Video

MPEG Streamclip,

Warning: I know nothing about video editing or sound.

Problems

• Sound from mp4 file low
  On Mac I used MPEG Streamclip to export mp4 without sound by deleting sound track then exporting and export the sound as an mp3.
  Edited the sound with Audacity > selected all of the track > Effect > Amplify > capped and saved sound file as mp3.
  Then used Avidemux to merge the video and sound. Had problems with audio setting in two places - in the left panel under audio and menu Audio > Main track > External MP3 > select mp3 file. > "Save" the file exports new file, then test.