modeling_tf_whisper.py

# coding=utf-8
# Copyright 2022 The OpenAI Authors and The HuggingFace Inc. team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""TensorFlow Whisper model."""

from __future__ import annotations

import math
import random
from typing import Dict, List, Optional, Tuple, Union

import numpy as np
import tensorflow as tf

from ...activations_tf import get_tf_activation
from ...generation.configuration_utils import GenerationConfig
from ...generation.tf_logits_process import TFLogitsProcessorList
from ...modeling_tf_outputs import (
    TFBaseModelOutput,
    TFBaseModelOutputWithPastAndCrossAttentions,
    TFSeq2SeqLMOutput,
    TFSeq2SeqModelOutput,
)
from ...modeling_tf_utils import (
    TFCausalLanguageModelingLoss,
    TFModelInputType,
    TFPreTrainedModel,
    keras,
    keras_serializable,
    unpack_inputs,
)
from ...tf_utils import check_embeddings_within_bounds, shape_list, stable_softmax
from ...utils import add_start_docstrings, add_start_docstrings_to_model_forward, logging, replace_return_docstrings
from .configuration_whisper import WhisperConfig
from .tokenization_whisper import TASK_IDS, TO_LANGUAGE_CODE


logger = logging.get_logger(__name__)

_CONFIG_FOR_DOC = "WhisperConfig"


LARGE_NEGATIVE = -1e8


def sinusoidal_embedding_init(shape, dtype=tf.float32) -> tf.Tensor:
    """Returns sinusoids for positional embedding"""
    length, channels = shape
    if channels % 2 != 0:
        raise ValueError(
            f"Number of channels has to be divisible by 2 for sinusoidal positional embeddings, got {channels} channels."
        )
    log_timescale_increment = math.log(10000) / (channels // 2 - 1)
    inv_timescales = tf.exp(-log_timescale_increment * tf.range(channels // 2, dtype=tf.float32))
    scaled_time = tf.reshape(tf.range(length, dtype=tf.float32), (-1, 1)) * tf.reshape(inv_timescales, (1, -1))
    return tf.cast(tf.concat([tf.sin(scaled_time), tf.cos(scaled_time)], axis=1), dtype)


# Copied from transformers.models.bart.modeling_tf_bart.shift_tokens_right
def shift_tokens_right(input_ids: tf.Tensor, pad_token_id: int, decoder_start_token_id: int):
    pad_token_id = tf.cast(pad_token_id, input_ids.dtype)
    decoder_start_token_id = tf.cast(decoder_start_token_id, input_ids.dtype)
    start_tokens = tf.fill(
        (shape_list(input_ids)[0], 1), tf.convert_to_tensor(decoder_start_token_id, input_ids.dtype)
    )
    shifted_input_ids = tf.concat([start_tokens, input_ids[:, :-1]], -1)
    # replace possible -100 values in labels by `pad_token_id`
    shifted_input_ids = tf.where(
        shifted_input_ids == -100,
        tf.fill(shape_list(shifted_input_ids), tf.convert_to_tensor(pad_token_id, input_ids.dtype)),
        shifted_input_ids,
    )

    # "Verify that `labels` has only positive values and -100"
    assert_gte0 = tf.debugging.assert_greater_equal(shifted_input_ids, tf.constant(0, dtype=input_ids.dtype))

    # Make sure the assertion op is called by wrapping the result in an identity no-op
    with tf.control_dependencies([assert_gte0]):
        shifted_input_ids = tf.identity(shifted_input_ids)

    return shifted_input_ids


# Copied from transformers.models.bart.modeling_tf_bart._make_causal_mask
def _make_causal_mask(input_ids_shape: tf.TensorShape, past_key_values_length: int = 0):
    """
    Make causal mask used for bi-directional self-attention.
    """
    bsz = input_ids_shape[0]
    tgt_len = input_ids_shape[1]
    mask = tf.ones((tgt_len, tgt_len)) * LARGE_NEGATIVE
    mask_cond = tf.range(shape_list(mask)[-1])

    mask = tf.where(mask_cond < tf.reshape(mask_cond + 1, (shape_list(mask)[-1], 1)), 0.0, mask)

    if past_key_values_length > 0:
        mask = tf.concat([tf.zeros((tgt_len, past_key_values_length)), mask], axis=-1)

    return tf.tile(mask[None, None, :, :], (bsz, 1, 1, 1))


# Copied from transformers.models.bart.modeling_tf_bart._expand_mask
def _expand_mask(mask: tf.Tensor, tgt_len: Optional[int] = None):
    """
    Expands attention_mask from `[bsz, seq_len]` to `[bsz, 1, tgt_seq_len, src_seq_len]`.
    """
    src_len = shape_list(mask)[1]
    tgt_len = tgt_len if tgt_len is not None else src_len
    one_cst = tf.constant(1.0)
    mask = tf.cast(mask, dtype=one_cst.dtype)
    expanded_mask = tf.tile(mask[:, None, None, :], (1, 1, tgt_len, 1))

    return (one_cst - expanded_mask) * LARGE_NEGATIVE


class TFWhisperPositionalEmbedding(keras.layers.Layer):
    def __init__(
        self,
        num_positions: int,
        embedding_dim: int,
        padding_idx: Optional[int] = None,
        embedding_initializer=None,
        **kwargs,
    ):
        super().__init__(**kwargs)
        self.num_positions = num_positions
        self.embedding_dim = embedding_dim
        self.padding_idx = padding_idx
        self.embedding_initializer = keras.initializers.get(embedding_initializer)

    def build(self, input_shape):
        self.weight = self.add_weight(
            name="weight",
            shape=[self.num_positions, self.embedding_dim],
            initializer=self.embedding_initializer,
            trainable=True,
        )
        super().build(input_shape)

    def call(self, input_ids, past_key_values_length=0):
        past_key_values_length = tf.cast(past_key_values_length, tf.int32)
        gather_indices = tf.range(tf.shape(input_ids)[1], delta=1) + past_key_values_length
        return tf.gather(self.weight, gather_indices)


class TFWhisperAttention(keras.layers.Layer):
    """Multi-headed attention from 'Attention Is All You Need' paper"""

    def __init__(
        self,
        embed_dim: int,
        num_heads: int,
        dropout: float = 0.0,
        is_decoder: bool = False,
        bias: bool = True,
        **kwargs,
    ):
        super().__init__(**kwargs)
        self.embed_dim = embed_dim
        self.num_heads = num_heads
        self.dropout = keras.layers.Dropout(dropout)
        self.head_dim = embed_dim // num_heads

        if (self.head_dim * num_heads) != self.embed_dim:
            raise ValueError(
                f"embed_dim must be divisible by num_heads (got `embed_dim`: {self.embed_dim}"
                f" and `num_heads`: {num_heads})."
            )
        self.scaling = self.head_dim**-0.5
        self.is_decoder = is_decoder

        self.k_proj = keras.layers.Dense(embed_dim, use_bias=False, name="k_proj")
        self.v_proj = keras.layers.Dense(embed_dim, use_bias=bias, name="v_proj")
        self.q_proj = keras.layers.Dense(embed_dim, use_bias=bias, name="q_proj")
        self.out_proj = keras.layers.Dense(embed_dim, use_bias=bias, name="out_proj")

    # Copied from transformers.models.bart.modeling_tf_bart.TFBartAttention._shape with BART->whisper
    def _shape(self, tensor: tf.Tensor, seq_len: int, bsz: int):
        return tf.transpose(tf.reshape(tensor, (bsz, seq_len, self.num_heads, self.head_dim)), (0, 2, 1, 3))

    # Copied from transformers.models.bart.modeling_tf_bart.TFBartAttention.call with BART->whisper
    def call(
        self,
        hidden_states: tf.Tensor,
        key_value_states: tf.Tensor | None = None,
        past_key_value: Tuple[Tuple[tf.Tensor]] | None = None,
        attention_mask: tf.Tensor | None = None,
        layer_head_mask: tf.Tensor | None = None,
        training: Optional[bool] = False,
    ) -> Tuple[tf.Tensor, tf.Tensor | None]:
        """Input shape: Batch x Time x Channel"""

        # if key_value_states are provided this layer is used as a cross-attention layer
        # for the decoder
        is_cross_attention = key_value_states is not None
        bsz, tgt_len, embed_dim = shape_list(hidden_states)

        # get query proj
        query_states = self.q_proj(hidden_states) * self.scaling
        # get key, value proj
        if is_cross_attention and past_key_value is not None:
            # reuse k,v, cross_attentions
            key_states = past_key_value[0]
            value_states = past_key_value[1]
        elif is_cross_attention:
            # cross_attentions
            key_states = self._shape(self.k_proj(key_value_states), -1, bsz)
            value_states = self._shape(self.v_proj(key_value_states), -1, bsz)
        elif past_key_value is not None:
            # reuse k, v, self_attention
            key_states = self._shape(self.k_proj(hidden_states), -1, bsz)
            value_states = self._shape(self.v_proj(hidden_states), -1, bsz)
            key_states = tf.concat([past_key_value[0], key_states], axis=2)
            value_states = tf.concat([past_key_value[1], value_states], axis=2)
        else:
            # self_attention
            key_states = self._shape(self.k_proj(hidden_states), -1, bsz)
            value_states = self._shape(self.v_proj(hidden_states), -1, bsz)

        if self.is_decoder:
            # if cross_attention save Tuple(tf.Tensor, tf.Tensor) of all cross attention key/value_states.
            # Further calls to cross_attention layer can then reuse all cross-attention
            # key/value_states (first "if" case)
            # if uni-directional self-attention (decoder) save Tuple(tf.Tensor, tf.Tensor) of
            # all previous decoder key/value_states. Further calls to uni-directional self-attention
            # can concat previous decoder key/value_states to current projected key/value_states (third "elif" case)
            # if encoder bi-directional self-attention `past_key_value` is always `None`
            past_key_value = (key_states, value_states)

        proj_shape = (bsz * self.num_heads, -1, self.head_dim)
        query_states = tf.reshape(self._shape(query_states, tgt_len, bsz), proj_shape)
        key_states = tf.reshape(key_states, proj_shape)
        value_states = tf.reshape(value_states, proj_shape)

        src_len = shape_list(key_states)[1]
        attn_weights = tf.matmul(query_states, key_states, transpose_b=True)

        tf.debugging.assert_equal(
            shape_list(attn_weights),
            [bsz * self.num_heads, tgt_len, src_len],
            message=(
                f"Attention weights should be of size {(bsz * self.num_heads, tgt_len, src_len)}, but is"
                f" {shape_list(attn_weights)}"
            ),
        )

        if attention_mask is not None:
            tf.debugging.assert_equal(
                shape_list(attention_mask),
                [bsz, 1, tgt_len, src_len],
                message=(
                    f"Attention mask should be of size {(bsz, 1, tgt_len, src_len)}, but is"
                    f" {shape_list(attention_mask)}"
                ),
            )

            attention_mask = tf.cast(attention_mask, dtype=attn_weights.dtype)
            attn_weights = tf.reshape(attn_weights, (bsz, self.num_heads, tgt_len, src_len)) + attention_mask
            attn_weights = tf.reshape(attn_weights, (bsz * self.num_heads, tgt_len, src_len))

        attn_weights = stable_softmax(attn_weights, axis=-1)

        if layer_head_mask is not None:
            tf.debugging.assert_equal(
                shape_list(layer_head_mask),
                [self.num_heads],
                message=(
                    f"Head mask for a single layer should be of size {(self.num_heads)}, but is"
                    f" {shape_list(layer_head_mask)}"
                ),
            )

            attn_weights = tf.reshape(layer_head_mask, (1, -1, 1, 1)) * tf.reshape(
                attn_weights, (bsz, self.num_heads, tgt_len, src_len)
            )
            attn_weights = tf.reshape(attn_weights, (bsz * self.num_heads, tgt_len, src_len))

        attn_probs = self.dropout(attn_weights, training=training)
        attn_output = tf.matmul(attn_probs, value_states)

        tf.debugging.assert_equal(
            shape_list(attn_output),
            [bsz * self.num_heads, tgt_len, self.head_dim],
            message=(
                f"`attn_output` should be of size {(bsz, self.num_heads, tgt_len, self.head_dim)}, but is"
                f" {shape_list(attn_output)}"
            ),
        )

        attn_output = tf.transpose(
            tf.reshape(attn_output, (bsz, self.num_heads, tgt_len, self.head_dim)), (0, 2, 1, 3)
        )
        attn_output = tf.reshape(attn_output, (bsz, tgt_len, embed_dim))

        attn_output = self.out_proj(attn_output)
        attn_weights: tf.Tensor = tf.reshape(attn_weights, (bsz, self.num_heads, tgt_len, src_len))

        return attn_output, attn_weights, past_key_value

    def build(self, input_shape=None):
        if self.built:
            return
        self.built = True
        if getattr(self, "k_proj", None) is not None:
            with tf.name_scope(self.k_proj.name):
                self.k_proj.build([None, None, self.embed_dim])
        if getattr(self, "v_proj", None) is not None:
            with tf.name_scope(self.v_proj.name):
                self.v_proj.build([None, None, self.embed_dim])
        if getattr(self, "q_proj", None) is not None:
            with tf.name_scope(self.q_proj.name):
                self.q_proj.build([None, None, self.embed_dim])
        if getattr(self, "out_proj", None) is not None:
            with tf.name_scope(self.out_proj.name):
                self.out_proj.build([None, None, self.embed_dim])


# Copied from transformers.models.speech_to_text.modeling_tf_speech_to_text.TFSpeech2TextEncoderLayer with Speech2Text->Whisper
class TFWhisperEncoderLayer(keras.layers.Layer):
    def __init__(self, config: WhisperConfig, **kwargs):
        super().__init__(**kwargs)
        self.embed_dim = config.d_model
        self.self_attn = TFWhisperAttention(
            self.embed_dim, config.encoder_attention_heads, dropout=config.attention_dropout, name="self_attn"
        )
        self.self_attn_layer_norm = keras.layers.LayerNormalization(epsilon=1e-5, name="self_attn_layer_norm")
        self.dropout = keras.layers.Dropout(config.dropout)
        self.activation_fn = get_tf_activation(config.activation_function)
        self.activation_dropout = keras.layers.Dropout(config.activation_dropout)
        self.fc1 = keras.layers.Dense(config.encoder_ffn_dim, name="fc1")
        self.fc2 = keras.layers.Dense(self.embed_dim, name="fc2")
        self.final_layer_norm = keras.layers.LayerNormalization(epsilon=1e-5, name="final_layer_norm")
        self.config = config

    def call(
        self, hidden_states: tf.Tensor, attention_mask: tf.Tensor, layer_head_mask: tf.Tensor, training: bool = False
    ):
        """
        Args:
            hidden_states (`tf.Tensor`): input to the layer of shape `(batch, seq_len, embed_dim)`
            attention_mask (`tf.Tensor`): attention mask of size
                `(batch, 1, tgt_len, src_len)` where padding elements are indicated by very large negative values.
            layer_head_mask (`tf.Tensor`): mask for attention heads in a given layer of size
                `(encoder_attention_heads,)`
        """
        residual = hidden_states
        hidden_states = self.self_attn_layer_norm(hidden_states)
        hidden_states, self_attn_weights, _ = self.self_attn(
            hidden_states=hidden_states,
            attention_mask=attention_mask,
            layer_head_mask=layer_head_mask,
            training=training,
        )

        tf.debugging.assert_equal(
            shape_list(hidden_states),
            shape_list(residual),
            message=f"Self attn modified the shape of query {shape_list(residual)} to {shape_list(hidden_states)}",
        )

        hidden_states = self.dropout(hidden_states, training=training)
        hidden_states = residual + hidden_states

        residual = hidden_states
        hidden_states = self.final_layer_norm(hidden_states)
        hidden_states = self.activation_fn(self.fc1(hidden_states))
        hidden_states = self.activation_dropout(hidden_states, training=training)
        hidden_states = self.fc2(hidden_states)
        hidden_states = self.dropout(hidden_states, training=training)
        hidden_states = residual + hidden_states

        return hidden_states, self_attn_weights

    def build(self, input_shape=None):
        if self.built:
            return
        self.built = True
        if getattr(self, "self_attn", None) is not None:
            with tf.name_scope(self.self_attn.name):
                self.self_attn.build(None)
        if getattr(self, "self_attn_layer_norm", None) is not None:
            with tf.name_scope(self.self_attn_layer_norm.name):
                self.self_attn_layer_norm.build([None, None, self.embed_dim])
        if getattr(self, "fc1", None) is not None:
            with tf.name_scope(self.fc1.name):
                self.fc1.build([None, None, self.embed_dim])
        if getattr(self, "fc2", None) is not None:
            with tf.name_scope(self.fc2.name):
                self.fc2.build([None, None, self.config.encoder_ffn_dim])
        if getattr(self, "final_layer_norm", None) is not None:
            with tf.name_scope(self.final_layer_norm.name):
                self.final_layer_norm.build([None, None, self.embed_dim])


# Copied from transformers.models.speech_to_text.modeling_tf_speech_to_text.TFSpeech2TextDecoderLayer with Speech2Text->Whisper
class TFWhisperDecoderLayer(keras.layers.Layer):
    def __init__(self, config: WhisperConfig, **kwargs):
        super().__init__(**kwargs)
        self.embed_dim = config.d_model

        self.self_attn = TFWhisperAttention(
            embed_dim=self.embed_dim,
            num_heads=config.decoder_attention_heads,
            dropout=config.attention_dropout,
            name="self_attn",
            is_decoder=True,
        )
        self.dropout = keras.layers.Dropout(config.dropout)
        self.activation_fn = get_tf_activation(config.activation_function)
        self.activation_dropout = keras.layers.Dropout(config.activation_dropout)

        self.self_attn_layer_norm = keras.layers.LayerNormalization(epsilon=1e-5, name="self_attn_layer_norm")
        self.encoder_attn = TFWhisperAttention(
            self.embed_dim,
            config.decoder_attention_heads,
            dropout=config.attention_dropout,
            name="encoder_attn",
            is_decoder=True,
        )
        self.encoder_attn_layer_norm = keras.layers.LayerNormalization(epsilon=1e-5, name="encoder_attn_layer_norm")
        self.fc1 = keras.layers.Dense(config.decoder_ffn_dim, name="fc1")
        self.fc2 = keras.layers.Dense(self.embed_dim, name="fc2")
        self.final_layer_norm = keras.layers.LayerNormalization(epsilon=1e-5, name="final_layer_norm")
        self.config = config

    def call(
        self,
        hidden_states,
        attention_mask: tf.Tensor | None = None,
        encoder_hidden_states: tf.Tensor | None = None,
        encoder_attention_mask: tf.Tensor | None = None,
        layer_head_mask: tf.Tensor | None = None,
        cross_attn_layer_head_mask: tf.Tensor | None = None,
        past_key_value: Tuple[tf.Tensor] | None = None,
        training=False,
    ) -> Tuple[tf.Tensor, tf.Tensor, Tuple[Tuple[tf.Tensor]]]:
        """
        Args:
            hidden_states (`tf.Tensor`): input to the layer of shape `(batch, seq_len, embed_dim)`
            attention_mask (`tf.Tensor`): attention mask of size
                `(batch, 1, tgt_len, src_len)` where padding elements are indicated by very large negative values.
            encoder_hidden_states (`tf.Tensor`):
                cross attention input to the layer of shape `(batch, seq_len, embed_dim)`
            encoder_attention_mask (`tf.Tensor`): encoder attention mask of size
                `(batch, 1, tgt_len, src_len)` where padding elements are indicated by very large negative values.
            layer_head_mask (`tf.Tensor`): mask for attention heads in a given layer of size
                `(decoder_attention_heads,)`
            cross_attn_layer_head_mask (`tf.Tensor`): mask for heads of the cross-attention module.
                `(decoder_attention_heads,)`
            past_key_value (`Tuple(tf.Tensor)`): cached past key and value projection states
        """
        residual = hidden_states
        hidden_states = self.self_attn_layer_norm(hidden_states)

        # Self Attention
        # decoder uni-directional self-attention cached key/values tuple is at positions 1,2
        self_attn_past_key_value = past_key_value[:2] if past_key_value is not None else None
        # add present self-attn cache to positions 1,2 of present_key_value tuple
        hidden_states, self_attn_weights, present_key_value = self.self_attn(
            hidden_states=hidden_states,
            past_key_value=self_attn_past_key_value,
            attention_mask=attention_mask,
            layer_head_mask=layer_head_mask,
            training=training,
        )
        hidden_states = self.dropout(hidden_states, training=training)
        hidden_states = residual + hidden_states

        # Cross-Attention Block
        cross_attn_present_key_value = None
        cross_attn_weights = None
        if encoder_hidden_states is not None:
            residual = hidden_states
            hidden_states = self.encoder_attn_layer_norm(hidden_states)

            # cross_attn cached key/values tuple is at positions 3,4 of present_key_value tuple
            cross_attn_past_key_value = past_key_value[-2:] if past_key_value is not None else None
            hidden_states, cross_attn_weights, cross_attn_present_key_value = self.encoder_attn(
                hidden_states=hidden_states,
                key_value_states=encoder_hidden_states,
                attention_mask=encoder_attention_mask,
                layer_head_mask=cross_attn_layer_head_mask,
                past_key_value=cross_attn_past_key_value,
                training=training,
            )
            hidden_states = self.dropout(hidden_states, training=training)
            hidden_states = residual + hidden_states

            # add cross-attn to positions 3,4 of present_key_value tuple
            present_key_value = present_key_value + cross_attn_present_key_value

        # Fully Connected
        residual = hidden_states
        hidden_states = self.final_layer_norm(hidden_states)
        hidden_states = self.activation_fn(self.fc1(hidden_states))
        hidden_states = self.activation_dropout(hidden_states, training=training)
        hidden_states = self.fc2(hidden_states)
        hidden_states = self.dropout(hidden_states, training=training)
        hidden_states = residual + hidden_states

        return (
            hidden_states,
            self_attn_weights,
            cross_attn_weights,
            present_key_value,
        )

    def build(self, input_shape=None):
        if self.built:
            return
        self.built = True
        if getattr(self, "self_attn", None) is not None:
            with tf.name_scope(self.self_attn.name):
                self.self_attn.build(None)
        if getattr(self, "self_attn_layer_norm", None) is not None:
            with tf.name_scope(self.self_attn_layer_norm.name):
                self.self_attn_layer_norm.build([None, None, self.embed_dim])
        if getattr(self, "encoder_attn", None) is not None:
            with tf.name_scope(self.encoder_attn.name):
                self.encoder_attn.build(None)
        if getattr(self, "encoder_attn_layer_norm", None) is not None:
            with tf.name_scope(self.encoder_attn_layer_norm.name):
                self.encoder_attn_layer_norm.build([None, None, self.embed_dim])
        if getattr(self, "fc1", None) is not None:
            with tf.name_scope(self.fc1.name):
                self.fc1.build([None, None, self.embed_dim])
        if getattr(self, "fc2", None) is not None:
            with tf.name_scope(self.fc2.name):
                self.fc2.build([None, None, self.config.decoder_ffn_dim])
        if getattr(self, "final_layer_norm", None) is not None:
            with tf.name_scope(self.final_layer_norm.name):
                self.final_layer_norm.build([None, None, self.embed_dim])


class TFWhisperPreTrainedModel(TFPreTrainedModel):
    config_class = WhisperConfig
    base_model_prefix = "model"
    main_input_name = "input_features"

    def _get_feat_extract_output_lengths(self, input_lengths: tf.Tensor) -> int:
        """
        Computes the output length of the convolutional layers
        """
        input_lengths = (input_lengths - 1) // 2 + 1

        return input_lengths

    @property
    def dummy_inputs(self) -> Dict[str, tf.Tensor]:
        """
        Dummy inputs to build the network.

        Returns:
            `Dict[str, tf.Tensor]`: The dummy inputs.
        """
        return {
            self.main_input_name: tf.random.uniform(
                [1, self.config.num_mel_bins, self.config.max_source_positions * 2 - 1], dtype=tf.float32
            ),
            "decoder_input_ids": tf.constant([[1, 3]], dtype=tf.int32),
        }

    @property
    def input_signature(self):
        return {
            "input_features": tf.TensorSpec((None, self.config.num_mel_bins, None), tf.float32, name="input_features"),
            "decoder_input_ids": tf.TensorSpec((None, None), tf.int32, name="decoder_input_ids"),
            "decoder_attention_mask": tf.TensorSpec((None, None), tf.int32, name="decoder_attention_mask"),
        }


WHISPER_START_DOCSTRING = r"""
    This model inherits from [`TFPreTrainedModel`]. Check the superclass documentation for the generic methods the
    library implements for all its model (such as downloading or saving, resizing the input embeddings, pruning heads
    etc.)

    This model is also a [keras.Model](https://www.tensorflow.org/api_docs/python/tf/keras/Model) subclass. Use it
    as a regular TF 2.0 Keras Model and refer to the TF 2.0 documentation for all matter related to general usage and
    behavior.

    Parameters:
        config ([`WhisperConfig`]):
            Model configuration class with all the parameters of the model. Initializing with a config file does not
            load the weights associated with the model, only the configuration. Check out the
            [`~TFPreTrainedModel.from_pretrained`] method to load the model weights.
"""

WHISPER_INPUTS_DOCSTRING = r"""
    Args:
        input_features (`tf.Tensor` of shape `(batch_size, feature_size, sequence_length)`):
            Float values of fbank features extracted from the raw speech waveform. Raw speech waveform can be obtained
            by loading a `.flac` or `.wav` audio file into an array of type `List[float]` or a `numpy.ndarray`, *e.g.*
            via the soundfile library (`pip install soundfile`). To prepare the array into `input_features`, the
            [`AutoFeatureExtractor`] should be used for extracting the fbank features, padding and conversion into a
            tensor of type `tf.Tensor`. See [`~WhisperFeatureExtractor.__call__`]
        decoder_input_ids (`tf.Tensor` of shape `(batch_size, target_sequence_length)`, *optional*):
            Indices of decoder input sequence tokens in the vocabulary.

            Indices can be obtained using [`SpeechToTextTokenizer`]. See [`PreTrainedTokenizer.encode`] and
            [`PreTrainedTokenizer.__call__`] for details.

            [What are decoder input IDs?](../glossary#decoder-input-ids)

            SpeechToText uses the `eos_token_id` as the starting token for `decoder_input_ids` generation. If
            `past_key_values` is used, optionally only the last `decoder_input_ids` have to be input (see
            `past_key_values`).
        decoder_attention_mask (`tf.Tensor` of shape `(batch_size, target_sequence_length)`, *optional*):
            Default behavior: generate a tensor that ignores pad tokens in `decoder_input_ids`. Causal mask will also
            be used by default.

            If you want to change padding behavior, you should read
            [`modeling_whisper._prepare_decoder_attention_mask`] and modify to your needs. See diagram 1 in [the
            paper](https://arxiv.org/abs/1910.13461) for more information on the default strategy.
        head_mask (`tf.Tensor` of shape `(encoder_layers, encoder_attention_heads)`, *optional*):
            Mask to nullify selected heads of the attention modules in the encoder. Mask values selected in `[0, 1]`:

            - 1 indicates the head is **not masked**,
            - 0 indicates the head is **masked**.

        decoder_head_mask (`tf.Tensor` of shape `(decoder_layers, decoder_attention_heads)`, *optional*):
            Mask to nullify selected heads of the attention modules in the decoder. Mask values selected in `[0, 1]`:

            - 1 indicates the head is **not masked**,
            - 0 indicates the head is **masked**.

        cross_attn_head_mask (`tf.Tensor` of shape `(decoder_layers, decoder_attention_heads)`, *optional*):
            Mask to nullify selected heads of the cross-attention modules. Mask values selected in `[0, 1]`:

            - 1 indicates the head is **not masked**,
            - 0 indicates the head is **masked**.

        encoder_outputs (`tuple(tuple(tf.Tensor)`, *optional*):
            Tuple consists of (`last_hidden_state`, *optional*: `hidden_states`, *optional*: `attentions`)
            `last_hidden_state` of shape `(batch_size, sequence_length, hidden_size)`, *optional*) is a sequence of
            hidden-states at the output of the last layer of the encoder. Used in the cross-attention of the decoder.
        past_key_values (`tuple(tuple(tf.Tensor))`, *optional*, returned when `use_cache=True` is passed or when `config.use_cache=True`):
            Tuple of `tuple(tf.Tensor)` of length `config.n_layers`, with each tuple having 2 tensors of shape
            `(batch_size, num_heads, sequence_length, embed_size_per_head)`) and 2 additional tensors of shape
            `(batch_size, num_heads, encoder_sequence_length, embed_size_per_head)`.

            Contains pre-computed hidden-states (key and values in the self-attention blocks and in the cross-attention
            blocks) that can be used (see `past_key_values` input) to speed up sequential decoding.

            If `past_key_values` are used, the user can optionally input only the last `decoder_input_ids` (those that
            don't have their past key value states given to this model) of shape `(batch_size, 1)` instead of all
            `decoder_input_ids` of shape `(batch_size, sequence_length)`.
        decoder_inputs_embeds (`tf.Tensor` of shape `(batch_size, target_sequence_length, hidden_size)`, *optional*):
            Optionally, instead of passing `decoder_input_ids` you can choose to directly pass an embedded
            representation. If `past_key_values` is used, optionally only the last `decoder_inputs_embeds` have to be
            input (see `past_key_values`). This is useful if you want more control over how to convert
            `decoder_input_ids` indices into associated vectors than the model's internal embedding lookup matrix.
        use_cache (`bool`, *optional*):
            If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding (see
            `past_key_values`).
        output_attentions (`bool`, *optional*):
            Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned
            tensors for more detail.
        output_hidden_states (`bool`, *optional*):
            Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for
            more detail.
        return_dict (`bool`, *optional*):
            Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple.
"""


@keras_serializable
class TFWhisperEncoder(keras.layers.Layer):
    config_class = WhisperConfig
    """
    Transformer encoder consisting of *config.encoder_layers* self attention layers. Each layer is a
    [`TFWhisperEncoderLayer`].

    Args:
        config: WhisperConfig
        embed_tokens (TFWhisperEmbedding): output embedding
    """

    def __init__(self, config: WhisperConfig, **kwargs):
        super().__init__(**kwargs)
        self.config = config
        self.layerdrop = config.encoder_layerdrop

        self.embed_dim = config.d_model
        self.num_mel_bins = config.num_mel_bins
        self.padding_idx = config.pad_token_id
        self.max_source_positions = config.max_source_positions
        self.embed_scale = math.sqrt(self.embed_dim) if config.scale_embedding else 1.0

        # Padding is added in call() to match the PyTorch implementation
        self.conv1 = keras.layers.Conv1D(self.embed_dim, kernel_size=3, strides=1, padding="valid", name="conv1")
        self.conv2 = keras.layers.Conv1D(self.embed_dim, kernel_size=3, strides=2, padding="valid", name="conv2")

        self.embed_positions = TFWhisperPositionalEmbedding(
            num_positions=self.max_source_positions,
            embedding_dim=self.embed_dim,
            embedding_initializer=sinusoidal_embedding_init,
            name="embed_positions",
        )
        self.embed_positions.trainable = False

        self.encoder_layers = [TFWhisperEncoderLayer(config, name=f"layers.{i}") for i in range(config.encoder_layers)]
        self.layer_norm = keras.layers.LayerNormalization(epsilon=1e-5, name="layer_norm")

        self.dropout = keras.layers.Dropout(config.dropout)

    @unpack_inputs
    def call(
        self,
        input_features=None,
        head_mask=None,
        output_attentions=None,
        output_hidden_states=None,
        return_dict=None,
        training=False,
    ):
        r"""
        Args:
            input_features (`tf.Tensor` of shape `(batch_size, feature_size, sequence_length)`):
                Float values of fbank features extracted from the raw speech waveform. Raw speech waveform can be
                obtained by loading a `.flac` or `.wav` audio file into an array of type `List[float]` or a
                `numpy.ndarray`, *e.g.* via the soundfile library (`pip install soundfile`). To prepare the array into
                `input_features`, the [`AutoFeatureExtractor`] should be used for extracting the fbank features,
                padding and conversion into a tensor of type `tf.Tensor`. See [`~WhisperFeatureExtractor.__call__`]
            head_mask (`tf.Tensor` of shape `(encoder_layers, encoder_attention_heads)`, *optional*):
                Mask to nullify selected heads of the attention modules. Mask values selected in `[0, 1]`:

                - 1 indicates the head is **not masked**,
                - 0 indicates the head is **masked**.

            output_attentions (`bool`, *optional*):
                Whether or not to return the attentions tensors of all attention layers. See `attentions` under
                returned tensors for more detail.
            output_hidden_states (`bool`, *optional*):
                Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors
                for more detail.
            return_dict (`bool`, *optional*):
                Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple.
        """

        output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
        output_hidden_states = (
            output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
        )
        return_dict = return_dict if return_dict is not None else self.config.use_return_dict

        # TF 2.0 layers can't use channels first format when running on CPU.
        input_features = tf.transpose(input_features, perm=(0, 2, 1))
        input_features = tf.pad(input_features, [[0, 0], [1, 1], [0, 0]])
        inputs_embeds = keras.activations.gelu(self.conv1(input_features))
        inputs_embeds = tf.pad(inputs_embeds, [[0, 0], [1, 1], [0, 0]])
        inputs_embeds = keras.activations.gelu(self.conv2(inputs_embeds))
        inputs_embeds = tf.transpose(inputs_embeds, perm=(0, 1, 2))

        embed_pos = self.embed_positions(input_ids=tf.zeros((1, self.max_source_positions), dtype=tf.int32))

        hidden_states = inputs_embeds + embed_pos
        hidden_states = self.dropout(hidden_states, training=training)

        encoder_states = () if output_hidden_states else None
        all_attentions = () if output_attentions else None

        # check if head_mask has a correct number of layers specified if desired
        if head_mask is not None:
            tf.debugging.assert_equal(
                shape_list(head_mask)[0],
                len(self.encoder_layers),
                message=(
                    f"The head_mask should be specified for {len(self.encoder_layers)} layers, but it is for"
                    f" {shape_list(head_mask)[0]}."
                ),
            )

        for idx, encoder_layer in enumerate(self.encoder_layers):
            if output_hidden_states:
                encoder_states = encoder_states + (hidden_states,)
            # add LayerDrop (see https://arxiv.org/abs/1909.11556 for description)
            dropout_probability = random.uniform(0, 1)
            if training and (dropout_probability < self.layerdrop):  # skip the layer
                continue

            hidden_states, attn = encoder_layer(
                hidden_states,
                None,
                layer_head_mask=(head_mask[idx] if head_mask is not None else None),
                training=training,
            )

            if output_attentions:
                all_attentions += (attn,)

        hidden_states = self.layer_norm(hidden_states)
        if output_hidden_states:
            encoder_states = encoder_states + (hidden_states,)

        if not return_dict:
            return tuple(v for v in [hidden_states, encoder_states, all_attentions] if v is not None)
        return TFBaseModelOutput(
            last_hidden_state=hidden_states, hidden_states=encoder_states, attentions=all_attentions
        )

    def build(self, input_shape=None):
        if self.built:
            return
        self.built = True
        if getattr(self, "conv1", None) is not None:
            with tf.name_scope(self.conv1.name):
                self.conv1.build([None, None, self.num_mel_bins])
        if getattr(self, "conv2", None) is not None:
            with tf.name_scope(self.conv2.name):
                self.conv2.build([None, None, self.embed_dim])
        if getattr(self, "embed_positions", None) is not None:
            with tf.name_scope(self.embed_positions.name):
                self.embed_positions.build(None)
        if getattr(self, "layer_norm", None) is not None:
            with tf.name_scope(self.layer_norm.name):
                self.layer_norm.build([None, None, self.config.d_model])
        if getattr(self, "encoder_layers", None) is not None:
            for layer in self.encoder_layers:
                with tf.name_scope(layer.name):
                    layer.build(None)


@keras_serializable
class TFWhisperDecoder(keras.layers.Layer):
    config_class = WhisperConfig
    """
    Transformer decoder consisting of *config.decoder_layers* layers. Each layer is a [`TFWhisperDecoderLayer`]

    Args:
        config: WhisperConfig
    """

    def __init__(self, config: WhisperConfig, **kwargs):
        super().__init__(**kwargs)
        self.config = config
        self.dropout = keras.layers.Dropout(config.dropout)
        self.layerdrop = config.decoder_layerdrop
        self.padding_idx = config.pad_token_id
        self.max_target_positions = config.max_target_positions
        self.max_source_positions = config.max_source_positions
        self.embed_scale = math.sqrt(config.d_model) if config.scale_embedding else 1.0

        self.embed_tokens = keras.layers.Embedding(
            input_dim=config.vocab_size,
            output_dim=config.d_model,
            embeddings_initializer=keras.initializers.TruncatedNormal(stddev=self.config.init_std),
            name="embed_tokens",
        )
        self.embed_positions = TFWhisperPositionalEmbedding(
            self.max_target_positions, config.d_model, name="embed_positions"
        )

        self.decoder_layers = [TFWhisperDecoderLayer(config, name=f"layers.{i}") for i in range(config.decoder_layers)]

        self.layer_norm = keras.layers.LayerNormalization(epsilon=1e-5, name="layer_norm")

    def get_input_embeddings(self):
        return self.embed_tokens

    def set_input_embeddings(self, value):
        self.embed_tokens = value

    def _prepare_decoder_attention_mask(self, attention_mask, input_shape, past_key_values_length):
        # create causal mask
        # [bsz, seq_len] -> [bsz, 1, tgt_seq_len, src_seq_len]
        batch_size, seq_len = input_shape[0], input_shape[1]

        combined_attention_mask = tf.cond(
            tf.math.greater(seq_len, 1),
            lambda: _make_causal_mask(input_shape, past_key_values_length=past_key_values_length),
            lambda: _expand_mask(tf.ones((batch_size, seq_len + past_key_values_length)), tgt_len=seq_len),
        )

        if attention_mask is not None:
            # [bsz, seq_len] -> [bsz, 1, tgt_seq_len, src_seq_len]
            expanded_attn_mask = _expand_mask(attention_mask, tgt_len=input_shape[-1])
            combined_attention_mask = (
                expanded_attn_mask if combined_attention_mask is None else expanded_attn_mask + combined_attention_mask
            )
        return combined_attention_mask

    @unpack_inputs
    def call(
        self,
        input_ids=None,
        attention_mask=None,
        position_ids=None,
        encoder_hidden_states=None,
        head_mask=None,
        cross_attn_head_mask=None,
        past_key_values=None,
        inputs_embeds=None,
        use_cache=None,
        output_attentions=None,
        output_hidden_states=None,
        return_dict=None,
        training=False,
    ):
        r"""
        Args:
            input_ids (`tf.Tensor` of shape `(batch_size, sequence_length)`):
                Indices of input sequence tokens in the vocabulary. Padding will be ignored by default should you
                provide it.

                Indices can be obtained using [`WhisperTokenizer`]. See [`PreTrainedTokenizer.encode`] and
                [`PreTrainedTokenizer.__call__`] for details.

                [What are input IDs?](../glossary#input-ids)
            attention_mask (`tf.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
                Mask to avoid performing attention on padding token indices. Mask values selected in `[0, 1]`:

                - 1 for tokens that are **not masked**,
                - 0 for tokens that are **masked**.

                [What are attention masks?](../glossary#attention-mask)
            position_ids (`tf.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
                Indices of positions of each decoder input sequence tokens in the position embeddings. Selected in the
                range `[0, config.max_position_embeddings - 1]`.
            encoder_hidden_states (`tf.Tensor` of shape `(batch_size, encoder_sequence_length, hidden_size)`, *optional*):
                Sequence of hidden-states at the output of the last layer of the encoder. Used in the cross-attention
                of the decoder.
            head_mask (`tf.Tensor` of shape `(decoder_layers, decoder_attention_heads)`, *optional*):
                Mask to nullify selected heads of the attention modules. Mask values selected in `[0, 1]`:

                - 1 indicates the head is **not masked**,
                - 0 indicates the head is **masked**.

            cross_attn_head_mask (`tf.Tensor` of shape `(decoder_layers, decoder_attention_heads)`, *optional*):
                Mask to nullify selected heads of the attention modules in encoder to avoid performing cross-attention
                on hidden heads. Mask values selected in `[0, 1]`:

                - 1 indicates the head is **not masked**,
                - 0 indicates the head is **masked**.

            past_key_values (`tuple(tuple(tf.Tensor))`, *optional*, returned when `use_cache=True` is passed or when `config.use_cache=True`):
                Tuple of `tuple(tf.Tensor)` of length `config.n_layers`, with each tuple having 2 tensors of shape
                `(batch_size, num_heads, sequence_length, embed_size_per_head)`) and 2 additional tensors of shape
                `(batch_size, num_heads, encoder_sequence_length, embed_size_per_head)`.

                Contains pre-computed hidden-states (key and values in the self-attention blocks and in the
                cross-attention blocks) that can be used (see `past_key_values` input) to speed up sequential decoding.

                If `past_key_values` are used, the user can optionally input only the last `decoder_input_ids` (those
                that don't have their past key value states given to this model) of shape `(batch_size, 1)` instead of
                all `decoder_input_ids` of shape `(batch_size, sequence_length)`.
            inputs_embeds (`tf.Tensor` of shape `(batch_size, sequence_length, hidden_size)`, *optional*):
                Optionally, instead of passing `input_ids` you can choose to directly pass an embedded representation.
                This is useful if you want more control over how to convert `input_ids` indices into associated vectors
                than the model's internal embedding lookup matrix.
            output_attentions (`bool`, *optional*):
                Whether or not to return the attentions tensors of all attention layers. See `attentions` under
                returned tensors for more detail.
            output_hidden_states (`bool`, *optional*):
                Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors
                for more detail.
            return_dict (`bool`, *optional*):
                Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple.
        """
        output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
        output_hidden_states = (
            output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
        )
        use_cache = use_cache if use_cache is not None else self.config.use_cache
        return_dict = return_dict if return_dict is not None else self.config.use_return_dict

        # retrieve input_ids and inputs_embeds
        if input_ids is not None and inputs_embeds is not None:
            raise ValueError("You cannot specify both decoder_input_ids and decoder_inputs_embeds at the same time")
        elif input_ids is not None:
            input_shape = tf.shape(input_ids)
            input_ids = tf.reshape(input_ids, (-1, input_shape[-1]))
        elif inputs_embeds is not None:
            input_shape = tf.shape(inputs_embeds)[:-1]
        else:
            raise ValueError("You have to specify either decoder_input_ids or decoder_inputs_embeds")

        # past_key_values_length
        past_key_values_length = tf.shape(past_key_values[0][0])[2] if past_key_values is not None else 0

        if inputs_embeds is None:
            check_embeddings_within_bounds(input_ids, self.embed_tokens.input_dim)
            inputs_embeds = self.embed_tokens(input_ids)

        attention_mask = self._prepare_decoder_attention_mask(attention_mask, input_shape, past_key_values_length)

        # embed positions
        filled_past_positions = past_key_values_length if position_ids is None else position_ids[0, -1]
        positions = self.embed_positions(input_ids, past_key_values_length=filled_past_positions)

        hidden_states = inputs_embeds + positions
        hidden_states = self.dropout(hidden_states, training=training)

        # decoder layers
        all_hidden_states = () if output_hidden_states else None
        all_self_attns = () if output_attentions else None
        all_cross_attentions = () if (output_attentions and encoder_hidden_states is not None) else None
        next_decoder_cache = () if use_cache else None

        # check if head_mask/cross_attn_head_mask has a correct number of layers specified if desired
        for attn_mask_name, attn_mask in [("head_mask", head_mask), ("cross_attn_head_mask", cross_attn_head_mask)]:
            if attn_mask is not None:
                tf.debugging.assert_equal(
                    shape_list(attn_mask)[0],
                    len(self.decoder_layers),
                    message=(
                        f"The {attn_mask_name} should be specified for {len(self.decoder_layers)} layers, but it is"
                        f" for {shape_list(attn_mask)[0]}."
                    ),
                )

        for idx, decoder_layer in enumerate(self.decoder_layers):
            # add LayerDrop (see https://arxiv.org/abs/1909.11556 for description)
            if output_hidden_states:
                all_hidden_states += (hidden_states,)
            dropout_probability = random.uniform(0, 1)
            if training and (dropout_probability < self.layerdrop):
                continue

            past_key_value = past_key_values[idx] if past_key_values is not None else None

            layer_outputs = decoder_layer(
                hidden_states,
                attention_mask=attention_mask,
                encoder_hidden_states=encoder_hidden_states,
                layer_head_mask=(head_mask[idx] if head_mask is not None else None),
                cross_attn_layer_head_mask=(cross_attn_head_mask[idx] if cross_attn_head_mask is not None else None),
                past_key_value=past_key_value,
                training=training,
            )
            hidden_states = layer_outputs[0]

            if use_cache:
                next_decoder_cache += (layer_outputs[3],)

            if output_attentions:
                all_self_attns += (layer_outputs[1],)

                if encoder_hidden_states is not None:
                    all_cross_attentions += (layer_outputs[2],)

        hidden_states = self.layer_norm(hidden_states)
        # add hidden states from the last decoder layer
        if output_hidden_states:
            all_hidden_states += (hidden_states,)

        next_cache = next_decoder_cache if use_cache else None
        if not return_dict:
            return tuple(
                v
                for v in [hidden_states, next_cache, all_hidden_states, all_self_attns, all_cross_attentions]
                if v is not None
            )
        return TFBaseModelOutputWithPastAndCrossAttentions(
            last_hidden_state=hidden_states,
            past_key_values=next_cache,
            hidden_states=all_hidden_states,
            attentions=all_self_attns,
            cross_attentions=all_cross_attentions,
        )

    def build(self, input_shape=None):
        if self.built:
            return
        self.built = True
        if getattr(self, "embed_tokens", None) is not None:
            with tf.name_scope(self.embed_tokens.name):
                self.embed_tokens.build(None)
        if getattr(self, "embed_positions", None) is not None:
            with tf.name_scope(self.embed_positions.name):
                self.embed_positions.build(None)
        if getattr(self, "layer_norm", None) is not None:
            with tf.name_scope(self.layer_norm.name):
                self.layer_norm.build([None, None, self.config.d_model])
        if getattr(self, "decoder_layers", None) is not None:
            for layer in self.decoder_layers:
                with tf.name_scope(layer.name):
                    layer.build(None)


@add_start_docstrings(
    "The bare Whisper Model outputting raw hidden-states without any specific head on top.",
    WHISPER_START_DOCSTRING,
)
@keras_serializable
class TFWhisperMainLayer(keras.layers.Layer):
    config_class = WhisperConfig

    def __init__(self, config: WhisperConfig, **kwargs):
        super().__init__(**kwargs)
        self.config = config
        self.encoder = TFWhisperEncoder(config, name="encoder")
        self.decoder = TFWhisperDecoder(config, name="decoder")

    def get_input_embeddings(self):
        return self.decoder.embed_tokens

    def set_input_embeddings(self, value):
        self.decoder.embed_tokens = value

    def get_encoder(self):
        return self.encoder

    def get_decoder(self):
        return self.decoder

    @add_start_docstrings_to_model_forward(WHISPER_INPUTS_DOCSTRING)
    @replace_return_docstrings(output_type=TFSeq2SeqLMOutput, config_class=_CONFIG_FOR_DOC)
    @unpack_inputs
    def call(
        self,
        input_features=None,
        decoder_input_ids=None,
        decoder_attention_mask=None,
        decoder_position_ids=None,
        head_mask=None,
        decoder_head_mask=None,
        cross_attn_head_mask=None,
        encoder_outputs=None,
        past_key_values=None,
        decoder_inputs_embeds=None,
        use_cache=None,
        output_attentions=None,
        output_hidden_states=None,
        return_dict=None,
        training=False,
    ):
        r"""
        Returns:

        Example:

         ```python
         >>> import tensorflow as tf
         >>> from transformers import TFWhisperModel, AutoFeatureExtractor
         >>> from datasets import load_dataset

         >>> model = TFWhisperModel.from_pretrained("openai/whisper-base")
         >>> feature_extractor = AutoFeatureExtractor.from_pretrained("openai/whisper-base")
         >>> ds = load_dataset("hf-internal-testing/librispeech_asr_dummy", "clean", split="validation")
         >>> inputs = feature_extractor(ds[0]["audio"]["array"], return_tensors="tf")
         >>> input_features = inputs.input_features
         >>> decoder_input_ids = tf.convert_to_tensor([[1, 1]]) * model.config.decoder_start_token_id
         >>> last_hidden_state = model(input_features, decoder_input_ids=decoder_input_ids).last_hidden_state
         >>> list(last_hidden_state.shape)
         [1, 2, 512]
         ```"""
        output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
        output_hidden_states = (
            output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
        )
        use_cache = use_cache if use_cache is not None else self.config.use_cache
        return_dict = return_dict if return_dict is not None else self.config.use_return_dict

        if encoder_outputs is None:
            encoder_outputs = self.encoder(
                input_features,
                head_mask=head_mask,
                output_attentions=output_attentions,
                output_hidden_states=output_hidden_states,
                return_dict=return_dict,
                training=training,
            )
        # If the user passed a tuple for encoder_outputs, we wrap it in a TFBaseModelOutput when return_dict=True
        elif return_dict and not isinstance(encoder_outputs, TFBaseModelOutput):
            encoder_outputs = TFBaseModelOutput(
                last_hidden_state=encoder_outputs[0],
                hidden_states=encoder_outputs[1] if len(encoder_outputs) > 1 else None,
                attentions=encoder_outputs[2] if len(encoder_outputs) > 2 else None,
            )

        # decoder outputs consists of (dec_features, past_key_value, dec_hidden, dec_attn)
        decoder_outputs = self.decoder(
            input_ids=decoder_input_ids,
            attention_mask=decoder_attention_mask,
            position_ids=decoder_position_ids,
            encoder_hidden_states=encoder_outputs[0],
            head_mask=decoder_head_mask,
            cross_attn_head_mask=cross_attn_head_mask,
            past_key_values=past_key_values,
            inputs_embeds=decoder_inputs_embeds,
            use_cache=use_cache,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            return_dict=return_dict,
            training=training,
        )

        if not return_dict:
            return decoder_outputs + encoder_outputs

        return TFSeq2SeqModelOutput(
            last_hidden_state=decoder_outputs.last_hidden_state,
            past_key_values=decoder_outputs.past_key_values,
            decoder_hidden_states=decoder_outputs.hidden_states,
            decoder_attentions=decoder_outputs.attentions,
            cross_attentions=decoder_outputs.cross_attentions,
            encoder_last_hidden_state=encoder_outputs.last_hidden_state,
            encoder_hidden_states=encoder_outputs.hidden_states,
            encoder_attentions=encoder_outputs.attentions,
        )

    def build(self, input_shape=None):
        if self.built:
            return
        self.built = True
        if getattr(self, "encoder", None) is not None:
            with tf.name_scope(self.encoder.name):
                self.encoder.build(None)
        if getattr(self, "decoder", None) is not None:
            with tf.name_scope(self.decoder.name):
                self.decoder.build(None)


@add_start_docstrings(
    "The bare Whisper Model outputting raw hidden-states without any specific head on top.",
    WHISPER_START_DOCSTRING,
)
class TFWhisperModel(TFWhisperPreTrainedModel):
    def __init__(self, config: WhisperConfig, **kwargs):
        super().__init__(config, **kwargs)

        self.model = TFWhisperMainLayer(config, name="model")

    def get_input_embeddings(self):
        return self.model.decoder.embed_tokens

    def set_input_embeddings(self, value):
        self.model.decoder.embed_tokens = value

    def get_encoder(self):
        return self.model.encoder

    def get_decoder(self):
        return self.model.decoder

    def decoder(self):
        return self.model.decoder

    def encoder(self):
        return self.model.encoder

    @add_start_docstrings_to_model_forward(WHISPER_INPUTS_DOCSTRING)
    @replace_return_docstrings(output_type=TFSeq2SeqModelOutput, config_class=_CONFIG_FOR_DOC)
    @unpack_inputs
    def call(
        self,
        input_features: TFModelInputType | None = None,
        decoder_input_ids: np.ndarray | tf.Tensor | None = None,
        decoder_attention_mask: np.ndarray | tf.Tensor | None = None,
        decoder_position_ids: np.ndarray | tf.Tensor | None = None,
        head_mask: np.ndarray | tf.Tensor | None = None,
        decoder_head_mask: np.ndarray | tf.Tensor | None = None,
        cross_attn_head_mask: np.ndarray | tf.Tensor | None = None,
        encoder_outputs: Optional[Tuple[Tuple[Union[np.ndarray, tf.Tensor]]]] = None,
        past_key_values: Optional[Tuple[Tuple[Union[np.ndarray, tf.Tensor]]]] = None,
        decoder_inputs_embeds: Optional[Tuple[Union[np.ndarray, tf.Tensor]]] = None,
        use_cache: Optional[bool] = None,
        output_attentions: Optional[bool] = None,
        output_hidden_states: Optional[bool] = None,
        return_dict: Optional[bool] = None,
        training: bool = False,
    ) -> Union[Tuple[tf.Tensor], TFSeq2SeqModelOutput]:
        r"""
        Returns:

        Example:

         ```python
         >>> import tensorflow as tf
         >>> from transformers import TFWhisperModel, AutoFeatureExtractor
         >>> from datasets import load_dataset

         >>> model = TFWhisperModel.from_pretrained("openai/whisper-base")
         >>> feature_extractor = AutoFeatureExtractor.from_pretrained("openai/whisper-base")
         >>> ds = load_dataset("hf-internal-testing/librispeech_asr_dummy", "clean", split="validation")
         >>> inputs = feature_extractor(ds[0]["audio"]["array"], return_tensors="tf")
         >>> input_features = inputs.input_features
         >>> decoder_input_ids = tf.convert_to_tensor([[1, 1]]) * model.config.decoder_start_token_id
         >>> last_hidden_state = model(input_features, decoder_input_ids=decoder_input_ids).last_hidden_state
         >>> list(last_hidden_state.shape)
         [1, 2, 512]
         ```"""
        outputs = self.model(
            input_features=input_features,
            decoder_input_ids=decoder_input_ids,
            decoder_attention_mask=decoder_attention_mask,
            decoder_position_ids=decoder_position_ids,
            head_mask=head_mask,
            decoder_head_mask=decoder_head_mask,
            cross_attn_head_mask=cross_attn_head_mask,
            encoder_outputs=encoder_outputs,
            past_key_values=past_key_values,
            decoder_inputs_embeds=decoder_inputs_embeds,
            use_cache=use_cache,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            return_dict=return_dict,
            training=training,
        )
        return outputs

    def serving_output(self, output):
        pkv = tf.tuple(output.past_key_values)[1] if self.config.use_cache else None
        dec_hs = tf.convert_to_tensor(output.decoder_hidden_states) if self.config.output_hidden_states else None
        dec_attns = tf.convert_to_tensor(output.decoder_attentions) if self.config.output_attentions else None
        cross_attns = tf.convert_to_tensor(output.cross_attentions) if self.config.output_attentions else None
        enc_hs = tf.convert_to_tensor(output.encoder_hidden_states) if self.config.output_hidden_states else None
        enc_attns = tf.convert_to_tensor(output.encoder_attentions) if self.config.output_attentions else None

        return TFSeq2SeqModelOutput(
            last_hidden_state=output.last_hidden_state,
            past_key_values=pkv,
            decoder_hidden_states=dec_hs,
            decoder_attentions=dec_attns,
            cross_attentions=cross_attns,
            encoder_last_hidden_state=output.encoder_last_hidden_state,
            encoder_hidden_states=enc_hs,
            encoder_attentions=enc_attns,
        )

    def build(self, input_shape=None):
        if self.built:
            return
        self.built = True
        if getattr(self, "model", None) is not None:
            with tf.name_scope(self.model.name):
                self.model.build(None)


@add_start_docstrings(
    "The Whisper Model with a language modeling head. Can be used for automatic speech recognition.",
    WHISPER_START_DOCSTRING,
)
class TFWhisperForConditionalGeneration(TFWhisperPreTrainedModel, TFCausalLanguageModelingLoss):
    base_model_prefix = "model"
    _keys_to_ignore_on_load_missing = [
        r"encoder.version",
        r"decoder.version",
        r"proj_out.weight",
    ]
    _keys_to_ignore_on_save = [
        r"proj_out.weight",
    ]

    def __init__(self, config: WhisperConfig, **kwargs):
        super().__init__(config, **kwargs)
        self.model = TFWhisperMainLayer(config, name="model")

    def get_encoder(self):
        return self.model.get_encoder()

    def get_decoder(self):
        return self.model.get_decoder()

    def get_output_embeddings(self):
        return self.get_input_embeddings()

    def set_output_embeddings(self, value):
        self.set_input_embeddings(value)

    def resize_token_embeddings(self, new_num_tokens: int) -> keras.layers.Embedding:
        new_embeddings = super().resize_token_embeddings(new_num_tokens)
        return new_embeddings

    @add_start_docstrings_to_model_forward(WHISPER_INPUTS_DOCSTRING)
    @replace_return_docstrings(output_type=TFSeq2SeqLMOutput, config_class=_CONFIG_FOR_DOC)
    @unpack_inputs
    def call(
        self,
        input_features: TFModelInputType | None = None,
        decoder_input_ids: np.ndarray | tf.Tensor | None = None,
        decoder_attention_mask: np.ndarray | tf.Tensor | None = None,
        decoder_position_ids: np.ndarray | tf.Tensor | None = None,
        head_mask: np.ndarray | tf.Tensor | None = None,
        decoder_head_mask: np.ndarray | tf.Tensor | None = None,
        cross_attn_head_mask: np.ndarray | tf.Tensor | None = None,
        encoder_outputs: Optional[Tuple[Tuple[Union[np.ndarray, tf.Tensor]]]] = None,
        past_key_values: Optional[Tuple[Tuple[Union[np.ndarray, tf.Tensor]]]] = None,
        decoder_inputs_embeds: Optional[Tuple[Union[np.ndarray, tf.Tensor]]] = None,
        labels: np.ndarray | tf.Tensor | None = None,
        use_cache: Optional[bool] = None,
        output_attentions: Optional[bool] = None,
        output_hidden_states: Optional[bool] = None,
        return_dict: Optional[bool] = None,
        training: bool = False,
    ) -> Union[Tuple[tf.Tensor], TFSeq2SeqLMOutput]:
        r"""
        labels (`tf.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
            Labels for computing the language modeling loss. Indices should either be in `[0, ..., config.vocab_size]`
            or -100 (see `input_ids` docstring). Tokens with indices set to `-100` are ignored (masked), the loss is
            only computed for the tokens with labels in `[0, ..., config.vocab_size]`.

        Returns:

        Example:

        ```python
        >>> import tensorflow as tf
        >>> from transformers import AutoProcessor, TFWhisperForConditionalGeneration
        >>> from datasets import load_dataset

        >>> processor = AutoProcessor.from_pretrained("openai/whisper-tiny.en")
        >>> model = TFWhisperForConditionalGeneration.from_pretrained("openai/whisper-tiny.en")

        >>> ds = load_dataset("hf-internal-testing/librispeech_asr_dummy", "clean", split="validation")

        >>> inputs = processor(ds[0]["audio"]["array"], return_tensors="tf")
        >>> input_features = inputs.input_features

        >>> generated_ids = model.generate(input_features=input_features)

        >>> transcription = processor.batch_decode(generated_ids, skip_special_tokens=True)[0]
        >>> transcription
        ' Mr. Quilter is the apostle of the middle classes, and we are glad to welcome his gospel.'
        ```"""
        return_dict = return_dict if return_dict is not None else self.config.use_return_dict

        if labels is not None:
            if decoder_input_ids is None and decoder_inputs_embeds is None:
                decoder_input_ids = shift_tokens_right(
                    labels, self.config.pad_token_id, self.config.decoder_start_token_id
                )

        outputs = self.model(
            input_features,
            decoder_input_ids=decoder_input_ids,
            encoder_outputs=encoder_outputs,
            decoder_attention_mask=decoder_attention_mask,
            decoder_position_ids=decoder_position_ids,
            head_mask=head_mask,
            decoder_head_mask=decoder_head_mask,
            cross_attn_head_mask=cross_attn_head_mask,
            past_key_values=past_key_values,
            decoder_inputs_embeds=decoder_inputs_embeds,
            use_cache=use_cache,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            return_dict=return_dict,
            training=training,
        )
        decoder_last_hidden_state = outputs[0]
        # Decoder and encoder embeddings are tied
        lm_logits = tf.matmul(decoder_last_hidden_state, self.get_output_embeddings().weights, transpose_b=True)

        loss = None if labels is None else self.hf_compute_loss(labels, lm_logits)

        if not return_dict:
            output = (lm_logits,) + outputs[1:]
            return ((loss,) + output) if loss is not None else output

        return TFSeq2SeqLMOutput(
            loss=loss,
            logits=lm_logits,
            past_key_values=outputs.past_key_values,
            decoder_hidden_states=outputs.decoder_hidden_states,
            decoder_attentions=outputs.decoder_attentions,
            cross_attentions=outputs.cross_attentions,
            encoder_last_hidden_state=outputs.encoder_last_hidden_state,
            encoder_hidden_states=outputs.encoder_hidden_states,
            encoder_attentions=outputs.encoder_attentions,
        )

    def generate(
        self,
        inputs: Optional[tf.Tensor] = None,
        generation_config: Optional[GenerationConfig] = None,
        logits_processor: Optional[TFLogitsProcessorList] = None,
        seed: Optional[List[int]] = None,
        return_timestamps: Optional[bool] = None,
        task: Optional[str] = None,
        language: Optional[str] = None,
        is_multilingual: Optional[bool] = None,
        prompt_ids: Optional[tf.Tensor] = None,
        return_token_timestamps=None,
        **kwargs,
    ):
        r"""
        Generates sequences of token ids for models with a language modeling head.

        <Tip warning={true}>

        Most generation-controlling parameters are set in `generation_config` which, if not passed, will be set to the
        model's default generation configuration. You can override any `generation_config` by passing the corresponding
        parameters to generate, e.g. `.generate(inputs, num_beams=4, do_sample=True)`.

        For an overview of generation strategies and code examples, check out the [following
        guide](../generation_strategies).

        </Tip>

        Parameters:
            inputs (`tf.Tensor` of varying shape depending on the modality, *optional*):
                The sequence used as a prompt for the generation or as model inputs to the encoder. If unset the method
                initializes it with `bos_token_id` and a batch size of 1. For decoder-only models `inputs` should of in
                the format of `input_ids`. For encoder-decoder models *inputs* can represent any of `input_ids`,
                `input_values`, `input_features`, or `pixel_values`.
            generation_config (`~generation.GenerationConfig`, *optional*):
                The generation configuration to be used as base parametrization for the generation call. `**kwargs`
                passed to generate matching the attributes of `generation_config` will override them. If
                `generation_config` is not provided, the default will be used, which had the following loading
                priority: 1) from the `generation_config.json` model file, if it exists; 2) from the model
                configuration. Please note that unspecified parameters will inherit [`~generation.GenerationConfig`]'s
                default values, whose documentation should be checked to parameterize generation.
            logits_processor (`LogitsProcessorList`, *optional*):
                Custom logits processors that complement the default logits processors built from arguments and
                generation config. If a logit processor is passed that is already created with the arguments or a
                generation config an error is thrown. This feature is intended for advanced users.
            seed (`List[int]`, *optional*):
                Random seed to control sampling, containing two integers, used when `do_sample` is `True`. See the
                `seed` argument from stateless functions in `tf.random`.
            return_timestamps (`bool`, *optional*):
                Whether to return the timestamps with the text. This enables the `TFWhisperTimestampsLogitsProcessor`.
            task (`str`, *optional*):
                Task to use for generation, either "translate" or "transcribe". The `model.config.forced_decoder_ids`
                will be updated accordingly.
            language (`str`, *optional*):
                Language token to use for generation, can be either in the form of `<|en|>`, `en` or `english`. You can
                find all the possible language tokens in the `model.generation_config.lang_to_id` dictionary.
            is_multilingual (`bool`, *optional*):
                Whether or not the model is multilingual.
            prompt_ids (`tf.Tensor`, *optional*):
                Rank-1 tensor of token IDs created by passing text to [`~WhisperProcessor.get_prompt_ids`] that is
                provided as a prompt to each chunk. This can be used to provide or "prompt-engineer" a context for
                transcription, e.g. custom vocabularies or proper nouns to make it more likely to predict those words
                correctly. It cannot be used in conjunction with `decoder_start_token_id` as it overwrites this value.
            return_token_timestamps (`bool`, *optional*):
                Whether to return token-level timestamps with the text. This can be used with or without the
                `return_timestamps` option. To get word-level timestamps, use the tokenizer to group the tokens into
                words.
            kwargs (`Dict[str, Any]`, *optional*):
                Ad hoc parametrization of `generate_config` and/or additional model-specific kwargs that will be
                forwarded to the `forward` function of the model. If the model is an encoder-decoder model, encoder
                specific kwargs should not be prefixed and decoder specific kwargs should be prefixed with *decoder_*.

        Return:
            [`~utils.ModelOutput`] or `tf.Tensor`: A [`~utils.ModelOutput`] (if `return_dict_in_generate=True` or when
            `config.return_dict_in_generate=True`) or a `tf.Tensor`.

                If the model is *not* an encoder-decoder model (`model.config.is_encoder_decoder=False`), the possible
                [`~utils.ModelOutput`] types are:

                    - [`~generation.TFGreedySearchDecoderOnlyOutput`],
                    - [`~generation.TFSampleDecoderOnlyOutput`],
                    - [`~generation.TFBeamSearchDecoderOnlyOutput`],
                    - [`~generation.TFBeamSampleDecoderOnlyOutput`]

                If the model is an encoder-decoder model (`model.config.is_encoder_decoder=True`), the possible
                [`~utils.ModelOutput`] types are:

                    - [`~generation.TFGreedySearchEncoderDecoderOutput`],
                    - [`~generation.TFSampleEncoderDecoderOutput`],
                    - [`~generation.TFBeamSearchEncoderDecoderOutput`],
                    - [`~generation.TFBeamSampleEncoderDecoderOutput`]

        """
        if generation_config is None:
            generation_config = self.generation_config

        if return_timestamps is not None:
            if not hasattr(generation_config, "no_timestamps_token_id"):
                raise ValueError(
                    "You are trying to return timestamps, but the generation config is not properly set. "
                    "Make sure to initialize the generation config with the correct attributes that are needed such as `no_timestamps_token_id`. "
                    "For more details on how to generate the approtiate config, refer to https://github.com/huggingface/transformers/issues/21878#issuecomment-1451902363"
                )

            generation_config.return_timestamps = return_timestamps
        else:
            generation_config.return_timestamps = False

        if language is not None:
            language = language.lower()
            generation_config.language = language
        if task is not None:
            generation_config.task = task

        forced_decoder_ids = None

        # Legacy code for backward compatibility
        if hasattr(self.config, "forced_decoder_ids") and self.config.forced_decoder_ids is not None:
            forced_decoder_ids = self.config.forced_decoder_ids
        elif (
            hasattr(self.generation_config, "forced_decoder_ids")
            and self.generation_config.forced_decoder_ids is not None
        ):
            forced_decoder_ids = self.generation_config.forced_decoder_ids
        else:
            forced_decoder_ids = kwargs.get("forced_decoder_ids", None)

        if task is not None or language is not None or (forced_decoder_ids is None and prompt_ids is not None):
            forced_decoder_ids = []
            if hasattr(generation_config, "language"):
                if generation_config.language in generation_config.lang_to_id.keys():
                    language_token = generation_config.language
                elif generation_config.language in TO_LANGUAGE_CODE.keys():
                    language_token = f"<|{TO_LANGUAGE_CODE[generation_config.language]}|>"
                elif generation_config.language in TO_LANGUAGE_CODE.values():
                    language_token = f"<|{generation_config.language}|>"
                else:
                    is_language_code = len(generation_config.language) == 2
                    raise ValueError(
                        f"Unsupported language: {generation_config.language}. Language should be one of:"
                        f" {list(TO_LANGUAGE_CODE.values()) if is_language_code else list(TO_LANGUAGE_CODE.keys())}."
                    )
                if language_token not in generation_config.lang_to_id:
                    raise ValueError(
                        f"{language_token} is not supported by this specific model as it is not in the `generation_config.lang_to_id`."
                        "(You should just add it to the generation config)"
                    )
                forced_decoder_ids.append((1, generation_config.lang_to_id[language_token]))
            else:
                forced_decoder_ids.append((1, None))  # automatically detect the language

            if hasattr(generation_config, "task"):
                if generation_config.task in TASK_IDS:
                    forced_decoder_ids.append((2, generation_config.task_to_id[generation_config.task]))
                else:
                    raise ValueError(
                        f"The `{generation_config.task}`task is not supported. The task should be one of `{TASK_IDS}`"
                    )
            elif hasattr(generation_config, "task_to_id"):
                forced_decoder_ids.append((2, generation_config.task_to_id["transcribe"]))  # defaults to transcribe
            if hasattr(generation_config, "no_timestamps_token_id") and not generation_config.return_timestamps:
                idx = forced_decoder_ids[-1][0] + 1 if forced_decoder_ids else 1
                forced_decoder_ids.append((idx, generation_config.no_timestamps_token_id))

        if forced_decoder_ids is not None:
            generation_config.forced_decoder_ids = forced_decoder_ids

        if prompt_ids is not None:
            if kwargs.get("decoder_start_token_id") is not None:
                raise ValueError(
                    "When specifying `prompt_ids`, you cannot also specify `decoder_start_token_id` as it gets overwritten."
                )
            prompt_ids = prompt_ids.tolist()
            decoder_start_token_id, *text_prompt_ids = prompt_ids
            # Slicing the text prompt ids in a manner consistent with the OpenAI implementation
            # to accommodate context space for the prefix (see https://github.com/openai/whisper/blob/c09a7ae299c4c34c5839a76380ae407e7d785914/whisper/decoding.py#L599)
            text_prompt_ids = text_prompt_ids[-self.config.max_length // 2 - 1 :]
            # Set the decoder_start_token_id to <|startofprev|>
            kwargs.update({"decoder_start_token_id": decoder_start_token_id})

            # Update the max generation length to include the prompt
            specified_max_length = kwargs.pop("max_new_tokens", None) or kwargs.pop("max_length", None)
            default_max_length = generation_config.max_new_tokens or generation_config.max_length
            non_prompt_max_length = specified_max_length or default_max_length
            kwargs["max_new_tokens"] = non_prompt_max_length + len(text_prompt_ids)

            # Reformat the forced_decoder_ids to incorporate the prompt
            non_prompt_forced_decoder_ids = (
                kwargs.pop("forced_decoder_ids", None) or generation_config.forced_decoder_ids
            )
            forced_decoder_ids = [
                *text_prompt_ids,
                generation_config.decoder_start_token_id,
                *[token for _rank, token in non_prompt_forced_decoder_ids],
            ]
            forced_decoder_ids = [(rank + 1, token) for rank, token in enumerate(forced_decoder_ids)]
            generation_config.forced_decoder_ids = forced_decoder_ids

        # TODO: Implement `WhisperTimeStampLogitsProcessor`.
        if generation_config.return_timestamps:
            # logits_processor = [TFWhisperTimeStampLogitsProcessor(generation_config)]
            raise ValueError("`TFWhisperForConditionalGeneration` doesn't support returning the timestamps yet.")

        if return_token_timestamps:
            kwargs["output_attentions"] = True
            kwargs["return_dict_in_generate"] = True

            if getattr(generation_config, "task", None) == "translate":
                logger.warning("Token-level timestamps may not be reliable for task 'translate'.")
            if not hasattr(generation_config, "alignment_heads"):
                raise ValueError(
                    "Model generation config has no `alignment_heads`, token-level timestamps not available. "
                    "See https://gist.github.com/hollance/42e32852f24243b748ae6bc1f985b13a on how to add this property to the generation config."
                )

        outputs = super().generate(
            inputs,
            generation_config,
            logits_processor,
            **kwargs,
        )

        if return_token_timestamps and hasattr(generation_config, "alignment_heads"):
            outputs["token_timestamps"] = self._extract_token_timestamps(outputs, generation_config.alignment_heads)

        return outputs

    def serving_output(self, output):
        pkv = tf.tuple(output.past_key_values)[1] if self.config.use_cache else None
        dec_hs = tf.convert_to_tensor(output.decoder_hidden_states) if self.config.output_hidden_states else None
        dec_attns = tf.convert_to_tensor(output.decoder_attentions) if self.config.output_attentions else None
        cross_attns = tf.convert_to_tensor(output.cross_attentions) if self.config.output_attentions else None
        enc_hs = tf.convert_to_tensor(output.encoder_hidden_states) if self.config.output_hidden_states else None
        enc_attns = tf.convert_to_tensor(output.encoder_attentions) if self.config.output_attentions else None

        return TFSeq2SeqLMOutput(
            logits=output.logits,
            past_key_values=pkv,
            decoder_hidden_states=dec_hs,
            decoder_attentions=dec_attns,
            cross_attentions=cross_attns,
            encoder_last_hidden_state=output.encoder_last_hidden_state,
            encoder_hidden_states=enc_hs,
            encoder_attentions=enc_attns,
        )

    def prepare_inputs_for_generation(
        self,
        decoder_input_ids,
        past_key_values=None,
        use_cache=None,
        encoder_outputs=None,
        attention_mask=None,
        decoder_attention_mask=None,
        **kwargs,
    ):
        # cut decoder_input_ids if past is used
        if past_key_values is not None:
            decoder_input_ids = decoder_input_ids[:, -1:]

        if decoder_attention_mask is not None:  # xla
            decoder_position_ids = tf.math.cumsum(decoder_attention_mask, axis=-1, exclusive=True)[:, -1:]
        elif past_key_values is not None:  # no xla + past
            decoder_position_ids = past_key_values[0][0].shape[2]
        else:  # no xla + no past
            decoder_position_ids = tf.range(decoder_input_ids.shape[1])
        decoder_position_ids = tf.broadcast_to(decoder_position_ids, decoder_input_ids.shape)

        return {
            "input_features": None,  # Needs to be passed to make Keras.layer.__call__ happy
            "encoder_outputs": encoder_outputs,
            "past_key_values": past_key_values,
            "decoder_input_ids": decoder_input_ids,
            "use_cache": use_cache,
            "decoder_attention_mask": decoder_attention_mask,
            "decoder_position_ids": decoder_position_ids,
        }

    def build(self, input_shape=None):
        if self.built:
            return
        self.built = True
        if getattr(self, "model", None) is not None:
            with tf.name_scope(self.model.name):
                self.model.build(None)