# Copyright 2020 Huawei Technologies Co., Ltd
#
# 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.
# ============================================================================


import argparse

import glob

import os

import os.path as osp

from multiprocessing import Pool



import mmcv





def extract_audio_wav(line):

    """Extract the audio wave from video streams using FFMPEG."""

    video_id, _ = osp.splitext(osp.basename(line))

    video_dir = osp.dirname(line)

    video_rel_dir = osp.relpath(video_dir, args.root)

    dst_dir = osp.join(args.dst_root, video_rel_dir)

    os.popen(f'mkdir -p {dst_dir}')

    try:

        if osp.exists(f'{dst_dir}/{video_id}.wav'):

            return

        cmd = f'ffmpeg -i ./{line}  -map 0:a  -y {dst_dir}/{video_id}.wav'

        os.popen(cmd)

    except BaseException:

        with open('extract_wav_err_file.txt', 'a+') as f:

            f.write(f'{line}\n')





def parse_args():

    parser = argparse.ArgumentParser(description='Extract audios')

    parser.add_argument('root', type=str, help='source video directory')

    parser.add_argument('dst_root', type=str, help='output audio directory')

    parser.add_argument(

        '--level', type=int, default=2, help='directory level of data')

    parser.add_argument(

        '--ext',

        type=str,

        default='mp4',

        choices=['avi', 'mp4', 'webm'],

        help='video file extensions')

    parser.add_argument(

        '--num-worker', type=int, default=8, help='number of workers')

    args = parser.parse_args()



    return args





if __name__ == '__main__':

    args = parse_args()



    mmcv.mkdir_or_exist(args.out_dir)



    print('Reading videos from folder: ', args.src_dir)

    print('Extension of videos: ', args.ext)

    fullpath_list = glob.glob(args.src_dir + '/*' * args.level + '.' +

                              args.ext)

    done_fullpath_list = glob.glob(args.out_dir + '/*' * args.level + '.wav')

    print('Total number of videos found: ', len(fullpath_list))

    print('Total number of videos extracted finished: ',

          len(done_fullpath_list))



    pool = Pool(args.num_worker)

    pool.map(extract_audio_wav, fullpath_list)