In order to have any chance of being able to help you we need a lot more information from you! Please read this post and supply us with everything requested there; at the moment we know nothing about your computer nor about the version of MEP you are using.
Then, since mp4 is a "container" format (the actual codecs used can vary widely) please tell us a little about the mp4 files you are trying to open in MEP: perhaps the easiest method of doing this is to download and install the free MediaInfo utility, point it to one of your mp4 files and post here the results of the Text view.
I've had this problem with MP4s from time to time. I've found that it always involves audio encoded to AAC with a sampling rate of 22050Hz. Strangely MP4s with audio encoded to AC3 at 22050Hz (mostly) seem to work.
On occasion I use any of the free audio/splitter converters around to change it to higher sampling rate - usually as a WAV - although, to be honest, the audio is usually so poor that it's not worth the effort.
Hi John EB, thanks for your reply, when I play the MP4 in media player the sound is fine. the problem is 1. just video only with no sound when playing the timeline. I have set (as per John CB’s reply) the video and sound to be imported as two separate files in the timeline. When I import the MP4 from the media pool to the timeline (by clicking the Import icon) I can see each frame of the movie but the second track is just a green line, no wave file showing. When previewing, there is no sound playing.
Greetings, I'm pleased to see your problem is resolved, although from your exif info and screenshots I can't for the life of me see how the solution you ticked cured the audio problem, but then MEP continues to surprise me even after 10+ years of use.
ps I do notice from the exif that your audio is sampled at 22.05 kHz (or 22050 Hz as I mentioned in my previous post) and, even more curious, it's frame rate is 21.533 fps while the video is 25 fps.
I thought that was only possible when combining separate audio and video to Matroska (MKV).
John EB - I'm convinced that the topic initially came up with resolved! Either that or …..
With regard to audio frame rate I accept that variable fps is quite common however I've found that MEP is somewhat fussy about whether to accept it or not but it's not really a point for discussion here, merely trying to answer why the OP has no audio in his MP4.
. . . . I'm convinced that the topic initially came up with resolved! . . . .
. . . . I've found that MEP is somewhat fussy about whether to accept it or not but it's not really a point for discussion here,merely trying to answer why the OP has no audio in his MP4 . . . .
Agreed - MEP appears to be very fussy about the sample rate of audio requiring either 44.1 or 48 kHz, and the discussion is relevant here, as you say audio is often variable bitrate which gives the lower framerate when calculated as an average over time and MEP does not really care except when it is in side a mpg file then the audio can get out of sync on import.