Secondly, it is relatively simple to operate with 3gp-video-converter, as long as you know the format and resolution supported by the mobile phone.
Third, check the video format and resolution supported by the mobile phone: 1 is clearly written in the manual. 2. Shoot video with mobile phone and import it into 3gp-video-converter. Right-click the imported material-attribute, and parameters such as compression mode (video format) and resolution will appear. Press this parameter to set normal playback in the future.
Fourthly, the format factory adjusts more parameters, including video format, resolution, frame rate, video sampling rate and audio sampling rate. As long as the settings are right, it is also very easy to use.
If the sound is out of sync, it is the reason why the audio sampling rate is wrong.