audio.py

from moviepy.editor import *
from gtts import gTTS
from pydub import AudioSegment
import tempfile
import os

os.environ["IMAGEIO_FFMPEG_EXE"] = "/usr/local/bin/ffmpeg"
# os.environ["IMAGEMAGICK_BINARY"] = "/usr/local/bin/convert"

def gen_audio(subtitles, tmpdir):
# subtitles = [
#    [[0, 3], "這裡請注意右臂"],
#     [[4, 8], "這裡請注意左臂"],
#     [[9, 12], "這裡請注意左手細節"]
# ]
    subtitles = merge_subtitles(subtitles)
    print("===> Subtitles:")
    for subtitle in subtitles:
        print(subtitle)
    combined_clip = VideoFileClip(tmpdir + "/output.mp4")
    total_duration = combined_clip.duration

    def add_subtitles(clip, subtitles):
        txt_clips = []
        for start_end, text in subtitles:
            start_time, end_time = start_end
            duration = end_time - start_time
            txt_clip = (TextClip(text, fontsize=clip.w//20, color='white', font='bold.ttf', method='caption', size=(clip.w * 0.9, None))  
                        .set_duration(duration)  
                        .set_position(('center', 4 * clip.h // 5))
                        .set_start(start_time))
            txt_clips.append(txt_clip)
        
        return CompositeVideoClip([clip, *txt_clips])

    if len(subtitles) != 0:
        video_with_subtitles = add_subtitles(combined_clip, subtitles)
    else:
        combined_clip.write_videofile(tmpdir + '/output_with_subtitles.mp4', fps=24)
        print("Generated Video with Subtitles to:", tmpdir + '/output_with_subtitles.mp4')
        return tmpdir + '/output_with_subtitles.mp4'

    def generate_audio(subtitles, total_duration):
        temp_audio_path = tempfile.mkdtemp()  
        clips = []

        for i, (start_end, text) in enumerate(subtitles):
            start_time, end_time = start_end
            duration = end_time - start_time

            tts = gTTS(text=text, lang='zh')
            audio_path = os.path.join(temp_audio_path, f'subtitle_{i}.mp3')
            tts.save(audio_path)
            
            audio_segment = AudioSegment.from_mp3(audio_path)

            new_audio_path = os.path.join(temp_audio_path, f'subtitle_{i}_adjusted.wav')
            audio_segment.export(new_audio_path, format="wav")

            audio_clip = AudioFileClip(new_audio_path).set_start(start_time).set_duration(min(duration, audio_segment.duration_seconds))
            
            clips.append(audio_clip)
        
        final_audio = CompositeAudioClip(clips)
        return final_audio

    audio_clip = generate_audio(subtitles, total_duration)

    video_with_audio = video_with_subtitles.set_audio(audio_clip)

    video_with_audio.write_videofile(tmpdir + '/output_with_subtitles.mp4', fps=24)

    print("Generated Video with Subtitles to:", tmpdir + '/output_with_subtitles.mp4')
    return tmpdir + '/output_with_subtitles.mp4'


def merge_subtitles(subtitles):
    merged_subtitles = []
    i = 0
    n = len(subtitles)
    
    while i < n:
        current_start, current_end = subtitles[i][0]
        current_content = subtitles[i][1]
        duration = current_end - current_start
        i += 1  

        while duration < 3:
            if i >= n:
                current_end = current_start + 3
                duration = current_end - current_start
                break
            next_start, next_end = subtitles[i][0]
            next_content = subtitles[i][1]
            if next_start == current_end:
                current_end = next_end
                current_content += "、" + next_content
                duration = current_end - current_start
                i += 1  
            else:
                if duration < 3:
                    current_end = current_start + 3
                    duration = current_end - current_start
                break  

        current_content = '這裡請注意' + '、'.join(list(set(current_content.replace("細節", "").split('、'))))
        merged_subtitles.append([[current_start, current_end], current_content])
    
    return merged_subtitles