app.py

import spaces
import gradio as gr
import librosa
import torch

from transformers import Wav2Vec2ForCTC, AutoProcessor
from huggingface_hub import hf_hub_download
from torchaudio.models.decoder import ctc_decoder
# https://github.com/facebookresearch/fairseq/tree/main/examples/mms/zero_shot

ASR_SAMPLING_RATE = 16_000

WORD_SCORE_DEFAULT_IF_LM = -0.18
WORD_SCORE_DEFAULT_IF_NOLM = -3.5
LM_SCORE_DEFAULT = 1.48

MODEL_ID = "mms-meta/mms-zeroshot-300m"

processor = AutoProcessor.from_pretrained(MODEL_ID)
model = Wav2Vec2ForCTC.from_pretrained(MODEL_ID)

token_file = hf_hub_download(
    repo_id=MODEL_ID,
    filename="tokens.txt",
)

lm5gram =  hf_hub_download(
    repo_id="alakxender/w2v-bert-2.0-dhivehi-syn",
    filename="language_model/5gram.bin",
)

lex_files = [
    "dv.domain.news.small.v1.lexicon",
    "dv.domain.news.small.v2.lexicon",
    "dv.domain.news.large.v1.lexicon",
    "dv.domain.stories.small.v1.lexicon",
]

lexicon_file =  hf_hub_download(
    repo_type="dataset",
    repo_id="alakxender/dv-domain-lexicons",
    filename=lex_files[0],
)

@spaces.GPU
def transcribe(
    audio_data,
    wscore=None,
    lmscore=None,
    wscore_usedefault=True,
    lmscore_usedefault=True,
    uselm=True,
    reference=None,
):

    if not audio_data:
        yield "ERROR: Empty audio data"
        return

    # audio
    if isinstance(audio_data, tuple):
        # microphone
        sr, audio_samples = audio_data
        audio_samples = (audio_samples / 32768.0).astype(float)

        if sr != ASR_SAMPLING_RATE:
            audio_samples = librosa.resample(
                audio_samples, orig_sr=sr, target_sr=ASR_SAMPLING_RATE
            )
    else:
        # file upload
        assert isinstance(audio_data, str)
        audio_samples = librosa.load(audio_data, sr=ASR_SAMPLING_RATE, mono=True)[0]

    inputs = processor(
        audio_samples, sampling_rate=ASR_SAMPLING_RATE, return_tensors="pt"
    )

    # set device
    if torch.cuda.is_available():
        device = torch.device("cuda")
    else:
        device = torch.device("cpu")

    model.to(device)
    inputs = inputs.to(device)

    with torch.no_grad():
        outputs = model(**inputs).logits
        
    # params
    if uselm == True:
        lm_path=lm5gram
    else:
        lm_path=None
    
    if lm_path is not None and not lm_path.strip():
        lm_path = None

    if wscore_usedefault:
        wscore = (
            WORD_SCORE_DEFAULT_IF_LM
            if lm_path is not None
            else WORD_SCORE_DEFAULT_IF_NOLM
        )
    if lmscore_usedefault:
        lmscore = LM_SCORE_DEFAULT if lm_path is not None else 0

    beam_search_decoder = ctc_decoder(
            lexicon=lexicon_file,
            tokens=token_file,
            lm=lm_path,
            nbest=1,
            beam_size=500,
            beam_size_token=50,
            lm_weight=lmscore,
            word_score=wscore,
            sil_score=0,
            blank_token="<s>",
        )

    beam_search_result = beam_search_decoder(outputs.to("cpu"))
    transcription = " ".join(beam_search_result[0][0].words).strip()

    yield transcription

styles = """
.thaana textarea {
    font-size: 18px !important;
    font-family: 'MV_Faseyha', 'Faruma', 'A_Faruma' !important;
    line-height: 1.8 !important;
}
.textbox2 textarea {
    display: none;
}
"""

with gr.Blocks(css=styles) as demo:
    gr.Markdown("# <center> Transcribe Dhivehi Audio with MMS-ZEROSHOT</center>")
    with gr.Row():
        with gr.Column():
            audio = gr.Audio(label="Audio Input\n(use microphone or upload a file)",min_length=1,max_length=60)

            with gr.Accordion("Advanced Settings", open=False):
                gr.Markdown(
                    "The following parameters are used for beam-search decoding. Use the default values if you are not sure."
                )
                with gr.Row(): 
                    with gr.Column():
                        wscore_usedefault = gr.Checkbox(
                            label="Use Default Word Insertion Score", value=True
                        )
                        wscore = gr.Slider(
                            minimum=-10.0,
                            maximum=10.0,
                            value=WORD_SCORE_DEFAULT_IF_LM,
                            step=0.1,
                            interactive=False,
                            label="Word Insertion Score",
                        )

                    with gr.Column():
                        lmscore_usedefault = gr.Checkbox(
                            label="Use Default Language Model Score", value=True
                        )
                        lmscore = gr.Slider(
                            minimum=-10.0,
                            maximum=10.0,
                            value=LM_SCORE_DEFAULT,
                            step=0.1,
                            interactive=False,
                            label="Language Model Score",
                        )
                    with gr.Column():
                        uselm = gr.Checkbox(
                            label="Use LM",
                            value=True,
                        )
            btn = gr.Button("Submit", elem_id="submit")

            @gr.on(
                inputs=[wscore_usedefault, lmscore_usedefault, uselm],
                outputs=[wscore, lmscore],
            )
            def update_slider(ws, ls, lm, alm):

                ws_slider = gr.Slider(
                    minimum=-10.0,
                    maximum=10.0,
                    value=LM_SCORE_DEFAULT if (lm is not None or alm) else 0,
                    step=0.1,
                    interactive=not ws,
                    label="Word Insertion Score",
                )
                ls_slider = gr.Slider(
                    minimum=-10.0,
                    maximum=10.0,
                    value=WORD_SCORE_DEFAULT_IF_NOLM
                    if (lm is None and not alm)
                    else WORD_SCORE_DEFAULT_IF_LM,
                    step=0.1,
                    interactive=not ls,
                    label="Language Model Score",
                )
                return ws_slider, ls_slider

        with gr.Column():
            text = gr.Textbox(label="Transcript",rtl=True,elem_classes="thaana")

    reference = gr.Textbox(label="Reference Transcript", visible=False)

    btn.click(
        transcribe,
        inputs=[
            audio,
            wscore,
            lmscore,
            wscore_usedefault,
            lmscore_usedefault,
            uselm,
            reference,
        ],
        outputs=[text],
    )

    # Examples
    gr.Examples(
        examples=[
            [
                "samples/audio1.mp3",
                "އަޅުގަނޑުވެސް ދާކަށް ބޭނުމެއްނުވި"
            ],
            [
                "samples/audio2.wav",
                "ރަނގަޅަށްވިއްޔާ އެވާނީ މުސްކުޅި ކުރެހުމަކަށް"
            ],

            [
                "samples/audio3.wav",
                "އެއީ ޞަހްޔޫނީންގެ ޒަމާންވީ ރޭވުމެއްގެ ދަށުން މެދުނުކެނޑި ކުރިއަށްވާ ޕްރޮގްރާމެއް"
            ],
        ],
        inputs=[audio, reference],
        label="Dhivehi Audio Samples",
    )
  
demo.launch(show_api=False)