This video problem is mainly due to the fact that videos without audio generally cannot be played.
The video you made with PPT should have no sound, so it can’t be played. You can integrated a sound in your video through technical methods.
As long as you don’t connect a device that plays sound such as speakers, then it can be played as a video without sound.
Also on this aspect of video format conversion, you need to strictly follow the requirements to convert, I have attached the format requirements.
Format requirements: The video files must be reformatted according to the AVI video file format requirements with ” Format Factory ” software before use. In the video stream, the video is encoded in mjpeg format, the resolution can be smaller or equal to the actual screen resolution, the bit rate is recommended to choose 1024KB/S, and 15-18 frames per second. The bit rate and frames per second should not be set too high, otherwise the video file will be will be very large. When playing video files on USB flash drive, the bit rate of the video file should not be larger than 4096KB/s, otherwise it will be stuttered by the USB transfer speed.
Otherwise, there will be a lag due to the limitation of USB transfer speed. In the audio stream, the audio is encoded in mp3 format with a sampling frequency of 16000 Hz and a bit rate of 128KB/sec, two channels.
