audio_language.py

# SPDX-License-Identifier: Apache-2.0
"""
This example shows how to use vLLM for running offline inference 
with the correct prompt format on audio language models.

For most models, the prompt format should follow corresponding examples
on HuggingFace model repository.
"""
import os
from dataclasses import asdict
from typing import NamedTuple, Optional

from huggingface_hub import snapshot_download
from transformers import AutoTokenizer

from vllm import LLM, EngineArgs, SamplingParams
from vllm.assets.audio import AudioAsset
from vllm.lora.request import LoRARequest
from vllm.utils import FlexibleArgumentParser

audio_assets = [AudioAsset("mary_had_lamb"), AudioAsset("winning_call")]
question_per_audio_count = {
    0: "What is 1+1?",
    1: "What is recited in the audio?",
    2: "What sport and what nursery rhyme are referenced?"
}


class ModelRequestData(NamedTuple):
    engine_args: EngineArgs
    prompt: str
    stop_token_ids: Optional[list[int]] = None
    lora_requests: Optional[list[LoRARequest]] = None


# NOTE: The default `max_num_seqs` and `max_model_len` may result in OOM on
# lower-end GPUs.
# Unless specified, these settings have been tested to work on a single L4.


# MiniCPM-O
def run_minicpmo(question: str, audio_count: int) -> ModelRequestData:
    model_name = "openbmb/MiniCPM-o-2_6"
    tokenizer = AutoTokenizer.from_pretrained(model_name,
                                              trust_remote_code=True)
    engine_args = EngineArgs(
        model=model_name,
        trust_remote_code=True,
        max_model_len=4096,
        max_num_seqs=2,
        limit_mm_per_prompt={"audio": audio_count},
    )

    stop_tokens = ['<|im_end|>', '<|endoftext|>']
    stop_token_ids = [tokenizer.convert_tokens_to_ids(i) for i in stop_tokens]

    audio_placeholder = "(<audio>./</audio>)" * audio_count
    audio_chat_template = "{% for message in messages %}{{'<|im_start|>' + message['role'] + '\n' + message['content'] + '<|im_end|>' + '\n'}}{% endfor %}{% if add_generation_prompt %}{{ '<|im_start|>assistant\n<|spk_bos|><|spk|><|spk_eos|><|tts_bos|>' }}{% endif %}"  # noqa: E501
    messages = [{
        'role': 'user',
        'content': f'{audio_placeholder}\n{question}'
    }]
    prompt = tokenizer.apply_chat_template(messages,
                                           tokenize=False,
                                           add_generation_prompt=True,
                                           chat_template=audio_chat_template)

    return ModelRequestData(
        engine_args=engine_args,
        prompt=prompt,
        stop_token_ids=stop_token_ids,
    )


# Phi-4-multimodal-instruct
def run_phi4mm(question: str, audio_count: int) -> ModelRequestData:
    """
    Phi-4-multimodal-instruct supports both image and audio inputs. Here, we
    show how to process audio inputs.
    """
    model_path = snapshot_download("microsoft/Phi-4-multimodal-instruct")
    # Since the vision-lora and speech-lora co-exist with the base model,
    # we have to manually specify the path of the lora weights.
    speech_lora_path = os.path.join(model_path, "speech-lora")
    placeholders = "".join([f"<|audio_{i+1}|>" for i in range(audio_count)])

    prompts = f"<|user|>{placeholders}{question}<|end|><|assistant|>"

    engine_args = EngineArgs(
        model=model_path,
        trust_remote_code=True,
        max_model_len=4096,
        max_num_seqs=2,
        enable_lora=True,
        max_lora_rank=320,
        limit_mm_per_prompt={"audio": audio_count},
    )

    return ModelRequestData(
        engine_args=engine_args,
        prompt=prompts,
        lora_requests=[LoRARequest("speech", 1, speech_lora_path)],
    )


# Qwen2-Audio
def run_qwen2_audio(question: str, audio_count: int) -> ModelRequestData:
    model_name = "Qwen/Qwen2-Audio-7B-Instruct"

    engine_args = EngineArgs(
        model=model_name,
        max_model_len=4096,
        max_num_seqs=5,
        limit_mm_per_prompt={"audio": audio_count},
    )

    audio_in_prompt = "".join([
        f"Audio {idx+1}: "
        f"<|audio_bos|><|AUDIO|><|audio_eos|>\n" for idx in range(audio_count)
    ])

    prompt = ("<|im_start|>system\nYou are a helpful assistant.<|im_end|>\n"
              "<|im_start|>user\n"
              f"{audio_in_prompt}{question}<|im_end|>\n"
              "<|im_start|>assistant\n")

    return ModelRequestData(
        engine_args=engine_args,
        prompt=prompt,
    )


# Ultravox 0.5-1B
def run_ultravox(question: str, audio_count: int) -> ModelRequestData:
    model_name = "fixie-ai/ultravox-v0_5-llama-3_2-1b"

    tokenizer = AutoTokenizer.from_pretrained(model_name)
    messages = [{
        'role': 'user',
        'content': "<|audio|>\n" * audio_count + question
    }]
    prompt = tokenizer.apply_chat_template(messages,
                                           tokenize=False,
                                           add_generation_prompt=True)

    engine_args = EngineArgs(
        model=model_name,
        max_model_len=4096,
        max_num_seqs=5,
        trust_remote_code=True,
        limit_mm_per_prompt={"audio": audio_count},
    )

    return ModelRequestData(
        engine_args=engine_args,
        prompt=prompt,
    )


# Whisper
def run_whisper(question: str, audio_count: int) -> ModelRequestData:
    assert audio_count == 1, (
        "Whisper only support single audio input per prompt")
    model_name = "openai/whisper-large-v3-turbo"

    prompt = "<|startoftranscript|>"

    engine_args = EngineArgs(
        model=model_name,
        max_model_len=448,
        max_num_seqs=5,
        limit_mm_per_prompt={"audio": audio_count},
    )

    return ModelRequestData(
        engine_args=engine_args,
        prompt=prompt,
    )


model_example_map = {
    "minicpmo": run_minicpmo,
    "phi4_mm": run_phi4mm,
    "qwen2_audio": run_qwen2_audio,
    "ultravox": run_ultravox,
    "whisper": run_whisper,
}


def main(args):
    model = args.model_type
    if model not in model_example_map:
        raise ValueError(f"Model type {model} is not supported.")

    audio_count = args.num_audios
    req_data = model_example_map[model](question_per_audio_count[audio_count],
                                        audio_count)

    engine_args = asdict(req_data.engine_args) | {"seed": args.seed}
    llm = LLM(**engine_args)

    # To maintain code compatibility in this script, we add LoRA here.
    # You can also add LoRA using:
    # llm.generate(prompts, lora_request=lora_request,...)
    if req_data.lora_requests:
        for lora_request in req_data.lora_requests:
            llm.llm_engine.add_lora(lora_request=lora_request)

    # We set temperature to 0.2 so that outputs can be different
    # even when all prompts are identical when running batch inference.
    sampling_params = SamplingParams(temperature=0.2,
                                     max_tokens=64,
                                     stop_token_ids=req_data.stop_token_ids)

    mm_data = {}
    if audio_count > 0:
        mm_data = {
            "audio": [
                asset.audio_and_sample_rate
                for asset in audio_assets[:audio_count]
            ]
        }

    assert args.num_prompts > 0
    inputs = {"prompt": req_data.prompt, "multi_modal_data": mm_data}
    if args.num_prompts > 1:
        # Batch inference
        inputs = [inputs] * args.num_prompts

    outputs = llm.generate(inputs, sampling_params=sampling_params)

    for o in outputs:
        generated_text = o.outputs[0].text
        print(generated_text)


if __name__ == "__main__":
    parser = FlexibleArgumentParser(
        description='Demo on using vLLM for offline inference with '
        'audio language models')
    parser.add_argument('--model-type',
                        '-m',
                        type=str,
                        default="ultravox",
                        choices=model_example_map.keys(),
                        help='Huggingface "model_type".')
    parser.add_argument('--num-prompts',
                        type=int,
                        default=1,
                        help='Number of prompts to run.')
    parser.add_argument("--num-audios",
                        type=int,
                        default=1,
                        choices=[0, 1, 2],
                        help="Number of audio items per prompt.")
    parser.add_argument("--seed",
                        type=int,
                        default=None,
                        help="Set the seed when initializing `vllm.LLM`.")

    args = parser.parse_args()
    main(args)