data_io.py

##########################################################
# pytorch-kaldi-gan
# Walter Heymans
# North West University
# 2020

# Adapted from:
# pytorch-kaldi v.0.1
# Mirco Ravanelli, Titouan Parcollet
# Mila, University of Montreal
# October 2018
##########################################################

import numpy as np
import sys
from utils import compute_cw_max, dict_fea_lab_arch, is_sequential_dict
import os
import configparser
import re, gzip, struct


def load_dataset(
    fea_scp, fea_opts, lab_folder, lab_opts, left, right, max_sequence_length, output_folder, fea_only=False
):
    def _input_is_wav_file(fea_scp):
        with open(fea_scp, "r") as f:
            first_line = f.readline()
        ark_file = first_line.split(" ")[1].split(":")[0]
        with open(ark_file, "rb") as f:
            first_ark_line = f.readline()
        return b"RIFF" in first_ark_line

    def _input_is_feature_file(fea_scp):
        return not _input_is_wav_file(fea_scp)

    def _read_features_and_labels_with_kaldi(fea_scp, fea_opts, fea_only, lab_folder, lab_opts, output_folder):
        fea = dict()
        lab = dict()
        if _input_is_feature_file(fea_scp):
            kaldi_bin = "copy-feats"
            read_function = read_mat_ark
        elif _input_is_wav_file(fea_scp):
            kaldi_bin = "wav-copy"
            read_function = read_vec_flt_ark
        fea = {
            k: m
            for k, m in read_function("ark:" + kaldi_bin + " scp:" + fea_scp + " ark:- |" + fea_opts, output_folder)
        }
        if not fea_only:
            lab = {
                k: v
                for k, v in read_vec_int_ark(
                    "gunzip -c " + lab_folder + "/ali*.gz | " + lab_opts + " " + lab_folder + "/final.mdl ark:- ark:-|",
                    output_folder,
                )
                if k in fea
            }  # Note that I'm copying only the aligments of the loaded fea
            fea = {
                k: v for k, v in fea.items() if k in lab
            }  # This way I remove all the features without an aligment (see log file in alidir "Did not Succeded")

        if "_ivector.lst" in fea_scp:
            for utterance in fea.keys():
                temp_features = fea[utterance]
                new_features = np.zeros((lab[utterance].shape[0], temp_features.shape[1]))

                for ivector in range(lab[utterance].shape[0]):
                    i_temp = int(ivector / 10)
                    new_features[ivector] = temp_features[i_temp]

                fea[utterance] = new_features

        return fea, lab

    def _chunk_features_and_labels(max_sequence_length, fea, lab, fea_only, input_is_wav):
        def _append_to_concat_list(fea_chunked, lab_chunked, fea_conc, lab_conc, name):
            for j in range(0, len(fea_chunked)):
                fea_conc.append(fea_chunked[j])
                lab_conc.append(lab_chunked[j])
                if len(fea_chunked) > 1:
                    snt_name.append(name + "_split" + str(j))
                else:
                    snt_name.append(k)
            return fea_conc, lab_conc

        def _chunk(max_sequence_length, fea, lab, fea_only):
            def _chunk_by_input_and_output_chunk_config(chunk_config, fea, lab, fea_only):
                """ 
                If the sequence length is above the threshold, we split it with a minimal length max/4
                If max length = 500, then the split will start at 500 + (500/4) = 625. 
                A seq of length 625 will be splitted in one of 500 and one of 125
                """
                chunk_size_fea, chunk_step_fea, chunk_size_lab, chunk_step_lab = (
                    chunk_config["chunk_size_fea"],
                    chunk_config["chunk_step_fea"],
                    chunk_config["chunk_size_lab"],
                    chunk_config["chunk_step_lab"],
                )
                fea_chunked = list()
                lab_chunked = list()
                split_threshold_fea = chunk_size_fea + (chunk_size_fea / 4)
                if (len(fea) > chunk_size_fea) and chunk_size_fea > 0:
                    nr_of_chunks = (len(fea) + chunk_size_fea - 1) // chunk_size_fea
                    for i in range(nr_of_chunks):
                        chunk_start_fea = i * chunk_step_fea
                        if len(fea[chunk_start_fea:]) > split_threshold_fea:
                            chunk_end_fea = chunk_start_fea + chunk_size_fea
                            fea_chunk = fea[chunk_start_fea:chunk_end_fea]
                            if not fea_only:
                                chunk_start_lab = i * chunk_step_lab
                                chunk_end_lab = chunk_start_lab + chunk_size_lab
                                lab_chunk = lab[chunk_start_lab:chunk_end_lab]
                            else:
                                lab_chunk = np.zeros((fea_chunk.shape[0],))
                            fea_chunked.append(fea_chunk)
                            lab_chunked.append(lab_chunk)
                        else:
                            fea_chunk = fea[chunk_start_fea:]
                            if not fea_only:
                                chunk_start_lab = i * chunk_step_lab
                                lab_chunk = lab[chunk_start_lab:]
                            else:
                                lab_chunk = np.zeros((fea_chunk.shape[0],))
                            lab_chunked.append(lab_chunk)
                            fea_chunked.append(fea_chunk)
                            break
                else:
                    fea_chunked.append(fea)
                    if not fea_only:
                        lab_chunked.append(lab)
                    else:
                        lab_chunked.append(np.zeros((fea.shape[0],)))
                return fea_chunked, lab_chunked

            chunk_config = dict()
            if type(max_sequence_length) == dict:
                chunk_config["chunk_size_fea"] = max_sequence_length["chunk_size_fea"]
                chunk_config["chunk_step_fea"] = max_sequence_length["chunk_step_fea"]
                chunk_config["chunk_size_lab"] = max_sequence_length["chunk_size_lab"]
                chunk_config["chunk_step_lab"] = max_sequence_length["chunk_step_lab"]
            elif type(max_sequence_length) == int:
                chunk_config["chunk_size_fea"] = max_sequence_length
                chunk_config["chunk_step_fea"] = max_sequence_length
                chunk_config["chunk_size_lab"] = max_sequence_length
                chunk_config["chunk_step_lab"] = max_sequence_length
            else:
                raise ValueError("Unknown type of max_sequence_length")
            return _chunk_by_input_and_output_chunk_config(chunk_config, fea, lab, fea_only)

        snt_name = list()
        fea_conc = list()
        lab_conc = list()
        feature_keys_soted_by_sequence_length = sorted(sorted(fea.keys()), key=lambda k: len(fea[k]))
        for k in feature_keys_soted_by_sequence_length:
            fea_el = fea[k]
            lab_el = None
            if not fea_only:
                lab_el = lab[k]
            fea_chunked, lab_chunked = _chunk(max_sequence_length, fea_el, lab_el, fea_only)
            fea_conc, lab_conc = _append_to_concat_list(fea_chunked, lab_chunked, fea_conc, lab_conc, k)
        return fea_conc, lab_conc, snt_name

    def _concatenate_features_and_labels(fea_conc, lab_conc):
        def _sort_chunks_by_length(fea_conc, lab_conc):
            fea_zipped = zip(fea_conc, lab_conc)
            fea_sorted = sorted(fea_zipped, key=lambda x: x[0].shape[0])
            fea_conc, lab_conc = zip(*fea_sorted)
            return fea_conc, lab_conc

        def _get_end_index_from_list(conc):
            end_snt = 0
            end_index = list()
            for entry in conc:
                end_snt = end_snt + entry.shape[0]
                end_index.append(end_snt)
            return end_index

        fea_conc, lab_conc = _sort_chunks_by_length(fea_conc, lab_conc)
        end_index_fea = _get_end_index_from_list(fea_conc)
        end_index_lab = _get_end_index_from_list(lab_conc)
        fea_conc = np.concatenate(fea_conc)
        lab_conc = np.concatenate(lab_conc)
        return fea_conc, lab_conc, end_index_fea, end_index_lab

    def _match_feature_and_label_sequence_lengths(fea, lab, max_sequence_length):
        ALLOW_FRAME_DIFF_LARGER_ONE = False

        def _adjust_feature_sequence_length(fea, nr_of_fea_for_lab):
            nr_of_fea = fea.shape[0]
            if nr_of_fea > nr_of_fea_for_lab:
                fea_adj = np.take(fea, range(nr_of_fea_for_lab), axis=0)
            elif nr_of_fea < nr_of_fea_for_lab:
                padding = np.zeros(shape=(nr_of_fea_for_lab - nr_of_fea,) + fea.shape[1:])
                fea_adj = np.concatenate([fea, padding], axis=0)
            else:
                fea_adj = fea
            return fea_adj

        chunk_size_fea = max_sequence_length["chunk_size_fea"]
        chunk_step_fea = max_sequence_length["chunk_step_fea"]
        chunk_size_lab = max_sequence_length["chunk_size_lab"]
        chunk_step_lab = max_sequence_length["chunk_step_lab"]
        window_shift = max_sequence_length["window_shift"]
        window_size = max_sequence_length["window_size"]
        for k in fea.keys():
            nr_of_fea = fea[k].shape[0]
            nr_of_lab = lab[k].shape[0]
            nr_of_fea_for_lab = (nr_of_lab - 1) * window_shift + window_size
            if abs(nr_of_fea - nr_of_fea_for_lab) > window_shift and not ALLOW_FRAME_DIFF_LARGER_ONE:
                raise ValueError(
                    "Nr. of features: "
                    + str(nr_of_fea)
                    + " does not match nr. of labels: "
                    + str(nr_of_lab)
                    + " with expected nr. of features: "
                    + str(nr_of_fea_for_lab)
                )
            fea[k] = _adjust_feature_sequence_length(fea[k], nr_of_fea_for_lab)
        return fea, lab

    fea, lab = _read_features_and_labels_with_kaldi(fea_scp, fea_opts, fea_only, lab_folder, lab_opts, output_folder)
    if _input_is_wav_file(fea_scp) and (not fea_only):
        fea, lab = _match_feature_and_label_sequence_lengths(fea, lab, max_sequence_length)
    fea_chunks, lab_chunks, chunk_names = _chunk_features_and_labels(
        max_sequence_length, fea, lab, fea_only, _input_is_wav_file(fea_scp)
    )
    fea_conc, lab_conc, end_index_fea, end_index_lab = _concatenate_features_and_labels(fea_chunks, lab_chunks)
    return [chunk_names, fea_conc, lab_conc, np.asarray(end_index_fea), np.asarray(end_index_lab)]


def context_window_old(fea, left, right):

    N_row = fea.shape[0]
    N_fea = fea.shape[1]
    frames = np.empty((N_row - left - right, N_fea * (left + right + 1)))

    for frame_index in range(left, N_row - right):
        right_context = fea[frame_index + 1 : frame_index + right + 1].flatten()  # right context
        left_context = fea[frame_index - left : frame_index].flatten()  # left context
        current_frame = np.concatenate([left_context, fea[frame_index], right_context])
        frames[frame_index - left] = current_frame

    return frames


def context_window(fea, left, right):

    N_elem = fea.shape[0]
    N_fea = fea.shape[1]

    fea_conc = np.empty([N_elem, N_fea * (left + right + 1)])

    index_fea = 0
    for lag in range(-left, right + 1):
        fea_conc[:, index_fea : index_fea + fea.shape[1]] = np.roll(fea, -lag, axis=0)
        index_fea = index_fea + fea.shape[1]

    fea_conc = fea_conc[left : fea_conc.shape[0] - right]
    return fea_conc


def load_chunk(
    fea_scp, fea_opts, lab_folder, lab_opts, left, right, max_sequence_length, output_folder, fea_only=False
):
    ''' CUSTOM CODE
    Loading chunks from Kaldi files '''

    # open the file
    [data_name, data_set, data_lab, end_index_fea, end_index_lab] = load_dataset(
        fea_scp, fea_opts, lab_folder, lab_opts, left, right, max_sequence_length, output_folder, fea_only
    )

    # TODO: currently end_index_lab is ignored

    # Context window
    if left != 0 or right != 0:
        data_set = context_window(data_set, left, right)

    end_index_fea = end_index_fea - left
    end_index_fea[-1] = end_index_fea[-1] - right

    # mean and variance normalization
    data_set = (data_set - np.mean(data_set, axis=0)) / np.std(data_set, axis=0)

    # Label processing
    data_lab = data_lab - data_lab.min()
    if right > 0:
        data_lab = data_lab[left:-right]
    else:
        data_lab = data_lab[left:]

    data_set = np.column_stack((data_set, data_lab))

    return [data_name, data_set, end_index_fea]


def load_counts(class_counts_file):
    with open(class_counts_file) as f:
        row = next(f).strip().strip("[]").strip()
        counts = np.array([np.float32(v) for v in row.split()])
    return counts


def read_lab_fea_refac01(cfg_file, fea_only, shared_list, output_folder):
    def _read_chunk_specific_config(cfg_file):
        if not (os.path.exists(cfg_file)):
            sys.stderr.write("ERROR: The config file %s does not exist!\n" % (cfg_file))
            sys.exit(0)
        else:
            config = configparser.ConfigParser()
            config.read(cfg_file)
        return config

    def _read_from_config(config, fea_only):
        def _get_max_seq_length_from_config_str(config_str):
            max_seq_length = [int(e) for e in config_str.split(",")]
            if len(max_seq_length) == 1:
                max_seq_length = max_seq_length[0]
            else:
                assert len(max_seq_length) == 6
                max_seq_length_list = max_seq_length
                max_seq_length = dict()
                max_seq_length["chunk_size_fea"] = max_seq_length_list[0]
                max_seq_length["chunk_step_fea"] = max_seq_length_list[1]
                max_seq_length["chunk_size_lab"] = max_seq_length_list[2]
                max_seq_length["chunk_step_lab"] = max_seq_length_list[3]
                max_seq_length["window_shift"] = max_seq_length_list[4]
                max_seq_length["window_size"] = max_seq_length_list[5]
            return max_seq_length

        to_do = config["exp"]["to_do"]
        if to_do == "train":
            max_seq_length = _get_max_seq_length_from_config_str(config["batches"]["max_seq_length_train"])
        if to_do == "valid":
            max_seq_length = _get_max_seq_length_from_config_str(config["batches"]["max_seq_length_valid"])
        if to_do == "forward":
            max_seq_length = -1  # do to break forward sentences
            fea_only = True
        fea_dict, lab_dict, arch_dict = dict_fea_lab_arch(config, fea_only)
        seq_model = is_sequential_dict(config, arch_dict)
        return to_do, max_seq_length, fea_dict, lab_dict, arch_dict, seq_model

    def _read_features_and_labels(fea_dict, lab_dict, max_seq_length, fea_only, output_folder):
        def _get_fea_config_from_dict(fea_dict_entr):
            fea_scp = fea_dict_entr[1]
            fea_opts = fea_dict_entr[2]
            cw_left = int(fea_dict_entr[3])
            cw_right = int(fea_dict_entr[4])
            return fea_scp, fea_opts, cw_left, cw_right

        def _get_lab_config_from_dict(lab_dict_entr, fea_only):
            if fea_only:
                lab_folder = None
                lab_opts = None
            else:
                lab_folder = lab_dict_entr[1]
                lab_opts = lab_dict_entr[2]
            return lab_folder, lab_opts

        def _compensate_for_different_context_windows(
            data_set_fea,
            data_set_lab,
            cw_left_max,
            cw_left,
            cw_right_max,
            cw_right,
            data_end_index_fea,
            data_end_index_lab,
        ):
            data_set_lab = np.take(
                data_set_lab,
                range(cw_left_max - cw_left, data_set_lab.shape[0] - (cw_right_max - cw_right)),
                axis=0,
                mode="clip",
            )
            data_set_fea = np.take(
                data_set_fea,
                range(cw_left_max - cw_left, data_set_fea.shape[0] - (cw_right_max - cw_right)),
                axis=0,
                mode="clip",
            )
            data_end_index_fea = data_end_index_fea - (cw_left_max - cw_left)
            data_end_index_lab = data_end_index_lab - (cw_left_max - cw_left)
            data_end_index_fea[-1] = data_end_index_fea[-1] - (cw_right_max - cw_right)
            data_end_index_lab[-1] = data_end_index_lab[-1] - (cw_right_max - cw_right)
            return data_set_lab, data_set_fea, data_end_index_fea, data_end_index_lab

        def _update_data(data_set, labs, fea_dict, fea, fea_index, data_set_fea, labs_fea, cnt_fea, cnt_lab):
            if cnt_fea == 0 and cnt_lab == 0:
                data_set = data_set_fea
                labs = labs_fea
                fea_dict[fea].append(fea_index)
                fea_index = fea_index + data_set_fea.shape[1]
                fea_dict[fea].append(fea_index)
                fea_dict[fea].append(fea_dict[fea][6] - fea_dict[fea][5])
            elif cnt_fea == 0 and (not cnt_lab == 0):
                labs = np.column_stack((labs, labs_fea))
            elif (not cnt_fea == 0) and cnt_lab == 0:
                data_set = np.column_stack((data_set, data_set_fea))
                fea_dict[fea].append(fea_index)
                fea_index = fea_index + data_set_fea.shape[1]
                fea_dict[fea].append(fea_index)
                fea_dict[fea].append(fea_dict[fea][6] - fea_dict[fea][5])
            return data_set, labs, fea_dict, fea_index

        def _check_consistency(
            data_name,
            data_name_fea,
            data_end_index_fea_ini,
            data_end_index_fea,
            data_end_index_lab_ini,
            data_end_index_lab,
        ):
            if not (data_name == data_name_fea):
                sys.stderr.write(
                    'ERROR: different sentence ids are detected for the different features. Plase check again input feature lists"\n'
                )
                sys.exit(0)
            if not (data_end_index_fea_ini == data_end_index_fea).all():
                sys.stderr.write('ERROR end_index must be the same for all the sentences"\n')
                sys.exit(0)
            if not (data_end_index_lab_ini == data_end_index_lab).all():
                sys.stderr.write('ERROR end_index must be the same for all the sentences"\n')
                sys.exit(0)

        def _update_lab_dict(lab_dict, data_set):
            cnt_lab = 0
            for lab in lab_dict.keys():
                lab_dict[lab].append(data_set.shape[1] + cnt_lab)
                cnt_lab = cnt_lab + 1
            return lab_dict

        def _load_chunk_refac01(
            fea_scp, fea_opts, lab_folder, lab_opts, left, right, max_sequence_length, output_folder, fea_only=False
        ):
            [data_name, data_set, data_lab, end_index_fea, end_index_lab] = load_dataset(
                fea_scp, fea_opts, lab_folder, lab_opts, left, right, max_sequence_length, output_folder, fea_only
            )
            # TODO: this function will currently only work well if no context window is given or fea and lab have the same time dimensionality
            # Context window
            if left != 0 or right != 0:
                data_set = context_window(data_set, left, right)
            end_index_fea = end_index_fea - left
            end_index_lab = end_index_lab - left
            end_index_fea[-1] = end_index_fea[-1] - right
            end_index_lab[-1] = end_index_lab[-1] - right
            # mean and variance normalization
            data_set = (data_set - np.mean(data_set, axis=0)) / np.std(data_set, axis=0)
            # Label processing
            data_lab = data_lab - data_lab.min()
            if right > 0:
                data_lab = data_lab[left:-right]
            else:
                data_lab = data_lab[left:]
            if len(data_set.shape) == 1:
                data_set = np.expand_dims(data_set, -1)
            return [data_name, data_set, data_lab, end_index_fea, end_index_lab]

        cw_left_max, cw_right_max = compute_cw_max(fea_dict)
        fea_index = 0
        cnt_fea = 0
        data_name = None
        data_end_index_fea_ini = None
        data_end_index_lab_ini = None
        data_set = None
        labs = None
        for fea in fea_dict.keys():
            fea_scp, fea_opts, cw_left, cw_right = _get_fea_config_from_dict(fea_dict[fea])
            cnt_lab = 0
            if fea_only:
                lab_dict.update({"lab_name": "none"})
            for lab in lab_dict.keys():
                lab_folder, lab_opts = _get_lab_config_from_dict(lab_dict[lab], fea_only)
                data_name_fea, data_set_fea, data_set_lab, data_end_index_fea, data_end_index_lab = _load_chunk_refac01(
                    fea_scp, fea_opts, lab_folder, lab_opts, cw_left, cw_right, max_seq_length, output_folder, fea_only
                )
                if sum([abs(e) for e in [cw_left_max, cw_right_max, cw_left, cw_right]]) != 0:
                    data_set_lab, data_set_fea, data_end_index_fea, data_end_index_lab = _compensate_for_different_context_windows(
                        data_set_fea,
                        data_set_lab,
                        cw_left_max,
                        cw_left,
                        cw_right_max,
                        cw_right,
                        data_end_index_fea,
                        data_end_index_lab,
                    )
                if cnt_fea == 0 and cnt_lab == 0:
                    data_end_index_fea_ini = data_end_index_fea
                    data_end_index_lab_ini = data_end_index_lab
                    data_name = data_name_fea
                data_set, labs, fea_dict, fea_index = _update_data(
                    data_set, labs, fea_dict, fea, fea_index, data_set_fea, data_set_lab, cnt_fea, cnt_lab
                )
                _check_consistency(
                    data_name,
                    data_name_fea,
                    data_end_index_fea_ini,
                    data_end_index_fea,
                    data_end_index_lab_ini,
                    data_end_index_lab,
                )
                cnt_lab = cnt_lab + 1
            cnt_fea = cnt_fea + 1
        if not fea_only:
            lab_dict = _update_lab_dict(lab_dict, data_set)
        return data_name, data_end_index_fea_ini, data_end_index_lab_ini, fea_dict, lab_dict, data_set, labs

    def _reorder_data_set(data_set, labs, seq_model, to_do):
        if not (seq_model) and to_do != "forward" and (data_set.shape[0] == labs.shape[0]):
            data_set_shape = data_set.shape[1]
            data_set_joint = np.column_stack((data_set, labs))
            ganset = True
            try:
                if str(config["ganset"]["create_set"]) == "True":
                    ganset = False
            except KeyError:
                pass
            if ganset:
                np.random.shuffle(data_set)
            data_set = data_set_joint[:, :data_set_shape]
            labs = np.squeeze(data_set_joint[:, data_set_shape:], axis=-1)
        return data_set, labs

    def _append_to_shared_list(
        shared_list, data_name, data_end_index_fea, data_end_index_lab, fea_dict, lab_dict, arch_dict, data_set
    ):
        shared_list.append(data_name)
        shared_list.append(data_end_index_fea)
        shared_list.append(data_end_index_lab)
        shared_list.append(fea_dict)
        shared_list.append(lab_dict)
        shared_list.append(arch_dict)
        shared_list.append(data_set)
        return shared_list

    config = _read_chunk_specific_config(cfg_file)
    to_do, max_seq_length, fea_dict, lab_dict, arch_dict, seq_model = _read_from_config(config, fea_only)
    data_name, data_end_index_fea, data_end_index_lab, fea_dict, lab_dict, data_set, labs = _read_features_and_labels(
        fea_dict, lab_dict, max_seq_length, fea_only, output_folder
    )
    data_set, labs = _reorder_data_set(data_set, labs, seq_model, to_do)
    data_set = {"input": data_set, "ref": labs}
    shared_list = _append_to_shared_list(
        shared_list, data_name, data_end_index_fea, data_end_index_lab, fea_dict, lab_dict, arch_dict, data_set
    )


def read_lab_fea(cfg_file, fea_only, shared_list, output_folder):
    # Reading chunk-specific cfg file (first argument-mandatory file)

    if not (os.path.exists(cfg_file)):
        sys.stderr.write("ERROR: The config file %s does not exist!\n" % (cfg_file))
        sys.exit(0)
    else:
        config = configparser.ConfigParser()
        config.read(cfg_file)

    # Reading some cfg parameters
    to_do = config["exp"]["to_do"]

    if to_do == "train":
        max_seq_length = int(
            config["batches"]["max_seq_length_train"]
        )  # *(int(info_file[-13:-10])+1) # increasing over the epochs

    if to_do == "valid":
        max_seq_length = int(config["batches"]["max_seq_length_valid"])

    if to_do == "forward":
        max_seq_length = -1  # do to break forward sentences

    [fea_dict, lab_dict, arch_dict] = dict_fea_lab_arch(config, fea_only)
    [cw_left_max, cw_right_max] = compute_cw_max(fea_dict)

    fea_index = 0
    cnt_fea = 0
    for fea in fea_dict.keys():

        # reading the features
        fea_scp = fea_dict[fea][1]
        fea_opts = fea_dict[fea][2]
        cw_left = int(fea_dict[fea][3])
        cw_right = int(fea_dict[fea][4])

        cnt_lab = 0

        # Production case, we don't have labels (lab_name = none)
        if fea_only:
            lab_dict.update({"lab_name": "none"})
        for lab in lab_dict.keys():
            # Production case, we don't have labels (lab_name = none)
            if fea_only:
                lab_folder = None
                lab_opts = None
            else:
                lab_folder = lab_dict[lab][1]
                lab_opts = lab_dict[lab][2]

            [data_name_fea, data_set_fea, data_end_index_fea] = load_chunk(
                fea_scp, fea_opts, lab_folder, lab_opts, cw_left, cw_right, max_seq_length, output_folder, fea_only
            )

            # making the same dimenion for all the features (compensating for different context windows)
            labs_fea = data_set_fea[cw_left_max - cw_left : data_set_fea.shape[0] - (cw_right_max - cw_right), -1]
            data_set_fea = data_set_fea[cw_left_max - cw_left : data_set_fea.shape[0] - (cw_right_max - cw_right), 0:-1]
            data_end_index_fea = data_end_index_fea - (cw_left_max - cw_left)
            data_end_index_fea[-1] = data_end_index_fea[-1] - (cw_right_max - cw_right)

            if cnt_fea == 0 and cnt_lab == 0:
                data_set = data_set_fea
                labs = labs_fea
                data_end_index = data_end_index_fea
                data_name = data_name_fea

                fea_dict[fea].append(fea_index)
                fea_index = fea_index + data_set_fea.shape[1]
                fea_dict[fea].append(fea_index)
                fea_dict[fea].append(fea_dict[fea][6] - fea_dict[fea][5])

            else:
                if cnt_fea == 0:
                    labs = np.column_stack((labs, labs_fea))

                if cnt_lab == 0:
                    data_set = np.column_stack((data_set, data_set_fea))

                    fea_dict[fea].append(fea_index)
                    fea_index = fea_index + data_set_fea.shape[1]
                    fea_dict[fea].append(fea_index)
                    fea_dict[fea].append(fea_dict[fea][6] - fea_dict[fea][5])

                # Checks if lab_names are the same for all the features
                if not (data_name == data_name_fea):
                    sys.stderr.write(
                        'ERROR: different sentence ids are detected for the different features. Plase check again input feature lists"\n'
                    )
                    sys.exit(0)

                # Checks if end indexes are the same for all the features
                if not (data_end_index == data_end_index_fea).all():
                    sys.stderr.write('ERROR end_index must be the same for all the sentences"\n')
                    sys.exit(0)

            cnt_lab = cnt_lab + 1

        cnt_fea = cnt_fea + 1

    cnt_lab = 0
    if not fea_only:
        for lab in lab_dict.keys():
            lab_dict[lab].append(data_set.shape[1] + cnt_lab)
            cnt_lab = cnt_lab + 1

    data_set = np.column_stack((data_set, labs))    # appends labels next to features

    # check automatically if the model is sequential
    seq_model = is_sequential_dict(config, arch_dict)

    ganset = True
    try:
        if str(config["ganset"]["create_set"]) == "True":
            ganset = False
    except KeyError:
        pass

    # Randomize if the model is not sequential
    if not (seq_model) and to_do != "forward" and ganset:
        np.random.shuffle(data_set)

    # Split dataset in many part. If the dataset is too big, we can have issues to copy it into the shared memory (due to pickle limits)
    # N_split=10
    # data_set=np.array_split(data_set, N_split)

    # Adding all the elements in the shared list
    shared_list.append(data_name)
    shared_list.append(data_end_index)
    shared_list.append(fea_dict)
    shared_list.append(lab_dict)
    shared_list.append(arch_dict)
    shared_list.append(data_set)


# The following libraries are copied from kaldi-io-for-python project (https://github.com/vesis84/kaldi-io-for-python)

# Copyright 2014-2016  Brno University of Technology (author: Karel Vesely)
# Licensed under the Apache License, Version 2.0 (the "License")

#################################################
# Define all custom exceptions,
class UnsupportedDataType(Exception):
    pass


class UnknownVectorHeader(Exception):
    pass


class UnknownMatrixHeader(Exception):
    pass


class BadSampleSize(Exception):
    pass


class BadInputFormat(Exception):
    pass


class SubprocessFailed(Exception):
    pass


#################################################
# Data-type independent helper functions,


def open_or_fd(file, output_folder, mode="rb"):
    """ fd = open_or_fd(file)
   Open file, gzipped file, pipe, or forward the file-descriptor.
   Eventually seeks in the 'file' argument contains ':offset' suffix.
  """
    offset = None

    try:
        # strip 'ark:' prefix from r{x,w}filename (optional),
        if re.search("^(ark|scp)(,scp|,b|,t|,n?f|,n?p|,b?o|,n?s|,n?cs)*:", file):
            (prefix, file) = file.split(":", 1)
        # separate offset from filename (optional),
        if re.search(":[0-9]+$", file):
            (file, offset) = file.rsplit(":", 1)
        # input pipe?
        if file[-1] == "|":
            fd = popen(file[:-1], output_folder, "rb")  # custom,
        # output pipe?
        elif file[0] == "|":
            fd = popen(file[1:], output_folder, "wb")  # custom,
        # is it gzipped?
        elif file.split(".")[-1] == "gz":
            fd = gzip.open(file, mode)
        # a normal file...
        else:
            fd = open(file, mode)
    except TypeError:
        # 'file' is opened file descriptor,
        fd = file
    # Eventually seek to offset,
    if offset != None:
        fd.seek(int(offset))

    return fd


# based on '/usr/local/lib/python3.4/os.py'
def popen(cmd, output_folder, mode="rb"):
    if not isinstance(cmd, str):
        raise TypeError("invalid cmd type (%s, expected string)" % type(cmd))

    import subprocess, io, threading

    # cleanup function for subprocesses,
    def cleanup(proc, cmd):
        ret = proc.wait()
        if ret > 0:
            raise SubprocessFailed("cmd %s returned %d !" % (cmd, ret))
        return

    # text-mode,
    if mode == "r":
        err = open(output_folder + "/log.log", "a")
        proc = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=err)
        threading.Thread(target=cleanup, args=(proc, cmd)).start()  # clean-up thread,
        return io.TextIOWrapper(proc.stdout)
    elif mode == "w":
        err = open(output_folder + "/log.log", "a")
        proc = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE, stderr=err)
        threading.Thread(target=cleanup, args=(proc, cmd)).start()  # clean-up thread,
        return io.TextIOWrapper(proc.stdin)
    # binary,
    elif mode == "rb":
        err = open(output_folder + "/log.log", "a")
        proc = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=err)
        threading.Thread(target=cleanup, args=(proc, cmd)).start()  # clean-up thread,
        return proc.stdout
    elif mode == "wb":
        err = open(output_folder + "/log.log", "a")
        proc = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE, stderr=err)
        threading.Thread(target=cleanup, args=(proc, cmd)).start()  # clean-up thread,
        return proc.stdin
    # sanity,
    else:
        raise ValueError("invalid mode %s" % mode)


def read_key(fd):
    """ [key] = read_key(fd)
   Read the utterance-key from the opened ark/stream descriptor 'fd'.
  """
    key = ""
    while 1:
        char = fd.read(1).decode("latin1")
        if char == "":
            break
        if char == " ":
            break
        key += char
    key = key.strip()
    if key == "":
        return None  # end of file,
    assert re.match("^\S+$", key) != None  # check format (no whitespace!)
    return key


#################################################
# Integer vectors (alignments, ...),


def read_ali_ark(file_or_fd, output_folder):
    """ Alias to 'read_vec_int_ark()' """
    return read_vec_int_ark(file_or_fd, output_folder)


def read_vec_int_ark(file_or_fd, output_folder):
    """ generator(key,vec) = read_vec_int_ark(file_or_fd)
   Create generator of (key,vector<int>) tuples, which reads from the ark file/stream.
   file_or_fd : ark, gzipped ark, pipe or opened file descriptor.

   Read ark to a 'dictionary':
   d = { u:d for u,d in kaldi_io.read_vec_int_ark(file) }
  """
    fd = open_or_fd(file_or_fd, output_folder)
    try:
        key = read_key(fd)
        while key:
            ali = read_vec_int(fd, output_folder)
            yield key, ali
            key = read_key(fd)
    finally:
        if fd is not file_or_fd:
            fd.close()


def read_vec_int(file_or_fd, output_folder):
    """ [int-vec] = read_vec_int(file_or_fd)
   Read kaldi integer vector, ascii or binary input,
  """
    fd = open_or_fd(file_or_fd, output_folder)
    binary = fd.read(2).decode()
    if binary == "\0B":  # binary flag
        assert fd.read(1).decode() == "\4"
        # int-size
        vec_size = np.frombuffer(fd.read(4), dtype="int32", count=1)[0]  # vector dim
        if vec_size == 0:
            return np.array([], dtype="int32")
        # Elements from int32 vector are sored in tuples: (sizeof(int32), value),
        vec = np.frombuffer(fd.read(vec_size * 5), dtype=[("size", "int8"), ("value", "int32")], count=vec_size)
        assert vec[0]["size"] == 4  # int32 size,
        ans = vec[:]["value"]  # values are in 2nd column,
    else:  # ascii,
        arr = (binary + fd.readline().decode()).strip().split()
        try:
            arr.remove("[")
            arr.remove("]")  # optionally
        except ValueError:
            pass
        ans = np.array(arr, dtype=int)
    if fd is not file_or_fd:
        fd.close()  # cleanup
    return ans


# Writing,
def write_vec_int(file_or_fd, output_folder, v, key=""):
    """ write_vec_int(f, v, key='')
   Write a binary kaldi integer vector to filename or stream.
   Arguments:
   file_or_fd : filename or opened file descriptor for writing,
   v : the vector to be stored,
   key (optional) : used for writing ark-file, the utterance-id gets written before the vector.

   Example of writing single vector:
   kaldi_io.write_vec_int(filename, vec)

   Example of writing arkfile:
   with open(ark_file,'w') as f:
     for key,vec in dict.iteritems():
       kaldi_io.write_vec_flt(f, vec, key=key)
  """
    fd = open_or_fd(file_or_fd, output_folder, mode="wb")
    if sys.version_info[0] == 3:
        assert fd.mode == "wb"
    try:
        if key != "":
            fd.write((key + " ").encode("latin1"))  # ark-files have keys (utterance-id),
        fd.write("\0B".encode())  # we write binary!
        # dim,
        fd.write("\4".encode())  # int32 type,
        fd.write(struct.pack(np.dtype("int32").char, v.shape[0]))
        # data,
        for i in range(len(v)):
            fd.write("\4".encode())  # int32 type,
            fd.write(struct.pack(np.dtype("int32").char, v[i]))  # binary,
    finally:
        if fd is not file_or_fd:
            fd.close()


#################################################
# Float vectors (confidences, ivectors, ...),

# Reading,
def read_vec_flt_scp(file_or_fd, output_folder):
    """ generator(key,mat) = read_vec_flt_scp(file_or_fd)
   Returns generator of (key,vector) tuples, read according to kaldi scp.
   file_or_fd : scp, gzipped scp, pipe or opened file descriptor.

   Iterate the scp:
   for key,vec in kaldi_io.read_vec_flt_scp(file):
     ...

   Read scp to a 'dictionary':
   d = { key:mat for key,mat in kaldi_io.read_mat_scp(file) }
  """
    fd = open_or_fd(file_or_fd, output_folder)
    try:
        for line in fd:
            (key, rxfile) = line.decode().split(" ")
            vec = read_vec_flt(rxfile, output_folder)
            yield key, vec
    finally:
        if fd is not file_or_fd:
            fd.close()


def read_vec_flt_ark(file_or_fd, output_folder):
    """ generator(key,vec) = read_vec_flt_ark(file_or_fd)
   Create generator of (key,vector<float>) tuples, reading from an ark file/stream.
   file_or_fd : ark, gzipped ark, pipe or opened file descriptor.

   Read ark to a 'dictionary':
   d = { u:d for u,d in kaldi_io.read_vec_flt_ark(file) }
  """
    fd = open_or_fd(file_or_fd, output_folder)
    try:
        key = read_key(fd)
        while key:
            ali = read_vec_flt(fd, output_folder)
            yield key, ali
            key = read_key(fd)
    finally:
        if fd is not file_or_fd:
            fd.close()


def read_vec_flt(file_or_fd, output_folder):
    """ [flt-vec] = read_vec_flt(file_or_fd)
   Read kaldi float vector, ascii or binary input,
  """
    fd = open_or_fd(file_or_fd, output_folder)
    binary = fd.read(2).decode()
    if binary == "\0B":  # binary flag
        return _read_vec_flt_binary(fd)
    elif binary == "RI":
        return _read_vec_flt_riff(fd)
    else:  # ascii,
        arr = (binary + fd.readline().decode()).strip().split()
        try:
            arr.remove("[")
            arr.remove("]")  # optionally
        except ValueError:
            pass
        ans = np.array(arr, dtype=float)
    if fd is not file_or_fd:
        fd.close()  # cleanup
    return ans


def _read_vec_flt_riff(fd):
    RIFF_CHUNK_DESCR_HEADER_SIZE = 12
    ALREADY_READ_HEADER_BYTES = 2
    SUB_CHUNK_HEADER_SIZE = 8
    DATA_CHUNK_HEADER_SIZE = 8

    def pcm2float(signal, dtype="float32"):
        signal = np.asarray(signal)
        dtype = np.dtype(dtype)
        return signal.astype(dtype) / dtype.type(-np.iinfo(signal.dtype).min)

    import struct

    header = fd.read(RIFF_CHUNK_DESCR_HEADER_SIZE - ALREADY_READ_HEADER_BYTES)
    assert header[:2] == b"FF"
    chunk_header = fd.read(SUB_CHUNK_HEADER_SIZE)
    subchunk_id, subchunk_size = struct.unpack("<4sI", chunk_header)
    aformat, channels, samplerate, byterate, block_align, bps = struct.unpack("HHIIHH", fd.read(subchunk_size))
    subchunk2_id, subchunk2_size = struct.unpack("<4sI", fd.read(DATA_CHUNK_HEADER_SIZE))
    pcm_data = np.frombuffer(fd.read(subchunk2_size), dtype="int" + str(bps))
    return pcm2float(pcm_data)


def _read_vec_flt_binary(fd):
    header = fd.read(3).decode()
    if header == "FV ":
        sample_size = 4  # floats
    elif header == "DV ":
        sample_size = 8  # doubles
    else:
        raise UnknownVectorHeader("The header contained '%s'" % header)
    assert sample_size > 0
    # Dimension,
    assert fd.read(1).decode() == "\4"
    # int-size
    vec_size = np.frombuffer(fd.read(4), dtype="int32", count=1)[0]  # vector dim
    if vec_size == 0:
        return np.array([], dtype="float32")
    # Read whole vector,
    buf = fd.read(vec_size * sample_size)
    if sample_size == 4:
        ans = np.frombuffer(buf, dtype="float32")
    elif sample_size == 8:
        ans = np.frombuffer(buf, dtype="float64")
    else:
        raise BadSampleSize
    return ans


# Writing,
def write_vec_flt(file_or_fd, output_folder, v, key=""):
    """ write_vec_flt(f, v, key='')
   Write a binary kaldi vector to filename or stream. Supports 32bit and 64bit floats.
   Arguments:
   file_or_fd : filename or opened file descriptor for writing,
   v : the vector to be stored,
   key (optional) : used for writing ark-file, the utterance-id gets written before the vector.

   Example of writing single vector:
   kaldi_io.write_vec_flt(filename, vec)

   Example of writing arkfile:
   with open(ark_file,'w') as f:
     for key,vec in dict.iteritems():
       kaldi_io.write_vec_flt(f, vec, key=key)
  """
    fd = open_or_fd(file_or_fd, output_folder, mode="wb")
    if sys.version_info[0] == 3:
        assert fd.mode == "wb"
    try:
        if key != "":
            fd.write((key + " ").encode("latin1"))  # ark-files have keys (utterance-id),
        fd.write("\0B".encode())  # we write binary!
        # Data-type,
        if v.dtype == "float32":
            fd.write("FV ".encode())
        elif v.dtype == "float64":
            fd.write("DV ".encode())
        else:
            raise UnsupportedDataType("'%s', please use 'float32' or 'float64'" % v.dtype)
        # Dim,
        fd.write("\04".encode())
        fd.write(struct.pack(np.dtype("uint32").char, v.shape[0]))  # dim
        # Data,
        fd.write(v.tobytes())
    finally:
        if fd is not file_or_fd:
            fd.close()


#################################################
# Float matrices (features, transformations, ...),

# Reading,
def read_mat_scp(file_or_fd, output_folder):
    """ generator(key,mat) = read_mat_scp(file_or_fd)
   Returns generator of (key,matrix) tuples, read according to kaldi scp.
   file_or_fd : scp, gzipped scp, pipe or opened file descriptor.

   Iterate the scp:
   for key,mat in kaldi_io.read_mat_scp(file):
     ...

   Read scp to a 'dictionary':
   d = { key:mat for key,mat in kaldi_io.read_mat_scp(file) }
  """
    fd = open_or_fd(file_or_fd, output_folder)
    try:
        for line in fd:
            (key, rxfile) = line.decode().split(" ")
            mat = read_mat(rxfile, output_folder)
            yield key, mat
    finally:
        if fd is not file_or_fd:
            fd.close()


def read_mat_ark(file_or_fd, output_folder):
    """ generator(key,mat) = read_mat_ark(file_or_fd)
   Returns generator of (key,matrix) tuples, read from ark file/stream.
   file_or_fd : scp, gzipped scp, pipe or opened file descriptor.

   Iterate the ark:
   for key,mat in kaldi_io.read_mat_ark(file):
     ...

   Read ark to a 'dictionary':
   d = { key:mat for key,mat in kaldi_io.read_mat_ark(file) }
  """

    fd = open_or_fd(file_or_fd, output_folder)
    try:
        key = read_key(fd)
        while key:
            mat = read_mat(fd, output_folder)
            yield key, mat
            key = read_key(fd)
    finally:
        if fd is not file_or_fd:
            fd.close()


def read_mat(file_or_fd, output_folder):
    """ [mat] = read_mat(file_or_fd)
   Reads single kaldi matrix, supports ascii and binary.
   file_or_fd : file, gzipped file, pipe or opened file descriptor.
  """
    fd = open_or_fd(file_or_fd, output_folder)
    try:
        binary = fd.read(2).decode()
        if binary == "\0B":
            mat = _read_mat_binary(fd)
        else:
            assert binary == " ["
            mat = _read_mat_ascii(fd)
    finally:
        if fd is not file_or_fd:
            fd.close()
    return mat


def _read_mat_binary(fd):
    # Data type
    header = fd.read(3).decode()
    # 'CM', 'CM2', 'CM3' are possible values,
    if header.startswith("CM"):
        return _read_compressed_mat(fd, header)
    elif header == "FM ":
        sample_size = 4  # floats
    elif header == "DM ":
        sample_size = 8  # doubles
    else:
        raise UnknownMatrixHeader("The header contained '%s'" % header)
    assert sample_size > 0
    # Dimensions
    s1, rows, s2, cols = np.frombuffer(fd.read(10), dtype="int8,int32,int8,int32", count=1)[0]
    # Read whole matrix
    buf = fd.read(rows * cols * sample_size)
    if sample_size == 4:
        vec = np.frombuffer(buf, dtype="float32")
    elif sample_size == 8:
        vec = np.frombuffer(buf, dtype="float64")
    else:
        raise BadSampleSize
    mat = np.reshape(vec, (rows, cols))
    return mat


def _read_mat_ascii(fd):
    rows = []
    while 1:
        line = fd.readline().decode()
        if len(line) == 0:
            raise BadInputFormat  # eof, should not happen!
        if len(line.strip()) == 0:
            continue  # skip empty line
        arr = line.strip().split()
        if arr[-1] != "]":
            rows.append(np.array(arr, dtype="float32"))  # not last line
        else:
            rows.append(np.array(arr[:-1], dtype="float32"))  # last line
            mat = np.vstack(rows)
            return mat


def _read_compressed_mat(fd, format):
    """ Read a compressed matrix,
      see: https://github.com/kaldi-asr/kaldi/blob/master/src/matrix/compressed-matrix.h
      methods: CompressedMatrix::Read(...), CompressedMatrix::CopyToMat(...),
  """
    assert format == "CM "  # The formats CM2, CM3 are not supported...

    # Format of header 'struct',
    global_header = np.dtype(
        [("minvalue", "float32"), ("range", "float32"), ("num_rows", "int32"), ("num_cols", "int32")]
    )  # member '.format' is not written,
    per_col_header = np.dtype(
        [
            ("percentile_0", "uint16"),
            ("percentile_25", "uint16"),
            ("percentile_75", "uint16"),
            ("percentile_100", "uint16"),
        ]
    )

    # Read global header,
    globmin, globrange, rows, cols = np.frombuffer(fd.read(16), dtype=global_header, count=1)[0]

    # The data is structed as [Colheader, ... , Colheader, Data, Data , .... ]
    #                         {           cols           }{     size         }
    col_headers = np.frombuffer(fd.read(cols * 8), dtype=per_col_header, count=cols)
    col_headers = np.array(
        [np.array([x for x in y]) * globrange * 1.52590218966964e-05 + globmin for y in col_headers], dtype=np.float32
    )
    data = np.reshape(
        np.frombuffer(fd.read(cols * rows), dtype="uint8", count=cols * rows), newshape=(cols, rows)
    )  # stored as col-major,

    mat = np.zeros((cols, rows), dtype="float32")
    p0 = col_headers[:, 0].reshape(-1, 1)
    p25 = col_headers[:, 1].reshape(-1, 1)
    p75 = col_headers[:, 2].reshape(-1, 1)
    p100 = col_headers[:, 3].reshape(-1, 1)
    mask_0_64 = data <= 64
    mask_193_255 = data > 192
    mask_65_192 = ~(mask_0_64 | mask_193_255)

    mat += (p0 + (p25 - p0) / 64.0 * data) * mask_0_64.astype(np.float32)
    mat += (p25 + (p75 - p25) / 128.0 * (data - 64)) * mask_65_192.astype(np.float32)
    mat += (p75 + (p100 - p75) / 63.0 * (data - 192)) * mask_193_255.astype(np.float32)

    return mat.T  # transpose! col-major -> row-major,


# Writing,
def write_mat(output_folder, file_or_fd, m, key=""):
    """ write_mat(f, m, key='')
  Write a binary kaldi matrix to filename or stream. Supports 32bit and 64bit floats.
  Arguments:
   file_or_fd : filename of opened file descriptor for writing,
   m : the matrix to be stored,
   key (optional) : used for writing ark-file, the utterance-id gets written before the matrix.

   Example of writing single matrix:
   kaldi_io.write_mat(filename, mat)

   Example of writing arkfile:
   with open(ark_file,'w') as f:
     for key,mat in dict.iteritems():
       kaldi_io.write_mat(f, mat, key=key)
  """
    fd = open_or_fd(file_or_fd, output_folder, mode="wb")
    if sys.version_info[0] == 3:
        assert fd.mode == "wb"
    try:
        if key != "":
            fd.write((key + " ").encode("latin1"))  # ark-files have keys (utterance-id),
        fd.write("\0B".encode())  # we write binary!
        # Data-type,
        if m.dtype == "float32":
            fd.write("FM ".encode())
        elif m.dtype == "float64":
            fd.write("DM ".encode())
        else:
            raise UnsupportedDataType("'%s', please use 'float32' or 'float64'" % m.dtype)
        # Dims,
        fd.write("\04".encode())
        fd.write(struct.pack(np.dtype("uint32").char, m.shape[0]))  # rows
        fd.write("\04".encode())
        fd.write(struct.pack(np.dtype("uint32").char, m.shape[1]))  # cols
        # Data,
        fd.write(m.tobytes())
    finally:
        if fd is not file_or_fd:
            fd.close()


#################################################
# 'Posterior' kaldi type (posteriors, confusion network, nnet1 training targets, ...)
# Corresponds to: vector<vector<tuple<int,float> > >
# - outer vector: time axis
# - inner vector: records at the time
# - tuple: int = index, float = value
#


def read_cnet_ark(file_or_fd, output_folder):
    """ Alias of function 'read_post_ark()', 'cnet' = confusion network """
    return read_post_ark(file_or_fd, output_folder)


def read_post_rxspec(file_):
    """ adaptor to read both 'ark:...' and 'scp:...' inputs of posteriors,
  """
    if file_.startswith("ark:"):
        return read_post_ark(file_)
    elif file_.startswith("scp:"):
        return read_post_scp(file_)
    else:
        print("unsupported intput type: %s" % file_)
        print("it should begint with 'ark:' or 'scp:'")
        sys.exit(1)


def read_post_scp(file_or_fd, output_folder):
    """ generator(key,post) = read_post_scp(file_or_fd)
   Returns generator of (key,post) tuples, read according to kaldi scp.
   file_or_fd : scp, gzipped scp, pipe or opened file descriptor.

   Iterate the scp:
   for key,post in kaldi_io.read_post_scp(file):
     ...

   Read scp to a 'dictionary':
   d = { key:post for key,post in kaldi_io.read_post_scp(file) }
  """
    fd = open_or_fd(file_or_fd, output_folder)
    try:
        for line in fd:
            (key, rxfile) = line.decode().split(" ")
            post = read_post(rxfile)
            yield key, post
    finally:
        if fd is not file_or_fd:
            fd.close()


def read_post_ark(file_or_fd, output_folder):
    """ generator(key,vec<vec<int,float>>) = read_post_ark(file)
   Returns generator of (key,posterior) tuples, read from ark file.
   file_or_fd : ark, gzipped ark, pipe or opened file descriptor.

   Iterate the ark:
   for key,post in kaldi_io.read_post_ark(file):
     ...

   Read ark to a 'dictionary':
   d = { key:post for key,post in kaldi_io.read_post_ark(file) }
  """
    fd = open_or_fd(file_or_fd, output_folder)
    try:
        key = read_key(fd)
        while key:
            post = read_post(fd)
            yield key, post
            key = read_key(fd)
    finally:
        if fd is not file_or_fd:
            fd.close()


def read_post(file_or_fd, output_folder):
    """ [post] = read_post(file_or_fd)
   Reads single kaldi 'Posterior' in binary format.

   The 'Posterior' is C++ type 'vector<vector<tuple<int,float> > >',
   the outer-vector is usually time axis, inner-vector are the records
   at given time,  and the tuple is composed of an 'index' (integer)
   and a 'float-value'. The 'float-value' can represent a probability
   or any other numeric value.

   Returns vector of vectors of tuples.
  """
    fd = open_or_fd(file_or_fd, output_folder)
    ans = []
    binary = fd.read(2).decode()
    assert binary == "\0B"
    # binary flag
    assert fd.read(1).decode() == "\4"
    # int-size
    outer_vec_size = np.frombuffer(fd.read(4), dtype="int32", count=1)[0]  # number of frames (or bins)

    # Loop over 'outer-vector',
    for i in range(outer_vec_size):
        assert fd.read(1).decode() == "\4"
        # int-size
        inner_vec_size = np.frombuffer(fd.read(4), dtype="int32", count=1)[0]  # number of records for frame (or bin)
        data = np.frombuffer(
            fd.read(inner_vec_size * 10),
            dtype=[("size_idx", "int8"), ("idx", "int32"), ("size_post", "int8"), ("post", "float32")],
            count=inner_vec_size,
        )
        assert data[0]["size_idx"] == 4
        assert data[0]["size_post"] == 4
        ans.append(data[["idx", "post"]].tolist())

    if fd is not file_or_fd:
        fd.close()
    return ans


#################################################
# Kaldi Confusion Network bin begin/end times,
# (kaldi stores CNs time info separately from the Posterior).
#


def read_cntime_ark(file_or_fd, output_folder):
    """ generator(key,vec<tuple<float,float>>) = read_cntime_ark(file_or_fd)
   Returns generator of (key,cntime) tuples, read from ark file.
   file_or_fd : file, gzipped file, pipe or opened file descriptor.

   Iterate the ark:
   for key,time in kaldi_io.read_cntime_ark(file):
     ...

   Read ark to a 'dictionary':
   d = { key:time for key,time in kaldi_io.read_post_ark(file) }
  """
    fd = open_or_fd(file_or_fd, output_folder)
    try:
        key = read_key(fd)
        while key:
            cntime = read_cntime(fd)
            yield key, cntime
            key = read_key(fd)
    finally:
        if fd is not file_or_fd:
            fd.close()


def read_cntime(file_or_fd, output_folder):
    """ [cntime] = read_cntime(file_or_fd)
   Reads single kaldi 'Confusion Network time info', in binary format:
   C++ type: vector<tuple<float,float> >.
   (begin/end times of bins at the confusion network).

   Binary layout is '<num-bins> <beg1> <end1> <beg2> <end2> ...'

   file_or_fd : file, gzipped file, pipe or opened file descriptor.

   Returns vector of tuples.
  """
    fd = open_or_fd(file_or_fd, output_folder)
    binary = fd.read(2).decode()
    assert binary == "\0B"
    # assuming it's binary

    assert fd.read(1).decode() == "\4"
    # int-size
    vec_size = np.frombuffer(fd.read(4), dtype="int32", count=1)[0]  # number of frames (or bins)

    data = np.frombuffer(
        fd.read(vec_size * 10),
        dtype=[("size_beg", "int8"), ("t_beg", "float32"), ("size_end", "int8"), ("t_end", "float32")],
        count=vec_size,
    )
    assert data[0]["size_beg"] == 4
    assert data[0]["size_end"] == 4
    ans = data[["t_beg", "t_end"]].tolist()  # Return vector of tuples (t_beg,t_end),

    if fd is not file_or_fd:
        fd.close()
    return ans


#################################################
# Segments related,
#

# Segments as 'Bool vectors' can be handy,
# - for 'superposing' the segmentations,
# - for frame-selection in Speaker-ID experiments,
def read_segments_as_bool_vec(segments_file):
    """ [ bool_vec ] = read_segments_as_bool_vec(segments_file)
   using kaldi 'segments' file for 1 wav, format : '<utt> <rec> <t-beg> <t-end>'
   - t-beg, t-end is in seconds,
   - assumed 100 frames/second,
  """
    segs = np.loadtxt(segments_file, dtype="object,object,f,f", ndmin=1)
    # Sanity checks,
    assert len(segs) > 0  # empty segmentation is an error,
    assert len(np.unique([rec[1] for rec in segs])) == 1  # segments with only 1 wav-file,
    # Convert time to frame-indexes,
    start = np.rint([100 * rec[2] for rec in segs]).astype(int)
    end = np.rint([100 * rec[3] for rec in segs]).astype(int)
    # Taken from 'read_lab_to_bool_vec', htk.py,
    frms = np.repeat(
        np.r_[np.tile([False, True], len(end)), False], np.r_[np.c_[start - np.r_[0, end[:-1]], end - start].flat, 0]
    )
    assert np.sum(end - start) == np.sum(frms)
    return frms