In my Android app, I want to compress mp4 video by changing its resolution, bitrate. I don't want to use FFmpeg (because I don't want to use NDK), so I decided to use MediaCodec API.
Here are my logical steps:
- Extract video file with MediaExtractor, then decode data.
- Create new encoder with my new resolution, bitrate and encode data.
- Using MediaMuxer to create a new mp4 file.
My problem is: I don't know how to setup the connection between output of decoder and input of encoder. I can decode the video to a Surface or encode a new video from a surface. But I don't understand how to connect them.
I read these links: Android MediaCodec: Reduce mp4 video size, Video compression on android using new MediaCodec Library and the example from Bigflake: https://android.googlesource.com/platform/cts/+/jb-mr2-release/tests/tests/media/src/android/media/cts/DecodeEditEncodeTest.java
Can anybody give me a clear explanation what I have to do?
I have used this to see how to manipulate video in android: https://github.com/hoolrory/AndroidVideoSamples , check the VideoResampler.java in the CommonVideoLibrary .
来源：https://stackoverflow.com/questions/30842668/how-to-compress-mp4-video-using-mediacodec-android