[HELP] MP4 can't encode with PCM, but why this MP4 file can?

[Selur]

i upload this, please research for me. thanks

Sorry, but I'm not downloading a 16GB sample,...

1) why this MP4 file can contain PCM audio tracks?

Probably because it does not care about the MPEG-4 container file standard,...

2) the MP4 file have many PCM tracks, can all these tracks mux a 5.1 or 7.1 true HD sound track by Hybrid?

I don't understand the question.
Hybrid does not support wav/pcm audio in mp4 files.
Hybrid does not limit the channel count as long as the audio format support the channel count.

-> If you want/need pcm/wav audio use another container, or some tool that does not care about standards.

Cu Selur