change_audio.py

import json
import moviepy.editor as mp

# name = 'audio'
def change_audio(dir, vid_file, cap_file):
    video = mp.VideoFileClip(dir + vid_file)

    with open(dir + cap_file) as f:
        j = json.loads(f.read())
        starts = list(map(lambda c: float(c['start']), j))

    nbrClips = len(starts)

    clips = list(map(lambda s: mp.AudioFileClip("./media/tmp/{}.mp3".format(s)), range(nbrClips)))
    clips = list(map(lambda c: c.subclip(0, c.duration*0.8), clips))

    # print(starts)

    current = 0

    make_frame = lambda t: [0]
    padded_clips = []
    for i in range(nbrClips):
        if current < starts[i]:
            padded_clips.append(mp.AudioClip(make_frame, duration=starts[i] - current))
            current = starts[i]
            padded_clips.append(clips[i])
            current += clips[i].duration

    concat = mp.concatenate_audioclips(padded_clips)
    concat.write_audiofile(dir + 'audio.mp3')
    video.write_videofile('media/ready/' + vid_file, audio = dir + 'audio.mp3')