fix sample rate error in asr_feat.py

[wujian752]

在 asr_feat.py 中，

1. frame_length, frame_shift 被传入了 KaldifeatFbank 但并未被使用
2. wav 中的 sample_rate 也没有传入 knf，导致所有音频都按照 16k 采样率提取特征

class KaldifeatFbank:
    def __init__(self, num_mel_bins=80, frame_length=25, frame_shift=10,
                 dither=1.0):
        self.dither = dither
        opts = knf.FbankOptions()
        opts.frame_opts.dither = dither
        opts.mel_opts.num_bins = num_mel_bins
        opts.frame_opts.snip_edges = True
        opts.mel_opts.debug_mel = False
        self.opts = opts

    def __call__(self, wav, is_train=False):
        if type(wav) is str:
            sample_rate, wav_np = kaldiio.load_mat(wav)
        elif type(wav) in [tuple, list] and len(wav) == 2:
            sample_rate, wav_np = wav
        assert len(wav_np.shape) == 1

        dither = self.dither if is_train else 0.0
        self.opts.frame_opts.dither = dither
        fbank = knf.OnlineFbank(self.opts)

        fbank.accept_waveform(sample_rate, wav_np.tolist())
        feat = []
        for i in range(fbank.num_frames_ready):
            feat.append(fbank.get_frame(i))
        if len(feat) == 0:
            print("Check data, len(feat) == 0", wav, flush=True)
            return np.zeros((0, self.opts.mel_opts.num_bins))
        feat = np.vstack(feat)
        return feat

[FireRedTeam]

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