids = self.tokenizer(txt_prompt, return_tensors="pt")['input_ids']
return input_ids
def forward(self, input_features):
input_features = input_features.to(dtype=self.audio_tower.conv1.weight.dtype, device=self.audio_tower.conv1.weight.device)
inputs_embeds = torch.nn.functional.gelu(self.audio_tower.conv1(input_features))
inputs_embeds = torch.nn.functional.gelu(self.audio_tower.conv2(inputs_embeds))
inputs_embeds = inputs_embeds.permute(0, 2, 1)
_, seq_len, _ = inputs_embeds.shape
embed_pos = self.audio_tower.embed_positions.weight[:seq_len, :]
hidden_states = inputs_embeds + embed_pos
for encoder_layer in self.audio_tower.layers:
hidden_states = encoder_layer(hidden_states, None, None)[0]
hidden_states = hidden_states.permute(0, 2, 1)
hidden_states = self.audio_tower.avg_pooler(hidden_states)
hidden_states = hidden_states.permute(0, 2, 1)
hidden_states = self.audio_tower.layer_norm(hidden_states)
audio_features = self.multi_modal_projector(hidden_states)
return audio_features
def _torch_extract_fbank_features(self, waveform):
window = torch.hann_window(self.n_fft)
stft = torch.stft(waveform, self.n_fft, self.hop_length, window=window, return_complex=True)
magnitudes = stft[..., :-1].abs() ** 2
mel_filters = torch.from_numpy(self.mel_filters).type(torch.float32)
mel_spec = mel_filters.T @ magnitudes
log_spec = torch.clamp(mel_spec, min=1e-10).log10()
if waveform.dim() == 2:
max_val = log_spec.max(dim=2, keepdim=True)[0].max(dim=1, keepdim=True)[0]
log_spec = torch.maximum(log_spec, max_val - 8.0)
else:
log_spec = torch.maximum(log_spec, log_spec.max() - 8.0)
log_spec = (log_spec + 4.0) / 4.0
return log_spec
def audio_process(self, audio_obj):
# audio_obj = np.pad(audio_obj, (0, self.n_samples - audio_obj.shape[0]))
waveform = torch.from_numpy(audio_obj).type(torch.float32)
input_features = self._torch_extract_fbank_features(waveform).unsqueeze(0)
audio_embeds = self.forward(input_features)
self.audio_embeds = audio_embeds.permute([1, 0, 2])
return self.audio_embeds.shape[0]
def embed(self, input_ids, images = None, videos = None):
input_embeds = self.embed_(input_ids)
if self.audio_embeds is not None:
audio_mask = (input_ids == self.audio_pad_id).squeeze()
input_embeds[audio_mask] = self.audio_embeds.type(input_embeds.dtype)
return input_embeds
@spinner_run(f'export audio to ')
def export(self, onnx_path):
input_features = torch.randn((1, self.feature_size, self.max_length))
model = self.float()
onnx_model = f'{onnx_path}/audio.onnx'
onnx_export(model, (input_features),
onnx_model,
input_names=['input_features'],
output_names=['audio_embeds'],
dynamic_axes={"input_features": {
2: "size"
}})
return onnx_model
class AudioMlp(torch.nn.Module):
def __init__(self, fc1, fc2, act):
super().__init__()
self.fc1 = fc1
self.fc2 = fc2
self.act = act
def forward(self, hidden_states):
hidden_states = self.fc1(hidden_states)
hidden_states = self.act(hidden_states)
hidden_states = self.fc2(hidden_states)
return hidden_states
class Qwen2_5OmniAudio(Qwen2Audio):
def __init__(self, audio, base):
super().__init__(audio, base)
self.quant_bit = 4
def load(self):
# config
config = self.audio.config
self.n_window = config.n_window
self.llm_config['is_audio'] = True
self.llm_config['n_window'] = self.n_window
self.hidden_size = config.d_model
self.num_attention_heads = config.encoder_attention_heads
self.num_key_value_heads = self.num_attention_heads
self.head_dim = self.hidden_size // self.num_attention_heads
self.rotary = None
self.model_map = {
'decoder': {
'self_attn': 'self_attn',
'input_layernorm': 'self_attn_layer_norm',
'post_attention_layernorm': 'final_layer_norm'
},
'attention': {
'q_proj': 'q_proj',
'k_proj': 'k_proj',
'v_proj': 'v_proj',
'o_proj': 'out_proj'
}
}
self.blocks = []
for layer in self.audio.layers:
layer_id = len(self.blocks)
block = Decoder(layer, layer_id, self)
block.mlp = AudioMlp(layer.fc1, layer.fc2, layer.activation_fn)
self.blocks.append(block)
def forward(self, input_features, attention_mask = None):
input_features = input_features.to(dtype=self.audio.conv1.weight.dtype, device=self.audio.conv1.weight.device)
inputs_embeds = torch.nn.functional.gelu(self.audio.conv1(input_features))
inputs_embeds = torch.nn.functional.gelu(self.audio.conv2(inputs_embeds))
inputs_embeds = inputs_embeds.permute(0, 2, 1)
_, seq_len, _ = inputs_embeds.shape
embed_pos = self.audio.positional_embedding.positional_embedding[:seq_len, :]
hidden_states = inputs_embeds + embed_pos
for block in self.blocks:
hidden_states = block(hidden_states, attention_mask=attention_mask)
hidden_states = hidden_states.permute(0, 2, 1)
hidden_states = self.audio.avg_pooler(hidden_states)
hidden_states = hidden_states.permute(0, 2, 1)
hidden_states = self.audio.ln_post(hidden_states)
audio_features = self.audio.proj(hidden_states)
return audio_features
def audio_process(self, audio_obj):
# audio_obj = np.pad(audio_obj, (0, self.n_samples - audio_obj.shape[0]))
waveform = torch.from_numpy(audio_obj).type(torch.float32)
input_features = self._torch_extract_fbank_features(waveform).unsqueeze(0)
_, _, seq_len = input_features.shape
seq_len = int(seq_len // 2)
cu_seqlens = [i for i in range(0, seq_len, self.n_window)]
if not cu_seqlens or cu_seqlens[-1] != seq_len:
cu_seqlens.append(seq_len)
cu_seqlens = torch.tensor(cu_seqlens)
attention_mask = torch.full(
[1, seq_len, seq_len], torch.finfo(torch.float32).min
)
for i in range(1, len(cu_seqlens)):
attention_mask[..., cu_seqlens[i - 1] : cu_seqlens[i], cu_seqlens[i - 1] : cu_seqlens[i]] = 0
audio_embeds = self.forward(input_features, attention_mask)
self.audio_embeds = audio_embeds.permute([1, 0, 2])
return self.audio_embeds.shape[0]
@spinner_run(f'export audio to ')
def export(self, onnx_path):
input_features = torch.randn((1, self.feature_size, self.max_length))
seq_len = self.max_length // 2
attention_mask = torch.randn([1, seq_len, seq_len])
model = self.float()
onnx_model = f'{onnx_path}/audio.onnx'
onnx_export(model, (input_features, attention_mask),
onnx_model,
input_names=['input_features', 'attention_mask'],
output_names=['audio_embeds'],
dynamic_axes={"input_features": {
0: "size"
}, "attention_mask": {
1: "size", 2: "size"
}})
return onnx_model
class FunAudioChatAudio(Qwen2_5OmniAudio):
def __init__(self, audio, base):
super().__init__(audio, base)
self.audio_pad_id = 151669
def load(self):
# model
self.audio = self.audio.float()
self.audio_tower = self.audio.audio_tower.float()
# config
self.group_size = self.audio.config.group_size
# call parent load
super().load()
def forward(self, input_features, attention_mask = None):
# call parent forward to get audio_features before group pooling
audio_features = super().forward(input_features, attention_mask)
# group pooling and continual_output_matching
batch, seqlen, hidden_size = audio_features.shape
padding_feature = torch.zeros(
(batch, (self.group_size - seqlen % self.group_size) % self.group_size, hidden_size),
dtype=torch.long,
device=audio_features.device,
)
audio_features = torch.cat([audio_features, padding_feature], dim=1)
audio_features = audio_features.reshape(batch, -1, self.group_size, hidden_size)
audio_features = audio_features.mean(dim=2)
audio_features = self.audio_tower.continual_output_matching(audio_features)
return audio_features
class Lfm2Audio(Audio):
"""Audio encoder for LFM2-Audio (FastConformer + MLP adapter).
Supports audio understanding: audio → conformer → adapter → inject into LFM → text.
"""
def __init__(self, audio, base):
# Store adapter and constants before super().__init__() using __dict__
# to bypass Module.__setattr__ (which requires __init__ to be called first)
self.__dict__['_audio_adapter_ref'] = base.audio_adapter
self.__dict__['audio_pad_id'] = 16 # <|reserved_6|> as audio placeholder
self.__dict__['sampling_rate'] = 16000
super().__init__(audio, base)
self.audio_embeds = None
self.quant_bit = 4
def load(self):
self.conformer = self.audio.float()
self.audio_adapter_module = self._audio_adapter_ref.float()
self.llm_config['is_audio'] = True
self.llm_config['audio_type'] = 'conformer'
self.llm_config['audio_pad'] = self.audio_pad_id
# Initialize mel spectrogram preprocessor (matching config.json preprocessor settings)
from liquid_audio.model.conformer.processor import AudioToMelSpectrogramPreprocessor
self.preprocessor = AudioToMelSpectrogramPreprocessor(
sample_rate=16000, window_size=0.025, window_stride=0.01,
window='hann', normalize='per_feature', n_fft=512,
features=128, log=True, dither=1e-5, pad_to=0, pad_value=0.0,
).eval().float()
def forward(self, input_features, input_lengths):
"""Run conformer encoder + adapter on mel features.
Args:
input_features: [B, 128, T] mel spectrogram
input_lengths: [B] actual mel lengths
Returns:
audio_features: [T_valid, hidden_size] (valid tokens only, padding removed)
enc_lens: [B] valid token counts
"""
audio_enc, enc_lens = self.conformer(input_features, input_lengths)
# audio_enc: [B, d_model=512, T_enc]
# Extract valid (non-padded) tokens using boolean mask
len_mask = torch.arange(audio_enc.shape[-1], device=audio_enc.device).unsqueeze(0) < enc_lens.unsqueeze(1)
audio_enc_valid = audio_enc.transpose(1, 2)[len_mask] # [T_valid, 512]
# Project to LFM hidden size
audio_features = self.audio_adapter_module(audio_enc_valid) # [T_valid, 2048]
return audio_features, enc_lens
def audio_process(self, audio_obj):
"""Process raw audio waveform to get audio embeddings.
Args:
audio_obj: numpy array of audio samples (16kHz)
Returns:
num_tokens: number of audio embedding tokens
"""
waveform = torch.from_numpy(audio_obj).float().unsqueeze(0) # [1, T]
length = torch.tensor([waveform.shape[1]], dtype=torch.long)
mel, mel_len = self.preprocessor(waveform, length) # [1, 128, T_mel]
audio_features, enc_lens = self.forward(mel, mel_len) # [T_valid, 2048]
self.audio_embeds = audio_features.unsqueeze(1) # [T_valid, 1, 2048]
return self.audio_embeds.shape[0]
def str_to_ids(self, prompt):
if '<audio>' not in prompt:
return self.tokenizer(prompt, return_tensors="pt")['input_ids']
import re
import librosa
pattern = r'(<audio>.*?</audio>)'
parts = re.split(pattern, prompt)
# No manual BOS — the chat template already includes <|startoftext|>
all_ids = []
for part in parts:
if re.match(pattern, part):
audio_path = re.search(r'<audio>(.*?)</audio>', part).group(1)
audio_obj = librosa.load(audio_path, sr=self.sampling_rate)[0]
num_tokens = self.audio_process(audio_obj)
all_ids.extend([self.audio_pad_id] * num_tokens)
else:
if part:
ids = self.tokenizer.encode(part, add_special_tokens=False)
all_ids.extend(ids)
return torch.tensor([all_ids])
def embed(self, input_ids, images=None, videos=None):
input_embeds = self.embed_(input_ids)
if self.audio_embeds is not None:
audio_mask = (input_ids == self.audio_pad_id).squeeze()
input_embeds[audio_mask] = self.audio_embeds.type(input_embeds.dtype)
return input_embeds
@spinner_run(f'export audio to ')
def export(self, onnx_path):
class AudioExport(torch.nn.Module):
def __init__(self, conformer, adapter):
super().__init__()
self.conformer = conformer
self.adapter = adapter
def forward(self, input_features):
# input_features: [1, 128, T_mel]
input_length = torch.tensor(
[input_features.shape[2]], dtype=torch.long, device=input_features.device
)
audio_enc, enc_lens = self.conformer(input_features, input_length)
# audio_enc: [1, 512, T_enc]
audio_enc = audio_enc.transpose(1, 2) # [1, T_enc, 512]
audio_features = self.adapter(audio_enc) # [1, T_enc, 2048]
return audio_features
model = AudioExport(self.conformer, self.audio_adapter_module).float().eval()
# Pre-allocate positional embeddings for max sequence length
model.conformer.set_max_audio_length(5000)
input_features = torch.randn((1, 128, 1000))
onnx_model = f'{onnx_path}/audio.onnx'
onnx_export(model, (input_features,),
onnx_model,
input_names=['input_features'],
output_names=['audio_embeds'],
dynamic_axes={"input_features": {
2: "size"
}})
return onnx_model
class Gemma4AudioExportModel(torch.nn.Module):
"""ONNX-exportable wrapper for gemma4 audio encoder.
Replaces unfold-based chunked attention with index-gather approach,
and skips HF's create_bidirectional_mask (not needed for non-padded audio).
"""
def __init__(self, audio_tower, embed_audio):
super().__init__()
self.audio_tower = audio_tower
self.embed_audio = embed_audio
cfg = audio_tower.config
self.chunk_size = cfg.attention_chunk_size
self.max_past = cfg.attention_context_left - 1
self.max_future = cfg.attention_context_right
self.context_size = self.chunk_size + self.max_past + self.max_future
self.gradient_clipping = cfg.gradient_clipping
def _clippable_linear(self, module, x):
if module.use_clipped_linears:
x = torch.clamp(x, module.input_min, module.input_max)
x = module.linear(x)
if module.use_clipped_linears:
x = torch.clamp(x, module.output_min, module.output_max)
return x
def _convert_to_block(self, hidden_states):
B, S, H, D = hidden_states.shape
num_blocks = (S + self.chunk_size - 1) // self.chunk_size
pad = num_blocks * self.chunk_size - S
if pad > 0:
hidden_states = torch.nn.functional.pad(hidden_states, (0, 0, 0, 0, 0, pad), value=0.0)
return hidden_states.reshape(B, num_blocks, self.chunk_size, H, D)
def _extract_block_context(self, hidden_states):
B, S, H, D = hidden_states.shape
num_blocks = (S + self.chunk_size - 1) // self.chunk_size
padded = torch.nn.functional.pad(
hidden_states, (0, 0, 0, 0, self.max_past, self.max_future + self.chunk_size - 1), value=0.0
)
offsets = torch.arange(self.context_size, device=hidden_states.device)
block_starts = torch.arange(num_blocks, device=hidden_states.device) * self.chunk_size
indices = (block_starts.unsqueeze(1) + offsets.unsqueeze(0)).reshape(-1)
result = padded[:, indices].reshape(B, num_blocks, self.context_size, H, D)
return result
def _rel_shift(self, x):
B, H, NB, BS, PL = x.shape
CS = self.context_size
x = torch.nn.functional.pad(x, (0, CS + 1 - PL), value=0.0)
x = x.reshape(B, H, NB, BS * (CS + 1))
x = x[..., :BS * CS]
return x.reshape(B, H, NB, BS, CS)
def _build_blocked_mask(self, S, device):
"""Build 5D blocked sliding window attention mask."""
num_blocks = (S + self.chunk_size - 1) // self.chunk_size
q_idx = torch.arange(self.chunk_size, device=device)
c_idx = torch.arange(self.context_size, device=device)
b_idx = torch.arange(num_blocks, device=device)
abs_query = b_idx.unsqueeze(1) * self.chunk_size + q_idx.unsqueeze(0)
abs_key = b_idx.unsqueeze(1) * self.chunk_size - self.max_past + c_idx.unsqueeze(0)
query_valid = abs_query < S
key_valid = (abs_key >= 0) & (abs_key < S)
# Sliding window: c > q AND c <= q + max_past (strict left, closed right)
slide = (c_idx.unsqueeze(0) > q_idx.unsqueeze(1)) & \
(c_idx.unsqueeze(0) <= q_idx.unsqueeze(1) + self.max_past)
mask = query_valid.unsqueeze(2) & key_valid.unsqueeze(1) & slide.unsqueeze(0)
return mask.unsqueeze(0).unsqueeze(0) # [1, 1, num_blocks, chunk_size, context_size]
def _conformer_attention(self, attn, hidden_states, position_embeddings, attention_mask):
B, S, _ = hidden_states.shape
num_heads = attn.num_heads
head_dim = attn.head_dim
query_states = self._clippable_linear(attn.q_proj, hidden_states).float()
key_states = self._clippable_linear(attn.k_proj, hidden_states).float()
value_states = self._clippable_linear(attn.v_proj, hidden_states).float()
query_states = query_states.view(B, S, num_heads, head_dim)
key_states = key_states.view(B, S, num_heads, head_dim)
value_states = value_states.view(B, S, num_heads, head_dim)
query_states = query_states * attn.q_scale * torch.nn.functional.softplus(attn.per_dim_scale)
key_states = key_states * attn.k_scale
query_blocked = self._convert_to_block(query_states)
key_context = self._extract_block_context(key_states)
value_context = self._extract_block_context(value_states)
num_blocks = query_blocked.shape[1]
relative_key_states = attn.relative_k_proj(position_embeddings)
relative_key_states = relative_key_states.view(-1, num_heads, head_dim).to(query_states.dtype)
queries = query_blocked.permute(0, 3, 1, 2, 4)
matrix_ac = queries @ key_context.permute(0, 3, 1, 4, 2)
queries_flat = queries.reshape(B, num_heads, -1, head_dim)
matrix_bd = queries_flat @ relative_key_states.permute(1, 2, 0)
matrix_bd = matrix_bd.reshape(B, num_heads, num_blocks, self.chunk_size, -1)
matrix_bd = self._rel_shift(matrix_bd)
attn_weights = matrix_ac + matrix_bd
attn_weights = attn_weights / attn.softcap
attn_weights = torch.tanh(attn_weights)
attn_weights = attn_weights * attn.softcap
# Apply sliding window mask
if attention_mask is not None:
invalid_value = torch.tensor(-1e9, dtype=attn_weights.dtype, device=attn_weights.device)
attn_weights = torch.where(attention_mask, attn_weights, invalid_value)
attn_weights = torch.nn.functional.softmax(attn_weights, dim=-1, dtype=torch.float32)
attn_weights = attn_weights.to(value_context.dtype)
attn_output = attn_weights @ value_context.permute(0, 3, 1, 2, 4)
attn_output = attn_output.permute(0, 2, 3, 1, 4).reshape(B, num_blocks * self.chunk_size, -1)
attn_output = attn_output[:, :S].contiguous()
attn_output = self._clippable_linear(attn.post, attn_output.to(attn.post.linear.weight.dtype))
return attn_output
def _feed_forward(self, ff, hidden_states):
gc = min(self.gradient_clipping, torch.finfo(ff.ffw_layer_1.linear.weight.dtype).max)
residual = hidden_states
hidden_states = torch.clamp(hidden_states, -gc, gc)
hidden_states = ff.pre_layer_norm(hidden_states)
hidden_states = self._clippable_linear(ff.ffw_layer_1, hidden_states)
hidden_states = ff.act_fn(hidden_states)
hidden_states = self._clippable_linear(ff.ffw_layer_2, hidden_states)
hidden_states = torch.clamp(hidden_states, -gc, gc)
hidden_states = ff.post_layer_norm(hidden_states)
hidden_states = hidden_states * ff.post_layer_scale
hidden_states = hidden_states + residual
return hidden_states
def _causal_conv1d(self, conv, x):
"""Causal Conv1d with explicit pad value for ONNX compatibility."""
left_pad = (conv.kernel_size[0] - 1) * conv.dilation[0] + 1 - conv.stride[0]
x = torch.nn.functional.pad(x, (left_pad, 0), value=0.0)
return torch.nn.functional.conv1d(x, conv.weight, conv.bias,
stride=conv.stride, dilation=conv.dilation, groups=conv.groups)
def _light_conv(self, lconv, hidden_states):
residual = hidden_states
hidden_states = lconv.pre_layer_norm(hidden_states)
hidden_states = self._clippable_linear(lconv.linear_start, hidden_states)
hidden_states = torch.nn.functional.glu(hidden_states, dim=-1)
hidden_states = self._causal_conv1d(lconv.depthwise_conv1d, hidden_states.transpose(1, 2)).transpose(1, 2)
gc = min(self.gradient_clipping, torch.finfo(lconv.linear_start.linear.weight.dtype).max)
hidden_states = torch.clamp(hidden_states, -gc, gc)
hidden_states = lconv.conv_norm(hidden_states)
hidden_states = lconv.act_fn(hidden_states)
hidden_states = self._clippable_linear(lconv.linear_end, hidden_states)
hidden_states = hidden_states + residual
return hidden_states
def _encoder_layer(self, layer, hidden_states, position_embeddings, attention_mask):
gc = min(self.gradient_clipping, torch.finfo(layer.norm_pre_attn.weight.dtype).max)
hidden_states = self._feed_forward(layer.feed_forward1, hidden_states)
residual = hidden_states
hidden_states = torch.clamp(hidden_states, -gc, gc)
hidden_states = layer.norm_pre_attn(hidden_states)
hidden_states = self._conformer_attention(layer.self_attn, hidden_states, position_embeddings, attention_mask)
hidden_states = torch.clamp(hidden_states, -gc, gc)
hidden_states = layer.norm_post_attn(hidden_states)
hidden_states = hidden_states + residual
hidden_states = self._light_conv(layer.lconv1d, hidden_states)
hidden_states = self._feed_forward(layer.feed_forward2, hidden_states)
hidden_states = torch.clamp(hidden_states, -gc, gc)
hidden_states = layer.norm_out(hidden_states)
return hidden_states
def forward(self, input_features):
at = self.audio_tower
# 1. Subsample conv projection (no mask needed for export)
hidden_states = input_features.unsqueeze(1) # [B, 1, T, F]
hidden_states = at.subsample_conv_projection.layer0.conv(hidden_states.to(at.subsample_conv_projection.layer0.conv.weight.dtype))
hidden_states = at.subsample_conv_projection.layer0.act(
at.subsample_conv_projection.layer0.norm(hidden_states.permute(0, 2, 3, 1)).permute(0, 3, 1, 2).contiguous()
)
hidden_states = at.subsample_conv_projection.layer1.conv(hidden_states)
hidden_states = at.subsample_conv_projection.layer1.act(
at.subsample_conv_projection.layer1.norm(hidden_states.permute(0, 2, 3, 1)).permute(0, 3, 1, 2).contiguous()
)
B, C, T, F = hidden_states.shape
hidden_states = hidden_states.permute(0, 2, 3, 1).contiguous().reshape(B, T, -1)
hidden_states = at.subsample_conv_projection.input_proj_linear(hidden_states)
# 2. Relative positional encoding
position_embeddings = at.rel_pos_enc(hidden_states)
# 3. Build sliding window attention mask
S = hidden_states.shape[1]
attention_mask = self._build_blocked_mask(S, hidden_states.device)
# 4. Encoder layers
for layer in at.layers:
hidden_states = self._encoder_layer(layer, hidden_states, position_embeddings, attention_mask)
# 4. Output projection
hidden_states = at.output_proj(hidden_states)
# 5. Multimodal embedder
audio_features = self.embed_audio(hidden_states)
return audio_features
class Gemma4Audio(Audio):
def __init__(self, audio, base):
object.__setattr__(self, 'embed_audio_ref', base.embed_audio)
super().__init__(audio, base)
self.sampling_rate = 16000
self.feature_size = 128
self.audio_embeds = None
def load(self):
self.audio_tower = self.audio.float()
self.embed_audio = self.embed_audio_ref.float()
self.llm_config['is_audio'] = True
self.llm_config['audio_pad'] = self.config.audio_token_id
self.llm_config['audio_start'] = self.config.boa_token_id
self.llm_config['audio_end'] = self.config.eoa_token_id
self.llm_config['audio_type'] = 'usm'
self.export_model = Gemma4AudioExportModel(self.audio_tower, self.embed_audio)
def init_config(self):
self.llm_config['is_audio'] = True
def _extract_mel_features(self, audio_obj):
"""USM-style mel spectrogram extraction matching Gemma4AudioFeatureExtractor."""
import numpy as np
from transformers.audio_utils import mel_filter_bank, window_function
waveform = audio_obj if isinstance(audio_obj, np.ndarray) else audio_obj.numpy()
if waveform.ndim == 1:
waveform = waveform[np.newaxis, :]
frame_length = 320 # 20ms * 16000
hop_length = 160 # 10ms * 16000
fft_length = 512
mel_floor = 0.001
# Semicausal padding
pad_left = frame_length // 2
waveform = np.pad(waveform, ((0, 0), (pad_left, 0)), mode='constant')
# Frame extraction (unfold)
frame_size = frame_length + 1 # 321
B, L = waveform.shape
num_frames = (L - frame_size) // hop_length + 1
strides = (waveform.strides[0], waveform.strides[1] * hop_length, waveform.strides[1])
frames = np.lib.stride_tricks.as_strided(waveform, (B, num_frames, frame_size), strides)
# No preemphasis (preemphasis=0), take first frame_length samples
frames = frames[..., :-1]
# Window
window = window_function(frame_length).astype(np.float32)
frames = frames * window
# RFFT
stft = np.fft.rfft(frames, n=fft_length, axis=-1)
magnitude = np.abs(stft)
# Mel filterbank
mel_filters = mel_filter_bank(
num_frequency_bins=fft_length // 2 + 1,
num_mel_filters=128,
min_frequency=0.0, max_frequency=8000.0,
sampling_rate=16000, norm=None, mel_scale='htk',
)
mel_spec = np.matmul(magnitude, mel_filters)
log_mel = np.log(mel_spec + mel_floor)
return torch.from_numpy(log_mel.astype(np.float32))
def forward(self, input_features):
return self.export_model(input_features)
def audio_process(self, audio_obj):
input_features = self._extract_mel_features(audio_obj) # [1, T, 128]
with torch.no_grad():
audio_embeds = self.forward(input_features) # [1, T/4, hidden_size]
self.audio_embeds = audio_embeds.permute(1, 0, 2) # [T/4, 1, hidden_size]
return self.audio_embeds.shape[0]
def str_to_ids(self, prompt):
if '<audio>' not in prompt:
return self.tokenizer(prompt, return_tensors="pt")['input_ids']
import re
import librosa
audio_pad_id = self.config.audio_token_id
boa_token = self.tokenizer.decode([self.config.boa_token_id])
eoa_token = self.tokenizer.decode([self.config.eoa_token_id])
pad_token = self.tokenizer.decode([audio_pad_id])
# Parse <audio> tags, process audio, and replace with placeholder tokens
pattern = r'(<audio>.*?</audio>)'
parts = re.split(pattern, prompt)
txt_prompt = ''
for part in parts:
if re.match(pattern, part):
audio_path = re.search(r'<audio>(.*?)</audio>', part).group(1)
audio_obj = librosa.load(audio_path, sr=self.sampling_rate)[0]
num_tokens = self.audio_process(audio_obj)
txt_prompt += boa_token + pad_token * num_tokens + eoa_token
else:
txt_prompt += part
input_ids = self.tokenizer(txt_prompt, return_tensors="pt", add_special_tokens=False)['input_ids']
return input_ids
def embed(self, input_ids, images=None, videos=None):
input_embeds = self.embed_(input_ids)
if self.audio_embeds is not None:
audio_pad_id = self.config.audio_token_id
audio_mask = (input_ids == audio_pad_id).squeeze()
input_embeds[audio_mask] = self.audio_embeds.to(input_embeds.dtype)
return input_embeds
@spinner_run(f'export audio to ')
def export(self, onnx_path):
input_features = torch.randn((1, 600, self.feature_size))
model = self.export_model.float().eval()
onnx_model = f'{onnx_path}/audio.onnx'
onnx_export(model, (input_features,),
onnx_model,
input_names=['input_features'],
output_names=['audio_embeds'],
dynamic_axes={"input_features": {1: "seq_len"}})
return onnx_model