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如何使用 Android MediaCodec 将视频分成更小的部分？

[英]How to split a video into smaller parts with Android MediaCodec?

原文 2020-09-07 12:58:38 4 1 android/ android-mediacodec

In my app I would like to split a selected video from the gallery into smaller pieces of the same length.在我的应用程序中，我想将图库中的选定视频拆分为相同长度的较小片段。 For example, if I want to split a 25 second video into pieces of up to 10 seconds, I would get 3 videos (10 sec, 10 sec, 5 sec).例如，如果我想将一个 25 秒的视频分成最多 10 秒的片段，我会得到 3 个视频（10 秒、10 秒、5 秒）。

So far I found this answer on Stack Overflow that allows me to just choose the beginning and end of a video.到目前为止，我在 Stack Overflow 上找到了这个答案，它允许我只选择视频的开头和结尾。

How can I use MediaCodec to achieve my goal?我如何使用 MediaCodec 来实现我的目标？

1 个解决方案

To produce segments of exact duration you would need to re-encode the video and possibly the audio track using pairs of decoders and encoders (instances of MediaCodec ) along with a MediaExtractor and a separate MediaMuxer for each output segment.要生成精确持续时间的片段，您需要使用成对的解码器和编码器（ MediaCodec的实例）以及一个MediaExtractor和一个单独的MediaMuxer为每个 output 片段重新编码视频和可能的音轨。

Each time you reach the end of a segment (looking at the presentation time of the frame) you would send an end-of-stream signal to the encoder and then restart it.每次到达片段的末尾（查看帧的呈现时间）时，您都会向编码器发送一个流结束信号，然后重新启动它。

For audio you would also need to split some of the decoded buffers at the segment boundaries.对于音频，您还需要在段边界处拆分一些解码缓冲区。