index-tts/indextts/utils/maskgct/models/codec/facodec/modules/quantize.py

# Copyright (c) 2023 Amphion.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.

from modules.dac.nn.quantize import ResidualVectorQuantize
from torch import nn
from .wavenet import WN
from .style_encoder import StyleEncoder
from .gradient_reversal import GradientReversal
import torch
import torchaudio
import torchaudio.functional as audio_F
import numpy as np
from ..alias_free_torch import *
from torch.nn.utils import weight_norm
from torch import nn, sin, pow
from einops.layers.torch import Rearrange
from modules.dac.model.encodec import SConv1d


def init_weights(m):
    if isinstance(m, nn.Conv1d):
        nn.init.trunc_normal_(m.weight, std=0.02)
        nn.init.constant_(m.bias, 0)


def WNConv1d(*args, **kwargs):
    return weight_norm(nn.Conv1d(*args, **kwargs))


def WNConvTranspose1d(*args, **kwargs):
    return weight_norm(nn.ConvTranspose1d(*args, **kwargs))


class SnakeBeta(nn.Module):
    """
    A modified Snake function which uses separate parameters for the magnitude of the periodic components
    Shape:
        - Input: (B, C, T)
        - Output: (B, C, T), same shape as the input
    Parameters:
        - alpha - trainable parameter that controls frequency
        - beta - trainable parameter that controls magnitude
    References:
        - This activation function is a modified version based on this paper by Liu Ziyin, Tilman Hartwig, Masahito Ueda:
        https://arxiv.org/abs/2006.08195
    Examples:
        >>> a1 = snakebeta(256)
        >>> x = torch.randn(256)
        >>> x = a1(x)
    """

    def __init__(
        self, in_features, alpha=1.0, alpha_trainable=True, alpha_logscale=False
    ):
        """
        Initialization.
        INPUT:
            - in_features: shape of the input
            - alpha - trainable parameter that controls frequency
            - beta - trainable parameter that controls magnitude
            alpha is initialized to 1 by default, higher values = higher-frequency.
            beta is initialized to 1 by default, higher values = higher-magnitude.
            alpha will be trained along with the rest of your model.
        """
        super(SnakeBeta, self).__init__()
        self.in_features = in_features

        # initialize alpha
        self.alpha_logscale = alpha_logscale
        if self.alpha_logscale:  # log scale alphas initialized to zeros
            self.alpha = nn.Parameter(torch.zeros(in_features) * alpha)
            self.beta = nn.Parameter(torch.zeros(in_features) * alpha)
        else:  # linear scale alphas initialized to ones
            self.alpha = nn.Parameter(torch.ones(in_features) * alpha)
            self.beta = nn.Parameter(torch.ones(in_features) * alpha)

        self.alpha.requires_grad = alpha_trainable
        self.beta.requires_grad = alpha_trainable

        self.no_div_by_zero = 0.000000001

    def forward(self, x):
        """
        Forward pass of the function.
        Applies the function to the input elementwise.
        SnakeBeta := x + 1/b * sin^2 (xa)
        """
        alpha = self.alpha.unsqueeze(0).unsqueeze(-1)  # line up with x to [B, C, T]
        beta = self.beta.unsqueeze(0).unsqueeze(-1)
        if self.alpha_logscale:
            alpha = torch.exp(alpha)
            beta = torch.exp(beta)
        x = x + (1.0 / (beta + self.no_div_by_zero)) * pow(sin(x * alpha), 2)

        return x


class ResidualUnit(nn.Module):
    def __init__(self, dim: int = 16, dilation: int = 1):
        super().__init__()
        pad = ((7 - 1) * dilation) // 2
        self.block = nn.Sequential(
            Activation1d(activation=SnakeBeta(dim, alpha_logscale=True)),
            WNConv1d(dim, dim, kernel_size=7, dilation=dilation, padding=pad),
            Activation1d(activation=SnakeBeta(dim, alpha_logscale=True)),
            WNConv1d(dim, dim, kernel_size=1),
        )

    def forward(self, x):
        return x + self.block(x)


class CNNLSTM(nn.Module):
    def __init__(self, indim, outdim, head, global_pred=False):
        super().__init__()
        self.global_pred = global_pred
        self.model = nn.Sequential(
            ResidualUnit(indim, dilation=1),
            ResidualUnit(indim, dilation=2),
            ResidualUnit(indim, dilation=3),
            Activation1d(activation=SnakeBeta(indim, alpha_logscale=True)),
            Rearrange("b c t -> b t c"),
        )
        self.heads = nn.ModuleList([nn.Linear(indim, outdim) for i in range(head)])

    def forward(self, x):
        # x: [B, C, T]
        x = self.model(x)
        if self.global_pred:
            x = torch.mean(x, dim=1, keepdim=False)
        outs = [head(x) for head in self.heads]
        return outs


def sequence_mask(length, max_length=None):
    if max_length is None:
        max_length = length.max()
    x = torch.arange(max_length, dtype=length.dtype, device=length.device)
    return x.unsqueeze(0) < length.unsqueeze(1)


class MFCC(nn.Module):
    def __init__(self, n_mfcc=40, n_mels=80):
        super(MFCC, self).__init__()
        self.n_mfcc = n_mfcc
        self.n_mels = n_mels
        self.norm = "ortho"
        dct_mat = audio_F.create_dct(self.n_mfcc, self.n_mels, self.norm)
        self.register_buffer("dct_mat", dct_mat)

    def forward(self, mel_specgram):
        if len(mel_specgram.shape) == 2:
            mel_specgram = mel_specgram.unsqueeze(0)
            unsqueezed = True
        else:
            unsqueezed = False
        # (channel, n_mels, time).tranpose(...) dot (n_mels, n_mfcc)
        # -> (channel, time, n_mfcc).tranpose(...)
        mfcc = torch.matmul(mel_specgram.transpose(1, 2), self.dct_mat).transpose(1, 2)

        # unpack batch
        if unsqueezed:
            mfcc = mfcc.squeeze(0)
        return mfcc


class FAquantizer(nn.Module):
    def __init__(
        self,
        in_dim=1024,
        n_p_codebooks=1,
        n_c_codebooks=2,
        n_t_codebooks=2,
        n_r_codebooks=3,
        codebook_size=1024,
        codebook_dim=8,
        quantizer_dropout=0.5,
        causal=False,
        separate_prosody_encoder=False,
        timbre_norm=False,
    ):
        super(FAquantizer, self).__init__()
        conv1d_type = SConv1d  # if causal else nn.Conv1d
        self.prosody_quantizer = ResidualVectorQuantize(
            input_dim=in_dim,
            n_codebooks=n_p_codebooks,
            codebook_size=codebook_size,
            codebook_dim=codebook_dim,
            quantizer_dropout=quantizer_dropout,
        )

        self.content_quantizer = ResidualVectorQuantize(
            input_dim=in_dim,
            n_codebooks=n_c_codebooks,
            codebook_size=codebook_size,
            codebook_dim=codebook_dim,
            quantizer_dropout=quantizer_dropout,
        )

        if not timbre_norm:
            self.timbre_quantizer = ResidualVectorQuantize(
                input_dim=in_dim,
                n_codebooks=n_t_codebooks,
                codebook_size=codebook_size,
                codebook_dim=codebook_dim,
                quantizer_dropout=quantizer_dropout,
            )
        else:
            self.timbre_encoder = StyleEncoder(
                in_dim=80, hidden_dim=512, out_dim=in_dim
            )
            self.timbre_linear = nn.Linear(1024, 1024 * 2)
            self.timbre_linear.bias.data[:1024] = 1
            self.timbre_linear.bias.data[1024:] = 0
            self.timbre_norm = nn.LayerNorm(1024, elementwise_affine=False)

        self.residual_quantizer = ResidualVectorQuantize(
            input_dim=in_dim,
            n_codebooks=n_r_codebooks,
            codebook_size=codebook_size,
            codebook_dim=codebook_dim,
            quantizer_dropout=quantizer_dropout,
        )

        if separate_prosody_encoder:
            self.melspec_linear = conv1d_type(
                in_channels=20, out_channels=256, kernel_size=1, causal=causal
            )
            self.melspec_encoder = WN(
                hidden_channels=256,
                kernel_size=5,
                dilation_rate=1,
                n_layers=8,
                gin_channels=0,
                p_dropout=0.2,
                causal=causal,
            )
            self.melspec_linear2 = conv1d_type(
                in_channels=256, out_channels=1024, kernel_size=1, causal=causal
            )
        else:
            pass
        self.separate_prosody_encoder = separate_prosody_encoder

        self.prob_random_mask_residual = 0.75

        SPECT_PARAMS = {
            "n_fft": 2048,
            "win_length": 1200,
            "hop_length": 300,
        }
        MEL_PARAMS = {
            "n_mels": 80,
        }

        self.to_mel = torchaudio.transforms.MelSpectrogram(
            n_mels=MEL_PARAMS["n_mels"], sample_rate=24000, **SPECT_PARAMS
        )
        self.mel_mean, self.mel_std = -4, 4
        self.frame_rate = 24000 / 300
        self.hop_length = 300

        self.is_timbre_norm = timbre_norm
        if timbre_norm:
            self.forward = self.forward_v2

    def preprocess(self, wave_tensor, n_bins=20):
        mel_tensor = self.to_mel(wave_tensor.squeeze(1))
        mel_tensor = (torch.log(1e-5 + mel_tensor) - self.mel_mean) / self.mel_std
        return mel_tensor[:, :n_bins, : int(wave_tensor.size(-1) / self.hop_length)]

    @torch.no_grad()
    def decode(self, codes):
        code_c, code_p, code_t = codes.split([1, 1, 2], dim=1)

        z_c = self.content_quantizer.from_codes(code_c)[0]
        z_p = self.prosody_quantizer.from_codes(code_p)[0]
        z_t = self.timbre_quantizer.from_codes(code_t)[0]

        z = z_c + z_p + z_t

        return z, [z_c, z_p, z_t]

    @torch.no_grad()
    def encode(self, x, wave_segments, n_c=1):
        outs = 0
        if self.separate_prosody_encoder:
            prosody_feature = self.preprocess(wave_segments)

            f0_input = prosody_feature  # (B, T, 20)
            f0_input = self.melspec_linear(f0_input)
            f0_input = self.melspec_encoder(
                f0_input,
                torch.ones(f0_input.shape[0], 1, f0_input.shape[2])
                .to(f0_input.device)
                .bool(),
            )
            f0_input = self.melspec_linear2(f0_input)

            common_min_size = min(f0_input.size(2), x.size(2))
            f0_input = f0_input[:, :, :common_min_size]

            x = x[:, :, :common_min_size]

            (
                z_p,
                codes_p,
                latents_p,
                commitment_loss_p,
                codebook_loss_p,
            ) = self.prosody_quantizer(f0_input, 1)
            outs += z_p.detach()
        else:
            (
                z_p,
                codes_p,
                latents_p,
                commitment_loss_p,
                codebook_loss_p,
            ) = self.prosody_quantizer(x, 1)
            outs += z_p.detach()

        (
            z_c,
            codes_c,
            latents_c,
            commitment_loss_c,
            codebook_loss_c,
        ) = self.content_quantizer(x, n_c)
        outs += z_c.detach()

        timbre_residual_feature = x - z_p.detach() - z_c.detach()

        (
            z_t,
            codes_t,
            latents_t,
            commitment_loss_t,
            codebook_loss_t,
        ) = self.timbre_quantizer(timbre_residual_feature, 2)
        outs += z_t  # we should not detach timbre

        residual_feature = timbre_residual_feature - z_t

        (
            z_r,
            codes_r,
            latents_r,
            commitment_loss_r,
            codebook_loss_r,
        ) = self.residual_quantizer(residual_feature, 3)

        return [codes_c, codes_p, codes_t, codes_r], [z_c, z_p, z_t, z_r]

    def forward(
        self, x, wave_segments, noise_added_flags, recon_noisy_flags, n_c=2, n_t=2
    ):
        # timbre = self.timbre_encoder(mels, sequence_mask(mel_lens, mels.size(-1)).unsqueeze(1))
        # timbre = self.timbre_encoder(mel_segments, torch.ones(mel_segments.size(0), 1, mel_segments.size(2)).bool().to(mel_segments.device))
        outs = 0
        if self.separate_prosody_encoder:
            prosody_feature = self.preprocess(wave_segments)

            f0_input = prosody_feature  # (B, T, 20)
            f0_input = self.melspec_linear(f0_input)
            f0_input = self.melspec_encoder(
                f0_input,
                torch.ones(f0_input.shape[0], 1, f0_input.shape[2])
                .to(f0_input.device)
                .bool(),
            )
            f0_input = self.melspec_linear2(f0_input)

            common_min_size = min(f0_input.size(2), x.size(2))
            f0_input = f0_input[:, :, :common_min_size]

            x = x[:, :, :common_min_size]

            (
                z_p,
                codes_p,
                latents_p,
                commitment_loss_p,
                codebook_loss_p,
            ) = self.prosody_quantizer(f0_input, 1)
            outs += z_p.detach()
        else:
            (
                z_p,
                codes_p,
                latents_p,
                commitment_loss_p,
                codebook_loss_p,
            ) = self.prosody_quantizer(x, 1)
            outs += z_p.detach()

        (
            z_c,
            codes_c,
            latents_c,
            commitment_loss_c,
            codebook_loss_c,
        ) = self.content_quantizer(x, n_c)
        outs += z_c.detach()

        timbre_residual_feature = x - z_p.detach() - z_c.detach()

        (
            z_t,
            codes_t,
            latents_t,
            commitment_loss_t,
            codebook_loss_t,
        ) = self.timbre_quantizer(timbre_residual_feature, n_t)
        outs += z_t  # we should not detach timbre

        residual_feature = timbre_residual_feature - z_t

        (
            z_r,
            codes_r,
            latents_r,
            commitment_loss_r,
            codebook_loss_r,
        ) = self.residual_quantizer(residual_feature, 3)

        bsz = z_r.shape[0]
        res_mask = np.random.choice(
            [0, 1],
            size=bsz,
            p=[
                self.prob_random_mask_residual,
                1 - self.prob_random_mask_residual,
            ],
        )
        res_mask = torch.from_numpy(res_mask).unsqueeze(1).unsqueeze(1)  # (B, 1, 1)
        res_mask = res_mask.to(device=z_r.device, dtype=z_r.dtype)
        noise_must_on = noise_added_flags * recon_noisy_flags
        noise_must_off = noise_added_flags * (~recon_noisy_flags)
        res_mask[noise_must_on] = 1
        res_mask[noise_must_off] = 0

        outs += z_r * res_mask

        quantized = [z_p, z_c, z_t, z_r]
        commitment_losses = (
            commitment_loss_p
            + commitment_loss_c
            + commitment_loss_t
            + commitment_loss_r
        )
        codebook_losses = (
            codebook_loss_p + codebook_loss_c + codebook_loss_t + codebook_loss_r
        )

        return outs, quantized, commitment_losses, codebook_losses

    def forward_v2(
        self,
        x,
        wave_segments,
        n_c=1,
        n_t=2,
        full_waves=None,
        wave_lens=None,
        return_codes=False,
    ):
        # timbre = self.timbre_encoder(x, sequence_mask(mel_lens, mels.size(-1)).unsqueeze(1))
        if full_waves is None:
            mel = self.preprocess(wave_segments, n_bins=80)
            timbre = self.timbre_encoder(
                mel, torch.ones(mel.size(0), 1, mel.size(2)).bool().to(mel.device)
            )
        else:
            mel = self.preprocess(full_waves, n_bins=80)
            timbre = self.timbre_encoder(
                mel,
                sequence_mask(wave_lens // self.hop_length, mel.size(-1)).unsqueeze(1),
            )
        outs = 0
        if self.separate_prosody_encoder:
            prosody_feature = self.preprocess(wave_segments)

            f0_input = prosody_feature  # (B, T, 20)
            f0_input = self.melspec_linear(f0_input)
            f0_input = self.melspec_encoder(
                f0_input,
                torch.ones(f0_input.shape[0], 1, f0_input.shape[2])
                .to(f0_input.device)
                .bool(),
            )
            f0_input = self.melspec_linear2(f0_input)

            common_min_size = min(f0_input.size(2), x.size(2))
            f0_input = f0_input[:, :, :common_min_size]

            x = x[:, :, :common_min_size]

            (
                z_p,
                codes_p,
                latents_p,
                commitment_loss_p,
                codebook_loss_p,
            ) = self.prosody_quantizer(f0_input, 1)
            outs += z_p.detach()
        else:
            (
                z_p,
                codes_p,
                latents_p,
                commitment_loss_p,
                codebook_loss_p,
            ) = self.prosody_quantizer(x, 1)
            outs += z_p.detach()

        (
            z_c,
            codes_c,
            latents_c,
            commitment_loss_c,
            codebook_loss_c,
        ) = self.content_quantizer(x, n_c)
        outs += z_c.detach()

        residual_feature = x - z_p.detach() - z_c.detach()

        (
            z_r,
            codes_r,
            latents_r,
            commitment_loss_r,
            codebook_loss_r,
        ) = self.residual_quantizer(residual_feature, 3)

        bsz = z_r.shape[0]
        res_mask = np.random.choice(
            [0, 1],
            size=bsz,
            p=[
                self.prob_random_mask_residual,
                1 - self.prob_random_mask_residual,
            ],
        )
        res_mask = torch.from_numpy(res_mask).unsqueeze(1).unsqueeze(1)  # (B, 1, 1)
        res_mask = res_mask.to(device=z_r.device, dtype=z_r.dtype)

        if not self.training:
            res_mask = torch.ones_like(res_mask)
        outs += z_r * res_mask

        quantized = [z_p, z_c, z_r]
        codes = [codes_p, codes_c, codes_r]
        commitment_losses = commitment_loss_p + commitment_loss_c + commitment_loss_r
        codebook_losses = codebook_loss_p + codebook_loss_c + codebook_loss_r

        style = self.timbre_linear(timbre).unsqueeze(2)  # (B, 2d, 1)
        gamma, beta = style.chunk(2, 1)  # (B, d, 1)
        outs = outs.transpose(1, 2)
        outs = self.timbre_norm(outs)
        outs = outs.transpose(1, 2)
        outs = outs * gamma + beta

        if return_codes:
            return outs, quantized, commitment_losses, codebook_losses, timbre, codes
        else:
            return outs, quantized, commitment_losses, codebook_losses, timbre

    def voice_conversion(self, z, ref_wave):
        ref_mel = self.preprocess(ref_wave, n_bins=80)
        ref_timbre = self.timbre_encoder(
            ref_mel,
            sequence_mask(
                torch.LongTensor([ref_wave.size(-1)]).to(z.device) // self.hop_length,
                ref_mel.size(-1),
            ).unsqueeze(1),
        )
        style = self.timbre_linear(ref_timbre).unsqueeze(2)  # (B, 2d, 1)
        gamma, beta = style.chunk(2, 1)  # (B, d, 1)
        outs = z.transpose(1, 2)
        outs = self.timbre_norm(outs)
        outs = outs.transpose(1, 2)
        outs = outs * gamma + beta

        return outs


class FApredictors(nn.Module):
    def __init__(
        self,
        in_dim=1024,
        use_gr_content_f0=False,
        use_gr_prosody_phone=False,
        use_gr_residual_f0=False,
        use_gr_residual_phone=False,
        use_gr_timbre_content=True,
        use_gr_timbre_prosody=True,
        use_gr_x_timbre=False,
        norm_f0=True,
        timbre_norm=False,
        use_gr_content_global_f0=False,
    ):
        super(FApredictors, self).__init__()
        self.f0_predictor = CNNLSTM(in_dim, 1, 2)
        self.phone_predictor = CNNLSTM(in_dim, 1024, 1)
        if timbre_norm:
            self.timbre_predictor = nn.Linear(in_dim, 20000)
        else:
            self.timbre_predictor = CNNLSTM(in_dim, 20000, 1, global_pred=True)

        self.use_gr_content_f0 = use_gr_content_f0
        self.use_gr_prosody_phone = use_gr_prosody_phone
        self.use_gr_residual_f0 = use_gr_residual_f0
        self.use_gr_residual_phone = use_gr_residual_phone
        self.use_gr_timbre_content = use_gr_timbre_content
        self.use_gr_timbre_prosody = use_gr_timbre_prosody
        self.use_gr_x_timbre = use_gr_x_timbre

        self.rev_f0_predictor = nn.Sequential(
            GradientReversal(alpha=1.0), CNNLSTM(in_dim, 1, 2)
        )
        self.rev_content_predictor = nn.Sequential(
            GradientReversal(alpha=1.0), CNNLSTM(in_dim, 1024, 1)
        )
        self.rev_timbre_predictor = nn.Sequential(
            GradientReversal(alpha=1.0), CNNLSTM(in_dim, 20000, 1, global_pred=True)
        )

        self.norm_f0 = norm_f0
        self.timbre_norm = timbre_norm
        if timbre_norm:
            self.forward = self.forward_v2
            self.global_f0_predictor = nn.Linear(in_dim, 1)

        self.use_gr_content_global_f0 = use_gr_content_global_f0
        if use_gr_content_global_f0:
            self.rev_global_f0_predictor = nn.Sequential(
                GradientReversal(alpha=1.0), CNNLSTM(in_dim, 1, 1, global_pred=True)
            )

    def forward(self, quantized):
        prosody_latent = quantized[0]
        content_latent = quantized[1]
        timbre_latent = quantized[2]
        residual_latent = quantized[3]
        content_pred = self.phone_predictor(content_latent)[0]

        if self.norm_f0:
            spk_pred = self.timbre_predictor(timbre_latent)[0]
            f0_pred, uv_pred = self.f0_predictor(prosody_latent)
        else:
            spk_pred = self.timbre_predictor(timbre_latent + prosody_latent)[0]
            f0_pred, uv_pred = self.f0_predictor(prosody_latent + timbre_latent)

        prosody_rev_latent = torch.zeros_like(quantized[0])
        if self.use_gr_content_f0:
            prosody_rev_latent += quantized[1]
        if self.use_gr_timbre_prosody:
            prosody_rev_latent += quantized[2]
        if self.use_gr_residual_f0:
            prosody_rev_latent += quantized[3]
        rev_f0_pred, rev_uv_pred = self.rev_f0_predictor(prosody_rev_latent)

        content_rev_latent = torch.zeros_like(quantized[1])
        if self.use_gr_prosody_phone:
            content_rev_latent += quantized[0]
        if self.use_gr_timbre_content:
            content_rev_latent += quantized[2]
        if self.use_gr_residual_phone:
            content_rev_latent += quantized[3]
        rev_content_pred = self.rev_content_predictor(content_rev_latent)[0]

        if self.norm_f0:
            timbre_rev_latent = quantized[0] + quantized[1] + quantized[3]
        else:
            timbre_rev_latent = quantized[1] + quantized[3]
        if self.use_gr_x_timbre:
            x_spk_pred = self.rev_timbre_predictor(timbre_rev_latent)[0]
        else:
            x_spk_pred = None

        preds = {
            "f0": f0_pred,
            "uv": uv_pred,
            "content": content_pred,
            "timbre": spk_pred,
        }

        rev_preds = {
            "rev_f0": rev_f0_pred,
            "rev_uv": rev_uv_pred,
            "rev_content": rev_content_pred,
            "x_timbre": x_spk_pred,
        }
        return preds, rev_preds

    def forward_v2(self, quantized, timbre):
        prosody_latent = quantized[0]
        content_latent = quantized[1]
        residual_latent = quantized[2]
        content_pred = self.phone_predictor(content_latent)[0]

        spk_pred = self.timbre_predictor(timbre)
        f0_pred, uv_pred = self.f0_predictor(prosody_latent)

        prosody_rev_latent = torch.zeros_like(prosody_latent)
        if self.use_gr_content_f0:
            prosody_rev_latent += content_latent
        if self.use_gr_residual_f0:
            prosody_rev_latent += residual_latent
        rev_f0_pred, rev_uv_pred = self.rev_f0_predictor(prosody_rev_latent)

        content_rev_latent = torch.zeros_like(content_latent)
        if self.use_gr_prosody_phone:
            content_rev_latent += prosody_latent
        if self.use_gr_residual_phone:
            content_rev_latent += residual_latent
        rev_content_pred = self.rev_content_predictor(content_rev_latent)[0]

        timbre_rev_latent = prosody_latent + content_latent + residual_latent
        if self.use_gr_x_timbre:
            x_spk_pred = self.rev_timbre_predictor(timbre_rev_latent)[0]
        else:
            x_spk_pred = None

        preds = {
            "f0": f0_pred,
            "uv": uv_pred,
            "content": content_pred,
            "timbre": spk_pred,
        }

        rev_preds = {
            "rev_f0": rev_f0_pred,
            "rev_uv": rev_uv_pred,
            "rev_content": rev_content_pred,
            "x_timbre": x_spk_pred,
        }
        return preds, rev_preds