如何使用 ffmpeg-python 将视频剪切到一定长度并添加介绍视频？

Question

How to cut a video to a certain length and add an intro video to it using ffmpeg-python?

What i am doing is:

        intro = ffmpeg.input(intro)
        mainvid = ffmpeg.input(mainvid)

        v1 = intro.video
        a1 = intro.audio
        v2 = mainvid.video
        a2 = mainvid.audio

        joined = ffmpeg.concat(v1, a1, v2, a2, v=1, a=1).node
        v3 = joined[0]
        a3 = joined[1]

        (
            ffmpeg
            .output(
                v3,
                a3,
                'out.mkv', 
                vcodec='libx265', )
            .run()
        )

But i dont know how to cut mainvid to a certain length like 10 mins before joining, i know ss will help but dont know how to use it for only mainvid.

Answer 1

You may use trim and atrim filters for trimming the video and the audio.
The suggested solution is based on the following answer .

• FFmpeg supports 3 types of concatenation: "Concat demuxer", "Concat protocol" and "Concat filter".
  The method ffmpeg.concat applies Concat filter .
  Since "Concat filter" is used, a practical solution is trimming the video and audio by "chaining" trim and atrim filters.
• setpts and asetpts filters are required for fixing the timestamps.

---

Replace v2 = mainvid.video and a2 = mainvid.audio with:

v2 = mainvid.video.filter('trim', start=0, end=600).filter('setpts', 'PTS-STARTPTS')
a2 = mainvid.audio.filter('atrim', start=0, end=600).filter('asetpts', 'PTS-STARTPTS')

Answer 2

I managed to do it using:

        intro = ffmpeg.input(intro)
        mainvid = ffmpeg.input(mainvid, ss='00:00:00', t='00:10:00') 

        v1 = intro.video
        a1 = intro.audio
        v2 = mainvid.video
        a2 = mainvid.audio

        joined = ffmpeg.concat(v1, a1, v2, a2, v=1, a=1).node
        v3 = joined[0]
        a3 = joined[1]

        (
            ffmpeg
            .output(
                v3,
                a3,
                'out.mkv', 
                vcodec='libx265', )
            .run()
        )