How to export the video of Sony camera in avchd format (no sound) to have sound?

There are two possible situations when there is no sound:

1. When shooting, an external microphone of 3.5mm was connected, resulting in no sound recording at all (Sony camera with AVCHD coding must be Handycam series, and there is almost no function to support multi-channel audio input except AX 1, so once the external microphone interface is plugged in, the internal recording will be replaced) Solution: retake.

2. The 2.AC3 encoder does not support playback devices and editing software. Handycam's built-in microphones are mostly Dolby 5. 1 channel, with AC3 coding. If there is no corresponding decoder, you can't play sound.