amidemux, will it filter out audio hiss on my video and resync the sound?

[vinckles]

Hi,    I have some mp4 videos, I plan to burn to dvd.  The audio tracks are very hissy, like fish frying.  Can Avidemux software filter the hiss out or play it down, so the audio will be clearer?
     
     I have another mp4 video with the audio very slightly out of sync with the picture.  Actually, it is a piece of old 1950's American tv I found on youtube and the audio clearly lags a shade after the picture.  It is not my pc or downloaders or video converters at fault here. The video is out of sync from source.  Can Avidimux fix it and make the audio faithful to the moving picture?

    Where can I find a full explicit tutorial guide; How to Use Avidemux?  Most of the video tutorials on youtube are poor when it comes to the nity-grity points.

[eumagga0x2a]

Can Avidemux software filter the hiss out or play it down, so the audio will be clearer?

No. Save the audio to a 16 bit PCM (.wav) file using a suitable video player (mpv or vlc), edit it with a suitable audio software (I wonder if Audacity could help here), then load the resulting audio file as external audio in Avidemux.
     

I have another mp4 video with the audio very slightly out of sync with the picture. [...]  Can Avidimux fix it and make the audio faithful to the moving picture?

Yes, it should be able to fix the sync. Please pay attention to that "Shift" checkbox below the "Audio Output" label in the codec widget of Avidemux.

Where can I find a full explicit tutorial guide; How to Use Avidemux?  Most of the video tutorials on youtube are poor when it comes to the nity-grity points.

There is no such thing yet, unless you write one. There is some useful stuff at http://www.avidemux.org/admWiki/doku.php?id=build:doctop which still applies though.