484 lines
18 KiB
Python

# Adapted from https://github.com/fixie-ai/ultravox/blob/ecd58c4041030bae2ad15aa6bcf04ab43199ea02/ultravox/model/ultravox_model.py
"""PyTorch Ultravox model."""
import math
from array import array
from functools import lru_cache
from typing import (Iterable, List, Literal, Mapping, Optional, Tuple,
TypedDict, Union, cast)
import numpy as np
import torch
import torch.utils.checkpoint
from torch import nn
from torch.nn import functional as F
from transformers.models.whisper import WhisperFeatureExtractor
from transformers.models.whisper.modeling_whisper import WhisperEncoder
from vllm.attention import AttentionMetadata
from vllm.config import CacheConfig, MultiModalConfig
from vllm.inputs import INPUT_REGISTRY
from vllm.inputs.data import LLMInputs
from vllm.inputs.registry import InputContext
from vllm.logger import init_logger
from vllm.model_executor.layers.activation import SiluAndMul, get_act_fn
from vllm.model_executor.layers.layernorm import RMSNorm
from vllm.model_executor.layers.quantization.base_config import (
QuantizationConfig)
from vllm.model_executor.layers.sampler import SamplerOutput
from vllm.model_executor.model_loader.weight_utils import default_weight_loader
from vllm.model_executor.models.interfaces import SupportsMultiModal
from vllm.model_executor.models.utils import (flatten_bn,
group_weights_with_prefix,
init_vllm_registered_model,
merge_multimodal_embeddings)
from vllm.model_executor.sampling_metadata import SamplingMetadata
from vllm.multimodal import MULTIMODAL_REGISTRY
from vllm.multimodal.base import MultiModalInputs, NestedTensors
from vllm.multimodal.utils import (cached_get_tokenizer,
repeat_and_pad_placeholder_tokens)
from vllm.sequence import VLLM_TOKEN_ID_ARRAY_TYPE, SequenceData
from vllm.transformers_utils.configs.ultravox import UltravoxConfig
_AUDIO_PLACEHOLDER_TOKEN = 128002
_AUDIO_TOKENS_PER_SECOND = 6.25
logger = init_logger(__name__)
class UltravoxAudioFeatureInputs(TypedDict):
type: Literal["audio_features"]
data: NestedTensors
"""Shape: `(batch_size, num_audios, 80, M)"""
class UltravoxAudioEmbeddingInputs(TypedDict):
type: Literal["audio_embeds"]
data: NestedTensors
"""Shape: `(batch_size, num_audios, audio_feature_size, hidden_size)"""
UltravoxAudioInputs = Union[UltravoxAudioFeatureInputs,
UltravoxAudioEmbeddingInputs]
@lru_cache
def cached_feature_extractor(model_id: str) -> WhisperFeatureExtractor:
return WhisperFeatureExtractor.from_pretrained(model_id)
def whisper_feature_extractor(ctx: InputContext) -> WhisperFeatureExtractor:
return cached_feature_extractor(
ctx.get_hf_config(UltravoxConfig).audio_model_id)
def get_ultravox_max_audio_tokens(ctx: InputContext):
feature_extractor = whisper_feature_extractor(ctx)
return math.ceil(feature_extractor.chunk_length * _AUDIO_TOKENS_PER_SECOND)
def dummy_seq_data_for_ultravox(
ctx: InputContext,
seq_len: int,
audio_count: int,
):
audio_placeholder = array(
VLLM_TOKEN_ID_ARRAY_TYPE,
[_AUDIO_PLACEHOLDER_TOKEN]) * get_ultravox_max_audio_tokens(ctx)
# Add a separator between each chunk.
audio_token_ids = (audio_placeholder +
array(VLLM_TOKEN_ID_ARRAY_TYPE, [0])) * audio_count
other_token_ids = array(VLLM_TOKEN_ID_ARRAY_TYPE,
[0]) * (seq_len - len(audio_token_ids))
return SequenceData(audio_token_ids + other_token_ids)
def dummy_audio_for_ultravox(
ctx: InputContext,
audio_count: int,
):
feature_extractor = whisper_feature_extractor(ctx)
audio_and_sr = (np.array([0.0] * feature_extractor.chunk_length), 1)
return {"audio": [audio_and_sr] * audio_count}
def dummy_data_for_ultravox(
ctx: InputContext,
seq_len: int,
mm_counts: Mapping[str, int],
):
audio_count = mm_counts["audio"]
seq_data = dummy_seq_data_for_ultravox(ctx, seq_len, audio_count)
mm_dict = dummy_audio_for_ultravox(ctx, audio_count)
return (seq_data, mm_dict)
def input_mapper_for_ultravox(ctx: InputContext, data: object):
if not isinstance(data, list):
data = [data]
audio_features = []
for audio_input in data:
if not isinstance(audio_input, tuple):
raise NotImplementedError(
f"Unsupported data type: {type(audio_input)}")
(audio, sr) = cast(Tuple[np.ndarray, Union[float, int]], audio_input)
feature_extractor = whisper_feature_extractor(ctx)
if sr != feature_extractor.sampling_rate:
try:
import librosa
except ImportError:
raise ImportError(
"Please install vllm[audio] for audio support.") from None
audio = librosa.resample(audio,
orig_sr=sr,
target_sr=feature_extractor.sampling_rate)
sr = feature_extractor.sampling_rate
minimum_audio_length = feature_extractor.n_fft // 2 + 1
if len(audio) < minimum_audio_length:
# Not enough audio; pad it.
audio = np.pad(audio, (0, minimum_audio_length - len(audio)))
single_audio_features = feature_extractor(
audio, sampling_rate=sr, padding="longest",
return_tensors="pt")["input_features"]
# Remove the batch dimension because we're wrapping it in a list.
audio_features.append(single_audio_features.squeeze(0))
return MultiModalInputs({"audio_features": audio_features})
def input_processor_for_ultravox(ctx: InputContext, llm_inputs: LLMInputs):
multi_modal_data = llm_inputs.get("multi_modal_data")
if multi_modal_data is None or "audio" not in multi_modal_data:
return llm_inputs
feature_extractor = whisper_feature_extractor(ctx)
audios = multi_modal_data["audio"]
if not isinstance(audios, list):
audios = [audios]
audio_token_counts = []
for audio_data, sample_rate in audios:
audio_length = audio_data.shape[0]
if sample_rate != feature_extractor.sampling_rate:
# Account for resampling.
adjustment = feature_extractor.sampling_rate / sample_rate
audio_length = math.ceil(adjustment * audio_length)
feature_extractor_output_length = math.ceil(
(audio_length - (feature_extractor.hop_length - 1)) /
feature_extractor.hop_length)
uv_config = ctx.get_hf_config(UltravoxConfig)
audio_num_tokens = min(
max(
1,
math.ceil(feature_extractor_output_length /
(uv_config.stack_factor * 2))),
get_ultravox_max_audio_tokens(ctx))
audio_token_counts.append(audio_num_tokens)
tokenizer = cached_get_tokenizer(ctx.model_config.tokenizer)
new_prompt, new_token_ids = repeat_and_pad_placeholder_tokens(
tokenizer,
llm_inputs.get("prompt"),
llm_inputs["prompt_token_ids"],
placeholder_token_id=_AUDIO_PLACEHOLDER_TOKEN,
repeat_count=audio_token_counts,
)
# NOTE: Create a defensive copy of the original inputs
return LLMInputs(prompt_token_ids=new_token_ids,
prompt=new_prompt,
multi_modal_data=multi_modal_data)
class StackAudioFrames(nn.Module):
"""
Stack the audio embedding frames to reduce the sequence length by a factor
of `stack_factor`.
"""
def __init__(self, stack_factor: int = 8):
super().__init__()
self.stack_factor = stack_factor
def forward(self, audio_embeds: torch.Tensor) -> torch.Tensor:
B, T, C = audio_embeds.shape
T_pad = (T + self.stack_factor -
1) // self.stack_factor * self.stack_factor
audio_embeds = F.pad(audio_embeds, (0, 0, 0, T_pad - T))
B, T, C = audio_embeds.shape
audio_embeds = audio_embeds.view(B, T // self.stack_factor,
C * self.stack_factor)
return audio_embeds
class FlippedSiluAndMul(SiluAndMul):
"""Ultravox is trained with SwiGLU with flipped halves."""
def forward(self, x: torch.Tensor):
a, b = x.chunk(2, dim=-1)
flipped = torch.cat((b, a), dim=-1)
return super().forward(flipped)
class UltravoxProjector(nn.Module):
def __init__(self, config: UltravoxConfig):
super().__init__()
self.hidden_dim = config.hidden_size
self._pad_and_stack = StackAudioFrames(config.stack_factor)
dim = config.audio_config.hidden_size * config.stack_factor
self.ln_pre = RMSNorm(dim)
self.linear_1 = nn.Linear(dim, self.hidden_dim, bias=False)
dim = self.hidden_dim
if config.projector_act == "swiglu":
self.act = FlippedSiluAndMul()
dim = dim // 2
else:
self.act = get_act_fn(config.projector_act)
self.linear_2 = nn.Linear(dim,
config.text_config.hidden_size,
bias=False)
self.ln_post = RMSNorm(config.text_config.hidden_size)
def forward(self, audio_features: torch.Tensor) -> torch.Tensor:
audio_features = self._pad_and_stack(audio_features)
audio_features = self.ln_pre(audio_features)
hidden_states = self.linear_1(audio_features)
hidden_states = self.act(hidden_states)
hidden_states = self.linear_2(hidden_states)
hidden_states = self.ln_post(hidden_states)
return hidden_states
class ModifiedWhisperEncoder(WhisperEncoder):
"""
Encoder portion of OpenAI's Whisper model.
This implementation is a slightly modified version of HF Transformers'
Whisper Encoder, with only a few fixes:
1. base_model_prefix updated to allow for doing `.from_pretrained`
directly on the encoder
2. allow less than 30 second of audio padding to be passed in:
- relaxed ValueError check for `input_features` length to be less
than or equal to `expected_seq_length` instead of strictly equal
- embed_pos is now sliced to match the length of `inputs_embeds`
Original: https://github.com/huggingface/transformers/blob/main/src/transformers/models/whisper/modeling_whisper.py
See commentary: https://github.com/huggingface/transformers/issues/25744
"""
base_model_prefix = "model.encoder"
def forward(
self,
input_features,
):
expected_seq_length = (self.config.max_source_positions *
self.conv1.stride[0] * self.conv2.stride[0])
if input_features.shape[-1] > expected_seq_length:
raise ValueError(
f"Whisper expects the mel input features to be of length "
f"{expected_seq_length} or less, but found "
f"{input_features.shape[-1]}. Make sure to pad the input mel "
f"features to {expected_seq_length}.")
inputs_embeds = nn.functional.gelu(self.conv1(input_features))
inputs_embeds = nn.functional.gelu(self.conv2(inputs_embeds))
inputs_embeds = inputs_embeds.permute(0, 2, 1)
embed_pos = self.embed_positions.weight[:inputs_embeds.size(-2)]
hidden_states = inputs_embeds + embed_pos
hidden_states = nn.functional.dropout(hidden_states,
p=self.dropout,
training=self.training)
for encoder_layer in self.layers:
layer_outputs = encoder_layer(
hidden_states,
None,
layer_head_mask=None,
)
hidden_states = layer_outputs[0]
hidden_states = self.layer_norm(hidden_states)
return hidden_states
@MULTIMODAL_REGISTRY.register_input_mapper("audio", input_mapper_for_ultravox)
@MULTIMODAL_REGISTRY.register_max_multimodal_tokens(
"audio", get_ultravox_max_audio_tokens)
@INPUT_REGISTRY.register_dummy_data(dummy_data_for_ultravox)
@INPUT_REGISTRY.register_input_processor(input_processor_for_ultravox)
class UltravoxModel(nn.Module, SupportsMultiModal):
def __init__(self,
config: UltravoxConfig,
multimodal_config: MultiModalConfig,
cache_config: Optional[CacheConfig] = None,
quant_config: Optional["QuantizationConfig"] = None):
super().__init__()
self.config = config
self.multi_modal_config = multimodal_config
assert self.multi_modal_config
if config.audio_model_id is not None:
self.audio_tower = ModifiedWhisperEncoder.from_pretrained(
config.audio_model_id)
else:
self.audio_tower = ModifiedWhisperEncoder(config.audio_config)
self.multi_modal_projector = UltravoxProjector(config)
self.language_model = init_vllm_registered_model(
config.text_config, cache_config, quant_config)
def _audio_features_to_embeddings(
self, input_features: torch.Tensor) -> torch.Tensor:
audio_input = input_features.to(self.audio_tower.dtype)
audio_features = self.audio_tower(audio_input)
audio_features = audio_features.to(self.audio_tower.dtype)
audio_embeddings = self.multi_modal_projector(audio_features)
return audio_embeddings
def _parse_and_validate_audio_input(
self, **kwargs: object) -> Optional[UltravoxAudioInputs]:
audio_features = kwargs.pop("audio_features", None)
audio_embeds = kwargs.pop("audio_embeds", None)
if audio_features is None and audio_embeds is None:
return None
if audio_features is not None:
if not isinstance(audio_features, (torch.Tensor, list)):
raise ValueError("Incorrect type of audio features. "
f"Got type: {type(audio_features)}")
return UltravoxAudioFeatureInputs(type="audio_features",
data=audio_features)
if audio_embeds is not None:
if not isinstance(audio_embeds, (torch.Tensor, list)):
raise ValueError("Incorrect type of audio embeds. "
f"Got type: {type(audio_embeds)}")
return UltravoxAudioEmbeddingInputs(type="audio_embeds",
data=audio_embeds)
raise AssertionError("This line should be unreachable.")
def _process_audio_input(
self, audio_input: UltravoxAudioInputs) -> NestedTensors:
if audio_input["type"] == "audio_embeds":
return audio_input["data"]
audio_features = audio_input["data"]
if isinstance(audio_features, torch.Tensor):
# Combine the B and N dimensions for the encoder/projector
flattened = flatten_bn(audio_features)
flattened_embeddings = self._audio_features_to_embeddings(
flattened)
# Restore the original dimensions
embeddings = flattened_embeddings.unflatten(
0, audio_features.shape[:2])
return embeddings
result = []
# TODO: Batch heterogeneous tensors through the encoder/projector
for audio_features_item in audio_features:
if isinstance(audio_features_item, torch.Tensor):
result.append(
self._audio_features_to_embeddings(audio_features_item))
else:
embeddings = [
# Add a batch dimension to embed it, then remove it.
self._audio_features_to_embeddings(tensor.unsqueeze(0)
).squeeze(0)
for tensor in audio_features_item
]
result.append(embeddings)
return result
def forward(self, input_ids: torch.Tensor, positions: torch.Tensor,
kv_caches: List[torch.Tensor],
attn_metadata: AttentionMetadata,
intermediate_tensors: Optional[torch.Tensor],
**kwargs) -> SamplerOutput:
"""Run forward pass for Ultravox
One key thing to understand is the `input_ids` already accounts for the
positions of the to-be-inserted audio embeddings. The to-be-inserted
audio has a size that is essentially 6.25 tokens per second of audio.
This way, the `positions` and `attn_metadata` are consistent
with the `input_ids`.
Args:
audio_features: A batch of audio inputs [B, N, 80, M].
"""
audio_input = self._parse_and_validate_audio_input(**kwargs)
if audio_input is not None:
audio_embeddings = self._process_audio_input(audio_input)
inputs_embeds = self.language_model.model.get_input_embeddings(
input_ids)
inputs_embeds = merge_multimodal_embeddings(
input_ids, inputs_embeds, audio_embeddings,
_AUDIO_PLACEHOLDER_TOKEN)
input_ids = None
else:
inputs_embeds = None
hidden_states = self.language_model.model(
input_ids=input_ids,
positions=positions,
kv_caches=kv_caches,
attn_metadata=attn_metadata,
intermediate_tensors=intermediate_tensors,
inputs_embeds=inputs_embeds)
return hidden_states
def compute_logits(self, hidden_states: torch.Tensor,
sampling_metadata: SamplingMetadata) -> torch.Tensor:
return self.language_model.compute_logits(hidden_states,
sampling_metadata)
def sample(
self,
logits: torch.Tensor,
sampling_metadata: SamplingMetadata,
) -> Optional[SamplerOutput]:
return self.language_model.sample(logits, sampling_metadata)
def load_weights(self, weights: Iterable[Tuple[str, torch.Tensor]]):
# prepare weight iterators for components
weights_group = group_weights_with_prefix(weights)
# load projector weights
projector_weights = weights_group["multi_modal_projector"]
projector_params_dict = dict(
self.multi_modal_projector.named_parameters())
for name, loaded_weight in projector_weights:
param = projector_params_dict[name]
weight_loader = getattr(param, "weight_loader",
default_weight_loader)
weight_loader(param, loaded_weight)
# load llm backbone
self.language_model.load_weights(weights_group["language_model"])