Ask, I in the video encoding to use nvidia nvenc hardware encoding, and then use ffmpeg coding of audio, mp4 can be used after encapsulation using mp4v2 ffplay, storm video, thunder players, players such as android, but with Mac QuickTimeplay and IOS native players play no sound, what reason is this? Compared with the original video file packet and frame and Mp4 header information, only the encoder is not the same as the ID, the other is consistent,