The mediacodec's official document said:
Data Types Codecs operate on three kinds of data: compressed data, raw audio data and raw video data. All three kinds of data can be processed using ByteBuffers, but you should use a Surface for raw video data to improve codec performance. Surface uses native video buffers without mapping or copying them to ByteBuffers; thus, it is much more efficient. You normally cannot access the raw video data when using a Surface, but you can use the ImageReader class to access unsecured decoded (raw) video frames. This may still be more efficient than using ByteBuffers, as some native buffers may be mapped into direct ByteBuffers. When using ByteBuffer mode, you can access raw video frames using the Image class and getInput/OutputImage(int).
How to under stande this? you should use a Surface for raw video data to improve codec performance, What is native video buffers? How do I use Surface to improve encode or decode performance?