funasr_detach/models/fsmn_vad_streaming/model.py

#!/usr/bin/env python3
# -*- encoding: utf-8 -*-
# Copyright FunASR (https://github.com/alibaba-damo-academy/FunASR). All Rights Reserved.
#  MIT License  (https://opensource.org/licenses/MIT)

import os
import json
import time
import math
import torch
from torch import nn
from enum import Enum
from dataclasses import dataclass
from funasr_detach.register import tables
from typing import List, Tuple, Dict, Any, Optional

from funasr_detach.utils.datadir_writer import DatadirWriter
from funasr_detach.utils.load_utils import load_audio_text_image_video, extract_fbank


class VadStateMachine(Enum):
    kVadInStateStartPointNotDetected = 1
    kVadInStateInSpeechSegment = 2
    kVadInStateEndPointDetected = 3


class FrameState(Enum):
    kFrameStateInvalid = -1
    kFrameStateSpeech = 1
    kFrameStateSil = 0


# final voice/unvoice state per frame
class AudioChangeState(Enum):
    kChangeStateSpeech2Speech = 0
    kChangeStateSpeech2Sil = 1
    kChangeStateSil2Sil = 2
    kChangeStateSil2Speech = 3
    kChangeStateNoBegin = 4
    kChangeStateInvalid = 5


class VadDetectMode(Enum):
    kVadSingleUtteranceDetectMode = 0
    kVadMutipleUtteranceDetectMode = 1


class VADXOptions:
    """
    Author: Speech Lab of DAMO Academy, Alibaba Group
    Deep-FSMN for Large Vocabulary Continuous Speech Recognition
    https://arxiv.org/abs/1803.05030
    """

    def __init__(
        self,
        sample_rate: int = 16000,
        detect_mode: int = VadDetectMode.kVadMutipleUtteranceDetectMode.value,
        snr_mode: int = 0,
        max_end_silence_time: int = 800,
        max_start_silence_time: int = 3000,
        do_start_point_detection: bool = True,
        do_end_point_detection: bool = True,
        window_size_ms: int = 200,
        sil_to_speech_time_thres: int = 150,
        speech_to_sil_time_thres: int = 150,
        speech_2_noise_ratio: float = 1.0,
        do_extend: int = 1,
        lookback_time_start_point: int = 200,
        lookahead_time_end_point: int = 100,
        max_single_segment_time: int = 60000,
        nn_eval_block_size: int = 8,
        dcd_block_size: int = 4,
        snr_thres: int = -100.0,
        noise_frame_num_used_for_snr: int = 100,
        decibel_thres: int = -100.0,
        speech_noise_thres: float = 0.6,
        fe_prior_thres: float = 1e-4,
        silence_pdf_num: int = 1,
        sil_pdf_ids: List[int] = [0],
        speech_noise_thresh_low: float = -0.1,
        speech_noise_thresh_high: float = 0.3,
        output_frame_probs: bool = False,
        frame_in_ms: int = 10,
        frame_length_ms: int = 25,
        **kwargs,
    ):
        self.sample_rate = sample_rate
        self.detect_mode = detect_mode
        self.snr_mode = snr_mode
        self.max_end_silence_time = max_end_silence_time
        self.max_start_silence_time = max_start_silence_time
        self.do_start_point_detection = do_start_point_detection
        self.do_end_point_detection = do_end_point_detection
        self.window_size_ms = window_size_ms
        self.sil_to_speech_time_thres = sil_to_speech_time_thres
        self.speech_to_sil_time_thres = speech_to_sil_time_thres
        self.speech_2_noise_ratio = speech_2_noise_ratio
        self.do_extend = do_extend
        self.lookback_time_start_point = lookback_time_start_point
        self.lookahead_time_end_point = lookahead_time_end_point
        self.max_single_segment_time = max_single_segment_time
        self.nn_eval_block_size = nn_eval_block_size
        self.dcd_block_size = dcd_block_size
        self.snr_thres = snr_thres
        self.noise_frame_num_used_for_snr = noise_frame_num_used_for_snr
        self.decibel_thres = decibel_thres
        self.speech_noise_thres = speech_noise_thres
        self.fe_prior_thres = fe_prior_thres
        self.silence_pdf_num = silence_pdf_num
        self.sil_pdf_ids = sil_pdf_ids
        self.speech_noise_thresh_low = speech_noise_thresh_low
        self.speech_noise_thresh_high = speech_noise_thresh_high
        self.output_frame_probs = output_frame_probs
        self.frame_in_ms = frame_in_ms
        self.frame_length_ms = frame_length_ms


class E2EVadSpeechBufWithDoa(object):
    """
    Author: Speech Lab of DAMO Academy, Alibaba Group
    Deep-FSMN for Large Vocabulary Continuous Speech Recognition
    https://arxiv.org/abs/1803.05030
    """

    def __init__(self):
        self.start_ms = 0
        self.end_ms = 0
        self.buffer = []
        self.contain_seg_start_point = False
        self.contain_seg_end_point = False
        self.doa = 0

    def Reset(self):
        self.start_ms = 0
        self.end_ms = 0
        self.buffer = []
        self.contain_seg_start_point = False
        self.contain_seg_end_point = False
        self.doa = 0


class E2EVadFrameProb(object):
    """
    Author: Speech Lab of DAMO Academy, Alibaba Group
    Deep-FSMN for Large Vocabulary Continuous Speech Recognition
    https://arxiv.org/abs/1803.05030
    """

    def __init__(self):
        self.noise_prob = 0.0
        self.speech_prob = 0.0
        self.score = 0.0
        self.frame_id = 0
        self.frm_state = 0


class WindowDetector(object):
    """
    Author: Speech Lab of DAMO Academy, Alibaba Group
    Deep-FSMN for Large Vocabulary Continuous Speech Recognition
    https://arxiv.org/abs/1803.05030
    """

    def __init__(
        self,
        window_size_ms: int,
        sil_to_speech_time: int,
        speech_to_sil_time: int,
        frame_size_ms: int,
    ):
        self.window_size_ms = window_size_ms
        self.sil_to_speech_time = sil_to_speech_time
        self.speech_to_sil_time = speech_to_sil_time
        self.frame_size_ms = frame_size_ms

        self.win_size_frame = int(window_size_ms / frame_size_ms)
        self.win_sum = 0
        self.win_state = [0] * self.win_size_frame  # 初始化窗

        self.cur_win_pos = 0
        self.pre_frame_state = FrameState.kFrameStateSil
        self.cur_frame_state = FrameState.kFrameStateSil
        self.sil_to_speech_frmcnt_thres = int(sil_to_speech_time / frame_size_ms)
        self.speech_to_sil_frmcnt_thres = int(speech_to_sil_time / frame_size_ms)

        self.voice_last_frame_count = 0
        self.noise_last_frame_count = 0
        self.hydre_frame_count = 0

    def Reset(self) -> None:
        self.cur_win_pos = 0
        self.win_sum = 0
        self.win_state = [0] * self.win_size_frame
        self.pre_frame_state = FrameState.kFrameStateSil
        self.cur_frame_state = FrameState.kFrameStateSil
        self.voice_last_frame_count = 0
        self.noise_last_frame_count = 0
        self.hydre_frame_count = 0

    def GetWinSize(self) -> int:
        return int(self.win_size_frame)

    def DetectOneFrame(
        self, frameState: FrameState, frame_count: int, cache: dict = {}
    ) -> AudioChangeState:
        cur_frame_state = FrameState.kFrameStateSil
        if frameState == FrameState.kFrameStateSpeech:
            cur_frame_state = 1
        elif frameState == FrameState.kFrameStateSil:
            cur_frame_state = 0
        else:
            return AudioChangeState.kChangeStateInvalid
        self.win_sum -= self.win_state[self.cur_win_pos]
        self.win_sum += cur_frame_state
        self.win_state[self.cur_win_pos] = cur_frame_state
        self.cur_win_pos = (self.cur_win_pos + 1) % self.win_size_frame

        if (
            self.pre_frame_state == FrameState.kFrameStateSil
            and self.win_sum >= self.sil_to_speech_frmcnt_thres
        ):
            self.pre_frame_state = FrameState.kFrameStateSpeech
            return AudioChangeState.kChangeStateSil2Speech

        if (
            self.pre_frame_state == FrameState.kFrameStateSpeech
            and self.win_sum <= self.speech_to_sil_frmcnt_thres
        ):
            self.pre_frame_state = FrameState.kFrameStateSil
            return AudioChangeState.kChangeStateSpeech2Sil

        if self.pre_frame_state == FrameState.kFrameStateSil:
            return AudioChangeState.kChangeStateSil2Sil
        if self.pre_frame_state == FrameState.kFrameStateSpeech:
            return AudioChangeState.kChangeStateSpeech2Speech
        return AudioChangeState.kChangeStateInvalid

    def FrameSizeMs(self) -> int:
        return int(self.frame_size_ms)


class Stats(object):
    def __init__(
        self,
        sil_pdf_ids,
        max_end_sil_frame_cnt_thresh,
        speech_noise_thres,
    ):
        self.data_buf_start_frame = 0
        self.frm_cnt = 0
        self.latest_confirmed_speech_frame = 0
        self.lastest_confirmed_silence_frame = -1
        self.continous_silence_frame_count = 0
        self.vad_state_machine = VadStateMachine.kVadInStateStartPointNotDetected
        self.confirmed_start_frame = -1
        self.confirmed_end_frame = -1
        self.number_end_time_detected = 0
        self.sil_frame = 0
        self.sil_pdf_ids = sil_pdf_ids
        self.noise_average_decibel = -100.0
        self.pre_end_silence_detected = False
        self.next_seg = True

        self.output_data_buf = []
        self.output_data_buf_offset = 0
        self.frame_probs = []
        self.max_end_sil_frame_cnt_thresh = max_end_sil_frame_cnt_thresh
        self.speech_noise_thres = speech_noise_thres
        self.scores = None
        self.max_time_out = False
        self.decibel = []
        self.data_buf = None
        self.data_buf_all = None
        self.waveform = None
        self.last_drop_frames = 0


@tables.register("model_classes", "FsmnVADStreaming")
class FsmnVADStreaming(nn.Module):
    """
    Author: Speech Lab of DAMO Academy, Alibaba Group
    Deep-FSMN for Large Vocabulary Continuous Speech Recognition
    https://arxiv.org/abs/1803.05030
    """

    def __init__(
        self,
        encoder: str = None,
        encoder_conf: Optional[Dict] = None,
        vad_post_args: Dict[str, Any] = None,
        **kwargs,
    ):
        super().__init__()
        self.vad_opts = VADXOptions(**kwargs)

        encoder_class = tables.encoder_classes.get(encoder)
        encoder = encoder_class(**encoder_conf)
        self.encoder = encoder

    def ResetDetection(self, cache: dict = {}):
        cache["stats"].continous_silence_frame_count = 0
        cache["stats"].latest_confirmed_speech_frame = 0
        cache["stats"].lastest_confirmed_silence_frame = -1
        cache["stats"].confirmed_start_frame = -1
        cache["stats"].confirmed_end_frame = -1
        cache["stats"].vad_state_machine = (
            VadStateMachine.kVadInStateStartPointNotDetected
        )
        cache["windows_detector"].Reset()
        cache["stats"].sil_frame = 0
        cache["stats"].frame_probs = []

        if cache["stats"].output_data_buf:
            assert cache["stats"].output_data_buf[-1].contain_seg_end_point == True
            drop_frames = int(
                cache["stats"].output_data_buf[-1].end_ms / self.vad_opts.frame_in_ms
            )
            real_drop_frames = drop_frames - cache["stats"].last_drop_frames
            cache["stats"].last_drop_frames = drop_frames
            cache["stats"].data_buf_all = cache["stats"].data_buf_all[
                real_drop_frames
                * int(self.vad_opts.frame_in_ms * self.vad_opts.sample_rate / 1000) :
            ]
            cache["stats"].decibel = cache["stats"].decibel[real_drop_frames:]
            cache["stats"].scores = cache["stats"].scores[:, real_drop_frames:, :]

    def ComputeDecibel(self, cache: dict = {}) -> None:
        frame_sample_length = int(
            self.vad_opts.frame_length_ms * self.vad_opts.sample_rate / 1000
        )
        frame_shift_length = int(
            self.vad_opts.frame_in_ms * self.vad_opts.sample_rate / 1000
        )
        if cache["stats"].data_buf_all is None:
            cache["stats"].data_buf_all = cache["stats"].waveform[
                0
            ]  # cache["stats"].data_buf is pointed to cache["stats"].waveform[0]
            cache["stats"].data_buf = cache["stats"].data_buf_all
        else:
            cache["stats"].data_buf_all = torch.cat(
                (cache["stats"].data_buf_all, cache["stats"].waveform[0])
            )
        for offset in range(
            0,
            cache["stats"].waveform.shape[1] - frame_sample_length + 1,
            frame_shift_length,
        ):
            cache["stats"].decibel.append(
                10
                * math.log10(
                    (cache["stats"].waveform[0][offset : offset + frame_sample_length])
                    .square()
                    .sum()
                    + 0.000001
                )
            )

    def ComputeScores(self, feats: torch.Tensor, cache: dict = {}) -> None:
        scores = self.encoder(feats, cache=cache["encoder"]).to(
            "cpu"
        )  # return B * T * D
        assert (
            scores.shape[1] == feats.shape[1]
        ), "The shape between feats and scores does not match"
        self.vad_opts.nn_eval_block_size = scores.shape[1]
        cache["stats"].frm_cnt += scores.shape[1]  # count total frames
        if cache["stats"].scores is None:
            cache["stats"].scores = scores  # the first calculation
        else:
            cache["stats"].scores = torch.cat((cache["stats"].scores, scores), dim=1)

    def PopDataBufTillFrame(
        self, frame_idx: int, cache: dict = {}
    ) -> None:  # need check again
        while cache["stats"].data_buf_start_frame < frame_idx:
            if len(cache["stats"].data_buf) >= int(
                self.vad_opts.frame_in_ms * self.vad_opts.sample_rate / 1000
            ):
                cache["stats"].data_buf_start_frame += 1
                cache["stats"].data_buf = cache["stats"].data_buf_all[
                    (
                        cache["stats"].data_buf_start_frame
                        - cache["stats"].last_drop_frames
                    )
                    * int(
                        self.vad_opts.frame_in_ms * self.vad_opts.sample_rate / 1000
                    ) :
                ]

    def PopDataToOutputBuf(
        self,
        start_frm: int,
        frm_cnt: int,
        first_frm_is_start_point: bool,
        last_frm_is_end_point: bool,
        end_point_is_sent_end: bool,
        cache: dict = {},
    ) -> None:
        self.PopDataBufTillFrame(start_frm, cache=cache)
        expected_sample_number = int(
            frm_cnt * self.vad_opts.sample_rate * self.vad_opts.frame_in_ms / 1000
        )
        if last_frm_is_end_point:
            extra_sample = max(
                0,
                int(
                    self.vad_opts.frame_length_ms * self.vad_opts.sample_rate / 1000
                    - self.vad_opts.sample_rate * self.vad_opts.frame_in_ms / 1000
                ),
            )
            expected_sample_number += int(extra_sample)
        if end_point_is_sent_end:
            expected_sample_number = max(
                expected_sample_number, len(cache["stats"].data_buf)
            )
        if len(cache["stats"].data_buf) < expected_sample_number:
            print("error in calling pop data_buf\n")

        if len(cache["stats"].output_data_buf) == 0 or first_frm_is_start_point:
            cache["stats"].output_data_buf.append(E2EVadSpeechBufWithDoa())
            cache["stats"].output_data_buf[-1].Reset()
            cache["stats"].output_data_buf[-1].start_ms = (
                start_frm * self.vad_opts.frame_in_ms
            )
            cache["stats"].output_data_buf[-1].end_ms = (
                cache["stats"].output_data_buf[-1].start_ms
            )
            cache["stats"].output_data_buf[-1].doa = 0
        cur_seg = cache["stats"].output_data_buf[-1]
        if cur_seg.end_ms != start_frm * self.vad_opts.frame_in_ms:
            print("warning\n")
        out_pos = len(cur_seg.buffer)  # cur_seg.buff现在没做任何操作
        data_to_pop = 0
        if end_point_is_sent_end:
            data_to_pop = expected_sample_number
        else:
            data_to_pop = int(
                frm_cnt * self.vad_opts.frame_in_ms * self.vad_opts.sample_rate / 1000
            )
        if data_to_pop > len(cache["stats"].data_buf):
            print('VAD data_to_pop is bigger than cache["stats"].data_buf.size()!!!\n')
            data_to_pop = len(cache["stats"].data_buf)
            expected_sample_number = len(cache["stats"].data_buf)

        cur_seg.doa = 0
        for sample_cpy_out in range(0, data_to_pop):
            # cur_seg.buffer[out_pos ++] = data_buf_.back();
            out_pos += 1
        for sample_cpy_out in range(data_to_pop, expected_sample_number):
            # cur_seg.buffer[out_pos++] = data_buf_.back()
            out_pos += 1
        if cur_seg.end_ms != start_frm * self.vad_opts.frame_in_ms:
            print("Something wrong with the VAD algorithm\n")
        cache["stats"].data_buf_start_frame += frm_cnt
        cur_seg.end_ms = (start_frm + frm_cnt) * self.vad_opts.frame_in_ms
        if first_frm_is_start_point:
            cur_seg.contain_seg_start_point = True
        if last_frm_is_end_point:
            cur_seg.contain_seg_end_point = True

    def OnSilenceDetected(self, valid_frame: int, cache: dict = {}):
        cache["stats"].lastest_confirmed_silence_frame = valid_frame
        if (
            cache["stats"].vad_state_machine
            == VadStateMachine.kVadInStateStartPointNotDetected
        ):
            self.PopDataBufTillFrame(valid_frame, cache=cache)

    # silence_detected_callback_
    # pass

    def OnVoiceDetected(self, valid_frame: int, cache: dict = {}) -> None:
        cache["stats"].latest_confirmed_speech_frame = valid_frame
        self.PopDataToOutputBuf(valid_frame, 1, False, False, False, cache=cache)

    def OnVoiceStart(
        self, start_frame: int, fake_result: bool = False, cache: dict = {}
    ) -> None:
        if self.vad_opts.do_start_point_detection:
            pass
        if cache["stats"].confirmed_start_frame != -1:
            print("not reset vad properly\n")
        else:
            cache["stats"].confirmed_start_frame = start_frame

        if (
            not fake_result
            and cache["stats"].vad_state_machine
            == VadStateMachine.kVadInStateStartPointNotDetected
        ):
            self.PopDataToOutputBuf(
                cache["stats"].confirmed_start_frame, 1, True, False, False, cache=cache
            )

    def OnVoiceEnd(
        self, end_frame: int, fake_result: bool, is_last_frame: bool, cache: dict = {}
    ) -> None:
        for t in range(cache["stats"].latest_confirmed_speech_frame + 1, end_frame):
            self.OnVoiceDetected(t, cache=cache)
        if self.vad_opts.do_end_point_detection:
            pass
        if cache["stats"].confirmed_end_frame != -1:
            print("not reset vad properly\n")
        else:
            cache["stats"].confirmed_end_frame = end_frame
        if not fake_result:
            cache["stats"].sil_frame = 0
            self.PopDataToOutputBuf(
                cache["stats"].confirmed_end_frame,
                1,
                False,
                True,
                is_last_frame,
                cache=cache,
            )
        cache["stats"].number_end_time_detected += 1

    def MaybeOnVoiceEndIfLastFrame(
        self, is_final_frame: bool, cur_frm_idx: int, cache: dict = {}
    ) -> None:
        if is_final_frame:
            self.OnVoiceEnd(cur_frm_idx, False, True, cache=cache)
            cache["stats"].vad_state_machine = (
                VadStateMachine.kVadInStateEndPointDetected
            )

    def GetLatency(self, cache: dict = {}) -> int:
        return int(
            self.LatencyFrmNumAtStartPoint(cache=cache) * self.vad_opts.frame_in_ms
        )

    def LatencyFrmNumAtStartPoint(self, cache: dict = {}) -> int:
        vad_latency = cache["windows_detector"].GetWinSize()
        if self.vad_opts.do_extend:
            vad_latency += int(
                self.vad_opts.lookback_time_start_point / self.vad_opts.frame_in_ms
            )
        return vad_latency

    def GetFrameState(self, t: int, cache: dict = {}):
        frame_state = FrameState.kFrameStateInvalid
        cur_decibel = cache["stats"].decibel[t]
        cur_snr = cur_decibel - cache["stats"].noise_average_decibel
        # for each frame, calc log posterior probability of each state
        if cur_decibel < self.vad_opts.decibel_thres:
            frame_state = FrameState.kFrameStateSil
            self.DetectOneFrame(frame_state, t, False, cache=cache)
            return frame_state

        sum_score = 0.0
        noise_prob = 0.0
        assert len(cache["stats"].sil_pdf_ids) == self.vad_opts.silence_pdf_num
        if len(cache["stats"].sil_pdf_ids) > 0:
            assert len(cache["stats"].scores) == 1  # 只支持batch_size = 1的测试
            sil_pdf_scores = [
                cache["stats"].scores[0][t][sil_pdf_id]
                for sil_pdf_id in cache["stats"].sil_pdf_ids
            ]
            sum_score = sum(sil_pdf_scores)
            noise_prob = math.log(sum_score) * self.vad_opts.speech_2_noise_ratio
            total_score = 1.0
            sum_score = total_score - sum_score
        speech_prob = math.log(sum_score)
        if self.vad_opts.output_frame_probs:
            frame_prob = E2EVadFrameProb()
            frame_prob.noise_prob = noise_prob
            frame_prob.speech_prob = speech_prob
            frame_prob.score = sum_score
            frame_prob.frame_id = t
            cache["stats"].frame_probs.append(frame_prob)
        if (
            math.exp(speech_prob)
            >= math.exp(noise_prob) + cache["stats"].speech_noise_thres
        ):
            if (
                cur_snr >= self.vad_opts.snr_thres
                and cur_decibel >= self.vad_opts.decibel_thres
            ):
                frame_state = FrameState.kFrameStateSpeech
            else:
                frame_state = FrameState.kFrameStateSil
        else:
            frame_state = FrameState.kFrameStateSil
            if cache["stats"].noise_average_decibel < -99.9:
                cache["stats"].noise_average_decibel = cur_decibel
            else:
                cache["stats"].noise_average_decibel = (
                    cur_decibel
                    + cache["stats"].noise_average_decibel
                    * (self.vad_opts.noise_frame_num_used_for_snr - 1)
                ) / self.vad_opts.noise_frame_num_used_for_snr

        return frame_state

    def forward(
        self,
        feats: torch.Tensor,
        waveform: torch.tensor,
        cache: dict = {},
        is_final: bool = False,
        **kwargs,
    ):
        # if len(cache) == 0:
        #     self.AllResetDetection()
        # self.waveform = waveform  # compute decibel for each frame
        cache["stats"].waveform = waveform
        is_streaming_input = kwargs.get("is_streaming_input", True)
        self.ComputeDecibel(cache=cache)
        self.ComputeScores(feats, cache=cache)
        if not is_final:
            self.DetectCommonFrames(cache=cache)
        else:
            self.DetectLastFrames(cache=cache)
        segments = []
        for batch_num in range(0, feats.shape[0]):  # only support batch_size = 1 now
            segment_batch = []
            if len(cache["stats"].output_data_buf) > 0:
                for i in range(
                    cache["stats"].output_data_buf_offset,
                    len(cache["stats"].output_data_buf),
                ):
                    if (
                        is_streaming_input
                    ):  # in this case, return [beg, -1], [], [-1, end], [beg, end]
                        if (
                            not cache["stats"]
                            .output_data_buf[i]
                            .contain_seg_start_point
                        ):
                            continue
                        if (
                            not cache["stats"].next_seg
                            and not cache["stats"]
                            .output_data_buf[i]
                            .contain_seg_end_point
                        ):
                            continue
                        start_ms = (
                            cache["stats"].output_data_buf[i].start_ms
                            if cache["stats"].next_seg
                            else -1
                        )
                        if cache["stats"].output_data_buf[i].contain_seg_end_point:
                            end_ms = cache["stats"].output_data_buf[i].end_ms
                            cache["stats"].next_seg = True
                            cache["stats"].output_data_buf_offset += 1
                        else:
                            end_ms = -1
                            cache["stats"].next_seg = False
                        segment = [start_ms, end_ms]

                    else:  # in this case, return [beg, end]

                        if not is_final and (
                            not cache["stats"]
                            .output_data_buf[i]
                            .contain_seg_start_point
                            or not cache["stats"]
                            .output_data_buf[i]
                            .contain_seg_end_point
                        ):
                            continue
                        segment = [
                            cache["stats"].output_data_buf[i].start_ms,
                            cache["stats"].output_data_buf[i].end_ms,
                        ]
                        cache[
                            "stats"
                        ].output_data_buf_offset += 1  # need update this parameter

                    segment_batch.append(segment)

            if segment_batch:
                segments.append(segment_batch)
        # if is_final:
        #     # reset class variables and clear the dict for the next query
        #     self.AllResetDetection()
        return segments

    def init_cache(self, cache: dict = {}, **kwargs):

        cache["frontend"] = {}
        cache["prev_samples"] = torch.empty(0)
        cache["encoder"] = {}
        windows_detector = WindowDetector(
            self.vad_opts.window_size_ms,
            self.vad_opts.sil_to_speech_time_thres,
            self.vad_opts.speech_to_sil_time_thres,
            self.vad_opts.frame_in_ms,
        )
        windows_detector.Reset()

        stats = Stats(
            sil_pdf_ids=self.vad_opts.sil_pdf_ids,
            max_end_sil_frame_cnt_thresh=self.vad_opts.max_end_silence_time
            - self.vad_opts.speech_to_sil_time_thres,
            speech_noise_thres=self.vad_opts.speech_noise_thres,
        )
        cache["windows_detector"] = windows_detector
        cache["stats"] = stats
        return cache

    def inference(
        self,
        data_in,
        data_lengths=None,
        key: list = None,
        tokenizer=None,
        frontend=None,
        cache: dict = {},
        **kwargs,
    ):

        if len(cache) == 0:
            self.init_cache(cache, **kwargs)

        meta_data = {}
        chunk_size = kwargs.get("chunk_size", 60000)  # 50ms
        chunk_stride_samples = int(chunk_size * frontend.fs / 1000)

        time1 = time.perf_counter()
        is_streaming_input = (
            kwargs.get("is_streaming_input", False)
            if chunk_size >= 15000
            else kwargs.get("is_streaming_input", True)
        )
        is_final = (
            kwargs.get("is_final", False)
            if is_streaming_input
            else kwargs.get("is_final", True)
        )
        cfg = {"is_final": is_final, "is_streaming_input": is_streaming_input}
        audio_sample_list = load_audio_text_image_video(
            data_in,
            fs=frontend.fs,
            audio_fs=kwargs.get("fs", 16000),
            data_type=kwargs.get("data_type", "sound"),
            tokenizer=tokenizer,
            cache=cfg,
        )
        _is_final = cfg["is_final"]  # if data_in is a file or url, set is_final=True
        is_streaming_input = cfg["is_streaming_input"]
        time2 = time.perf_counter()
        meta_data["load_data"] = f"{time2 - time1:0.3f}"
        assert len(audio_sample_list) == 1, "batch_size must be set 1"

        audio_sample = torch.cat((cache["prev_samples"], audio_sample_list[0]))

        n = int(len(audio_sample) // chunk_stride_samples + int(_is_final))
        m = int(len(audio_sample) % chunk_stride_samples * (1 - int(_is_final)))
        segments = []
        for i in range(n):
            kwargs["is_final"] = _is_final and i == n - 1
            audio_sample_i = audio_sample[
                i * chunk_stride_samples : (i + 1) * chunk_stride_samples
            ]

            # extract fbank feats
            speech, speech_lengths = extract_fbank(
                [audio_sample_i],
                data_type=kwargs.get("data_type", "sound"),
                frontend=frontend,
                cache=cache["frontend"],
                is_final=kwargs["is_final"],
            )
            time3 = time.perf_counter()
            meta_data["extract_feat"] = f"{time3 - time2:0.3f}"
            meta_data["batch_data_time"] = (
                speech_lengths.sum().item()
                * frontend.frame_shift
                * frontend.lfr_n
                / 1000
            )
            speech = speech.to(device=kwargs["device"])
            speech_lengths = speech_lengths.to(device=kwargs["device"])

            batch = {
                "feats": speech,
                "waveform": cache["frontend"]["waveforms"],
                "is_final": kwargs["is_final"],
                "cache": cache,
                "is_streaming_input": is_streaming_input,
            }
            segments_i = self.forward(**batch)
            if len(segments_i) > 0:
                segments.extend(*segments_i)

        cache["prev_samples"] = audio_sample[:-m]
        if _is_final:
            self.init_cache(cache)

        ibest_writer = None
        if kwargs.get("output_dir") is not None:
            if not hasattr(self, "writer"):
                self.writer = DatadirWriter(kwargs.get("output_dir"))
            ibest_writer = self.writer[f"{1}best_recog"]

        results = []
        result_i = {"key": key[0], "value": segments}
        if (
            "MODELSCOPE_ENVIRONMENT" in os.environ
            and os.environ["MODELSCOPE_ENVIRONMENT"] == "eas"
        ):
            result_i = json.dumps(result_i)

        results.append(result_i)

        if ibest_writer is not None:
            ibest_writer["text"][key[0]] = segments

        return results, meta_data

    def DetectCommonFrames(self, cache: dict = {}) -> int:
        if (
            cache["stats"].vad_state_machine
            == VadStateMachine.kVadInStateEndPointDetected
        ):
            return 0
        for i in range(self.vad_opts.nn_eval_block_size - 1, -1, -1):
            frame_state = FrameState.kFrameStateInvalid
            frame_state = self.GetFrameState(
                cache["stats"].frm_cnt - 1 - i - cache["stats"].last_drop_frames,
                cache=cache,
            )
            self.DetectOneFrame(
                frame_state, cache["stats"].frm_cnt - 1 - i, False, cache=cache
            )

        return 0

    def DetectLastFrames(self, cache: dict = {}) -> int:
        if (
            cache["stats"].vad_state_machine
            == VadStateMachine.kVadInStateEndPointDetected
        ):
            return 0
        for i in range(self.vad_opts.nn_eval_block_size - 1, -1, -1):
            frame_state = FrameState.kFrameStateInvalid
            frame_state = self.GetFrameState(
                cache["stats"].frm_cnt - 1 - i - cache["stats"].last_drop_frames,
                cache=cache,
            )
            if i != 0:
                self.DetectOneFrame(
                    frame_state, cache["stats"].frm_cnt - 1 - i, False, cache=cache
                )
            else:
                self.DetectOneFrame(
                    frame_state, cache["stats"].frm_cnt - 1, True, cache=cache
                )

        return 0

    def DetectOneFrame(
        self,
        cur_frm_state: FrameState,
        cur_frm_idx: int,
        is_final_frame: bool,
        cache: dict = {},
    ) -> None:
        tmp_cur_frm_state = FrameState.kFrameStateInvalid
        if cur_frm_state == FrameState.kFrameStateSpeech:
            if math.fabs(1.0) > self.vad_opts.fe_prior_thres:
                tmp_cur_frm_state = FrameState.kFrameStateSpeech
            else:
                tmp_cur_frm_state = FrameState.kFrameStateSil
        elif cur_frm_state == FrameState.kFrameStateSil:
            tmp_cur_frm_state = FrameState.kFrameStateSil
        state_change = cache["windows_detector"].DetectOneFrame(
            tmp_cur_frm_state, cur_frm_idx, cache=cache
        )
        frm_shift_in_ms = self.vad_opts.frame_in_ms
        if AudioChangeState.kChangeStateSil2Speech == state_change:
            silence_frame_count = cache["stats"].continous_silence_frame_count
            cache["stats"].continous_silence_frame_count = 0
            cache["stats"].pre_end_silence_detected = False
            start_frame = 0
            if (
                cache["stats"].vad_state_machine
                == VadStateMachine.kVadInStateStartPointNotDetected
            ):
                start_frame = max(
                    cache["stats"].data_buf_start_frame,
                    cur_frm_idx - self.LatencyFrmNumAtStartPoint(cache=cache),
                )
                self.OnVoiceStart(start_frame, cache=cache)
                cache["stats"].vad_state_machine = (
                    VadStateMachine.kVadInStateInSpeechSegment
                )
                for t in range(start_frame + 1, cur_frm_idx + 1):
                    self.OnVoiceDetected(t, cache=cache)
            elif (
                cache["stats"].vad_state_machine
                == VadStateMachine.kVadInStateInSpeechSegment
            ):
                for t in range(
                    cache["stats"].latest_confirmed_speech_frame + 1, cur_frm_idx
                ):
                    self.OnVoiceDetected(t, cache=cache)
                if (
                    cur_frm_idx - cache["stats"].confirmed_start_frame + 1
                    > self.vad_opts.max_single_segment_time / frm_shift_in_ms
                ):
                    self.OnVoiceEnd(cur_frm_idx, False, False, cache=cache)
                    cache["stats"].vad_state_machine = (
                        VadStateMachine.kVadInStateEndPointDetected
                    )
                elif not is_final_frame:
                    self.OnVoiceDetected(cur_frm_idx, cache=cache)
                else:
                    self.MaybeOnVoiceEndIfLastFrame(
                        is_final_frame, cur_frm_idx, cache=cache
                    )
            else:
                pass
        elif AudioChangeState.kChangeStateSpeech2Sil == state_change:
            cache["stats"].continous_silence_frame_count = 0
            if (
                cache["stats"].vad_state_machine
                == VadStateMachine.kVadInStateStartPointNotDetected
            ):
                pass
            elif (
                cache["stats"].vad_state_machine
                == VadStateMachine.kVadInStateInSpeechSegment
            ):
                if (
                    cur_frm_idx - cache["stats"].confirmed_start_frame + 1
                    > self.vad_opts.max_single_segment_time / frm_shift_in_ms
                ):
                    self.OnVoiceEnd(cur_frm_idx, False, False, cache=cache)
                    cache["stats"].vad_state_machine = (
                        VadStateMachine.kVadInStateEndPointDetected
                    )
                elif not is_final_frame:
                    self.OnVoiceDetected(cur_frm_idx, cache=cache)
                else:
                    self.MaybeOnVoiceEndIfLastFrame(
                        is_final_frame, cur_frm_idx, cache=cache
                    )
            else:
                pass
        elif AudioChangeState.kChangeStateSpeech2Speech == state_change:
            cache["stats"].continous_silence_frame_count = 0
            if (
                cache["stats"].vad_state_machine
                == VadStateMachine.kVadInStateInSpeechSegment
            ):
                if (
                    cur_frm_idx - cache["stats"].confirmed_start_frame + 1
                    > self.vad_opts.max_single_segment_time / frm_shift_in_ms
                ):
                    cache["stats"].max_time_out = True
                    self.OnVoiceEnd(cur_frm_idx, False, False, cache=cache)
                    cache["stats"].vad_state_machine = (
                        VadStateMachine.kVadInStateEndPointDetected
                    )
                elif not is_final_frame:
                    self.OnVoiceDetected(cur_frm_idx, cache=cache)
                else:
                    self.MaybeOnVoiceEndIfLastFrame(
                        is_final_frame, cur_frm_idx, cache=cache
                    )
            else:
                pass
        elif AudioChangeState.kChangeStateSil2Sil == state_change:
            cache["stats"].continous_silence_frame_count += 1
            if (
                cache["stats"].vad_state_machine
                == VadStateMachine.kVadInStateStartPointNotDetected
            ):
                # silence timeout, return zero length decision
                if (
                    (
                        self.vad_opts.detect_mode
                        == VadDetectMode.kVadSingleUtteranceDetectMode.value
                    )
                    and (
                        cache["stats"].continous_silence_frame_count * frm_shift_in_ms
                        > self.vad_opts.max_start_silence_time
                    )
                ) or (is_final_frame and cache["stats"].number_end_time_detected == 0):
                    for t in range(
                        cache["stats"].lastest_confirmed_silence_frame + 1, cur_frm_idx
                    ):
                        self.OnSilenceDetected(t, cache=cache)
                    self.OnVoiceStart(0, True, cache=cache)
                    self.OnVoiceEnd(0, True, False, cache=cache)
                    cache["stats"].vad_state_machine = (
                        VadStateMachine.kVadInStateEndPointDetected
                    )
                else:
                    if cur_frm_idx >= self.LatencyFrmNumAtStartPoint(cache=cache):
                        self.OnSilenceDetected(
                            cur_frm_idx - self.LatencyFrmNumAtStartPoint(cache=cache),
                            cache=cache,
                        )
            elif (
                cache["stats"].vad_state_machine
                == VadStateMachine.kVadInStateInSpeechSegment
            ):
                if (
                    cache["stats"].continous_silence_frame_count * frm_shift_in_ms
                    >= cache["stats"].max_end_sil_frame_cnt_thresh
                ):
                    lookback_frame = int(
                        cache["stats"].max_end_sil_frame_cnt_thresh / frm_shift_in_ms
                    )
                    if self.vad_opts.do_extend:
                        lookback_frame -= int(
                            self.vad_opts.lookahead_time_end_point / frm_shift_in_ms
                        )
                        lookback_frame -= 1
                        lookback_frame = max(0, lookback_frame)
                    self.OnVoiceEnd(
                        cur_frm_idx - lookback_frame, False, False, cache=cache
                    )
                    cache["stats"].vad_state_machine = (
                        VadStateMachine.kVadInStateEndPointDetected
                    )
                elif (
                    cur_frm_idx - cache["stats"].confirmed_start_frame + 1
                    > self.vad_opts.max_single_segment_time / frm_shift_in_ms
                ):
                    self.OnVoiceEnd(cur_frm_idx, False, False, cache=cache)
                    cache["stats"].vad_state_machine = (
                        VadStateMachine.kVadInStateEndPointDetected
                    )
                elif self.vad_opts.do_extend and not is_final_frame:
                    if cache["stats"].continous_silence_frame_count <= int(
                        self.vad_opts.lookahead_time_end_point / frm_shift_in_ms
                    ):
                        self.OnVoiceDetected(cur_frm_idx, cache=cache)
                else:
                    self.MaybeOnVoiceEndIfLastFrame(
                        is_final_frame, cur_frm_idx, cache=cache
                    )
            else:
                pass

        if (
            cache["stats"].vad_state_machine
            == VadStateMachine.kVadInStateEndPointDetected
            and self.vad_opts.detect_mode
            == VadDetectMode.kVadMutipleUtteranceDetectMode.value
        ):
            self.ResetDetection(cache=cache)